100 resultados para 1300
Resumo:
Mafic granulite xenoliths have been extensively concerned over the recent years because they are critical not only to studies of composition and evolution of the deep parts of continental crust but to understanding of the crust-mantle interaction. Detailed petrology, geochemistry and isotope geochronology of the Early Mesozoic mafic-ultramafic cumulate xenoliths and mafic granulite xenoliths and their host diorites from Harqin area, eastern Inner-Mongolia have been studied here. Systematic Rb-Sr isochron, ~(40)Ar-~(39)Ar and K-Ar datings for mafic-ultramafic cumulate xenoliths give ages ranging from 237Ma to 221Ma. Geochemical research and forming temperature and pressure estimates suggest that cumulates are products of the Early Mesozoic mantle-derived magmatic underplating and they formed in the magmatic ponds at the lowermost of the continental crust and are later enclaved by the dioritic magma. Detailed study on the first-discovered mafic granulite xenoliths reveals that their modal composition, mineral chemistry and metamorphic P-T conditions are all different from those of the Precambrian granulite exposed on the earth surface of the North China craton. High-resolution zircon U-Pb dating suggests that the granulite facies metamorphism may take place in 253 ~ 236Ma. Hypersthene single mineral K-Ar dating gives an age of 229Ma, which is believed to represent a cooling age of the granulite. As the host rock of the cumulate and granulite xenoliths, diorites intruded into Archean metamorphic rocks and Permian granite. They are mainly composed of grandodiorite, tonalite and monzogranite and show metaluminous and calc-alkaline features. Whole rock and single mineral K-Ar dating yields age of 221 ~ 223Ma, suggesting a rapid uplift in the forming process of the diorites. Detailed field investigation and geochemical characteristics indicate that these diorites with different rock types are comagmatic rocks, and they have no genetic correlation with cumulate and granulite xenoliths. Geochemical model simulating demonstrates that these diorites in different lithologies are products of highly partial melting of Archean amphibolite. It is considered that the Early Mesozoic underplating induced the intrusion of diorites, and it reflects an extensional geotectonic setting. Compression wave velocity V_P have been measured on 10 representative rock samples from the Early Mesozoic granulite and mafic-ultramafic cumulate xenoliths population as an aid to interpret in-situ seismic velocity data and investigating velocity variation with depth in a mafic lower crust. The experiments have been carried out at constant confining pressures up to 1000MPa and temperatures ranging from 20 ℃ to around 1300 ℃, using the ultrasonic transmission technique. After corrections for estimated in situ crustal pressures and temperatures, elastic wave velocities range from 6.5 ~ 7.4 km s~(-1). On the basis of these experimental data, the Early-Mesozoic continental compression velocity profile has also been reestablished and compared with those of the present and of the different tectonic environments in the world. The result shows that it is similar to the velocity structure of the extensional tectonic area, providing new constraints on the Early Mesozoic continental structure and tectonic evolution of the North-China craton. Combining with some newly advancements about the regional geology, the thesis further proposes some constraints on the Mesozoic geotectonic evolution history, especially the features of deep geology of the North China craton.
