906 resultados para Risky and Normal Traffic
Resumo:
We describe a first-principles-based strategy to predict the macroscopic toughness of a gamma-Ni(Al)/alpha-Al2O3 interface. Density functional theory calculations are used to ascertain energy changes upon displacing the two materials adjacent to the interface, with relaxation conducted over all atoms located within adjoining rows. Traction/displacernent curves are obtained from derivatives of the energy. Calculations are performed in mode I (opening), mode II (shear) and at a phase angle of 45 degrees. The shear calculations are conducted for displacements along < 110 > and < 112 > of the Ni lattice. A generalized interface potential function is used to characterize the results. Initial fitting to both the shear and normal stress results is required to calibrate the unknowns. Thereafter, consistency is established by using the potential to predict other traction quantities. The potential is incorporated as a traction/displacement function within a cohesive zone model and used to predict the steady-state toughness of the interface. For this purpose, the plasticity of the Ni alloy must be known, including the plasticity length scale. Measurements obtained for a gamma-Ni superalloy are used and the toughness predicted over the full range of mode mixity. Additional results for a range of alloys are used to demonstrate the influences of yield strength and length scale.
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株高是农作物的重要农艺性状之一,适度矮化有利于农作物的耐肥、抗倒、高产等。20世纪50年代,以日本的赤小麦为矮源的半矮秆小麦的培育和推广,使得世界粮食产量显著增长,被誉为“绿色革命”。迄今为止,已报到的麦类矮秆、半矮秆基因已达70多个,但由于某些矮源极度矮化或者矮化的同时伴随不利的农艺性状,使得真正运用于育种实践的矮源较少。因此,发掘和鉴定新的控制麦类作物株高的基因,开展株高基因定位、克隆及作用机理等方面的研究,对实现麦类作物株高的定向改良,具有重要的理论意义和应用价值。簇毛麦(Dasypyrum villosum,2n=14,VV)是禾本科簇毛麦属一年生二倍体异花授粉植物,为栽培小麦的近缘属。本课题组在不同来源的簇毛麦杂交后代中发现了一株自然突变产生的矮秆突变体。观察分析了该突变体的生物学特性,对矮秆性状进行了遗传分析,对茎节细胞长度、花粉的活力进行了细胞学观察,考察了该突变体内源赤霉素含量及不同浓度外施赤霉素对突变体的作用,分析了赤霉素生物合成途径中的内根贝壳杉烯氧化酶(KO)和赤霉素20氧化酶(GA20ox)的转录水平,对赤霉素20氧化酶和赤霉素3-β羟化酶(GA3ox)进行了克隆和序列分析,并对GA20ox进行了原核表达和表达的组织特异性研究。主要研究结果如下:1. 该突变体与对照植株在苗期无差异,在拔节后期才表现出植株矮小,相对对照植株,节间伸长明显受到抑制,叶鞘长度基本不变。在成熟期,对照植株的平均株高为110cm,而突变株的平均株高为32cm,仅为对照植株的1/3 左右。除了株高变矮以外,在成熟后期,突变株还表现一定程度的早衰和雄性不育。I2-KI染色法观察花粉活力结果表明,对照植株花粉90%以上都是有活力的,而突变植株的花粉仅20%左右有活力。2. 突变株与对照植株的杂交F1代均表现正常株高,表明该突变性状为隐性突变。F1代植株相互授粉得到的168株F2代植株中,株高出现分离,正常株高(株高高于80cm)与矮秆植株(株高矮于40cm)的株数比为130:38,经卡方检验,其分离比符合3:1的分离比,因此推测该突变体属于单基因的隐性突变。3. 用ELISA方法检测突变株和对照植株的幼嫩种子中内源性生物活性赤霉素(GA1+3)含量,结果表明突变株的赤霉素含量为36 ng/ml,而对照植株的赤霉素含量为900 ng/ml。对突变株外施赤霉素,发现矮秆突变株的株高和花粉育性均可得到恢复。这些结果表明该突变株为赤霉素缺陷型突变。4. 用荧光定量PCR方法比较突变株与对照植株中内根贝壳杉烯氧化酶和赤霉素20氧化酶的转录水平,结果表明突变株的KO转录水平比对照植株分别提高了6倍(苗期)和16倍(成熟期),突变株的GA20ox转录水平与对照植株在苗期无明显差异,在成熟期突变株较对照植株则提高了10倍左右。这些结果表明该矮秆突变体与赤霉素的生物合成途径密切相关,而且极有可能在赤霉素的生物合成途径早期就发生了改变。5. 以簇毛麦总基因组为模板,同源克隆了GenBank登录号为EU142950,RT-PCR分离克隆了簇毛麦的GA3ox基因cDNA全长序列,分析结果表明该cDNA全长1206bp,含完整编码区1104bp,推测该序列编码蛋白含368个氨基酸残基,分子量为40.063KD,等电点为6.27。预测的氨基酸序列含有双加氧酶的活性结构,在酶活性中心2个Fe离子结合的氨基酸残基非常保守。该序列与小麦、大麦和水稻的GA3ox基因一致性分别为98%、96%、86%。基因组序列与cDNA序列在外显子部分一致,在478-715bp和879-1019bp处分别含238bp和140bp的内含子。6. 通过RT-PCR技术克隆了簇毛麦的GA20ox基因全长,命名为DvGA20ox,GenBank登录号为EU142949。该基因全长1080个碱基,编码359个氨基酸,具有典型的植物GA20ox基因结构。该基因编码的蛋白质与小麦、大麦、黑麦草等GA20ox蛋白的同源性分别为98%,97% 和91%。该序列重组到原核表达载体pET-32a(+)上,将获得的重组子pET-32a(+)-DvGA20ox转化大肠杆菌BL21pLysS后用IPTG进行诱导表达。SDS-PAGE分析表明,DvGA20ox基因在大肠杆菌中获得了高效表达,融合蛋白分子量为55kDa。定量PCR分析表明,该基因在簇毛麦不同器官中的表达差异明显:叶片中表达水平最高,根部表达水平次之,茎部和穗中表达较弱。在外施赤霉素后,该基因的表达水平在两小时以后急剧下降,表明该基因的表达受自身的反馈调节。