基于遗传算法的人工神经网络模型在冬小麦根系吸水模型中的应用

基于土壤水分与冠部数据,应用遗传算法优化人工神经网络模型的权值,将获得的冬小麦根长密度分布应用于根系吸水模型中,并进行了水分数值模拟,水分模拟效果整体较好,表明应用该方法可以为根系吸水模型提供准确的根系参数,并且较为方便,这对于根系吸水模型的建立及应用有着重要的意义。     

抗谷胱甘肽-S-转移酶(GST)单克隆抗体的研制及初步应用

以纯化的谷胱甘肽转移酶标签蛋白(GST)免疫Balb/C小鼠,取免疫鼠脾细胞与NSO骨髓瘤细胞按常规方法融合,用纯化的GST经间接ELISA筛选,阳性孔经3次有限稀释法亚克隆,最终获得2株抗GST的单克隆杂交瘤细胞株,分别命名为4B7-F4和4B7-F4.间接ELISA检测4B7-E4、4B7-F4细胞培养上清的效价分...     

黑胫病菌诱导的烟草SSH文库构建及其分析

黑胫病是危害严重的世界性烟草主要病害之一,探究烟草对黑胫病的抗病机制,可以为该病的综合防治提供理论依据。本研究以烟草黑胫病抗性品种革新3号为材料,利用黑胫病0号生理小种诱导其水平抗性,分别在接种后0.5、1、3、6、10和16 d取样,通过抑制差减杂交技术(SSH)构建cDNA文库,获得了960个阳性克隆。利用反向Northern斑点杂交技术对其中240个阳性克隆进行杂交筛选,筛选出57个表达差异明显的基因,序列拼接后获得33条高质量EST,测序及其比对分析表明,革新3号对烟草黑胫病抗性相关基因主要涉及抗病防卫、光合作用、信号传导和能量代谢等方面。进一步基因功能分析显示,病程相关PR1b蛋白、半胱氨酸蛋白、延伸因子1-α、α-微管蛋白、细胞色素P450、精胺合成酶、水通道蛋白、过氧化物酶体膜蛋白、甘氨酸延伸因子等可能参与了烟草与黑胫病菌非亲和互作过程。     

盐胁迫及贮藏时间对4种补血草种子发芽特性的影响

研究了盐胁迫和贮藏时间对二色补血草、黄花补血草、中华补血草和德国补血草种子发芽特性的影响,以探讨其种子萌发时的耐盐性差异,并了解适宜种子发芽的贮藏时间.试验对发芽率、胚根长度、发芽速度、耐盐指数等指标进行了测定分析,结果表明:在0 ～8 g/L NaCl浓度范围内,二色、黄花、德国补血草种子发芽率之间的差异均不显著,但中华补血草种子在8 g/L NaCl浓度下的发芽率显著低于对照及2 g/L和4 g/L的盐处理;随着盐胁迫程度加深,4种补血草的胚根和幼苗长均呈现出先上升后下降的趋势;盐胁迫下德国补血草发芽速度最快,黄花补血草发芽速度最慢;4种补血草有较强的耐盐性,种子萌发时均可耐8 g/L的盐浓度,4种补血草耐盐性强弱表现为:二色补血草＞德国补血草＞中华补血草＞黄花补血草.贮藏1年的4种补血草种子的发芽率均极显著高于贮藏2年的,贮藏时间对中华补血草种子发芽特性影响最小,对德国补血草影响最大,德国补血草不宜采用隔年种子育苗.     

多效唑处理对蔓性千斤拔种子产量及质量的影响

目的:研究多效唑处理对蔓性千斤拔种子产量及质量的影响.方法:采用单因素随机区组试验,以多效唑喷施为因素,研究其对种子产量及质量的影响.结果:蔓性千斤拔种子产量排序为T2＞T3＞T1 ＞ck,分别较ck增加107.82％、78.52％、72.07％;而且经处理,其种子内在质量及幼苗潜在抗逆能力均高于ck.结论:适宜的多效唑处理浓度可提高蔓性千斤拔种子产量及种子质量.     

Characteristics and thermodynamics analysis ofoxyacetylene flame brazing joint of Cu/Al tubes

以磨盘柿为试材,研究不同液浸处理对冰温贮藏(-0.5～-0.2)℃柿果涩味转变、品质及生理指标的影响。结果表明:在冰温条件下,用2%浓度的NaCl溶液贮藏磨盘柿,可使果实的乙醇含量在贮藏30～45 d内急剧增加,促进可溶性单宁的降低,在贮藏45 d时达到完全脱涩,并可有效延缓果实硬度的下降,具有脱涩和保脆的双重作用,同时可保持相对较高的可溶性固形物和可滴定酸含量,抑制贮藏后期果实丙二醛和膜相对电导率的增加,减缓果实的衰老进程。     

Near Crack Line Elastoplastic Solution for an Eccentric Cracks Loaded by the Pore Water Pressure

By using near crack line analysis method and Mohr-Coulomb strength criterion,the elastic-plastic solution for near crack line of an eccentric cracks loaded by the pore water pressure under large scale yielding condition is analyzed.The elastic stress fields,the plastic stress field,the unit normal vector of the elastic-plastic boundary near the crack line,the elastic-plastic stress fields near crack line are identified.The change pattern of the length of the plastic zone and the pore water pressure is presented.Besides,the elastic-plastic analytical solution for an eccentric cracks loaded by the pore water pressure is obtained.     

Ratio control strategy for solving system response lag of continuously variable transmission system

Generally, there’s a system response lag in the continuously variable transmission system, and this leads to a deviation of the engine work point from the optimal operation line of the minimum fuel consumption. To reduce the influence of system response lag, a new CVT ratio control strategy with the system response lag parameter during computing target ratio is proposed. Simulation results indicate that the proposed control strategy can overcome the effect of system response lag, so as to keep the engine work point on the optimal operation line effectively. A comparison of fuel consumption is made between the proposed control strategy and the traditional one by simulation, and results indicate that the proposed control strategy reduces the fuel consumption of the system by 2.85％.     

Improvement of circulatory circle design method forautomobile hydraulic torque converters

A design method to reduce the circulatory circle axle size for automobile hydraulic torque converters is proposed. According to the beam flow theory, the variety of the axle size has little effect on the characteristics of torque converters. Based on analyzing traditional design method, it’s found that the basic reason for oversize of axle is the unreasonable semi-empirical expression of the first and third arc radius. An improved design semi-empirical expression is proposed for passage car torque converters based on the analysis of several foreign mature torque converters, and an improved design method is established. The improved method is used to design a torque converter, and the results show that the circulation circle axle size reduces about 26% in the condition of keeping the same characteristics of the traditional method. It means the improved design method can better meet the design requirement of automobile torque converters.     

The influence of stress sensitivity on productionof hydraulically-fractured tight gas wells

This paper takes Sulige Gas Field as a case study and used three methods including laboratory experiments,production performance analysis and reservoir simulation to study the influence of stress sensitivity on production of fractured tight gas wells.The results show that the fracture length and conductivity of hydraulically created fracture are reduced more than 50%,and the stress sensitivity of hydraulically created fracture is stronger than that of matrix.With the increase of gas production,the influence of stress sensitivity becomes stronger,and finally results in 18% reduction of gas production,and hydraulically created fractures play an important role in the influence of stress sensitivity.