Resumo:
Data on seawater carbon isotope in the Mesoproterozoic and Neoproterozoic is abundant. However, the sulfur isotopic age curve of seawater sulfates determined through the analysis of sulfur isotopic composition of marine evaporite is uncertain in the Mesoproterozoic and Neoproterozoic since evaporites are generally rare in Precambrian. The Mesoproterozoic and Neoproterozoic Carbonate Formations preserve not only the carbon isotopic records, but also the sulfur isotopic records of coeval seawater in the Huabei Platform and the Yangtze Platform, China. Sulfur isotopic composition can be determined by the extraction of trace sulfate from carbonate samples. Successive measurements of sulfur and carbon isotopic compositions of carbonate samples from the Mesoproterozoic and Neoproterozoic strata in the Huabei Platform and the Yangtze Platform was accomplished through the extracting of trace sulfate from carbonates. Sulfur and carbon isotopic compositions of coeval seawater were obtained from analytical results of sulfur and carbon isotopes of the same sample without diagenetic alteration. The high-resolution age curve of sulfur isotope given in this paper may reflect the trend of variations in sulfur isotope composition of seawater sulfates during the Mesoproterozoic and Neoproterozoic. It can be correlated with the characteristics of variation in age curve of carbon isotope of coeval seawater carbonates. The δ34S values of seawater varied from +10.3-37.0‰ during the Mesoproterozoic, which took on oscillated variation on the whole. The δ34S values took on high values in the Mesoproterozoic Chuanlinggou stage, Tuanshanzi stage Tieling stage and in Neoproterozoic Jing'eryu stage. The average of those was about +30‰. The sulfates have low δ34S values in the Mesoproterozoic Yangzhuang stage and Hongshuizhuang stage, The average of those was all lower than +20‰. There occured large-amplitude changs in δ34S values of seawater during the Mesoproterozoic. Large-amplitude oscillate of 534S values occured in the intervals of 1600~1400Ma and 1300~1200Ma. The δ13C values of seawater are mostly negative in Changcheng stage of late Paleoproterozoic, -0 ± 1‰ range in Jixian stage of Mesoproterozoic , and the positive 2±2‰ commonly in early Neoproterozoic Jing'eryu stage. From 1000 Ma to 900 Ma, about 108 years interval of oceanic 513C record is shortage. At the end of Paleoproterozoic (1700 - 1600 Ma), the oceanic 813C values change from -3‰ to 0‰, but strongly oscillate near 1600 Ma. Two larger variations of seawater 513C values occur in the Mesoproterozoic: one is a cycle of about 4%o happens at ca. 1400 Ma; another is rise from >2‰ to>5‰ at ca. 1250 Ma and then become stable at the near 1000 Ma. There appears a large positive excursion over +20‰ in 534S value of ancient seawater sulfates in the early Doushantuo stage. Simultaneously, 8 C values of ancient seawater occur a positive excursion reaching 10‰. These allow δ4S values and 513C values to reach high values of+51.7‰ and +6.9‰, respectively. The range of variation in 834S values of seawater is relatively narrow and 513C values are quite high in the middle Doushantuo stage. Then, δ34S values of seawater become oscillating, the same happens in δ13C values. Negative excursions in 834S values and 813C values occur simultaneously at the end of the Doushantuo stage, and the minimum of δ34S values and δ13C values dropped to -11.3‰ and -5.7‰, respectively. The ancient seawater in the Dengying stage has high δS values and δ13C values. Most of the δ34S values of the trace sulfate samples varied between +23.6‰ and +37.9‰ except two boundaries of the Dengying Formation, and the S13C values of the carbonate samples of the Dengying Formation varied between +0.5‰ and +5.0‰. There appeared large negative excursion in 834S values and δ13C values of ancient seawater at the bounder of Precambrian-Cambrian. The isotopic characteristics of sulfur and carbon implicated that the organic productivity and isotopic fractionation caused by biology were low and the palaeoceanic environment was quite unstable during the Mesoproterozoic. The increase and subsequent oscillation of seawater δ13C value occurred from 1700 to 1600 Ma and near 1300 Ma may be responsible to the two global tectonic events happened at coeval time. The characteristics of variation in sulfur and carbon isotopes of ancient seawater imply strong changes in oceanic environment, which became beneficial to inhabitation and propagation of organism. The organic production and the burial rate of organic carbon once reached a quite high level during the Doushantuo stage. However, the state of environment became unstable that means the global climate and the environment possibly were fluctuating and reiterating after the global glaciation. The negative excursions of S34S values and δ13C values occurring at the end of the Doushantuo stage represent a global event, which might be relative to the oxidation of deep seawater. The isotopic characteristics of sulfur and carbon implicated that there were a high organic productivity and a high burial rate of organic carbon in the Dengying stage. It is obvious that the palaeoceanic environment in Dengying stage was stable corresponding and beneficial for biology to inhabit and propagate except for the two boundaries. The tendency of sulfur and carbon isotopic variations maybe resulted from the gradual oxygenation of ocean environment during the Dengying stage. It has been reported that the secular variations of the sulfur isotopic compositions in seawater was negative correlated with that of carbon isotopic compositions. However, our results show that it is not the case. They were negatively correlated in some intervals and positively in some other intervals of the Mesoproterozoic and Neoproterozoic. The difference in correlation may be associated with the changes in conditions of redox in oceanic environment, e.g. sharp change of the oxidation-reduction interface. The strong changes in global environment may induce the abnormality to occur in the biogeo chemical S and C cycles in the ocean and accordingly sharp Variations in isotopic composition of seawater sulfur and carbon during the Mesoproterozoic and Neoproterozoic. Simultaneously, the global tectonism caused large changes of 87Sr/86Sr ratios. The leading factor that causes the variation in isotopic composition is different in the different intervals of the Mesoproterozoic and Neoproterozoic. Thus, there may exist different models of the biogeochemical S and C cycles in the ocean during the Mesoproterozoic and Neoproterozoic.
