一株西藏牦牛源格氏乳球菌的分离鉴定

为了弄清引起西藏牦牛乳腺炎的病原,采集患有乳腺炎的牦牛乳汁样品进行细菌培养,将分离到的1株细菌命名为XZ-1并进行染色镜检和16S rRNA基因扩增、比对,从GenBank上下载相似性最高细菌的16S rRNA基因,采用DNA Star软件进行同源性和遗传进化分析。结果显示,分离株细菌革兰氏染色,镜检为阳性,散在或成双或短链排列的球状菌;16S rRNA基因比对表明,与GenBank中格氏乳球菌的相似性达到99.43%~99.93%,与格氏乳球菌参考株的同源性为99.5%~100%;遗传进化分析表明,西藏分离株XZ-1与格氏乳球菌参考株形成一个大的分支,且与格氏乳球菌SCH和MS4-2参考株亲缘关系较近,聚为一簇。研究表明,该分离株为格氏乳球菌,是引起乳腺炎的病原之一,为今后开展牦牛乳腺炎病原及格氏乳球菌的研究提供参考依据。

基于Adams的逃生缓降器结构设计分析

逃生缓降器作为可居家配置的逃生工具,因其体积小、操作简单、可往复使用等特点,已成为高层建筑发生火灾时居民逃生自救的重要辅助设备。文章通过Creo和Adams等工业设计软件进行结构设计、理论计算和仿真分析,得到一种新的缓降器结构方案,该方案不仅为复合式逃生缓降器的开发设计提供了参考,还对缓降器结构多样化发展起到了一定的推动作用。

海油陆采钻完井技术现状分析

滩海地区油田建设存在“陆上设备下不去、海上设备上不来”的问题,这导致我国渤海滩海地区油气资源丰富但难以开采。海油陆采技术是开采滩海地区油气资源的特殊技术,海油陆采钻完井技术包括丛式钻井技术、大位移井技术、工厂化钻井技术和固完井技术。通过对海油陆采钻完井关键技术的介绍和技术现状进行分析,总结了我国近几十年来海油陆采技术的发展现状及趋势,预测了我国海油陆采技术的发展方向,对我国海油陆采钻完井技术与理论的完善具有一定的指导意义。

Gaseous Loss of Nitrogen from Fertilizers Applied to Wheat on a Calcareous Soil in North China Plain

Nitrogen (N) losses from ammonium bicarbonate or urea applied to wheat and then followed immediately by irrigation were investigated. Ammonia volatilization was determined by a micrometeorological method (ammonia sampler), total N loss was estimated by the 15N mass balance method, and denitrification loss was measured by the difference method (calculated from the difference between the total N loss and ammonia loss)and a direct method (measuring the emission of (N2+N2O)-15N ). Total ammonia losses from ammonium bicarbonate and urea in 33 days were 8.7% and 0.9% of the applied nitrogen, respectively. The corresponding total N losses were 21.6% and 29.5%. Apparent denitrification losses (by the difference method) were rather high, being 12.9% from ammonium bicarbonate and 28.6% from urea. However, no emission of (N2+N2O)-15N was detected using the direct method.

COMPRESSED SPEECH SIGNAL SENSING BASED ON THE STRUCTURED BLOCK SPARSITY WITH PARTIAL KNOWLEDGE OF SUPPORT

Structural and statistical characteristics of signals can improve the performance of Compressed Sensing (CS). Two kinds of features of Discrete Cosine Transform (DCT) coefficients of voiced speech signals are discussed in this paper. The first one is the block sparsity of DCT coefficients of voiced speech formulated from two different aspects which are the distribution of the DCT coefficients of voiced speech and the comparison of reconstruction performance between the mixed program and Basis Pursuit (BP). The block sparsity of DCT coefficients of voiced speech means that some algorithms of block-sparse CS can be used to improve the recovery performance of speech signals. It is proved by the simulation results of the mixed program which is an improved version of the mixed program. The second one is the well known large DCT coefficients of voiced speech focus on low frequency. In line with this feature, a special Gaussian and Partial Identity Joint (GPIJ) matrix is constructed as the sensing matrix for voiced speech signals. Simulation results show that the GPIJ matrix outperforms the classical Gaussian matrix for speech signals of male and female adults.

某综合医院SARS暴发与控制

Objective:To investigate the SARS epidemic and the control effectiveness in a general hospital. Methods:Clinical and suspected cases of SARS were queried in the hospital, the emerging of the disease was described and the effectiveness of control measures were analyzed according to the rules and protective materials used during the epidemic. Results:The outbreak started with a patient from Beijing on 15 April. The disease spread quickly among the healthcare workers and the cohabit patients in the hospital which the first cases were admitted. By 17 May, 112 probable (clinical cases) and suspected cases had been reported with 14 deaths. 89 cases in the hospital were surely sourced from the index SARS patient whose admission for the sake of coronary heart disease caused the SARS outbreak. With the stringent control measures and the endeavors of the hospital staff, the epidemic was controlled successfully in a short period. From May 17 to now, no new cases occurred. Conclusion:Though with high infectivity, SARS can also be controlled with proper strategy and methods.

社区支持对农村互助养老参与意愿的影响研究

文章使用2020年山东省农村互助养老专项调查数据,基于logit模型和sobel中介效应模型,检验社区支持对农村老年人互助养老参与意愿的影响,并分析社区信任的中介作用。研究发现:(1)社区支持显著提高老年人的互助养老参与意愿。(2)在社区支持影响参与意愿的总效应中,约42%由老年人对村干部的信任传导,约22%由邻里信任传导。(3)社区支持对不了解互助养老、不关心村居事务、家庭养老满意度低和担忧将来养老的老年人的边际影响更大。文章建议从强化社区支持和培育社区信任等方面出发,建立完善社区支持的常态化机制,增进老年人对社区的信任和老年人互信,为农村互助养老推广和发展奠定群众基础。