60 resultados para 757
Resumo:
对沈阳市郊区43对蔬菜保护地与相邻的露地土壤中交换性Ca、Mg含量状况及Ca/Mg比值进行对比研究的结果表明:与露地土壤相比,保护地土壤交换性Ca平均含量下降6.38%,Ca/Mg比值下降10.34%,交换性Mg平均含量上升4.74%。蔬菜保护地及露地土壤的Ca/Mg比值与交换性Ca含量呈极显著相关(r分别为0.721和0.757,n=43,P<0.01),Ca/Mg比值与交换性Mg含量无显著相关性(r分别为-0.065和-0.117,n=43)。交换性Ca含量下降的主要原因是随蔬菜输出到系统外的Ca量相对较多、含钙肥料施用量减少及土壤pH下降;交换性Mg含量上升的主要原因是土壤中适宜的pH范围(5.0~6.5)有利于Mg以交换性形态存在,土壤中高浓度的Ca2+、K+、NH+4抑制了蔬菜对Mg2+的选择性吸收。
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An organic integrated pixel with organic light-emitting diodes (OLEDs) driven by organic thin film transistors (OTFTs) is fabricated by a greatly simplified processing. The OTFTs are based on copper phthalocyanine as the active medium and fabricated on indium-tin-oxide (ITO) glass with top-gate structure, thus an organic integrated pixel is easily made by integrating OLED with OTFT. The OTFTs show field-effect mobility of 0.4 cm(2) /Vs and on/off ratio of 10(3) order. The OLED is driven well and emits the brightness as large as 2100cd/m(2) at a current density of 14.6 mu A/cm(2) at -19.7 V gate voltage. This simple device structure is promising in the future large-area flexible OLED displays.
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LiBa2B5O10:RE3+ (RE = Dy, Tb and Tm) was synthesized by the method of high-temperature solid-state reaction and the thermoluminescence (TL) properties of the samples under the irradiation of the gamma-ray were studied. The result showed that Dy3+ ion was the most efficient activator. When the concentration of Dy3+ was 2 mol%, LiBa2B5O10:Dy3+ exhibited a maximum TL output. The kinetic parameter of LiBa2B5O10:0.02Dy was estimated by the peak shape method, for which the average activation energy was 0.757 eV and the frequency factor was 1.50 x 10(7) s(-1). By the three-dimensional (3D) TL spectrum, the TL of the sample was contributed to the characteristic f-f transition of DY3+. The dose-response of LiBa2B5O10:0.02Dy to gamma-ray was linear in the range from 1 to 1000 mGy. In addition, the decay of the TL intensity of LiBa2B5O10:0.02Dy was also investigated.
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利用PVT 10 0分析仪对 4种不同牌号的无规共聚聚丙烯的压力 体积 温度特性进行了测定。通过定义法和Tait方程法得出PPR的热膨胀系数 (α)随温度以及等温压缩系数 (β)随压力的变化关系。发现 2种计算方法的结果在高于结晶温度时 ,互相吻合较好。比较了 4种样品的热膨胀系数、等温压缩系数和结晶温度 ,结果表明 ,在 2 0~ 30MPa或 80~ 10 0MPa范围内 ,齐鲁PPR(QLPPR)的等温压缩系数低于其它牌号的样品 ,它在不同压力下的结晶温度也低于其它牌号的样品。
Resumo:
Colloidal Au particles have been deposited on the gold electrode through layer-by-layer self-assembly using cysteamine as cross-linkers. Self-assembly of colloidal Au on the gold electrode resulted in ail easier attachment of antibody, larger electrode surface and ideal electrode behavior. The redox reactions of [Fe(CN)(6)]-/[Fe(CN)(6)](3-) on the gold surface were blocked due to antibody immobilization, which were investigated by cyclic voltammetry and impedance spectroscopy. The interaction of antigen with grafted antibody recognition layers was carried out by soaking the modified electrode into a phosphate buffer at pH 7.0 with various concentrations of antigen at 37degreesC for 30 min. Further, an amplification strategy to use biotin conjugated antibody was introduced for improving the sensitivity of impedance measurements. Thus, the sensor based oil this immobilization method exhibits a large linear dynamic range, from 5 - 400 mug/L for detection of Human IgG. The detection limit is about 0.5 mug/L.