本研究结果认为,(1)该簇毛麦矮秆突变体为单基因的隐性突变;(2)该矮秆突变体为赤霉素敏感突变,内源赤霉素含量检测表明突变体的内源性赤霉素含量仅为对照植株的1/30;(3)荧光定量PCR结果表明突变株的赤霉素生物合成途径的关键酶基因表达水平比对照植株高,而且突变植株的赤霉素生物合成改变很可能发生在赤霉素生物合成途径的早期;(4)GA20ox有表达的组织特异性,且受到自身产物的反馈调节。 Plant height is an impotrant agronomic trait of triticeae crops.Semi-dwarf cropcultivars, including those of wheat, maize and rice, have significantly increased grainproduction that has been known as “green revolution”. The new dwarf varieties couldraise the harvest Index at the expense of straw biomass, and, at the sametime, improvelodging resistance and responsiveness to nitrogen fertilizer. Moreover, dwarf traits ofplant are crucial for elucidating mechanisms for plant growth and development aswell. In many plant species, various dwarf mutants have been isolated and theirmodles of inheritance and physiology also have been widely investigated.The causesfor their dwarf phenotypes were found to be associated with plant hormones,especially, gibberellins GAs.Dasypyrum villosum Candargy (syn.Haynaldia villosa) is a cross-pollinating,diploid (2n = 2x = 14) annual species that belongs to the tribe Triticeae. It is native toSouthern Europe and West Asia, especially the Caucasuses, and grows underconditions unfavorable to most cultivated crops. The genome of D. villosum,designated V by Sears, is considered an important donor of genes to wheat for improving powdery mildew resistance, take-all, eyespot, and plant and seed storageprotein content. A spontaneous dwarf mutant was found in D. villosum populations.The biological character and modles of inheritance of this dwarf mutant are studied.The cell length of stem cell is observed. The influence of extraneous gibberellin tothe dwarf mutant is also examined; the transcript level of key enzyme of gibberellinbiosynthesis pathway in mutant and control plants is compared. GA3ox and GA20oxare cloned and its expression pattern is researched.1. The dwarf mutant showed no difference with control plants at seedlingstage.At mature stage, the average height of control plants were 110cm and the dwarfplants were 33cm. The height of the mutant plant was only one third of the normalplants due to the shortened internodes. Cytology observation showed that theelongation of stem epidermal and the parenchyma cells were reduced. The dwarfmutant also shows partly male sterile. Pollen viability test indicates that more than80% of the pollen of the mutant is not viable.2. The inheritance modle of this dwarf mutant is studied. All The F1 plantsshowed normal phenotype indicating that the dwarfism is controlled by recessivealleles. Among the 168 F2 plants, there are 130 normal plants and 30 dwarf plants, thesegregation proportion accord with Mendel’s 3:1 segregation. We therefore proposethat this dwarf phenotype is controlled by a single recessive gene.3. Quantitative analyses of endogenous GA1+3 in the young seeds indicated thatthe content of GA1+3 was 36ng/ml in mutant plants and 900ng/ml in normal plants.The endogenous bioactive GA1+3 in mutant plants are only about 1/30 of that innormal plants. In addition, exogenously supplied GA3 could considerably restore themutant plant to normal phenotype. These results showed that this mutant wasdefective in the GA biosynthesis.4. More than ten enzymes are involved in GA biosynthesis. KO catalyzes thefirst cytochrome P450-mediated step in the gibberellin biosynthetic pathway and themutant of KO lead to a gibberellin-responsive dwarf mutant. GA20ox catalyze therate-limited steps so that their