双抗转基因烟草纯合系的选育及田间试验

为了将双抗转基因烟草推向实用,进行了双抗转基因烟草纯合系的选育。在试验田中利用人工攻毒进行了T1代植物的抗病毒特性的分离试验;在抗性良好的T1植株的后代T2代植物上进行了田间的病毒接种试验和转基因表达的分析,从中选育出双抗转基因烟草纯合系。又于试验田中,在这些纯合系后代T3代上验证了抗病毒特性的遗传稳定性。在转基因表达分析中,发现CMV外壳蛋白基因的表达在翻译水平上受到抑制。     

A Density Functional Theory Study on Electronic Structure and Second—order Nonlinear Optical Properties of Some Push—Pull Molecules

Time-dependent density-functional theory(TDDFT)has been applied to calculate the electronic structure and second-order nonlinear optical(NLO) properties of some organic molecules.The two-dimensional(2-D)charge transfer charateristics of calculated molecules were studied and compared with corresponding experimental results.All the theoretical results agree well with the measurement.For 2-D molecule with two-fold symmetry,the dominant charge transfer is off-diagonal,while for three-fold symmetry 2-D molecule,the dominant charge transfer is not only between branches and central group but also among branches.     

过渡金属体系非线性光学性质计算的ECP基组研究

有效核势(ECP)方法是计算含有过渡金属体系的电子结构及物理性质的有效方法. 本文比较了一系列典型的ECP基组对计算含过渡金属体系非线性光学性质精度的影响. 分别在HF, MP2和DFT理论水平上对过渡金属元素使用不同的ECP基组, 计算了几个过渡金属有机化合物的静态一阶超极化率β₀. 研究结果表明: 使用有效核势计算含过渡金属体系时, 核电子的选取是提高计算精度的前提, ns和np电子应该和nd电子一同作为价电子处理; 对于重原子, 必须考虑自旋-轨道耦合相对论效应. 经过综合评估, 认为使用Stuttgart/Dresden赝势的ECP基组, MHF, 在计算含有过渡金属体系非线性光学性质方面是比较好的基组; Stuttgart RSC 1997和SBKJC VDZ相对而言是较好的基组; 基组Lanl2dz, Hay-Wadt MB (n＋1)和Hay-Wadt VDZ (n＋1)由于没有考虑自旋-轨道耦合, 计算精确度次之; 而基组CRENBL和CRENBS计算的偏差要大一些, 尤其是CRENBS基组由于价电子选择得太少而导致与实验值的偏差最大.     

Introducing Bt Gene Into Maize With Ovary Injection

It is reported here that Bt toxin gene has been successfully transferred into maize inbred line by ovary injection for the first time both at home and abroad. One transgenic plant (To) has been confirmed by Southern blotting and PCR test, and 71 progenies (T1) from T0 have been obtained through self-pollination. Of these 71 progenies, seven plants demonstrated positive results in the PCR test; four were used to feed Asian corn borer, and certain effect of insect-resistance was observed. The experiments on the ovary injection in Hainan Province have also been repeated, thus providing new chance to the application of genetic engineering to the maize improvement.     

电极曲率对同轴介质阻挡放电非线性行为的影响

采用一维自洽的等离子体流体模型数值研究了大气压同轴介质阻挡放电中电极曲率对放电非线性行为的影响.研究表明,在不同的电极曲率下放电可以呈现不同的非线性现象.传统的单倍周期放电只能在一定曲率范围内保持稳定,反之则经历倍周期分岔过程而转变为双倍周期放电,且转变时间与系统偏离分岔点的距离成反比.前次放电产生的空间电荷的记忆效应...     

建议鞍钢采用液芯钢锭轧制技术

本文着重介绍液芯钢锭轧制技术中几个重要问题,如成份偏析、鼓肚和凝固率,实现液芯锭轧制工艺制度、加热制度及对产品质量的影响。建议鞍钢采用液芯钢锭轧制技术的实施方案。     

基于FPGA与SDRAM的高效LCD控制器设计

为满足出租车拼车系统对LCD(Liquid Crystal Display)液晶显示屏的高分辨率和高刷新率的要求, 提出一种在FPGA（Field-ProgrammableGate Array）中集成高效率LCD控制器的设计方案, 给出了该控制器的基本结构与实现功能。设计中采用自定义图形处理命令, 使用高速SDRAM (Synchronous Dynamic Random Access Memory)作为显存, 以提升像素填充率、 DMA(Direct Memory Access)操作方式和硬件多缓冲帧同步切换方法提高控制器工作速度与工作效率。研究结果表明, 该LCD控制器能实现图片的循环刷新功能, 输出图像不失真, 刷新率达到60帧/s以上, 理论像素填充率达到8.8千万像素/s。同时, 提高了系统的灵活性, 并在拼车系统中获得良好的效果。     

STUDY ON THE GENOME OF CAULIFLOWER MOSAIC VIRUS (XINJIANG ISOLATE)——RESTRICTION MAPPING OF VIRION AND CLONED VIRAL DNA

The genomie DNA of CaMV (Xinjiang isolate) was mapped on the virion DNA with anumber of restriction endonueleases by double digestions and partial digestions of one-end~(32)P-labelled fragments. It contained the unique sites of BglI, SalI and XhoI. BamHI andHhaI each cut it at two sites, EeoRI at five sites (three of which were located), Hpa Ⅱ atseven sites, BglⅡ at eight sites, and HaeⅢ at ten sites. The sites of all the enzymes usedabove, as well as HindⅢ which cut at ton sites were also mapped on the cloned CaMVDNA. Virion DNA and cloned viral DNA gave the same results in the number and locationof cleavage sites of the restriction enzymes tested on both DNAs. Like most of the otherisolates, CaMV-Xinjiang isolate has three single-stranded discontinuities. From the diges-tion patterns of SalI, XhoI, EcoRI and HhaI, it is concluded that the restriction map ofCaMV-XJ genome is closely related to that of BKMV isolate from East Germany.     

基于FPGA的CAN总线故障分析仪

针对CAN( Controller Area Network)总线网络物理传输性能测试的需要,提出一种基于FPGA( FieldProgrammable Gate Array)测试系统,该系统通过采集物理层信号波形分析CAN总线故障并输出相关信息.分析了测试系统原理,给出了系统方案,并详细论述了频率的自动识别、数据帧提...     

39例脾脏占位性病变的临床诊断和治疗分析

目的:探讨脾占位性病变的临床诊断特点和治疗对策.方法:回顾性分析1990年至2010年收住我院的39例脾占位性病变患者的临床资料,总结更佳的治疗策略.结果:21例患者无症状,脾占位性病变临床表现无特异性,诊断依据影像学检查如B超、CT、MRI、数字减影血管造影(DSA)和病理检查.39例脾占位性病变中良性35例,其中手术切除脾脏23例,非手术治疗16例,包括恶性4例.随访5月～5年,手术与否,良性疾病均获得长期生存,而恶性者诊断后4月内死亡率100%.结论:脾占位性病变以良性为主,恶性少见,影像学检查是发现脾占位性病变的主要手段.根治性切除是治疗恶性占位性病变的唯一手段,而脾切除对成年人可能是最佳的治疗方案,但脾部分切除更适宜儿童患者.