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A nitrate-citrate combustion route to synthesize nanocrystalline samarium-doped ceria powders for solid electrolyte ceramics is presented. This route is based on the gelling of nitrate solutions by the addition of citric acid and ammonium hydroxide, followed by an intense combustion process due to an exothermic redox reaction between nitrate and citrate ions. The influence of ignition temperature on the characteristics of the powders was studied. The change of the crystal structure with the content of doped Sm was investigated. High temperature X-ray, and Raman scattering were used to characterize the sample. The lattice constant and unit volume increase with doping level and increasing temperature. Dense ceramic samples prepared by uniaxial pressing and sintering in air were also studied.
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A novel organic-inorganic hybrid complex [(CuCl)(2) (o-phen)](infinity) 1 (o-phen = o-phenanthroline) has been hydrothermally synthesized and structurally characterized by elemental analyses, XPS spectrum, TG analysis, and single-crystal X-ray diffraction. Compound I crystallizes in the monoclinic system, space group P2(1)/n, a = 3.7285(7) Angstrom, b = 19.603(4) Angstrom, c = 16.757(3) Angstrom, beta = 95.83(3)degrees, V = 1218.4(4) Angstrom(3), Z = 4, lambda(MoKalpha) = 0.71073 Angstrom (R(F) = 0.0643 for 2559 reflections). Data were collected on an R-axis RAPID diffractometer at 293 K in the range of 1.60 < θ < 27.48degrees. The title compound exhibits a one-dimensional chain-like scaffolding constructed by the unusual [Cu3Cl3] hexagon motifs by, sharing opposite edges. Only Cu(1) sites of the [Cu3Cl3] hexagon are coordinated with N donors of o-phen groups. Furthermore, the three-dimensional supermolecular architecture is formed by C-H...Cl hydrogen bonds between o-phen groups and CuCl chains.
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The new double-cubane cluster compound [NEt(4)](3)[Mo2Fe6S8(mu-OMe)(3)(SPh)(3)Cl-3] is synthesized from (NH4)(2)MoS4, FeCl3, Fe powder, S powder, NaSPh and NEt(4)Br in MeOH-DMF, its crystal structure is determined by X-ray crystallography, and results of XPS indicate a valence state of +4 for Mo.
Resumo:
Transglutaminase can catalyze the cross-linking reaction between soluble clotting protein molecules from the plasma for prevention of excess blood loss from a wound and obstructing micro-organisms from invading the wound in crustaceans. A novel transglutaminase (FcTG) gene was cloned from hemocytes of Chinese shrimp Fenneropenaeus chinensis by 3' and 5' rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA consists of 2972 bp, encoding 757 amino acids with a calculated molecular mass of 84.96 kDa and a theoretical isoelectric point of 5.61. FcTG contains a typical transglutaminase-like homologue (TGc domain: E-value = 1.94e-38). Three catalytic sites (Cys-324, His-391 and Asp-414) are present in this domain. The deduced amino acid sequence of FcTG showed high identity with black tiger shrimp TG, kuruma shrimp TG and crayfish TG. Transcripts of FcTG mRNA were mainly detected in gill, lymphoid organ and hemocytes by RT-PCR. RNA in situ hybridization further confirmed that FcTG was constitutively expressed in hemocytes both in the circulatory system and lymphoid organ. The variation of mRNA transcription level in hemocytes and lymphoid organ following injection of killed bacteria or infection with white spot syndrome virus (WSSV) was quantified by RT-PCR. The up-regulated expression of FcTG in shrimp lymphoid organ following injection of bacteria indicates that it is inducible and might be associated with bacterial challenge. (c) 2006 Elsevier Ltd. All rights reserved.