transcript level will influence the endogenous GAbiosynthesis and modifies plant architecture. The relative expression levels of genesencoding KO and GA20ox were quantified by real time PCR to assess whether thechanges in GA content correlated with the expression of GA metabolism genes andwhere the mutant occurred during the GA biosynthesis pathway. In mutant plants,the transcript levels of KO increased about 6-fold and 16-fold at the seedling stage and elongating stage respectively comparing with the normal plants. For theseedlings, there was no notable difference in the expression of GA20ox betweenmutant and normal plants. At the elongating stage, GA20ox transcript increased 10times in mutant plants, suggesting that the GA biosynthesis pathway in mutant plantshad changed from the early steps rather than the late steps.5. A full length cDNA of D. villosum gibberellin 3β-hydroxylase homology(designated as DvGA3ox) was isolated and consisted of 1206bp containing an openreading frame of 1104bp encoding 368 predicted amino acid residues. Identityanalysis showed that the gibberellin 3β-hydroxylase nucleotide sequence shared 98%,96% and 86% homology with that of wheat, barley and rice. The predicted peptidecontained the active-site Fe of known gibberellin 3β-hydroxylase and the regionhomologous to wheat, barley and Arabidopsis. The genomic clone of gibberellin3β-hydroxylase has two introns.6. The full-length cDNA of D. villosum gibberellin 20 oxidase (designated asDvGA20ox) was isolated and consisted of 1080-bp and encoded 359 amino acidresidues with a calculated mol wt of 42.46 KD. Comparative and bio-informaticsanalyses revealed that DvGA20ox had close similarity with GA20ox from otherspecies and contained a conserved LPWKET and NYYPXCQKP regions. Tissueexpression pattern analysis revealed DvGA20ox expressed in all the tissues that wereexamined and the highest expression of DvGA20ox in expanding leaves followed byroots. Heterologous expression of this cDNA clone in Escherichia coli gave a fusionprotein that about 55KD. Transcript levels of DvGA20ox dramatically reduced twohours after application of biologically active GA3, suggesting that the biosynthesis ofthis enzymes might be under feedback control.
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恶性肿瘤(癌症)是危及人类生命健康最严重的疾病之一,放射治疗是一种较为有效的治疗手段。不同种类细胞对射线的敏感性有很大区别,即使同一细胞在不同的细胞周期时相、同一器官的不同部位其辐射敏感性也存在着明显的差异。为了认识人类不同种类月γ瘤细胞对γ射线的辐射敏感性的差异以及正常人细胞接受Y射线照射后染色体的损伤及修复,本研究以染色体断裂为预测指标,应用CalyculinA诱导的早熟染色体凝集技术对肝癌细胞系SMMC-7721、胃癌细胞系BGC-823、宫颈癌细胞系HeL。、黑色素瘤细胞系A375、肝细胞系L02等五种人类肿瘤细胞对Y射线的辐射敏感性及人类正常肝细胞染色体损伤的动态修复过程进行了研究。发现:1.Y射线照射后,肿瘤细胞染色体断裂与吸收剂量及染色体断裂和细胞存活率之间存在正相关关系,其中,在相同吸收剂量下染色单体断裂数目远较等点染色单体数目多;2.正常肝细胞在经过射线照射后染色体断裂数目也与吸收剂量和细胞存活率之间存在正相关关系,经过4昆小时的修复,染色单体断裂85%以上得到了有效修复,等点染色单体断裂修复率小于15%。结果提示:γ射线诱导产生的染色体断裂可以作为预测细胞辐射敏感性的可靠指标;辐射诱发正常细胞的癌变可能与等点染色单体的不能有效修复存在着密切的联系。这不仅对于具有个案针对性的临床放射治疗有着极为重要的指导意义,而且对于恶性肿瘤的发病机理也有重要意义。
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以土垫旱耕人为土为供试土壤,采用大田试验,研究半湿润农田生态系统两种种植密度下不同施肥处理对冬小麦生物学性状及子粒产量的影响。试验设两种种植密度:常规密度(播种量为150.0kg/hm~2)和低密度(播种量为90.0kg/hm~2)。常规密度设7个施肥处理,即不施肥(CK),单施磷肥(PN0),单施氮肥(P0N135)和在施P的基础上每公顷施N45、90、135和180kg(即PN45、PN90、PN135、PN180);低密度施肥处理设不施肥(CK)、单施磷(PN0)、单施氮(P0N135)和氮磷配施(PN135)。结果表明,低密度时,CK处理分蘖数最低(每株平均3.2个),PN135分蘖数最高(每株平均6.9个);常规密度时,仍以CK分蘖数最低(每株平均3.2个),PN180分蘖数最大(每株平均6.8个)。低密度下,PN0和CK与P0N135和PN135间植株绿叶面积差异达显著水平(P<0.05),以PN135绿叶面积最大,PN0绿叶面积最小;常规密度下,PN180绿叶面积最大,为80.7cm~2/单茎,PN0绿叶面积最小,为44.4cm~2/单茎。低密度时,CK旗叶面积最小,PN135旗叶面积最大;常规...