Resumo:
Daihai Lake, a graben-type closed lake, lies ca. 10 km east of Liangcheng County, Inner Mongolia, north-central China. For its location at the transition of semi-humid and semi-arid areas, and in the north edge of the East Asian monsoon, the lake is sensitive to changes in climate and environment. Based on analyses of total inorganic carbon (TIC), total organic carbon (TOC) and the ratio of total organic carbon to total nitrogen (C/N ratio) of DH99a core sediments recovered in the central part of Daihai Lake, the data suggest Holocene climatic history of the lake region is reconstructed. In this paper, the TIC and TOC contents of the lake sediments are closely related to climate changes. 1) Changes in TIC content of the lake sediments is closely related to climate, which directly reflect changes of temperature in the lake region, i.e., higher TIC content is linked with warmer temperature and stronger evaporation; 2) Changes in TOC and C/N ratio reflect the regional precipitation, i.e., relatively higher TOC content and C/N ratio indicate higher rainfall which results in stronger river flow and more organic matter entering into the lake. Data of the TIC content, TOC content and C/N ratio of DH99a core sediments suggest that climatic history of the Daihai Lake region is characterized by 4 stages. During the interval of ca. 11200-7500 a BP, higher TIC content, relatively lower TOC content and C/N ratio value indicate a warmer and slight dry condition over the lake area. From ca. 7500 to 4500 a BP, high values of TIC content, with an increase in TOC content and C/N ratio suggest the climate was warm and humid. Changes of TIC content, TOC content show that both temperature and precipitation displayed obvious fluctuations during the period, i.e., slightly cool and humid ca. 7500-6700 a BP, warm and moist ca. 6700-5300a BP, mild and comparatively humid ca. 5300-4500a BP. Between ca. 4500 and 2900 a BP, TIC content and TOC content decreased gradually while fluctuating, C/N ratio displayed a decreasing trend. These data imply that the climate generally became cooler and drier than the preceding period. The lowest values of TIC content, TOC content and C/N ratio during the interval of ca. 2900-0 a BP, demonstrate that the climate was severe, and became cool and dry. However the relative higher values of TIC content, TOC content and C/N ratio between ca. 1700 and 1300 a BP may denote an increase both in temperature and in precipitation. Data of TIC content, TOC content and C/N ratio in Daihai DH99a core sediments indicate that the warm period was asynchronous with the humid time, the warm interval began in ca. 11200 a BP, and ended in ca. 2900 a BP. The humid period was ca. 7500-2900 a BP. During ca. 7500^500 a BP, the climate was warm and humid, which was the climatic optimum of the Holocene Epoch in the Daihai Lake region. Data of TIC content, TOC content and C/N ratio in Daihai DH99a core sediments imply that the Holocene climate was unstable, the fluctuating events happened occasionally. Such as the cold and dry climate in ca. 4400-4200a BP, the warm and humid climatic condition in the period between ca.1700 and 1300a BP.
