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911.
Neural network model for the constitutive relations of soil 总被引:1,自引:0,他引:1
Zeng Jing Wang J ing |tao School of Civil Engineering Mechanics Huazhong University of Science Technology Wuhan Hubei China 《武汉大学学报:自然科学英文版》2003,8(1):86-90
0 IntroductionAccordingtothedifferenttheoriesappliedintheestablishingconstitutivemodel,theconstitutivemodelisgenerallygroupedintotwocategories :elasticmodelandelasto plasticmodel.Asoneoftheelasticmodels,Duncan Chang’smodel[1] iswidelyappliedinengineeringpr… 相似文献
912.
研究求广义强非线性补问题和拟补问题的逼近解的迭代算法.作为特例,概括了该领域中一些熟知的结果.我们的结果推广、改进和补充了先前由几位作者包括Noor,Chang与Huang及Li与Ding得到的早期和最近的结果. 相似文献
913.
四对羟基苯基杯[4]间苯二酚芳烃的合成及其性质研究 总被引:1,自引:0,他引:1
本文报道了2,8,14,20-四对羟基苯基杯[4]间苯二酚芳烃的合成及其化学反应性质(乙酰化、丁酰化、甲基化、苄基化).讨论了反应温度,反应时间,溶剂效应等因素对反应的影响。各产物通过IR、1HNMR以及MS进行了表征。 相似文献
914.
根据国家科技攻关研究的结果,论证了长江中下游地区地下水中Ni,Ti,Mo元素的形成、含量及其分布规律与地下水的含水介质成分、氧化还原环境以及地下水酸碱度的关系。 相似文献
915.
螺旋藻水溶性多糖的分离纯化 总被引:2,自引:0,他引:2
螺旋藻干粉经乙醇脱脂后用水提取,乙醇沉淀,并经凝胶Sephadex-G柱层析精制,获得4种螺旋藻制多糖SPA-1,SPA-2,SPA-3,SPA-4,研究表明均为均一多糖组分。 相似文献
916.
The mass recognizing property of DLC film for formic acid vapors 总被引:2,自引:0,他引:2
Yonghong Yan Yun Zeng Jiannan Xiang Xia Yin Jiucheng Jin Zengzhang Che 《科学通报(英文版)》1998,43(15):1307-1307
The carbon films are prepared by r. f. plasma method with n-butylamine as carbon source. The analysis of Raman spectrosewpy
shows that this kind of carbon film has diamond-like structure, and IR spectroscopy measurement indicats that there are SP2 bonding, SP3 bonding and amino-group in the film. It is the existence of amino-group and hydrogen atom that cause the amorphous structure
and the deformation of bonding to increase, thus leading the Raman spectrum to form a broad absorption band. The quartz crystal
microbalance (QCM) deposited with this kind of carbon film as recognizing coating is very sensitive to formic acid vapors.
This QCM sensor has good reproducibility, high stability, rapid response and long lifetime. 相似文献
917.
Ying Huang Kezhong Zhang Wenying Huang Daru Lu Ying Huang Zhanlu Ma Zhaorui Ren Xinfang Qiu Jinglun Xue Yitao Zeng Shuzhen Huang 《科学通报(英文版)》1998,43(15):1294-1298
The DNA of human factor IX (hF IX) gene vector pMC IX m, which had been proven to be able to express inin vitro and living cells, was introduced into 586 zygotes of Kunming Whlte Mice by positive pressure microinjection technique with
manual operation. The 499 survival embryos after microinjection were then transferred into pseudopregnant recipient mice and
216 F, pups were born. The analysis of PCR and Southern blot hybridization showed that, of the 216, 6 (2 females and 4 males)
were integrated with foreign DNA in their genornes, giving an integration frequency of 3% (6/216). Two F0 female transgenic mice could express hF IX protein in their milk and the content was over 100 ng/mL as measured with ELISA.
The biological activities of hF IV in the milk of two F0 mike were 44.67 % and 79.43 %, respectively. 相似文献
918.
The method of determining grid sizes of finite element method of water quality models is presented on the basis of characteristics
of pollutant distributed in the just downstream grid of discharge. A given length of the grid is applied to calculate the
minimum distance for the pollutant to complete mixing in the lateral direction n the just downstream grid of the discharge,
and the minimum distance is regarded as the maximum width of the grid. Application of the maximum width of the grid and flow
rate per unit width of the river results in the number of flow zones in the lateral direction of the river. Consequently division
of grids and numerical calculation of water quality with finite clement method can be carried out on the basis of available
method and topographic map of the river course. Analysis of scnsitivity shows that the effect of the width of the river and
the effect of the length of the grids on the minimum number of flow zones in the lateral direction is relatively small, and
that the effect of the given lateral mixing degree of the pollutants on the minimum number of flow zones is acceptable, which
indicates that the method presented is relatively stable. The method can avoid thc blindness and randomness in determining
the number of flow zones, and can decrease the amount of computation under the condition that the accuracy requirement is
mct. The problem that determining the sizes of the grids must rely on empirical knowledge has bcen solved. 相似文献
919.
The mega-thick oil-bearing sandstone has been discovered in the Jurassic System in the Tula Basin, among which there are asphalt
veins in fractures. The crude oil from oil-bearing sandstone and asphalt in the basin is mature, and similar to that of the
Jurassic crude oil in the Qaidam Basin in geochemistry. The discovery not only shows that the Tula Basin can generate hydrocarbon
and take on great exploration prospects but also has great implications for the oil and gas exploration in the Qaidam Basin. 相似文献
920.
对向靶反应溅射制备AlN薄膜的结构及物性 总被引:1,自引:0,他引:1
用对向靶反应溅射制备的AlN薄膜,高气压为取向,低气压下为取向,精确测量XRD衍射峰位可看出AlN薄膜有较大应力。对硬度的测量发现AlN薄膜硬度较大,取向对硬度没有影响。 相似文献