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在黄土旱塬长期定位研究表明 ,根据小麦生育年降水量施用氮肥 ,将能更好地发挥肥料效益。丰水年、平水年氮肥增产效果极为显著 ,应加大施用量 ;干旱年氮肥效果受抑 ,应减少施用量。氮肥利用率受降水等因素影响 ,年际间变化幅度为 6.4%~ 58.6%。氮肥利用率亦随施用量的增加而降低 ,变化幅度为 2 5.4%~ 42 .9%,且其利用率与施肥利润的高低并不同步。施用有机肥或氮磷有机肥配施、轮作中增加豆科作物 (或牧草 )能有效地调节改善土壤氮素状况
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Multivariate classification methods were used to evaluate data on the concentrations of eight metals in human senile lenses measured by atomic absorption spectrometry. Principal components analysis and hierarchical clustering separated senile cataract lenses, nuclei from cataract lenses, and normal lenses into three classes on the basis of the eight elements. Stepwise discriminant analysis was applied to give discriminant functions with five selected variables. Results provided by the linear learning machine method were also satisfactory; the k-nearest neighbour method was less useful.
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介绍了摇杆-转向架悬挂系统的收缩和展开状态,根据展开过程,分析了举升机构的任务。采用双重四杆机构设计举升机构,以满足摇杆-转向架展开过程中两大步骤的需要。详细介绍了该举升机构的工作原理和双重四杆机构的切换过程。最后对举升过程中的四杆机构参数进行了分析设计,给出了机构参数设计模型,利用该模型可以对四杆机构的受力进行优化设计。
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根据目前中国路桥车辆收费标准,提出了一种基于模糊模式识别的车型分类系统。车辆经过环形线圈传感器时,形成感应曲线,提取感应曲线的特征并进行特征分离,利用模糊模式识别方法对车型进行匹配分类。研究结果已在路桥收费系统以及交通流量统计中得到应用。
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The black rock series of the Upper Ordovician - Lower Silurian in Yangtze area are important source rocks and have exceptional characteristics of sediment, biology, element geochemistry, carbon and oxygen isotope, organic geochemistry and etc. These characteristics are the reflection of important geology events. Due to scarce system research, many problems that relate to the development mechanism of source rocks are not solved. And this restricts the exploration of Oil and gas in South China. In this paper, author studied the palaeo-climate, palaeo-structure and palaeo-environment of the Upper Ordovician - Lower Silurian in Yangtze area by sedimentology, palaeobiology and geochemistry, especially the element geochemistry and isotope geochemistry. The environment model of source rocks is established and some conclusions are drawn. The Upper Ordovician - Lower Silurian sediment types in Yangtze area are mostly black shales, next, mudstone, shell limestone and siltystone. During the Late Ordovician and Earily Silurian periods, a series of big upheaval and depressed are distributed in Yangtze area, and the strata pattern of interphase upheaval and depressed led to Yangtze palaeosea isolated with outside sea. So the stagnant and anoxic environment that are the favorable factor of rich organic black shales sediment is formed in Yangtze area. That Chemical Index of Alteration (CIA) values of the lower Wufeng formation and Longmaxi formation exhibits moderate chemistry weathering suggests they were deposited under the circumstances of the warm and humid climate. However, the large difference of the CIA values of N.extraordinarius-N.ojsuensis biozone suggests that climate is changeful. Therefore, there were two different kinds of climates in the course of the deposition of the Wufeng formation and Longmaxi formation. During the Late Ordovician - Earily Silurian periods, in Yangtze palaeosea, the surface water which is full of rich nutriment and abundant bacterium - algae has high palaeo-productivity that is obvious difference in the different space – time. The content of sulphate changes gradually from the surface water columns to the deep water columns. That is, salinity in the surface water columns is serious low and the salinity in deep water columns is normal. Salinity delamination is favor of the forming of deep anoxic environment. During Wufeng period, the oxidated and low sulfate environment exists in the upper Yangtze palaeosea, while the anoxic and normal salinity environment occurs in the lower Yangtze palaeosea. During the Late Wufeng and Guanyinqiao periods, the steady anoxic environment is