气相色谱法测定猪肉脂肪酸组成

实验采用极性毛细管柱气相色谱法测定了猪肉脂肪酸组成的相对百分含量和实际含量。测定结果表明,此方法能准确分离出猪肉中的主要8种脂肪酸:豆蔻酸、棕榈酸、棕榈油酸、硬脂酸、油酸、亚油酸、亚麻酸和花生酸,有较好的精密度和重复性、可靠性。     

陕西小麦品种生态亚型的分类

对陕西5个麦区大面积推广的小麦品种(系),采用模糊聚类法将供试小麦品种分成:春性品种生态亚型、弱春性品种生态亚型、偏春性品种生态亚型、偏冬性品种生态亚型、弱冬性品种生态亚型、冬性品种生态亚型、强冬性品种生态亚型等7个生态亚型.陕北麦区主要种植强冬性和冬性品种生态亚型;陕南麦区主要种植春性和弱春性品种生态亚型.     

发酵床技术在猪生产中的应用

针对发酵床养猪技术的原理及其在养猪生产中的应用效果和存在问题等方面作一综述。     

充分利用乡土植物营造具有地域特色的园林景观

通过对湟源县石刻广场植物选择与配置进行分析,说明充分利用乡土植物进行高原园林造景,不仅可以体现景观的多样性和植物的多样性,而且充分体现出地域特色与风格,提升高原园林景观的品味。     

高校图书馆自助借还系统的服务失误与补救策略分析

结合河北农业大学渤海校区新图书馆自助借还服务建设现状,探讨了高校图书馆自助借还系统中的常见服务失误与服务补救对策。     

Seroprevalence of chlamydial infection in dairy cattle in Guangzhou, southern China

Chlamydia spp. are obligate intracellular gram-negative bacteria that cause a wide range of significant diseases in humans and animals worldwide, resulting in significant economic losses. Chlamydial infection in cattle has been reported in many countries including China. However, there has been no survey of chlamydial infection of dairy cattle in Guangzhou, southern China. The objective of the present investigation was to examine the chlamydial seroprevalence in dairy cattle in Guangzhou, subtropical southern China by using an indirect hemagglutination assay (IHA). The overall seroprevalence of chlamydial infection in dairy cattle was 7.25% (29/400). Greater than or equal to eight-yr-old dairy cattle had the highest seroprevalence (10.34%), followed by those that were ≥ 6 years old or < 7 years old dairy cattle (10.20%), although there were no statistically significant differences among different groups (P > 0.05). Dairy cattle with 5 pregnancies had the highest seroprevalence (10.81%). These results indicate that chlamydial infection was present in dairy cattle in Guangzhou, subtropical southern China, and integrated strategies and measures should be executed to control and prevent chlamydial infection and disease outbreak in the study region.     

Characterization of microbial communities in intensive GIFT tilapia (Oreochromis niloticus) pond systems during the peak period of breeding

Aquaculture pond is a complex ecosystem where the microorganisms in the sediments, in the animal intestinal tract and in water interact with each other to influence the water quality and health of aquatic animals. In order to understand the spatial distribution and relationship of microbial communities in intensively farmed genetically improved farmed tilapia (GIFT, Oreochromis niloticus), 454 high‐throughput pyrosequencing was applied to analyse the 16S rRNA gene of bacteria in intensive GIFT ponds in Wuxi City, Jiangsu Province, China. A total of 72 747 initial sequences were obtained from four depths of pond water, from tilapia large intestines and from pond sediment. The most common phylum in all samples was Proteobacteria, Actinobacteria and Cyanobacteria were the most abundant in water, Fusobacteria and Firmicutes in the large intestine and Chloroflexi in sediment samples. The sediment microbial community structure was comparatively similar to that of the tilapia large intestine. The microbial communities from different water depths were somewhat similar, especially the three most shallow samples, although the abundance of Actinobacteria gradually decreased with increased water depth. This data offer a preliminary exploration of the response mechanisms of the bacterial communities to aquafarming and contributes to the understanding of the status of bacterial communities of tilapia pond systems during the peak period of breeding from the aspect of their spatial distributions.     

茶蛀梗虫幼虫寄生性昆虫的调查

茶蛀梗虫Casmara patrona Mey rick是湖南茶树的一种重要害虫。已发现有4种天敌昆虫可寄生其幼虫,其学名是:Psen pulcherrimus,Bracon sp.,Macrocentrus sp.和Eriborus tere-brans (Gravenhorst)。前2种是中国新记载种,后2种是中国新寄主记录种。本文叙述了它们的形态特征、生活习性和采集地或分布。Eriborus terebrans是湖南茶园寄生茶蛀梗虫幼虫的优势种类,在长沙它的自然寄生率可达11%。Psen pulcherrimus是次优的寄生蜂,其自然寄生率稍低于前者。     

商务英语教学与学生潜能的培养

本文从商务英语教学中存在的问题入手,结合高校英语专业学生的特点和实际需要,运用心理语言学原理,以能够激发学生的潜能为目的,指出教师要具备必要的专业素质和先进的教学理念---要使自己成为一名CEO式的教师,以身作则,强化学生的自我管理意识,以期成为具有巨大潜能的自主学习者,保持长久的竞争力。本文的结论是教学应以学生为中心,尊重他们的需求和兴趣,这样才能激发出他们无限的潜能,从而发挥无穷的创造力。