首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   12篇
  免费   2篇
  国内免费   9篇
大气科学   1篇
地球物理   1篇
地质学   1篇
海洋学   12篇
综合类   6篇
自然地理   2篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   1篇
  2013年   3篇
  2011年   1篇
  2007年   1篇
  2006年   2篇
  2004年   2篇
  2003年   1篇
  2001年   4篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1995年   1篇
排序方式: 共有23条查询结果,搜索用时 218 毫秒
1.
INTRODUCTIONFromthe1990’s,thescallop,C.farreri,culturedinthenorthernChinaSea,deterioratedinsize,healthandoutputbecauseofhighstockingdensities,shortageofnaturalfoodanddiseases.Massmortalityof50%-90%occurredinJiaozhouBay,Qingdao,andSishiliwanBay,Yantai,fromJulyto…  相似文献   
2.
鉴于舟山沿海日本囊对虾秋苗养殖成活率显著低于春季和夏季人工养殖苗种之实际,深入开展适合于本地沿海养殖的日本囊对虾秋苗的优质亲体的选种研究显得十分必要。为此,作者采用聚类分析、主成分分析和判别分析等方法定量研究了舟山近海日本囊对虾野生群体和露天池塘越冬养成群体间的形质特征差异。结果表明:两者在本研究所涉18项形质评价指标中的相似性指数仅为11.11%,欧氏距离为4.243(P0.01);经主成分分析,提取到的5个特征值均大于1的主成分,累计贡献率达85.27%,其中第1主成分为以营养生理状况指数、额剑上缘锯齿数以及腹部肌肉发达程度为主导的体质强壮因子,第2主成分为以寻食视野与胸腔空间大小为主导的捕食运动功能因子,后3个主成分为以尾节肌肉发达程度为主导的避敌运动功能因子;采用逐步判别法,以判别贡献率较大的9项形质评价指标为自变量,所建Fisher分类函数方程组可清晰区分日本囊对虾野生群体和越冬养成群体,其中野生群体的判别准确率P1、P2分别为99.33%和96.13%,越冬养成群体的判别准确率P1、P2分别为96%和99.31%,两者综合判别准确率为97.67%。因此,日本囊对虾秋苗野生亲本形质特征的选择,应以秋苗越冬养成群体为参照。  相似文献   
3.
This paper uses pork as a lens on China’s rural transformations. Taking the industrialization of pig farming in the reform era as a trace on broader processes of social and environmental change, it advances three arguments. First, the massive increase in pork production and consumption since 1978 has been propelled by an industrial meat regime. A party-state led and agribusiness-operated regime, it articulates modernist notions of meat-as-progress with the relentless drive for capital accumulation. Second, using Marx’s concept of metabolic rift, the paper examines how processes of concentration in the industrial meat regime are at the same time processes of separation. This dialectical approach highlights the contradictions inherent in ongoing attempts to disembed capitalist production from biological and social relations. Finally, while official party-state discourse conceptualizes “the rural” as a production base for surplus value, and/or as a site for preserving environmental integrity, the paper’s analysis reveals a further unofficial recasting of the rural: in the process of agroindustrialization, the rural is also a sink for offloading capitalist crises. Between the rivers of manure that flow from industrial livestock operations and contaminate rural waterways; the loss of soil nutrients and food calories in the inefficient conversion of grains and oilseeds into industrial meat; the erosion of agricultural knowledge and practice that accompanies the dispossession of China’s farmers; and the shifting values of pigs, pork, and manure, this is a system that “wastes” the rural in service of capital.  相似文献   
4.
A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibility coefficient (ADC) of Japanese flounder (Paralichthys olivaceus). The experimental diets included 0%, 20%, 40%, 60% and 80% MBM or PBM replacement of total fishmeal respectively. All diets were iso-nitrogenous and isocaloric. The results showed that there are no significant differences (P 〉0.05) in growth performance among the treatments fed with 0% -60% MBM replacement of fishmeal, while the percent weight gain (WG, % ), body length gain (BLG, % ) and ADC significantly decrease when fishmeal is replaced by 80% MBM. The result showed also that there are no significant differences (P 〉0.05) in growth performance and ADC among all treatments fed with the diets with 0% -80% replacements of fishmeal with PBM.  相似文献   
5.