replaced by oxidated environment. During the Longmaxi period, layered and anoxic environment recur. In Yangtze area, studies of δ13C of sedimentary organic carbon show a positive δ13C excursion up to 4‰ in the Guanyinqiao stage and then, acute negative excursion in the earily Longmaxi stage. These organic carbon isotopes curve are not only efficient measure of carving up strata borderline, but also reflected the change of originality productivity. These organic carbon isotopes curves showed the process of the enhanced embedding of the global organic carbon. Anoxic event is the main factor of increasing organic carbon embedding speed. And the reduced organic carbon embedding in Hirnantian stage is due to the water column with abundant oxygen. The δ34S values are gradually positive excursion from P.pacificus biozone to N.extraordinarius biozone, and reach the maximum in the Upper Hirnantian stage. Then, the δ34S values are negative excursion. The excursions of δ13C and δ34S reflect the acute change of environment. The formation of source rocks is largely dependent on the nature of organisms from which kerogen is derived and the preservation conditions of organic matter, which are fundamentally dependent on a favourable combination of various elements in which organisms live and are subsequently buried. These elements include palaeoclimate, palaeostructure and palaeoenvironmental conditions. Based on above mentioned circumstance, the coupling connection of source rock and the palaeoclimate, and of palaeostructure and palaeoenvironmental conditions are confirmed, and the “anoxic-marginal depression-photosynthesis” environemental model is established. It is indicated that anoxic played important role in production of organic matter. The produced organic matter was accumulated in marginal depression of the Yangtze area. The photosynthesis is favor of the high productivity. Source rocks have a good perspective, like that of “hot shale” deposited in North Africa.
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There are two major problems that have been concerned all the times, which are the mechanics characters of joint rock mass and the criterion for stability of engineering rock. Aim at the two problems, several works were conducted as follow: (1) Firstly, the mechanics characters of rock mass was studied by means of the Distinct Element Code. Subsequently, it was studied that the sensibility of joint surface roughness, strength of joint wall, joint stiffness ( i.e. tangential and normal stiffness) on the rock mass strength. (2) Based on the experimental rock mass classification methods of RMR and GSI, the program of “Parameters Calculation of the Rock Mass ” was developed. It has realized the rapid choice of rock mass parameters. (3) The concept of Representive Element Volume was induced based on the study of dimensional effect of rock mass. The Representive Element Volume of the horizontal and vertical pillar (ab. Two Pillars ) in the 2nd zone of Jinchuan mine were gained by the Geology Statistic Method and the Distinct Element Code. And then, the strength and deformatiom parameters of rock mass of the Two Pillars were obtained through numerical experiment. (4) From the confining depressure after thriaxial compression test of rock sample, it was concluded that the failure of rock is caused mainly by the lateral deformation and energy release happened during the confining depressure processure. The criterion of plastic energy catastrophe of rock engineering failure was proposed and validated. Subsquently, the stability of the horizontal pillar and Qianjiangping landslide in Three Gorges was judged by means of above-mentioned method. (5) Based on the fact there is a phenomenon of increasing energy concentration while the rock mass was compressed, rock information entropy (i.e. energy distribution entropy) was proposed. And it was revealed that there was change of energy distribution entropy while the rock mass was compressed to failure.
