27 resultados para BOMBYX-MORI SILK


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In this paper, a theory is developed to calculate the average strain field in the materials with randomly distributed inclusions. Many previous researches investigating the average field behaviors were based upon Mori and Tanaka's idea. Since they were restricted to studying those materials with uniform distributions of inclusions they did not need detailed statistical information of random microstructures, and could use the volume average to replace the ensemble average. To study more general materials with randomly distributed inclusions, the number density function is introduced in formulating the average field equation in this research. Both uniform and nonuniform distributions of inclusions are taken into account in detail.

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本书共有16篇论文,论述了国内外有关复合材料及其结构力学等方面新近进展的情况。如:复合材料及其结构的粘弹性力学、三相模型下复合材料的细观力学性质等。

目录

第一章 复合材料力学的统计断裂理论和单向复合材料的随机临界核理论

范赋群 曾庆敦

第一节 引言

第二节 纤维强度分布的统计特性

第三节 纤维束的统计分析

第四节 链式模型

第五节 单向复合材料纵向拉伸的破坏形式

第六节 应力集中因子

第七节 复合材料力学的统计断裂理论

第八节 杂交(混杂)复合材料的统计分析

第九节 单向复合材料的随机临界核理论

参考文献

第二章 含夹杂脆性基体复合材料的几个力学问题&杜善义 韩杰才

第一节 引言

第二节 脆性基体含脆性夹杂的微结构力学

第三节 含随机分布晶须和微裂纹的脆性复合材料本构关系

第四节 含随机分布相变夹杂的陶瓷复合材料增韧

第五节 脆性基体含延性夹杂的增韧分析

第六节 结束语

参考文献

第三章 复合材料及其结构的粘弹性力学&张恒 王震鸣 李江

第一节 引言

第二节 聚合物材料的粘弹性本构关系

第三节 复合材料的粘弹性本构方程

第四节 动态粘弹性性能研究

第五节 复合材料结构粘弹性问题的求解

参考文献

第四章 复合材料含孔层合板拉伸强度的分析方法&李顺林 熊中侃

第一节 引言

第二节 应力集中系数法

第三节 材料力学分析模型法

第四节 断裂力学分析模型法

第五节 复合材料力学分析模型法

参考文献

第五章 纤维束及其单向复合材料应变率相关的统计本构理论研究

夏源明 杨报昌

第一节 引言

第二节 冲击拉伸试验技术

第三节 组分材料的应变率相关性

第四节 单向纤维增强复合材料的应变率相关性

第五节 环境影响

第六节 展望

参考文献

第六章 复合材料层合结构层间应力的计算研究&顾德淦

第一节 引言

第二节 线弹性均匀拉伸模型的计算

第三节 其它线弹性模型的计算

第四节 非线性弹性模型的计算

第五节 弹塑性模型的计算

第六节 结语

参考文献

第七章 纤维增强复合材料的细观压缩失稳&魏悦广 杨卫

第一节 引言

第二节 细观压缩失稳的研究概况

第三节 平面弹塑性失稳理论

第四节 贯穿折曲带

第五节 表面失稳与扩展折曲带

第六节 压缩失稳模式的缺陷敏感性

第七节 水平破坏带的扩展

第八节 承压复合材料的增强与增韧

参考文献

第八章 复合材料在复杂加载下的强度与损伤研究&王兴业 杨光松

第一节 引言

第二节 复合材料在复杂应力状态下的强度问题

第三节 复合材料张量多项式强度准则的分析

第四节 张量多项式强度准则相互作用系数确定方法的探讨

第五节 复合材料在复杂应力状态下强度准则的实验研究

第六节 复合材料在双向载荷下的损伤

参考文献

第九章 任意铺设复合材料层板在复杂载荷下的屈曲与后屈曲分析

曹大卫 成广民 马兰芝

第一节 引言

第二节 不对称层板屈曲、后屈曲的能量表达式

第三节 应用Rayleigh-Ritz法解屈曲与屈曲后问题

第四节 算例与讨论

参考文献

第十章 复合材料柱型壳的铺层优化和初始后屈曲特性&孙国钧

第一节 引言

第二节 80年代复合材料圆柱壳铺层优化的研究进展

第三节 组合载荷作用下层合圆柱壳的铺层优化和实验研究

第四节 双向铺设层合圆柱壳的优化设计

第五节 复合材料加筋圆柱壳的优化设计

第六节 复合材料椭圆柱壳在轴压下的稳定性

参考文献

第十一章 三相模型下复合材料的细观力学性质&罗海安

第一节 引言

第二节 三相模型下的Eshelby张量与修正的Mori-Tanaka方法

第三节 三相柱形模型下的刃型位错

第四节 三相模型下纤维增强复合材料的基体裂纹

第五节 三相模型下纤维增强复合材料的界面裂纹

第六节 结论

参考文献

第十二章 复合材料结构连接的应力分析&吴代华 晏石林

第一节 引言

第二节 复合材料胶接接头分析

第三节 复合材料机械接头分析

参考文献

第十三章 复合材料及其结构的湿热效应研究&陈浩然 息志臣 孙延波

第一节 引言

第二节 湿热瞬态分析

第三节 热自由边界效应

第四节 湿热变形和湿热应力

参考文献

第十四章 用加权残值法分析计算不同边界条件下层板的屈曲问题&李卓球

第一节 引言

第二节 层板非线性弹性的屈曲计算与分析

第三节 层合圆柱曲板的非线性弹性屈曲

第四节 用加权残值法计算层板的后屈曲问题

第五节 层板高阶剪切变形理论的屈曲分析

参考文献

第十五章 复合材料多连通板的应力场计算&林佳铿 王林江

第一节 引言

第二节 分析方法

第三节 算例

第四节 讨论和结论

参考文献

第十六章 基体对玻璃纤维缠绕火箭发动机壳体强度影响机理的研究

嵇醒 卢天健 顾星若

第一节 引言

第二节 实验结果分析

第三节 有限元分析

第四节 实验验证

第五节 最佳平衡系数K?

第六节 环氧复合材料基体的层间剪切强度

第七节 层间剪切破坏的扫描电镜观察

第八节 结语

参考文献

