Effects of Silver on the Photocatalytic Degradation of Gaseous Isopropanol

Water, Air, & Soil Pollution - The decomposition of gaseous isopropanol (IPA) by UV/TiO2 process in an annular photoreactor was studied under various conditions such as UV light intensity and...     

猪繁殖与呼吸综合征病毒双基因多组合DNA疫苗的构建

本实验根据PRRSV结构蛋白的特性和IFNγ及IL-2这两种细胞因子的特性,构建表达PRRSVGP4-GP5、GP5-M、GP5-N、GP5-IFNγ、GP5-IL-2、N-IFNγ、N-IL-2的重组质粒。这些重组质粒在真核细胞中得到了表达。用这些真核表达质粒可以免疫小猪,通过检测其对猪体免疫应答的诱导能力和接种后动物对PRRSV的抵抗力来对基因疫苗的效能进行研究,以期筛选到有效的基因疫苗并为今后进一步的研究提供思路和理论基础。     

浅谈桥梁工程中存在的质量通病及防治方法

就东北地区气候特点,论述了桥梁工程中普遍存在的质量通病,并提出了相应防治方法。     

现代居住区绿化景观设计基本原则

现代居民区生态景观营造越来越受人们关注。文章阐述了居住区绿化的构成要素、发展趋势及基本原则,可供居住区园林设计者参考。       

Artificial insemination of Holstein heifers with sex-sorted semen during the hot season in a subtropical region

Our aim was to investigate insemination techniques in order to improve pregnancy rates of artificial insemination (AI) using sex-sorted semen (sexed AI) in cattle in tropical and subtropical (T/ST) regions. In T/ST regions, the pregnancy rates by sexed AI are reportedly the lowest in the hottest months of the year, with less than 15% in cows and 35–40% in heifers (PMID 24048822). We compared sexed AI by depositing the semen into the uterine body (UB-AI, n = 12) versus the unilateral uterine horn (UUH-AI, n = 14) of pre-ovulation heifers. The ovary and follicle were assessed by rectal ultrasound before AI. After insemination, pregnancy was determined by ultrasound at approximately 40 days and approximately 70 days. In the present study, we demonstrated that high pregnancy rates (>70%) by sexed AI in the hottest season in a subtropical region such as Taiwan can be achieved when heifers with pre-ovulation follicles are used. The overall pregnancy rates were 54% higher in the UUH-AI (71%) group than in the UB-AI (42%) group (P = 0.06), examined on approximately 40 days post-sexed AI. Surprisingly, however, the pregnancy outcome appeared to be higher in the hot season (62%) than in the cool season (46%) although this difference was not statistically significant. Based on the present study, we recommend that cattle breeders perform UUH-AI using sex-sorted semen for heifers with pre-ovulation follicles in order to achieve satisfactory pregnancy outcome in the hot seasons in T/ST regions.     

Haemoglobin in normal and neoplastic canine mammary glands

Four types of globins for oxygen transport are known in vertebrates, and the haemoglobin is responsible for carrying oxygen in blood. In this study, we found that haemoglobin was also expressed in canine mammary glands. Samples were taken from 26 malignant mammary tumors, 16 normal mammary glands and 10 other normal tissues. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting and mass spectrometry were used to investigate haemoglobin in mammary tissues. The results indicated that normal canine mammary glands expressed high levels of haemoglobin protein as shown by Coomassie blue staining. The identity of haemoglobin was confirmed by immunoblotting and mass spectrometry, and the mass spectrometry data revealed that both alpha-haemoglobin and beta-haemoglobin were expressed. Relative to normal mammary glands, the levels of haemoglobin expression in mammary tumors were lower. Our results also indicated that the haemoglobin was endogenously produced in mammary gland tissues and was not derived from the erythroid cells.     

幼坪乐防除禾本科草坪杂草效果

幼坪乐防除禾本科草坪杂草试验结果表明,禾本科草坪每667m2用幼坪乐90～120g能有效防除龙葵、稗草、荠菜、扁蓄、苋菜、车前菜、灰菜等杂草,幼坪乐在草坪杂草出土前使用,兑水25～30kg均匀喷雾处理,可在生产中推广应用。     

适宜原料压实度改善玉米秸秆厌氧干发酵特性

干发酵原料中固形物含量高,结构疏松,原料的压实度直接关系到发酵罐的利用率和生产成本。为了探讨原料压实度对厌氧干发酵过程的影响,该文以玉米秸秆粉为试验材料,研究了不同固形物含量(TS)条件下原料压实度对厌氧干发酵产气特性及物料特性变化的影响,结果表明:相同TS下,随着压实度的增加,日产气量(基于可挥发性固形物,VS)峰值降低且出峰时间略有滞后;原料压实度对累积产气量、日产气量变化趋势以及甲烷体积分数的影响不明显。基于发酵罐容积计算产气量时,原料压实度与日产气量峰值、累积产气总量以及累积甲烷产量均呈显著正相关。不同TS条件下的原料压实度对厌氧干发酵过程的影响程度不同,TS含量越高原料压实度对产气量的影响越明显。TS为20%和25%时,逐层压实发酵罐的单位容积累积产气量比自然填料罐分别提高了37.1%和60.2%。当发酵料初始TS为20%时,原料压实度的增加可促使物料中形成连续的液相,改善物料层间的传质,从而使发酵料上下层间的差异减小。当发酵料初始TS提高到25%时,原料压实度增加对传质特性无明显影响。综上所述,在该试验研究范围内,提高原料压实度可以保证玉米秸秆厌氧干发酵产气过程的正常进行,且可以显著提高发酵罐的容积利用率。该研究对厌氧干发酵原料压实度与发酵特性之间的关系进行了初步探讨,以期为有效提高厌氧干发酵罐的产能能力提供参考。     

珠江三角洲Copula径流模型及西水东调缺水风险分析

基于两变量Copula函数模拟、变点识别和均值平移时序重构方法,构建珠江三角洲西水东调工程受水区东江和水源区西江的枯水径流联合分布模型。以生态环境流量及最小流量管理目标为设计阈值,研究区域联合缺水风险特征及对变化环境的响应。结果表明：Archimedean copula的Clayton、Frank和GH模型,均能较好地模拟两区域枯水径流联合分布特征。变化环境下特别是流域内水利工程径流调节作用,东江枯水径流时序非一致性显著,均值跳跃明显,变点时间为1972年,最枯月径流量增加了65.5%。若要满足最小下泄流量管理目标,东江缺水风险率较高,为37.7%。与东江天然径流（还原系列）相比,在东江流域内水利工程影响下（还现系列）,东、西江同时缺水风险率由35.8%下降到16.7%。但由于2江枯水径流的正相关性,西江有水可调保证率也由54.8%下降到21.0%。在已知东江缺水情形下,西江有水可调保证率（55.8%）仅略高于西江缺水风险率（44.2%）。因此,珠江三角洲西水东调工程运行,需要科学设计更为精细的水资源调度规则。     

农业机械化工程研究生创新能力的研究

研究生教育作为我国教育结构中的高层次的教育,有责任而且有义务为国家培养高水平、高素质,且具备高层次创新能力的人才,教育体系应加强创新教育,逐步提高研究生的创新能力.在了解了农业机械化工程学科现状与进展后,提出了农业机械化工程学科研究生创新能力培养的建议:进行创新性学习,提高创新意识和创新思维;学校改进教学课程体系;多参...