Resumo:
Since 1990s, commercial conditions in China including commercial environment, retail types, scale of retail enterprises, spatial structure of retail and shopping decision making factors have changed. In order to keep up with these changes, commercial geography should set up new perspectives, theories and methods to analyze its internal mechanism and changing rules, and thus provide reasonable and practical scientific basis to commercial planning, location decision of retail enterprises and commercial environment construction. Taking Xicheng and Haidian District of Beijing as research case, which is a sector region from city center to rural region, this paper selects 12 commercial centers as most important study objects of this sector. This paper mainly makes use of the methods of Modeling, Pearson Bivaiiate Correlations Analysis, Factor Analysis and Logit model. Based on 1300 questionnaires and fieldwork, this paper focuses on modeling of Consumer Satisfaction of Commercial Environment (CSCE), evaluation of commercial environment and driving factors of consumers' shopping location decision. Firstly, this paper discusses the development of commercial geography and commercial environment evaluation, the new characteristics and trends of commercial development in Beijing and physical commercial environment of Xicheng and Haidian District of Beijing from chapter 1 to chapter 4. Secondly, this paper summarizes characteristics of residents' shopping behavior in chapter 5. Thirdly, this paper sets up an evaluative model of CSCE, and analyzes consumer satisfaction indexes of commercial environment and their spatial features in chapter 6. Fourthly, this paper infers how residents' attributes and shopping behaviors affect their preferences of shopping location and what are residents' shopping location decisions and their influencing factors in chapter 7. Fifthly, this paper constructs a significant index model and a pyramidal framework of CSCE, and further analyzes the diversity and competitive advantage of commercial environment in chapter 8. Finally, some conclusions are drawn as follows: 1. Characteristics of residents' shopping behavior mostly embody residents' time distance preference, commodity consumption preference, shopping time distribution and shopping activity characteristics. The important factors that influence shopping location choice of residents are distance, transportation, commodity price, commodity types and commodity quality. However, the important factors, which influence shopping location re-choice of residents, are commodity price, commodity quality, commodity types and transportation. 2. CSCE indexes of 12 commercial centers show us significant spatial characteristics, such as spatial differences of "Center-fringe region", spatial characteristics of axes, spatial diversity of ring roads and so on. 3. Influencing factors including factor endowments, relative establishment factor and location and transportation factor of commercial environment are of importance for CSCE. 4. Logit model 1 indicates that shopping behavior of residents is significantly and positively related to working in high-tech companies, high income and by car and positively related to high school diploma, by bus and subway. 