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Evaluating the mechanical properties of rock masses is the base of rock engineering design and construction. It has great influence on the safety and cost of rock project. The recognition is inevitable consequence of new engineering activities in rock, including high-rise building, super bridge, complex underground installations, hydraulic project and etc. During the constructions, lots of engineering accidents happened, which bring great damage to people. According to the investigation, many failures are due to choosing improper mechanical properties. ‘Can’t give the proper properties’ becomes one of big problems for theoretic analysis and numerical simulation. Selecting the properties reasonably and effectively is very significant for the planning, design and construction of rock engineering works. A multiple method based on site investigation, theoretic analysis, model test, numerical test and back analysis by artificial neural network is conducted to determine and optimize the mechanical properties for engineering design. The following outcomes are obtained: (1) Mapping of the rock mass structure Detailed geological investigation is the soul of the fine structure description. Based on statistical window,geological sketch and digital photography,a new method for rock mass fine structure in-situ mapping is developed. It has already been taken into practice and received good comments in Baihetan Hydropower Station. (2) Theoretic analysis of rock mass containing intermittent joints The shear strength mechanisms of joint and rock bridge are analyzed respectively. And the multiple modes of failure on different stress condition are summarized and supplied. Then, through introducing deformation compatibility equation in normal direction, the direct shear strength formulation and compression shear strength formulation for coplanar intermittent joints, as well as compression shear strength formulation for ladderlike intermittent joints are deducted respectively. In order to apply the deducted formulation conveniently in the real projects, a relationship between these formulations and Mohr-Coulomb hypothesis is built up. (3) Model test of rock mass containing intermittent joints Model tests are adopted to study the mechanical mechanism of joints to rock masses. The failure modes of rock mass containing intermittent joints are summarized from the model test. Six typical failure modes are found in the test, and brittle failures are the main failure mode. The evolvement processes of shear stress, shear displacement, normal stress and normal displacement are monitored by using rigid servo test machine. And the deformation and failure character during the loading process is analyzed. According to the model test, the failure modes quite depend on the joint distribution, connectivity and stress states. According to the contrastive analysis of complete stress strain curve, different failure developing stages are found in the intact rock, across jointed rock mass and intermittent jointed rock mass. There are four typical stages in the stress strain curve of intact rock, namely shear contraction stage, linear elastic stage, failure stage and residual strength stage. There are three typical stages in the across jointed rock mass, namely linear elastic stage, transition zone and sliding failure stage. Correspondingly, five typical stages are found in the intermittent jointed rock mass, namely linear elastic stage, sliding of joint, steady growth of post-crack, joint coalescence failure, and residual strength. According to strength analysis, the failure envelopes of intact rock and across jointed rock mass are the upper bound and lower bound separately. The strength of intermittent jointed rock mass can be evaluated by reducing the bandwidth of the failure envelope with geo-mechanics analysis. (4) Numerical test of rock mass Two sets of methods, i.e. the distinct element method (DEC) based on in-situ geology mapping and the realistic failure process analysis (RFPA) based on high-definition digital imaging, are developed and introduced. The operation process and analysis results are demonstrated detailedly from the research on parameters of rock mass based on numerical test in the Jinping First Stage Hydropower Station and Baihetan Hydropower Station. By comparison,the advantages and disadvantages are discussed. Then the applicable fields are figured out respectively. (5) Intelligent evaluation based on artificial neural network (ANN) The characters of both ANN and parameter evaluation of rock mass are discussed and summarized. According to the investigations, ANN has a bright application future in the field of parameter evaluation of rock mass. Intelligent evaluation of mechanical parameters in the Jinping First Stage Hydropower Station is taken as an example to demonstrate the analysis process. The problems in five aspects, i. e. sample selection, network design, initial value selection, learning rate and expected error, are discussed detailedly.
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A large number of catastrophic accidents were aroused by the instability and destruction of anti-dip rock masses in the worldwide engineering projects, such as hydropower station, mine, railways and so on. Problems in relation to deformation and failure about anti-dip rock slopes are significant for engineering geology research. This dissertation takes the Longpan slope in the Jinsha River as a case to study the deformation mechanism of large-scale anti-dip rock masses and the slope stability analysis method. The primary conclusions are as follows. The Dale Reach of Jinsha River, from Longpan to the debouchment of Chongjiang tributary, is located in the southeastern margin of the Qinghai-Tibet Plateau. Longpan slope is the right embankment of Dale dam, it is only 26 km to the Shigu and 18 km to Tiger Leaping Gorge. The areal geology tectonic structures here area are complicated and blurry. Base on the information of geophysical exploration (CSAMT and seismology) and engineering geological investigation, the perdue tectonic pattern of Dale Reach is put forward for the first time in this paper. Due to the reverse slip of Longpan fault and normal left-rotation of Baihanchang fault, the old faulted valley came into being. The thick riverbed sediments have layered characters of different components and corresponding causes, which attribute to the sedimentary environments according with the new tectonic movements such as periodic mountain uplifting in middle Pleistocene. Longpan slope consists of anti-dip alternate