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Manu National Park of southern Peru is one of the most renowned protected areas in the world, yet large-bodied vertebrate surveys conducted to date have been restricted to Cocha Cashu Biological Station, a research station covering <0.06 percent of the 1.7Mha park. Manu Park is occupied by >460 settled Matsigenka Amerindians, 300-400 isolated Matsigenka, and several, little-known groups of isolated hunter-gatherers, yet the impact of these native Amazonians on game vertebrate populations within the park remains poorly understood. On the basis of 1495 km of standardized line-transect censuses, we present density and biomass estimates for 23 mammal, bird, and reptile species for seven lowland and upland forest sites in Manu Park, including Cocha Cashu. We compare these estimates between hunted and nonhunted sites within Manu Park, and with other Neotropical forest sites. Manu Park safeguards some of the most species-rich and highest biomass assemblages of arboreal and terrestrial mammals ever recorded in Neotropical forests, most likely because of its direct Andean influence and high levels of soil fertility. Relative to Barro Colorado Island, seed predators and arboreal folivores in Manu are rare, and generalist frugivores specializing on mature fruit pulp are abundant. The impact of such a qualitative shift in the vertebrate community on the dynamics of plant regeneration, and therefore, on our understanding of tropical plant ecology, must be profound. Despite a number of external threats, Manu Park continues to serve as a baseline against which other Neotropical forests can be gauged.

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<正> 细鳞鱼和哲罗鱼在分类学上隶属于(鱼非)形目(Clupeiformes)鲑鳟亚目(Salmonidei)的鲑科(salmonidae)。在中国只为黑龙江流域所特有。鲑科鱼类中,细鳞鱼属(Brachymystax)内仅细鳞鱼Brachymystax lenok(Pallas)一种。在哲罗鱼属(Hucho)内,除哲罗鱼Hucho taimen(Pallas)外,在北半球还分布着另外四种,即:Hucho hucho(Linne)棲息于苏联境内的多瑙河流域;Hucho ishikawai Mori,棲息于鸭

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畜牧业是否成长为农村经济的支柱产业,是衡量一个国家农业发达程度的主要标志。现阶段.我国畜牧业的增长方式、发展路径、动力、市场和地位都发生了重大变化,给畜牧业的可持续发展提出了许多新问题和新挑战。近年来.我国畜牧业的发展取得了举世嘱目的成就,促进了国民经济的快速发展,丰富了城乡人民物质和文化生活的需要。随着经济的发展和人们生活水平的逐步提高.对畜牧产品的需求将有较大增长,大力加强和发展畜牧业将是我国农业的最终方向。依据现有统计资料,结合我国畜牧业的实际情况,根据"十一五"规划和建设社会主义新农村的要求,文章分析了畜牧业发展的地位,探讨了畜牧业存在的问题.并提出了相应的对策和建议。

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We have successfully achieved the integration of isothermal amplification and the subsequent analysis of specific gene fragments on poly(methyl methacrylate) microchips. In our experiments, loop-mediated isothermal amplification, which can offer higher specificity and efficiency than PCR, has been performed at a constant temperature (65 degreesC). After amplification, products could be either examined by the integrated microchip-based electrophoresis or directly observed by naked eye with SYBR Green I added into the reaction solution. By such an integrated microsystem, the amplification and the subsequent analysis of prostate-specific antigen gene with template concentration at 23 fg/muL could be finished within 15 min, which demonstrates its advantages of high specificity, good reproducibility, and fast speed in gene detection.