ABSTRACT

In this article, I scrutinize three art, design, and architecture projects engaging with “cultured,” or “in vitro,” meat (primarily muscle cells cultured outside of bodies) to illuminate the entanglements of academic and extra-academic environments that have characterized cultured meat’s history to date, and the conversations that this technology has spurred. In envisioning new ways of eating, and living, these projects (a book of hypothetical recipes, The In Vitro Meat Cookbook, Catts and Zurr’s bioartistic engagements with tissue engineering, and Terreform1’s tissue-house prototype “The In Vitro Meat Habitat”) illustrate cultural practices thought to be enabled by cell culturing’s new applications. Emphasizing such visions and conversations allows me to highlight an inattention to discursive dynamics within research on natures subsumed to industrial production processes (Boyd, Prudham, and Schurman 2001 Boyd, W., W. S. Prudham, and R. A. Schurman. 2001. Industrial dynamics and the problem of nature. Society and Natural Resources 14 (7):55570. doi:10.1080/089419201750341862[Taylor & Francis Online], [Web of Science ®] [Google Scholar]). But engaging with the “subsumption of nature” framework simultaneously allows me to problematize artistic visions presenting nature as fully malleable.  相似文献   
6.
虾池长竹蛏肥满度的研究   总被引:2,自引:0,他引:2  
王云  郑升阳 《台湾海峡》2001,20(Z1):57-59
本文作者于1997年4月至1998年3月期间,对幸福洋垦区虾池生长的长竹蛏进行了周年肥满度测定研究.结果表明长竹蛏5~9月份较肥,肥满度在60%~80%之间,11月至翌年4月份较瘦,肥满度在55%~47%之间;根据肥满度的测定,长竹蛏的繁殖期为6~8月份.  相似文献   
7.
以添加质量浓度为 5 0 kg/m3 的粉末化鱼油的饲料及一般饲料喂养小鹌鹑。 2个月后 ,对所产的鹌鹑蛋和鹌鹑肉进行 EPA和 DHA测试。结果表明 :全蛋黄中的 EPA和 DHA平均值 ,喂添加鱼油饲料的鹌鹑蛋远高于喂一般饲料的鹌鹑蛋 ;喂 5 d添加鱼油饲料的鹌鹑蛋其 EPA和 DHA平均值可达 49.0 6 mg;且该值将随着喂添加鱼油饲料天数的增加而增大。喂 6 0 d添加鱼油饲料时 ,每只鹌鹑肉含 EPA和 DHA的平均值为喂 6 0 d一般饲料的 5 2倍。这种富含 DHA的蛋和肉没有鱼油的特殊腥味 ,特别适合孕妇、婴儿食用 ,也适合于中、老年人作为保健品食用  相似文献   
8.
The effects of 60-day starvation on survival rate. condition index (CI) , changes ofnutrient composition of different tissues, respiration and excretion of scallop ChlartnCs farreri were studiedin laboratory from Oct. 17 to Dec. 15 ,1997. Two groups (control and starvation with 200 individualseach) were cultured in two 2 m3 tanks, with 31 to 32 salinity water at 1 7 “C . Starvation effects were mea-sured alter 1 0, 20, 40 and 60 days. There was no mass mortality of scallops cf the two tanks and survivalrates of the control and starvation groups were 93 .5 % and 92.0 %, respectively. Starvation had strongeffect on the meat condition of the scallops, especially after 10 days; when relative lipid percentagedropped sharply while relative protein percentage increased. The impact of starvation on the oxygen consumption mtc (OCR) and the ammonia-N cxcretion mtc (AER) was obvious.  相似文献   
9.
对野生长肋日月贝(Amusium pleuronectes)的闭壳肌和贝肉其他部分的基本营养成分进行分析.结果表明:闭壳肌的平均质量分数为18.13%±2.15%,超过优良养殖海湾扇贝"中科红".闭壳肌的蛋白质质量比(干质量)为847.62 g/kg,贝肉其他部分蛋白质质量比为662.50 g/kg.必需氨基酸与非必需...  相似文献   
10.
A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fish meal in the diets on the growth performance, survival and apparent digestibility coefficients (ADC) of Litopenaeus vannamei. The basal diets were formulated with 22% fish meal and other ingredients which provided about 40% protein and 9% lipid in the diet. The experimental diets included MBM or PBM to replace 0, 20%, 40%, 60% and 80% of total fish meal respectively. All diets were iso-nitrogenous and isocaloric in gross terms. The results showed that there were no significant differences (Pτ;0.05) in growth performance and ADC among the treatments fed with the diets in which 0–60% fish meal had been replaced with MBM, while the percent weight gain (WG, %), body length gain (BLG, %) and ADC significantly decreased when the MBM was up to 80% of the fish meal. There were no significant differences (Pτ;0.05) in growth performance and ADC among all the treatments fed with the diets in which 0–80% fish meal had been replaced with PBM.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号