Design of nondestructive examination system for bridge cables surface defect

Aiming at the drawbacks of the current detecting methods, a nondestructive examination system design for bridge cables based on high speed digital signal processors chip DM642 is presented, and the hardware platform of the system is built. This examination system mainly consists of four parts: the image defaults acquisition part, DM642 hardware platform, creeping part and defaults locating equipment. The designed system is tested on the hardware platform based on digital image processing algorithm. The experimental results show that the detecting system has the advantages of high stability and reliability, real time, mass storage, and nondestructive examination, etc. This system uses high technology and has significant meaning on detecting the current bridge cables health, furthermore, this method can be used in other examination fields.     

Effects of gastric distention-volvulus on coronary blood flow and myocardial oxygen consumption in the dog

Gastric distention-volvulus (GDV; at 50 mm of Hg gastric inflation pressure) was experimentally induced in 8 dogs anesthetized using pentobarbital. Hemodynamic indices including heart rate, mean arterial pressure, cardiac output, and coronary blood flow (4 dogs) were measured during a 20-minute period of GDV and for 10 minutes after decompression. Arterial and coronary venous oxygen tensions were also measured for calculation of myocardial oxygen extraction (7 dogs) and myocardial oxygen consumption (4 dogs). Dogs were monitored for 72 hours postoperatively for the occurrence of arrhythmias, then were euthanatized for gross and histologic examination of the heart. Experimental GDV resulted in significant (P less than 0.05) decreases in cardiac output (89%), mean arterial pressure (45%), and coronary blood flow (50%) compared with control values. Myocardial oxygen extraction increased (30%) and overall myocardial oxygen consumption decreased (50%), compared with control values. Evidence of subendocardial necrosis was seen in 6 dogs, 4 of which had developed ventricular arrhythmias 8 to 24 hours postoperatively.     

加工类型黄瓜品质性状的主成分及聚类分析

对19个加工类型黄瓜品种的7个品质性状进行了主成分和聚类分析.结果表明19个品种分为产量、形态和品质3个主成分因子,其主成分的累计贡献率达89.81%,而且基本上可描述7个品质性状的遗传变异.当类平均距离为1.035时,19个品种被聚为短果和长果2种类型,而当类平均距离为0.942时,19个品种被聚为短果中等品质、短果优质和长果高产3种类型.     

转基因棉上非靶标害虫棉蚜取食行为的EPG研究

应用EPG技术记录了棉蚜在单价转基因棉保铃棉32B、双价转基因棉国抗22以及常规棉泗棉3号上连续生活10代前后的取食行为。结果表明,棉蚜在3个棉花品种上刺吸的各种特征波型基本相同,但各波型所占比例、重复出现的频次及平均周期表现不尽一致。棉蚜在单价转Bt棉上取食时,反映被动取食行为也即主要取食行为的E波所占比例和平均周期均显著高于在常规棉上,表示未取食状态的np波所占比例和平均周期均显著低于在常规棉上;双价转基因棉上与常规棉上无差异;而反映蚜虫刺探食物行为的C波在转基因棉和常规棉间均无差异。     

越橘品种的ISSR鉴定及其亲缘关系分析

利用ISSR分子标记对由北美引种到南京的7个南高丛越橘品种(Vaccinium darrowi×V.corymbosum)、9个南高丛越橘实生选择系和12个兔眼越橘(V.ashei)品种共28份材料进行分子鉴别和亲缘关系分析.10个引物共扩增出98条谱带,其中37条为多态性条带,多态率为37.8%.利用其中8个引物扩增的17条多态带可以区分19个品种和9个实生选择系.利用POPGENE1.31软件进行了Nei's遗传距离计算,利用UPGMA法构建了聚类树状图.聚类结果将各类群单独聚成一大类,证实了它们的亲缘关系.同时显示实生选择系间的遗传差异相对较大,其中7个与南高丛越橘品种聚为一类,而其余2个与兔眼越橘品种聚为另一大类.但是在同一类群内各品种间的遗传关系与谱系数据不完全相吻合,表明本试验所用的ISSR引物不足以用来估算兔眼越橘品种间的遗传关系.     

2JC―500型旋转嫁接机的研发

主要介绍东北农业大学研发的2JC-500型旋转嫁接机,首先论证了研发该机的必要性,接着介绍了该机研发的基础,阐述了该机的独特点如增加了断根作业步骤、增设了微调节机构和应用了铝型材等以及解决的实际问题,概述了机器的结构组成和工作原理.最后通过嫁接试验和生产试验,获得了适合嫁接的标准苗的形态,得出机器运行可靠,嫁接成活率大于88%.     

苏云金芽孢杆菌晶体毒素感染敏感昆虫离体与活体细胞的病理学比较研究

用苏云金芽孢杆菌蜡螟变种81—6菌株的晶体毒素感染菜青虫幼虫和家蚕离体细胞 感染早期两类细胞的线粒体都发生内脊膨大鼓起,随后细胞质内出现较大的空泡,感染后期线粒体膜和细胞质膜都发生溶解和破裂,细胞解体死亡。研究结果表明:离体细胞和活体细胞在感染苏云金芽孢杆菌晶体毒素后,细胞的病变过程相同。     

失地农民农转非的社会保障制度建设研究

随着工业化、城市化进程的加快,近年来我国征地规模不断扩大,失地农民的人数逐年增多,他们的生产、生活问题日益凸显,已成为社会矛盾的一个焦点.失地农民是城市化过程中产生的一个特殊群体,亟待为其建立相应的社会保障制度.     

Epidemiology of Bovine Venereal Campylobacteriosis: Geographic Distribution and Recent Advances in Molecular Diagnostic Techniques

Bovine venereal campylobacteriosis (BVC) is a major cause of economic loss to the cattle industries in different parts of the world. Camplylobacter fetus subsp. venerealis (Cfv), the main causative agent of BVC, is highly adapted to the genital tract of cattle and is transmitted by carrier bulls. However, infertility and abortions can also be caused by the intestinal pathogens C. fetus subsp. fetus (Cff), and C. jenuni, which are not venereally transmitted. Bovine venereal campylobacteriosis, caused by Cfv associated with lowered fertility, embryo mortality and abortion, repeated returns to service, reduced pregnancy rates and extended calving intervals, has the highest prevalence in developing countries where natural breeding in cattle is widely practised. The epidemiology, pathogenesis and diagnosis of the disease have been the subject of previous reviews. The main focus of this review is to highlight the epidemiology of this disease with particular reference to geographical distribution and recent advances in molecular diagnostic techniques. It is hoped that further research interest of scientists will be stimulated with a view to finding lasting solutions to the reproductive problems associated with the disease for better livestock productivity, particularly in developing endemic countries.