Resumo:
2002年4~8月在中国科学院海北高寒草甸生态系统定位站研究了鸲岩鹨(Prunella rubeculoides)亲鸟的递食率与巢中位置的关系。结果表明:亲鸟的总递食率对巢中的每个具体位置有显著变化(Kruskas-Wallis H = 14.633, P < 0.01, df = 3),雄性和雌性对巢中的位置有不同的响应,雄性对巢中的每个具体位置的递食率有显著差异(H = 16.720, P < 0.01, df = 3),而雌性递食率差异不显著(H = 3.557, P > 0.05, df = 3);雄鸟和雌鸟间递食的方式随着日龄和日时间变化也有显著差异。结果证实巢中的位置能够影响鸲岩鹨亲代资源的分配,同时与证实了鸲岩鹨双亲对巢中的位置有不同的响应。
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机器人学研究的目标之一就是提供一种智能移动式机器人,通过传感器获取几何世界模型,并把周围的这些环境信息表示成一张图,机器人利用它进行导航和路径规划。本论文详细地描述了一种面向任务的机器人语言的设计过程,利用这种误言编程不必要给出机器人动作细节,只要给出任务和环境信息,机器人自动规划,寻找出一条从初始位置到目标位置的最优路径,并且避免与环境中任何障碍物碰撞。路径规划了系统是整个系统的核心部分。我们改进了结构空间规划方法,整个寻找无碰撞的最优路径的步骤如下:1. 环境建模,用户采用谓词逻辑方法输入任务和环境信息,然后系统把这些信息自动转化为黑板结构中的内部信息。2. 膨胀障碍物,根据机器人的形状和大小膨胀机器人世界中的所有障碍物的体积。3. 建立搜索图,首先我们建造一张可视图,然后消除所有内视点等,从而得到一张可搜索的外视图。4. 路径寻找,我们以目前位置到目标位置的直线距置作为启发式函数数值,采用A~*算法搜索已建立的搜索图,寻找从初始位置到目标位置的最优路径的有序点集合。本算法有一些很好的优点:(a). 运行速度快、效率高。(b). 在路径寻找过程中,基计算量不依赖于所先取的坐标系统。
Resumo:
Increasing attentions have been paid to the subsurface geological storage for CO2 in view of the huge storage capacity of subsurface reservoirs. The basic requirement for subsurface CO2 storage is that the CO2 should be sequestrated as supercritical fluids (physical trapping), which may also interact with ambient reservoir rocks and formation waters, forming new minerals (chemical trapping). In order to the effective, durable and safe storage for CO2, enough storage space and stable sealing caprock with strong sealing capacity are necessitated, in an appropriate geological framework. Up till now, hydrocarbon reservoirs are to the most valid and appropriate CO2 storage container, which is well proven as the favorable compartment with huge storage capacity and sealing condition. The thesis focuses on two principal issues related to the storage and sealing capacity of storage compartment for the Qingshankou and Yaojia formations in the Daqingzijing block, Southern Songliao Basin, which was selected as the pilot well site for CO2-EOR storage. In the operation area, three facies, including deltaic plain, deltaic front and subdeep-deep lake facies associations, are recognized, in which 11 subfacies such as subaqueous distributary channel, river- mouth bar, interdistributary bay, sheet sandbody, crevasse splay and overflooding plain are further identified. These subfacies are the basic genetic units in the reservoir and sealing rocks. These facies further comprise the retrogradational and progradational depositional cycles, which were formed base- level rise and fall, respectively. During the regressive or lake lowstand stage, various sands including some turbidites and fans occurred mostly at the bottom of the hinged slope. During the progradation stage, these sands became smaller in size and episodically stepped backwards upon the slope, with greatly expanded and deeped lake. However, most of Cretaceous strata in the study area, localized in the basin centre under this stage, are mainly composed of grey or grizzly siltstones and grey or dark grey mudstones intercalated with minor fine sandstones and purple mudstones. On the base of borehole and core data, these siltstones are widespread, thin from 10 to 50 m thick, good grain sorting, and have relative mature sedimentary structures with graded bedding and cross- lamination or crossbeds such as ripples, which reflect strong hydrodynamic causes. Due to late diagenesis, pores are not widespread in the reservoirs, especially the first member of Qingshankou formation. There are two types of pores: primary pore and secondary cores. The primary pores include intergranular pores and micropores, and the secondary pores include emposieus and fracture