基于本体的玉米领域知识表示构建研究

传统的人工智能采用不同的建模方法、开发工具进行知识表示,使得各种知识表示之间缺乏互操作性,本体的引入解决了这一问题。对基于本体的知识表示方法进行了探索,对玉米领域知识本体进行了构建。结果表明,本体可有效地解决复杂知识间表达的异构问题,使计算机对信息的理解升至为语义层次,利于玉米智能系统的研制。     

Chemokine receptors and co-stimulatory molecules: unravelling feline immunodeficiency virus infection

Feline immunodeficiency virus (FIV) infection of the domestic cat induces an immunodeficiency characterised by a gradual depletion of CD4+ T-helper lymphocytes. The virus targets T-helper cells by way of an interaction between its envelope glycoprotein (Env) and the cell surface molecule CD134 (OX40), a member of the nerve growth factor receptor/tumour necrosis factor receptor superfamily. The Env–CD134 interaction is a necessary prerequisite for the subsequent interaction with CXCR4, the only chemokine receptor identified to date to act as a co-receptor for FIV. As T-helper cell expression of CD134 and CXCR4 is restricted to activated cells, FIV targets selectively antigen-specific T-helper cells. With disease progression the cell tropism of the virus expands; this may be the result of changes in the way in which Env interacts with CD134, a less stringent Env–CD134 interaction enabling the Env to interact more readily with CXCR4 and thus broadening the cell tropism of virus. In contrast, viruses that are present in early infection may have a narrower cell tropism, reflecting a more stringent interaction with CD134. Accordingly, “early” viruses may target CD134-expressing cells more efficiently and be more resistant to neutralising antibody. It is these early viruses that may be transmitted and should be considered as candidates for the development of vaccine regimes and novel therapeutic agents.     

扑·乙乳油防除大豆田杂草田间药效试验

采用田间小区试验方法,进行了质量分数为40%扑·乙乳油播后苗前土壤封闭处理防除大豆田杂草田间药效试验。结果表明:质量分数为40%扑·乙乳油对大豆田杂草有较好的防除效果,对单、双子叶杂草均有较高防效,45d杂草总防效为81 21%～88 34%,鲜重抑制效果为80 29%～88 21%。随使用剂量增加,药效逐渐提高,以400g 667m2防效最好,而且对大豆出苗及生长发育无不良影响,增产幅度为10 85%～14 55%。     

口蹄疫感染性克隆疫苗的发展前景

口蹄疫是一种严重威胁畜牧业发展的重要传染病,目前世界上许多国家和地区都有该病的流行与发生。开展新型口蹄疫疫苗的研究一直是口蹄疫防制技术的一项重要内容。鉴于传统疫苗所存在的诸多缺点,人们先后研制开发了口蹄疫的第二代基因工程苗和第三代基因疫苗,这些新型疫苗都具有一定的优越性,显示出进一步发展的潜力。文章着重讨论了在感染性cDNA的基础上所构建的一类新型基因疫苗-感染性克隆疫苗及其发展前景。感染性克隆疫苗不仅继承了以往基因疫苗的许多优点,而且克服了其表达量低,免疫效果不理想的缺点,为新型疫苗的研制提供了一种新的思路。     

转基因大豆中外源基因g10evo-epsps的qPCR检测方法的建立和验证

耐除草剂基因g10evo-epsps在我国转基因农作物研发中常常被用作目标性状基因或筛选标记基因,因此可作为转基因成分检测的重要筛查基因,但目前缺少相应的检测方法.本研究旨在建立g10evo-epsps基因特异性的实时荧光定量PCR(qPCR)检测方法,从而为转基因大豆的监测提供一种稳定可靠的方法体系.本研究基于转基因...     

Radiological risk assessment of fish feed and feed raw materials

In this study, natural radioactivity concentrations of fish feed and feed raw materials were assessed. Several feeds and raw materials were provided from the suppliers who dominate the aquaculture sector. ²²⁶Ra, ²³²Th and ⁴⁰K concentrations were determined by using a high‐purity germanium detector. The measured activity concentrations of samples ranged from 3.28 ± 0.27 to 15.90 ± 1.36, from 1.27 ± 0.10 to 12.07 ± 1.21 and from 52.01 ± 2.60 to 1,158.96 ± 54.42 Bq/kg for ²²⁶Ra, ²³²Th and ⁴⁰K respectively. The gamma dose rate and annual effective dose rate of samples were calculated to be in the range of 1.99–50.47 nGy/h and 2.44–61.89 µSv/yr respectively. Since the calculated radiological risk parameters of the samples were lower than the world wide average values, the radiation hazard is insignificant for human handlers.     

噻虫嗪防治油菜籽苗期黄条跳甲的药效试验

以十字花科油菜籽为试材,应用常规种子拌种包衣的方式,以1 kg种子用600 g/L吡虫啉悬浮种衣剂有效成分4.2 g为药剂对照,进行了1 kg种子用70％噻虫嗪种子处理可分散粉剂有效成分280 g和350 g以及40％噻虫嗪悬浮种衣剂有效成分280 g和350 g对油菜籽苗期黄条跳甲防治效果的田间试验。结果表明：使用70％噻虫嗪种子处理可分散粉剂和40％噻虫嗪悬浮种衣剂有效成分280 g和350 g进行油菜籽种子包衣,均能有效防治油菜籽苗期黄条跳甲的为害。其中,70％噻虫嗪种子处理可分散粉剂有效成分用量为350 g时防效最高,40％噻虫嗪悬浮种衣剂有效成分用量为350 g时防效次之,且这2个药剂处理的持效期均长,防治效果均好。该技术可以在防治油菜籽及其他十字花科蔬菜苗期黄条跳甲上大面积推广使用。     

人参茎叶中丙二酸单酰基人参皂苷高效液相色谱-质谱分析

采用高效液相色谱-质谱联用仪对储藏1年的干燥人参茎叶中丙二酸单酰基人参皂苷进行了定性分析。从干燥的人参茎、叶中鉴定了8种丙二酸单酰基人参皂苷类成分,分别是丙二酸单酰基三七人参皂苷R3（Malonyl notoginsenoside R3,M—N—R3,1）、丙二酸单酰基人参皂苷Rg1（Malonyl ginsenoside Rg1,M—Rg1,2）、丙二酸单酰基人参皂苷Re（Malonyl ginsenosideRe,M—Re,3）、丙二酸单酰基人参皂苷Rb1（Malonyl ginsenoside Rb1,M—Rb1,4）及其同分异构体、丙二酸单酰基人参皂苷Rc（Malonyl ginsenoside Rc,M—Rc,5）、丙二酸单酰基人参皂苷Rb2（Malonyl ginsenoside Rb2,M—Rb2,6）、丙二酸单酰基人参皂苷Rb（Malonyl ginsenoside Rb3,M—Rb3,7）、丙二酸单酰基人参皂苷Rd（Malonyl ginsenoside Rd,M—Rd,8）。     

天然气输差问题的分析

随着天然气用量的增加，市场供需双方对计量准确度的要求越来越高，目前国内天然气市场以供方计量为准，由于诸多因素的影响，供需双方交接时的误差较大。针对输气系统的输差问题，从误差理论出发，以输气干线系统为研究对象，分析了产生输差问题的原因以及减少输差的措施和方法，并以标准孔板流量计的误差为基础，对中济输气干线的输差进行了计算。