5. Logit model 2 indicates that residents' shopping location decision is significantly and positively related to leisure establishment and relative restaurant and entertainment establishment and negatively related to commercial location, commodity price, service quality, parking site. 6. The significant index model and the pyramidal framework of CSCE indicate competitive advantages are crucial to attractive capability of commercial center, and competitive weakness limits development of commercial centers, in particular the weakness of service quality and parking site now is the chief factors restricting development of commercial centers
Resumo:
全新世气候变化研究是古气候研究的一个重点。中国全新世气候变化的研究也是全球变化研究中重要的一部分。大量的研究工作为恢复中国全新世气候做了重大贡献。中国地形地貌复杂,又处在具有复杂时空变率的东亚季风控制范围内,这使得不同的研究工作者在一些问题上存在意见分歧。比较统一的意见是:中国全新世始于约10. 5ka BP ;在约9~8 ka BP 左右为一段降温期;7~4 ka BP 为一段温暖期,通常称之为全新世大暖期;大约3 kaBP 左右开始降温,至近代才又升温; 约1300 a A. D. 左右进入小冰期,到1850 aA.D. 左右结束,其间又有几次比较明显的温度振荡。1850 a A. D. 至今为温度的上升期。对于气候变动的驱动因素,不同的学者看法不一;从长时间尺度看,太阳辐射变化是气候变化的主要驱动力。
Resumo:
以矿物学理论为基础,采用XRD、AAS、TEM和OM等分析仪器,对国产70kN、日本120kN和210kN高强度瓷绝缘子的化学成分、显微结构等特征进行了分析,找出造成国内外瓷绝缘子性能差异的主要因素。并对贵州地区的高强瓷非金属矿物原料进行了较系统的矿物学研究,确定了6个主要原料基地。在以上研究的基础上,优化设计了420kN和300kN高强度瓷绝缘子的配方及相关生产工艺。并对烧结出420kN高强度瓷绝缘子的化学成分与显微结构进行了研究分析。得到的主要结论如下: (1)对比国内外高强瓷得出,造成国内高强瓷性能差的主要因素是化学成分和显微结构。国内70kN样品含有较高的K2O和TiO2,严重超过了高强瓷标准配方值,而国外配方恰好落在标准值范围内;国内70kN样品晶相含量仅为35%,而国外210kN样品的晶相含量为48%,且晶粒细小分布均匀,玻璃相和气孔相含量也比国内产品少且分布均匀。 (2)采用XRD对贵州地区矿物原料进行分析,最终选定了毕节、大方6个高强瓷原材料产地。这些基地粘土类矿物原料,具有可塑性好,有害矿物含量少,化学成分中Si、Al比适中,Fe、Ti等杂质元素含量低的特点;铝氧类矿物具有含Al2O3含量高且杂质元素少的特点,是制备高强度瓷绝缘子的优质原料。 (3)在主要使用贵州所产的矿物原料基础上,结合国内外高强瓷的性能差异,优化设计了300kN和420kN高强瓷的配方和工艺。其中将坯料的颗粒度组成设定在:≥5µm43-48%,≥10µm25-31%,≥20µm5-12%,并采用合理烧结制度下烧结出420kN高强瓷,其烧结温度范围在13001400℃,最终产品通过IEC检测且显微结构较好。
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富营养化是目前水资源管理的一个主要环境问题。水体中过量的营养元素是引起富营养化的根本原因,其中磷和氮是主要的控制因素。多数湖泊中磷是藻类自然生长的限制因子,因此多年来人们治理富营养化水体的主要策略是减少磷的排放,然而,通过此法成功恢复湖泊生态的例子屈指可数,一个主要的原因就是沉积物中的磷的再释放。因此,沉积物营养元素(尤其是沉积物-水界面上)的生物地球化学过程一直是湖泊科学研究的焦点。本次工作选择贵州的两个人工湖泊—红枫湖、百花湖,通过对磷、氮、碳在沉积物中的化学形态、垂直剖面等方面的研究,结合室内模拟实验和模式计算,揭示了沉积物早期成岩过程中磷、氮、碳的地球化学行为及其潜在的环境效应。尤其是对沉积物磷开展了较深入的研究。红枫湖、百花湖水体中的N/P为46~126,磷是湖泊的限制性营养因子。分析表明,红枫湖、百花湖沉积物中的全磷的平均含量为1300~1500μg.g~(-1),与其它湖泊相比,红枫湖、百花湖具有较高的磷负荷。根据Ruttenberg提出的化学连续提取法(SEDEX),可以把沉积物中的磷分为五种形态:(弱)吸附态磷、铁结合态磷、自生磷灰石磷、残留岩屑磷和有机磷。两湖沉积物中以有机磷和铁结合态磷为主,有机磷分别占全磷的60%(红枫湖)和50.3%(百花湖),铁结合态磷为28.25%(红枫湖)和34%(百花湖),这在其它湖泊是极少见的,红枫湖、百花湖沉积物磷具有很高的迁移活性。有机物质是沉积物磷的主要载体,沉积物中-部分有机质被保存下来,其余的矿化降解,同时释放出溶解磷(HPO_4~(2-)),这些溶解磷可以扩散到上覆水体为浮游生物吸收利用,或是以其它形态滞留在沉积物中。沉积物孔隙水中NO_3~-、SO_4~(2-)、Fe~(2+)、Mn~(2+)的剖面分布表明,红枫湖、百花湖沉积物最活跃的有机质降解发生在表层2厘米的沉积物内。根据孔隙水HPO_4~(2-)的浓度梯度,可以计算沉积物-水界面HPO_4~(2-)的交换通量(J_s),红枫湖、百花湖沉积物-水界面磷的扩散通量(J_s)存在明显的季节性变化:在冬春季扩散通量最大,而夏秋季较小,这与传统的认识相反,我们认为这是由于表层沉积物中有机质的矿化降解有关。