sandstone and slate stratums, and the deformable volume is 6.5×107m3 approximately. It was taken for an ancient landslide or toppling failure in the past so that Dale dam became a vexed question. Through the latest field surveying, displacement monitoring and rock masses deforming characters analyses, the geological mechanism is actually a deep-seated gravitational bending deformation. And then the discrete element method is used to simulate the deforming evolution process, the conclusion accords very well with the geo-mechanical patterns analyses. In addition strength reduction method based on DEM is introduced to evaluate the factor of safety of anti-dip rock slope, and in accordance with the expansion way of the shear yielding zones, the progressive shear failure mechanism of large-scale anti-dip rock masses is proposed for the first time. As an embankment or a close reservoir bank to the lower dam, the stability of Longpan slope especially whether or not resulting in sliding with high velocity and activating water waves is a key question for engineering design. In fact it is difficult to decide the unified slip surface of anti-dip rock slope for traditional methods. The author takes the shear yielding zones acquired form the discrete element strength reduction calculation as the potential sliding surface and then evaluates the change of excess pore pressure and factor of stability of the slope generated by rapid drawdown of ponded water. At the same time the dynamic response of the slope under seismic loading is simulated through DEM numerical modeling, the following results are obtained. Firstly the effective effect of seismic inertia force is resulting in accumulation of shear stresses. Secondly the discontinuous structures are crucial to wave transmission. Thirdly the ultimate dynamic response of slope system takes place at the initial period of seismic loading. Lastly but essentially the effect of earthquake load to bringing on deformation and failure of rock slope is the coupling effect of shear stresses and excess pore water pressure accumulation. In view of limitations in searching the critical slip surface of rock slope of the existing domestic and international software for limit equilibrium slope stability analyses, this article proposes a new method named GA-Sarma Algorithm for rock slope stability analyses. Just as its name implies, GA-Sarma Algorithm bases on Genetic Algorithm and Sarma method. GA-Sarma Algorithm assumes the morphology of slip surface to be a broken line with traceability to extend along the discontinuous surface structures, and the slice boundaries is consistent with rock mass discontinuities such as rock layers, faults, cracks, and so on. GA-Sarma Algorithm is revolutionary method that is suitable for global optimization of the critical slip surface for rock slopes. The topics and contents including in this dissertation are closely related to the difficulties in practice, the main conclusions have been authorized by the engineering design institute. The research work is very meaningful and useful for the engineering construction of Longpan hydropower station.
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Based on the study of sequence stratigraphy, modern sedimentary, basin analysis, and petroleum system in Gubei depression, this paper builds high resolution sequence stratigraphic structure, sedimentary system, sandbody distribution, the effect of tectonic in sequence and sedimentary system evolution and model of tectonic-lithofacies. The pool formation mechanism of subtle trap is developed. There are some conclusions and views as follows. 1.With the synthetic sequence analysis of drilling, seismic, and well log, the highly resolution sequence structure is build in Gubei depression. They are divided two secondary sequences and seven three-order sequences in Shahejie formation. They are include 4 kinds of system traces and 7 kinds of sedimentary systems which are alluvial fan, under water fan, alluvial fan and fan-delta, fan-delta, lacustrine-fan, fluvial-delta-turbidite, lakeshore beach and bar, and deep lake system. Sandbody distribution is show base on third order sequence. 2.Based on a lot of experiment and well log, it is point out that there are many types of pore in reservoir with the styles of corrosion pore, weak cementing, matrix cementing, impure filling, and 7 kinds of diagenetic facies. These reservoirs are evaluated by lateral and profile characteristics of diagenetic facies and reservoir properties. 3.The effect of simultaneous faulting on sediment process is analyzed from abrupt slope, gentle slope, and hollow zone. The 4 kinds of tectonic lithofacies models are developed in several periods in Gubei depression; the regional distribution of subtle trap is predicted by hydro accumulation characteristics of different tectonic lithofacies. 4.There are 4 types of compacting process, which are normal compaction, abnormal high pressure, abnormal low pressure and complex abnormal pressure. The domain type is normal compaction that locates any area of depression, but normal high pressure is located only deep hollow zone (depth more than 3000m), abnormal low pressures are located gentle slope and faulted abrupt slope (depth between 1200~2500m). 5.Two types dynamic systems of pool formation (enclosed and partly enclosed system) are recognized. They are composed by which source rocks are from Es3 and Es4, cap rocks are deep lacustrine shale of Esl and Es3, and sandstone reservoirs are 7 kinds of sedimentary system in Es3 and Es4. According to theory of petroleum system, two petroleum systems are divided in Es3 and Es4 of Gubei depression, which are high or normal pressure self-source system and normal or low pressure external-source system. 6.There are 3 kinds of combination model of pool formation, the first is litholgical pool of inner depression (high or normal pressure self-source type), the second is fault block or fault nose pool in marginal of depression (normal type), the third is fault block-lithological pool of central low lifted block (high or normal pressure type). The lithological pool is located central of depression, other pool are located gentle or abrupt slope that are controlled by lithological, faulting, unconfirmed. 7.This paper raise a new technique and process of exploration subtle trap which include geological modeling, coring description and logging recognition, and well log constrained inversion. These are composed to method and theory of predicting subtle trap. Application these methods and techniques, 6 hydro objects are predicted in three zone of depression.