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Single crystals of PrMnO3 and TbMnO3 were grown by floating zone method and the crystal structure was determined by single crystal X-ray diffractometry. The structure of these compounds belongs to the orthorhombic system (space group is Pnma, No. 62) with the lattice parameters alpha approximate to root (.) - a(p), b approximate to 2 (.) a(p) , c approximate to root 2.a(p) and Z = 4, where a(p) is ideal cubic perovskite cell parameter.

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A hydrogen peroxide biosensor was fabricated by coating a sol-gel-peroxidase layer onto a Nafion-methylene green modified electrode. Immobilization of methylene green (MG) was attributed to the electrostatic force between MG(+) and the negatively charged sulfonic acid groups in Nafion polymer, whereas immobilization of horseradish peroxidase was attributed to the encapsulation function of the silica sol-gel network. Cyclic voltammetry and chronoamperometry were employed to demonstrate the feasibility of electron transfer between sol-gel-immobilized peroxidase and a glassy carbon electrode. Performance of the sensor was evaluated with respect to response time, sensitivity as well as operational stability. The enzyme electrode has a sensitivity of 13.5 mu A mM(-1) with a detection limit of 1.0 x 10(-7) M H2O2, and the sensor achieved 95% of the steady-state current within 20 s. (C) 2000 Elsevier Science B.V. All rights reserved.

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In this paper, the graft copolymers of styrene to nascent linear polyethylene reactor powders were prepared through plasma graft polymerization. The grafting reaction was initiated by the alkyl radicals formed on the surface of nascent polyethylene with plasma treatment as indicated by electron spin resonance spectra. In graft copolymerization by alkyl radicals, the grafting yield increased with either the plasma power or the plasma treatment lime. Compared with ordinary polyethylene powders, nascent polyethylene reactor powders were found to be more easily plasma-grafted. This has been attributed to the greater sensitivity to irradiation in producing reactive centres under the same conditions. High density polyethylene showed almost the same grafting yield as linear low density polyethylene at 50 degrees C. The surface morphology of nascent polyethylene observed by scanning electron microscope before and after the grafting showed that the silk-like fibrils were not destroyed by plasma treatment.