我们研究了沉积物吸附作用对沉积物磷循环的影响。吸附动力学实验表明,吸附的动力学过程可以用Langmuir或Freundlich方程描述;红枫湖、百花湖沉积物具有很大的理论吸附容量极值(红枫湖的S_m为21.05mgP.g~(-1),百花湖的S_m为15.83mgP.g~(-1));沉积物对磷酸盐的吸附主要是由于其中的未定型的铁氧化物矿物造成的;铁氧化矿物的吸附作用是沉积物中磷滞留的重要机制;经CDB去除铁氧化物处理后,沉积物吸附磷酸根的能力仅为原来的10%。对原状沉积物-界面水柱的释磷实验结果表明:好氧条件下沉积物的溶解磷的释放通量较高,而厌氧条件下相反较低。进一步说明了有机质降解在磷循环中的地位。将沉积物中磷的形态分析数据、孔隙水溶解磷以及吸附盐实验的数据,用于“扩散-平流-反应”模式,结果表明:红枫湖、百花湖沉积物表层有机质(磷)的降解释磷是沉积物-水界面磷交换通量的主要部分,由于沉积物表层易分解有机质的含量较高,铁氧化物的吸附不足以完全阻止沉积物磷酸盐的释放,有机质的氧化降解速率决定了释放通量的大小;而在表层以下的沉积物中铁氧化物的吸附作用是控制孔隙水溶解磷剖面分布的主要因素;红枫湖、百花湖沉积物的整个埋藏历史中(40年),基本没有稳定自生磷灰石矿物的形成。红枫湖、百花湖沉积物全氮平均为沉积物干重的0.36~0.40%,表层含量为0.69~1.06%,沉积物中的含氮化合物主要85%以上是有机氮,沉积物全氮和有机氮呈现表层富集,随沉积深度增加而减少的剖面特征。红枫湖、百花湖沉积物对固定铵氮的能力较强,固定铵的绝对含量分别为434.05 mg.kg~(-1)和(16.94mg.kg~(-1),分别相对于总氮含量的13.53%和12.53%。红枫湖、百花湖水体和沉积物孔隙水中氨态氮(NH_4~+)和硝态氮(NO_3~-)的剖面分布表明:在沉积物-水界面上发生着最剧烈的氮循环作用,这也是清除水体氮负荷的最彻底和唯一的机制。沉积物水界面起到向上覆水体的营养供给和对污染水体自然净化的双重功能。红枫湖、百花湖的沉积物柱芯上有机质剖面通常仅表现“降解阶段”和“堆积阶段”,对红枫湖HF980903-1-2柱芯的分析,发现红枫湖沉积物有机质(碳、氮)的降解代谢过程同样包括类似于洱海沉积物的“沉降-降解-堆积”三个阶段,我们认为是样品的分隔精度不足以反映沉积剖面的细节;同时也说明,红枫湖、百花湖沉积物有机质组成中有较多的“新鲜”、活性的组分,它们的快速降解使得沉积物中有机质不能长期保存。研究表明,经过10年堆积埋藏,沉积物有机质大约有35~76%被降解。上层沉积物中(活性)有机质的迅速分解,是引起沉积物-水界面强烈的营养元素循环的重要原因。剖面对比分析显示,红枫湖、百花湖沉积物有机物质分解过程中,有机碳、磷、氮的改造是不同步的,有机碳相对稳定,而含氮化合物和有机磷则相对易于降解。C_(Org): N_(Org): P_(Org)比值的分析结果表明:红枫湖、百花湖沉积物有机质的来源主要是来源于无纤维素植物。较高的C/N、C/P和较低的N/P,反映了小型湖泊受到较多的人为干扰和流域物质输入影响的特点。
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本论文选取了斜长角闪岩和榴辉岩作为实验样品,在压力为1.0-3.0 GPa和温度为室温-1300 ℃的条件下,进行了弹性纵波速度和弹性波衰减的实验研究。实验是在YJ-3000吨压力机上进行的,利用超声脉冲透射的方法,首次获得了在压力大于1.0GPa和温度高于800 ℃的条件下的岩石的声波衰减及其各向异性的实验数据。取得如下主要结论:1.榴辉岩的Vp值随压力的升高而增大,在P < 2.0GPa时,上升的速率较快,表明微裂隙逐渐闭合;当P > 2.0GPa时,上升的速率变慢,且表现出很好的线性趋势,这时测得的纵波速度表明了榴辉岩本征的纵波速度,这与前人的实验结果相同。斜长角闪岩的Vp值随压力的变化与榴辉岩的变化相似,不同的是斜长角闪岩的微裂隙闭合压力为1.5GPa。榴辉岩的Vp的Av_p(%)随压力的升高基本保持不变,而斜长角闪岩的Av_p(%)随压力的升高逐渐增大。2.榴辉岩和斜长角闪岩在1.0-3.0 GPa压力下的Vp值随温度的升高而降低,但Vp值在不同的温度阶段,不同的方向上降低的速率和形式不同。如在1.0GPa压力下,当温度小于500 ℃时,Vp值下降较快,说明温度对纵波速度的影响较小;当T > 500 ℃时,Vp值下降的缓慢,说明榴辉岩内部可能发生了结构和应力状态的变化。斜长角闪岩在升温的初始阶段,Vp缓慢下降,并表现出很好的线性趋势。当T > 647 ℃时,Vp下降的速率增大,线性趋势也较好,当T > 1051 ℃时,Vp下降的速率又变小,且比初始时下降的速率要小。榴辉岩Vp的Av_p(%)值随温度的升高而下降,在不同的压力上其下降的速率不同。如在1.0GPa条件下,Av_p(%)随温度的升高而快速下降;在3.0GPa条件下,Av_p(%)值随温度下降缓慢。而斜长角闪岩的Vp的Av_p(%)随温度的变化较复杂,如在1.0GPa条件下,当T < 647 ℃时,Av_p(%)值随温度的升高缓慢增加,当T > 647 ℃时,Av_p(%)值快速增大,当温度达到922 ℃时,Av_p(%)上升到最大值,此后又随温度而减小。3.榴辉岩和斜长角闪岩的弹性波的Q值随压力的升高而增大,其增大的速率和幅度与Vp值的增大形式相同。榴辉岩的Q值的A_Q(%)随压力而升高,而斜长角闪岩的Q值的A_Q(%)随压力基本保持不变。4.榴辉岩和斜长角闪岩的弹性波的Q值随温度的升高而降低,在不同的压力下其降低的速率不同。如在1.0GPa压力下,Q值降低的速率较大;3.0GPa压力下,当T < 300 ℃时,榴辉岩的Q值快速下降,随后下降的幅度减慢,当T > 700 ℃时,榴辉岩的Q值很低,且减小的幅度很小。斜长角闪岩的Q值随温度的变化在1.0-3.0GPa条件下,Q值很小的幅度和趋势相似:当T < 647 ℃时,Q值下降的缓慢,当647 ℃ < T < 1051 ℃时,Q值快速下降,随后下降速率又变小。榴辉岩Q值的A_Q(%)随温度的升高而降低,在1.0和2.0GPa压力下降低较快;3.0GPa压力下A_Q(%)降低较缓慢。斜长角闪岩Q值的A_Q(%)随温度的升高开始缓慢降低,当647 ℃ < T < 105l ℃时,A_Q(%)快速增大,当T > 105l ℃时,A_Q(%)又降低。