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Low resistivity reservoir is a special reservoir which is different from normal reservoir in identification and evaluation.Through core experiment and analysis, the achievement of which resistivity is resulted from clay additive electric conductivities and high bound water saturation in Junggar basin is gained. For accurately evaluating low resistivity, a good many of experiment have been completed, such as resistivity index and formation factor in hi^jher temperature and higher pressure, semi-permeability board, cation exchange, bound water, NMR (nucleus magnetism response), non-Nad water in different temperature and salinity, the experiments result show that lower resistivity has complex relation with these electric-parameters and chloric ion content in non-NaCl water.Based on comprehensive interpretation of NMR and normal resistivity data, the volume of moved water, bound water, moved oil and residual oil in the strata can be determined quantitatively and which have significant influence on reservoir recognition and perforation optimized.Experiment data (SEM mold, thin section, X ray diffraction, mercury penetration) can be used to analysis low resistivity forming and the relation between low resistivity and pore texture, to set up relation between porosity, permeability and petrophysical property. The reservoir was sorted, evaluated and described. The oil bedding in southern margin of Junggar basin is low porosity, low resistivity reservoir.Based on invasion theory of electric well-logging, modelling and inversion of resistivity well-logging are accomplished. For enhancing low resistivity resulted from higher bound water saturation and cation exchange, invasion period, invasion radius, the relation between fluid distribution in pore and response of laterolog logging have been studied. Virgin zone resistivity, invasion zone resistivity and invasion radius were inversed and which enhanced evaluation accuracy of reservoir. The method was used to process well-logging data in Luliang oilfield and southern margin in Junggar basin, and reservoir resistivity was enhanced effectively, appropriate oil saturation gained and it has better effect on oil exploration.
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An Approach to the Rehabilitation of Prelingually Deaf Children After Cochlear Implantation Zheng Xiujin(Medical Psychology) Directed by Professor Yin WenGang Abstract Objective: To sum up the acquirement rule of speech and language capability which is for the prelingually deaf children after cochlear implantation by listening and language rehabilitation training and to investigate the factors that affect rehabilitation speed. Method: Sixty-four children received a cochlear implant at the age of 2 to 5 years from 2001 to 2005. They begin to be trained under group pattern after switch on 1 month. The whole training program lasted more than 7 months; after that, according to the teacher’s plan the training program was to be continued at home. Result: The period is 108±7.7 days that they can pronounce correctly 50 percent of all of simple-finals and compound-finals, the period is 115.0±7.8 days that they begin auditory repeating, the period is 135.3±10.9 days that they can speech the first specific word independently and the period is 200.3±13.9 days that they can speak 70 words and come into tri-gamut-word and two-word sentence period. The patient that is the group at the age of 2-3 years can take part in normal kindergarten after switch on about 10 months. There are no significant differences in various grades of speech-language development with different age groups and so do with different sex groups. There are significant differences in various grade of speech-language development with various IQ group (P<0.01) and so do with using and not using hearing aids before implantation. Conclusion: From the research we find that the speech and language development sequence is the same level between the prelingually deaf children of 2 to 5 years who received cochlear implant after speech training and normal children and which are stages of uncomplicated sound production, continuous syllabic (babbling), speech sprout, single-word utterances and two-word utterances in proper order. The time is short significantly and the reason is that cognition capability is enhanced along with the increase of age. The intelligence is main factor that affect rehabilitation speed and the speed in the group of high IQ is faster than common IQ. It is not because of the dominance cognition of the senior group that makes the increasing of the rehabilitation, it even makes slowly. The reason of which is that the senior group are exposed the language environment too late to achieve speech and language development. So we should perform an operation and training early. The effectiveness of rehabilitation after cochlear implantation is improved by using hearing aids before implantation. The reason is auditory stimulate can be benefit of to deaf children. The rehabilitation speeds in the children at the age of 2 to 5 years have nothing to do with sex. Key words: cochlear implant; speech therapy; paediatric rehabilitation