Growth and feed efficiency of juvenile shrimp Litopenaeus vannamei fed formulated diets containing different levels of poultry by-product meal

This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture ofLitopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.     

煤的形成过程

煤,早在800年前就被广泛用作工业生产的燃料,推动了当时工业的向前发展,随之发展起煤炭、钢铁、化工、采矿、冶金等工业。煤在地球上的储量丰富,除了作为燃料以取得热量和动能以外,更为重要的是从中制取冶金用的焦炭和制取人造石油,即煤的低温干馏的液体产品——煤焦油。经过化学加工,从煤炭中能制造出成千上万种化学产品,所以它又是一种非常重要的化工原料,我国相当多的中、小氮肥厂都以煤炭作原料生产化肥。煤也被人们誉为“黑色的金子”。     

Analysis of petroleum hydrocarbons in mangrove sediments of Red Sea of Yemen

A field work has been carried out to identify the occurrence of oil and oil products pollution in mangrove sediment from Red Sea of Yemen. The concentration of total petroleum hydrocarbons is from 700 ng/g at Kamaran Island station to 400 ng/g at Al-Hodiedah station, and the total organic carbon ( TOC) in samples ranges from 0.07% at Dhubab station to 0.03% at Kamaran Island station. This pollution is as a result of localized oil pollution and /or heavy ship traffic in the Red Sea and Gulf of Aden.     

基层台站关于温带气旋诱发风暴潮的预报与检验

本文利用地转风计算公式、增水公式和日本数值预报产品相结合的方法,计算由温带气旋诱发渤海湾风暴湖时的增水值,并结合天文湖资料,估算高潮位.应用该预报方法对渤海湾发生的"070304"风暴潮个例进行检验,预报值与实测值基本相当,是基层台站较实用的一种风暴潮预报方法.但此方法是否适用干其它造成风暴湖的影响系统有待于进一步求证.风暴潮的发生与风向、风速关系密切,一般当渤海湾盛行东北风或偏东风,且风向维持时间较长、风速较大时,易造成风暴潮的天气.日本数值预报产品对渤海风向、风速的预报对预报渤海的大风有较好的参考价值.     

Analysis of petroleum hydrocarbons in mangrove sediments of Red Sea of Yemen

A field work has been carried out to identify the occurrence of oil and oil products pollution in mangrove sediment from Red Sea of Yemen. The concentration of total petroleum hydrocarbons is from 700ng/g at Kamaran Island station to 400 ng/g at Al-Hodiedah station, and the total organic carbon （TOC） in samples ranges from 0. 07% at Dhubab station to 0. 03% at Kamaran Island station. This pollution is as a result of localized oil pollution and/or heavy ship traffic in the Red Sea and Gulf of Aden.     

机载激光点云与影像联合测图的技术进展和趋势

本文通过对激光点云与光学影像联合测图所涵盖的关键技术进展进行分析,重点指出目前激光扫描仪进行测绘生产所面临的主要挑战。结合激光扫描技术与光学影像融合后的数据特点与实际行业生产需求,简要探讨了未来激光测图技术发展的趋势及新产品体系构建设想,以期对激光扫描软硬件系统在相关行业应用推广中具有一定参考意义。     

国家西部测图工程产品模式设计与实践——以1:50000影像地形图为例

为实现国家西部1∶50 000地形图空白区测图工程:丰富产品种类,拓展服务领域的设计宗旨,根据ISO 9000对产品的概念,提出了西部测图工程整体产品模式,并对其进行细化,建立了国家两部测图工程地形图产品模式.本文以西部测图工程1∶50 000影像地形图的设计与实现为实例,详细介绍了1∶50 000影像地形图测绘新产品...     

高分辨SAR-GEC影像严密成像几何模型及其应用研究

提出并构建SAR影像GEC(Geocoded Ellipsoid Corrected)产品严密成像几何模型,并在此基础上研究用RPC模型替代SAR影像GEC产品严密成像几何模型的町行性以及基于RPC模型的GEC产品的定向和纠正.最后用TerraSAR-X影像验证其理论和算法,得到如下结论:针对高分辨SAR影像GEC级别产晶的严密成像几何模型能用于SAR影像的定向以及正射纠正.     

城市测绘技术进步与产品结构的发展

测绘是国民经济和社会发展的基础性保障工作,是发展高新技术又充分应用高新技术的行业,信息技术、3S技术的发展,对城市测绘行业产生深远影响,空间数据的采集技术、处理技术、管理技术和利用技术不断创新,信息采集效率、管理水平和成果质量不断提高。与此同时,城市测绘的产品日益丰富,应用日益广泛,形成包括模拟产品、数字产品、系统产品和综合服务在内的完整的产品结构体系,测绘工作的社会经济价值充分显现出来。     

《全球定位系统》征稿启事

《全球定位系统》是目前我国唯一反映卫星导航与定位技术的专业性科技期刊。本刊主要报道卫星定位技术在导航、定位、测绘与授时领域的应用与发展,报道GPS、GLO-NASS、Galileo和我国“北斗系统”在我国国民经济建设中各个领域的最新进展与应用及其相关的产品信息,同时为客户刊登广告。