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The research studied self-efficacy and job mechanism of insurance salesmen in China by the methods of in-depth interview, focus-group, semi-open questionnaire, standard questionnaire. There were about 1300 samples surveyed. The way of data analysis such as factor analysis, correlation analysis, regreesion analysis and structure equation was used. Four following conclusions were drawn: First, self-efficacy of inssurance salesmen in China consists of eight factorswhich are interview skills, manner, persistence, control of emotion, plans and comments, master of knowledge, intuition and judgement, preparation. Second, the relationship between self-efficacy and other job variables such as achievement motivation, work incentive, coping strategy, view of ability, performance, goalsetting, colleague relationship, the way of feedback from leader, job satisfaction and exertion were tested and all the correlations were significant. Third, regression analysis was used to test the relationship between self-efficacy and the antecedent variables. The result was that four antecedent varialbes enter equation (p<.05). They are self-oriented achievement motivation, stability of emotion, performance and colleague relationship.. Finally, vertified by path-analysis, the research posits a comprehensive model about job for insurance salesmen, in which self-efficacy was the most important factor. On the one hand, self-efficacy has dominant effects on the consequent variables, such as mastery goal, performance- approach goal, job satisfaction, exertion, coping strategy, on the another hand, self-efficacy was found as mediator of the relationship between the antecedent variables and consequent variables.
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La0.8Sr0.2Mn1.1O3 (LSM1.1)-10 mol% Sc2O3-Stabilized ZrO2 co-doped with CeO2 (ScSZ) composite cathodes were investigated for anode-supported solid oxide fuel cells (SOFCs) with thin 8 mol% Y2O3-stabilized ZrO2 (YSZ) electrolyte. X-ray diffraction (XRD) results indicated that the ScSZ electrolytes displayed good chemical compatibility with the nonstoichiometric LSM1.1 against co-firing at 1300 degrees C. Increasing the CeO2 content in the ScSZ electrolytes dramatically suppressed the electrode polarization resistance, which may be related to the improved surface oxygen exchange or the enlarged active area of cathode. The 5Ce10ScZr was the best electrolyte for the composite cathodes, which caused a small ohmic resistance decrease and the reduced polarization resistance and brought about the highest cell performance. The cell performances at lower temperatures seemed to rely on the electrode polarization resistance more seriously, than the ohmic resistance. Compared with the cell impedance at higher temperatures, the higher the 5Ce10ScZr proportion in the composite cathodes, the smaller the increment of the charge transfer resistance at lower temperatures. The anode-supported SOFC with the LSM1.1-5Ce10ScZr (60:40) composite cathode achieved the maximum power densities of 0.82 W/cm(2) at 650 degrees C and 2.24 W/cm(2) at 800 degrees C, respectively. (c) 2005 Elsevier B.V. All rights reserved.