基于Pro/E的水稻插秧机分插机构运动仿真与分析

基于Pro/E建立了后插式曲柄摇杆分插机构的三维模型,并进行了运动仿真模拟和动力学分析,参数设定为分插机构工作插次200次/min,主动轴转速为n=200r/min,运动时间为t=1.5s的情况下,得到秧针的运动速度图和加速度图,使得机构运动分析变得可视化、直观化和简单化,为分插机构的设计提供了方法,有利于机构参数的合理选择,同时降低分插机构的研发周期,提高工作效率.利用Pro/E找出了分插机构的振动源和受力情况,结果指出,曲柄添加平衡块和减轻摇杆质量有利于减小冲击和振动.     

不同氮营养水平对水葫芦根系活力的影响

[目的]研究水葫芦(Eichhornia crassipes)根系活力与水体中氮浓度的关系。[方法]以不同氮营养水平培养水葫芦,研究水体中氮浓度对水葫芦根系活力的影响。[结果]氮浓度对水葫芦根系有较大的影响,在适宜的氮浓度水环境中水葫芦生长良好,并且根系活力和根系过氧化物酶活性都比较高。其中3.5 mg/L氮水平处理的水葫芦根系活力和根系过氧化物酶活性达到最高,过高的氮水平不但抑制水葫芦的根系活力,同时也抑制水葫芦根系的过氧化物酶活性。[结论]不同氮营养水平不仅影响水葫芦的根系活力,而且对根系过氧化物酶的活性也有明显影响。     

3种兔球虫ITS-1序列测定与系统发育分析

从河北省兔场分别单卵囊分离孢子化大型艾美耳球虫卵囊、黄艾美耳球虫卵囊及肠艾美耳球虫卵囊,接种无球虫兔后获得纯种卵囊,CTAB法提取孢子化卵囊基因组DNA。利用艾美耳属球虫18SrDNA和5．8SrDNA保守引物,PCR扩增3种兔球虫ITS-1片段,产物纯化后测序。将3种球虫ITS-1测序结果与GenBank发布的兔球虫ITS-1序列进行比对和遗传距离比较,绘制系统发育树。结果表明,大型艾美耳球虫、黄艾美耳球虫及肠艾美耳球虫河北株分别扩增出424、455、434bp的ITS-1片段。大型艾美耳球虫、黄艾美耳球虫及肠艾关耳球虫河北株与GenBank中发布的同种兔球虫ITS-1序列相似性分别为97．4％、97．9％和96．9％。系统发育树显示兔球虫ITS-1序列形成1个单系群,该单系群根据寄生部位分为2个姊妹群。     

Life cycle assessment of windows for the North American residential market: Case study

Abstract

A life cycle assessment (LCA) of residential windows was conducted to evaluate the environmental impacts of those made with aluminum-clad wood, polyvinyl chloride (PVC) and fiberglass frames for sale in North America. The LCA was a case study in which specific-site data were used for the manufacturing stage of each window, while published data were adapted to complete the life cycle inventories using Sima Pro software. These inventories were grouped into impact categories and scaled based on IMPACT 2002+ version 2.1 characterization and damage factors. The damage modeling indicated that the life cycle impacts are dominated by the combustion of non-renewable energy resources. The PVC life cycle used the most non-renewable energy and caused the most damage owing to that window's shorter service life. The disposal of aluminum cladding in the municipal waste stream caused greater aquatic ecotoxicity for the wood window. The sensitivity analysis revealed that replacing the virgin material in aluminum cladding with recycled content improved the life cycle impacts of the wood window. Using fiberglass or PVC to clad the wood window also improved the environmental performance. Other potential improvements to the life cycle impacts of the three windows include improving energy efficiency, particularly during the secondary manufacturing.     

Anti-inflammatory homoisoflavonoids from the tuberous roots of Ophiopogon japonicus

Two new homoisoflavonoids, named ophiopogonone E (1) and ophiopogonanone H (2), together with thirteen known ones (3-15) were isolated from the tuberous roots of Ophiopogon japonicus. Their structures were elucidated by spectroscopic and chemical analyses. Compounds 7 and 15 were isolated from the genus for the first time. In addition, compounds 2-15 were evaluated for their effects on the inhibition of NO production induced by lipopolysaccharide in the murine microglial cell line BV-2. Compounds 2, 4, 6, 7, 10, 11 showed potent inhibitory effects on NO production with IC(50) values of 20.1, 17.0, 7.8, 5.1, 19.2 and 14.4 μM respectively.     

表达CSFV E2蛋白重组AcNPV载体的构建

利用基因重组技术成功构建两株含猪瘟兔化弱毒株E2基因的重组苜蓿银纹夜蛾核型多角体病毒(AcNPV),重组病毒能够在昆虫细胞中分泌表达CSFV E2蛋白。将重组病毒注射入家蚕蛹内,于注射后第7天收获蚕蛹血淋巴并进行Western-blot鉴定目的蛋白的表达。结果显示,重组病毒在家蚕蛹中成功表达了CSFV E2蛋白。本研究为进一步开发猪瘟亚单位疫苗和诊断试剂盒用抗原提供了新的途径。     

抗球虫中药方剂对柔嫩艾美尔球虫感染鸡的疗效研究

为研究中药方剂对鸡感染柔嫩艾美尔球虫的疗效,试验将80只AA肉鸡随机分为4组,除空白对照外,其余各组经口感染混合孢子化球虫卵囊;第3组按5%剂量拌料添加中药,第4组按0.06%的比例拌料添加磺胺氯吡嗪钠。试验中药方剂抗球虫指数(ACI)为167.4,属中效抗球虫药。结果表明,该中药方剂可以用于鸡球虫病的防治。     

中药制剂对大肠杆菌耐药性逆转的作用研究

经药敏试验测定,复方苍术口服液和复方十大功劳颗粒对5株耐药大肠杆菌无抑菌活性。但将其加入耐恩诺沙星大肠杆菌的肉汤培养基中进行传代,连传7代后,发现3株菌株的MIC降低了8倍以上,耐药逆转率为60%。其中2号菌株GyrA基因83位氨基酸突变为正常的氨基酸序列,3号菌株ParC基因80位氨基酸也有原来的氟喹诺酮耐药性突变状态转变为正常状态。结果表明中药制剂能逆转大肠杆菌的耐药性。     

尾巨桉萌芽林定株高度试验研究

对尾巨桉4种萌芽高度(0.5 m、1.0m、1.5 m和2.0 m)进行定株除萌,结果表明:各处理之间树高、胸径生长差异均显著;以萌芽高度为1.5～2.0 m时定株除萌林木生长较好,8个月生2m定株除萌的萌芽林平均树高、平均胸径达5.30m、4.12 cm。考虑生产成本,定株除萌高度以1.5 m为佳。