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The biothermocatalytic transitional zone gas is a new type of natural gas genetic theory, and also an clean, effective and high quality energy with shallow burial depth, wide distribution and few investment. Meanwhile, this puts biothermocatalytic transitional zone gas in important position to the energy resource and it is a challenging front study project. This paper introduces the concept, the present situation of study and developmental trend about biothermocatalytic transitional zone gas in detail. Then by using heat simulating of source rocks and catalysis mechanism analysis in the laboratory and studying structural evolution, sedimentation, diagenesis and the conditions of accumulation formation and so on, this paper also discusses catalytic mechanism and evolutionary model of the biothermocatalytic transitional zone gas formation, and establishes the methods of appraisal parameter and resources prediction about the biothermocatalytic transitional zone gas. At last, it shows that geochemical characteristics and differentiated mark of the biothermocatalytic transitional zone gas, and perfect natural gas genetic theory, and points out the conditions of accumulation formation, distribution characteristics and potential distribution region on the biothermocatalytic transitional zone gas m China. The paper mainly focuses on the formation mechanism and the resources potential about the biothermocatalytic transitional zone gas. Based on filed work, it is attached importance to a combination of macroscopic and microcosmic analysis, and the firsthand data are obtained to build up framework and model of the study by applying geologic theory. Based on sedimentary structure, it is expounded that structural actions have an effect on filling space and developmental cource of sediments and evolution of source rocks. Carried out sedimentary environment, sequence stratigraphy, sedimentary system and diagenesis and so on, it is concluded that diagenesis influences developmental evolution of source rocks, and basic geologic conditions of the biothermocatalytic transitional zone gas. Applying experiment simulating and catalytic simulating as well as chemical analysis, catalytic mechanism of clay minerals is discussed. Combined diagenecic dynamics with isotope fractionation dynamics, it is established that basis and method of resource appraisal about the biothermocatalytic transitional zone gas. All these results effectively assess and predict oil&gas resources about the biothermocatalytic transitional zone gas-bearing typical basin in China. I read more than 170 volumes on the biothermocatalytic transitional zone gas and complete the dissertation' summary with some 2.4 ten thousand words, draw up study contents in some detail and set up feasible experimental method and technologic course. 160 pieces of samples are obtained in oilfield such as Liaohe, Shengli, Dagang and Subei and so on, some 86 natural gas samples and more than 30 crude oil samples. Core profiles about 12 wells were observed and some 300 geologic photos were taken. Six papers were published in the center academic journal at home and abroad. Collected samples were analysised more than 1000 times, at last I complete this dissertation with more than 8 ten thousand words, and with 40 figures and 4 plates. According to these studies, it is concluded the following results and understandings. 1. The study indicates structural evolution and action of sedimentary basin influence and control the formation and accumulation the biothermocatalytic transitional zone gas. Then, the structural action can not only control accommodation space of sediments and the origin, migration and accumulation of hydrocarbon matters, but also can supply the origin of energy for hygrocarbon matters foramtion. 2. Sedimentary environments of the biothermocatalytic transitional zone gas are lake, river and swamp delta- alluvial fan sedimentary systems, having a warm, hot and humid climate. Fluctuation of lake level is from low to high., frequency, and piling rate of sedimentary center is high, which reflect a stable depression and rapidly filling sedimentary course, then resulting in source rocks with organic matter. 3. The paper perfects the natural gas genetic theory which is compound and continuous. It expounds the biothermocatalytic transitional zone gas is a special gas formation stage in continuous evolutionary sequence of organic matter, whose exogenic force is temperture and catalysis of clay minerals, at the same time, having decarbxylation, deamination and so on. 4. The methodology is established which is a combination of SEM, TEM and Engery spectrum analysis to identify microstructure of crystal morphology about clay minerals. Using differential thermal-chromatographic analysis, it can understand that hydrocarbon formation potential of different typies kerogens and catalytic method of all kinds of mineral matrix, and improve the surface acidity technology of clay minerals measured by the pyridine analytic method. 5. The experiments confirm catalysis of clay minerals to organic matter hygrocarbon formation. At low temperature (<300 ℃), there is mainly catalysis of montmorillonite, which can improve 2-3 times about produced gas of organic matters and the pyrolyzed temperature decreased 50 ℃; while at the high temperature, there is mainly catalysis of illite which can improve more than 2 times about produced gas of organic matters. 6. It is established the function relationship between organic matter (reactant) concentration and temperature, pressure, time, water and so on, that is C=f (D, t). Using Rali isotope fractionation effect to get methane isotope fractionation formula. According to the relationship between isotope fractionation of diagenesis and depth, and combined with sedimentary rate of the region, it is estimated that relict gas of the biothermocatalytic transitional zone gas in the representative basin. 7. It is revealed that hydrocarbon formation mechanism of the biothermocatalytic transitional zone gas is mainly from montmorillonite to mixed minerals during diagenesis. In interlayer, a lot of Al~(3+) substitute for Si~(4+), resulting in a imbalance between surface charge and interlayer charge of clay minerals and the occurrence of the Lewis and Bronsted acid sites, which promote to form the carbon cation. The cation can form alkene or small carbon cation. 8. It is addressed the comprehensive identification mark of the biothermo - catalytic transitional zone gas. In the temproal-spatial' distribution, its source rocks is mainly Palaeogene, secondly Cretaceous and Jurassic of Mesozoic, Triassic, having mudy rocks and coal-rich, their organic carbon being 0.2% and 0.4% respectively. The vitrinite reflection factor in source rocks Ro is 0.3-0.65%, a few up to 0.2%. The burial depth is 1000-3000m, being characterized by emerge of itself, reservoir of itself, shallow burial depth. In the transitional zone, from shallow to deep, contents of montmorillonites are progressively reduced while contents of illites increasing. Under SEM, it is observed that montmorillonites change into illite.s, firstly being mixed illite/ montmorillonite with burr-like, then itlite with silk-like. Carbon isotope of methane in the biothermocatatytic transitional zone gas , namely δ~(13)C_1-45‰- -60 ‰. 9. From the evolutionary sequence of time, distribution of the biothermocatalytic transitional zone gas is mainly oil&gas bearing basin in the Mesozoic-Neozoic Era. From the distribution region, it is mainly eastern stuctural active region and three large depressions in Bohaiwang basin. But most of them are located in evolutionary stage of the transitional zone, having the better relationship between produced, reservoir and seal layers, which is favorable about forming the biothermocatalytic transitional zone gas reservoir, and finding large gas (oil) field.