pores. Throat channels related to pores is also small and the radius of throat in the first, second and third member of Qingshankou formation is only 0.757 μm, 0.802 μm and 0.631 μm respectively. In addition, based on analyzing the probability plot according to frequency of occurrence of porosity and permeability, they appear single- peaked distribution, which reflects strong hetero- geneity. All these facts indicate that the conditions of physical property of reservoirs are not better. One reason may be provided to interpret this question is that physical property of reservoirs in the study area is strong controlled by the depositional microfacies. From the statistics, the average porosity and permeability of microfacies such as subaqueous distributary channel, channel mouth bar, turbidites, is more than 9 percent and 1md respectively. On the contrary, the average porosity and permeability of microfacies including sand sheet, flagstone and crevasse splay are less than 9 percent and 0.2md respectively. Basically, different hydrodynamic environment under different microfacies can decide different physical property. According to the reservoir models of the first member of Qingshankou formation in the No. well Hei47 block, the character of sedimentary according to the facies models is accord to regional disposition evolution. Meantime, the parameter models of physical property of reservoir indicate that low porosity and low permeability reservoirs widespread widely in the study area, but the sand reservoirs located in the channels are better than other places and they are the main sand reservoirs. The distribution and sealing ability of fault- fractures and caprock are the key aspects to evaluate the stable conditions of compartments to store CO2 in the study area. Based on the core observation, the fractures widespread in the study area, especially around the wells, and most of them are located in the first and second member of Qingshankou formation, almost very few in the third member of Qingshankou formation and Yaojia formation instead. In addition, analyzing the sealing ability of eleven faults in the three-dimensional area in the study area demonstrates that most of faults have strong sealing ability, especially in the No. well Hei56 and Qing90-27. To some extent, the sealing ability of faults in the No. well Hei49, Qing4-6 and Qing84-29 are worse than others. Besides, the deposition environment of most of formations in the study area belongs to moderately deep and deep lake facies, which undoubtedly take advantage to caprocks composed of mudstones widespread and large scale under this deposition environment. In the study area, these mudstones distribute widely in the third member of Qingshankou formation, Yaojia and Nenjiang formation. The effective thickness of mudstone is nearly ~550m on an average with few or simple faults and fractures. In addition, there are many reservoir beds with widely- developed insulated interbeds consist of mudstones or silty mudstone, which can be the valid barrier to CO2 upper movement or leakage through diffusion, dispersion and convection. Above all, the closed thick mud caprock with underdeveloped fractures and reservoir beds can be taken regard as the favorable caprocks to provide stable conditions to avoid CO2 leakage.
Resumo:
陆相断陷湖盆陡坡带由于具有特殊的构造背景,在下降盘易发育各种类型的砂砾岩扇体,且具有很好的含油气前景,近几年各大油田也都将其作为增储上产的重要勘探领域.但由于这些扇体一般都具有较大的隐蔽性,而且控制影响因素复杂,尤其是对于为数较多的受高角度大断层控制的断陷湖盆,在陡坡带进行砂砾岩扇体的勘探具有更大的风险性.本文运用层序地层学、地震精细描述等勘探新理论、新技术和新方法,结合生产实际,对东濮凹陷高角度兰聊陡坡带砂砾岩扇体形成机制及成藏规律进行了多学科综合研究,查明了扇体的成因机制、控制因素、分布规律,并进一步探讨了扇体成藏机理和成藏规律,为下一步勘探指明了有利方向和钻探目标,期望为国内外同类盆地陡坡带油气资源的勘探也提供了一定的借鉴.