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   40篇
  免费   3篇
  国内免费   1篇
林业   13篇
农学   3篇
基础科学   3篇
  3篇
综合类   6篇
水产渔业   2篇
畜牧兽医   11篇
园艺   3篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   3篇
  2013年   7篇
  2012年   3篇
  2011年   2篇
  2010年   1篇
  2009年   4篇
  2007年   1篇
  2006年   2篇
  2004年   1篇
  2003年   4篇
  2002年   7篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1995年   1篇
  1990年   1篇
排序方式: 共有44条查询结果,搜索用时 14 毫秒
1.
According to the industrial character of old industrial basement, such as Chongqing, we select preliminarily the candidated inferior position industries by using DEA analyse model. The synthetical basical coefficient of candidated inferior industries is obtained by analysing their indices such as income elasticity of demand, compared superiority coefficient, compared rate coefficient and technical progress rate, etc. Finally determine inferior industries which was supposed to exit by considing fully society progress and continuable development. A new idea are provided for industral structure adjustment for old industrial basement in China.  相似文献   
2.
本文论述了建筑工程中地下室防水和屋面防水的构造措施及不同部位出现渗漏的原因及解决办法,对建筑工程的设计和施工具有一定的指导意义。  相似文献   
3.
随着城市建设的发展,地下空间得到了更多的开发和利用。由于各种设计手册和教科书中对关于“地下室排水系统设计”的篇幅较少。为此根据多年的设计经验,总结了不同情况下地下室排水系统设计方法,并对设计中易出现的问题提出了注意事项。  相似文献   
4.
Rapid urban development in cities often requires construction activities close to existing tunnels, including basement excavation directly above the tunnels. Based on three dimensional finite element method, the influence of basement excavation on the underlying tunnels was studied. In the numerical model, A tunnel was located under a rectangular excavation with its axes parallel to the long side of the rectangle. The results of numerical analyses indicate that for the tunnel located underneath the centerline of the excavation, overlying excavation will cause the shortening of horizontal diameter and the lengthening of vertical diameter of the tunnel lining. For the tunnel located close to the diaphragm wall, maximum diameter changes often take place in a sub-vertical direction due to the rotation of the tunnel lining during excavation. The spatial effect of the excavation also has an obvious influence on the displacement and distortion of the tunnel cross section.  相似文献   
5.
《园艺学报》2013,29(2):361-363
AIM: To explore the relationship between the ultrastructural lesions of glomerular filtration barrier (GFB) and proteinuria in Alport syndrome (AS). METHODS: Thirty-five AS patients (24 males and 11 females), who were admitted to our hospital from 2008 to 2012, were enrolled in this study. The median age was 6 years (1.17 ~ 24 years) according to the time of renal biopsy. The data of clinical and electron microscopic examination were collected for retrospective analysis. The patients were divided into 2 groups according to the degree of urinary protein: non-/interval proteinuria group (13 cases) and persistent proteinuria group (22 cases). The length of glomerular basement membrane(GBM) attenuation, thickening, and dense layer splitting and layering was measured, and the percentages of these lesions were calculated. The foot process width (FPW) was measured according to the formula average FPW=π/4× (∑ GBM length/∑ foot process number). The differences of the ultrastructural lesions in GFB between the 2 groups were compared, and the association between GFB ultrastructural lesions and proteinuria were analyzed. RESULTS: The percentages of GBM thickening, splitting and layering were higher, and the foot processes were wider in persistent proteinuria group than those in non-/interval proteinuria group. The median age at renal biopsy in persistent proteinuria group was older than that in non-/interval proteinuria group. The average FPW of the 35 patients was positively correlated with the percentage of GBM thickening, splitting and layering, and the age at biopsy, respectively. CONCLUSION: The severity of GBM lesions is associated with the severity of foot process damage and the severity of proteinuria, suggesting that foot process damage associated with proteinuria in AS may be secondary to GBM lesions.  相似文献   
6.
大鲵引进与地下室人工养殖试验研究   总被引:1,自引:0,他引:1  
2009年11月山东省成功引进大鲵(Andrias davidianus),开晨了大鲵地下室人工养殖试验.其结果表明:放养1 100尾,平均体重5.43 g、体长8.5 cm,经过2年饲养,平均体重1.146 kg、平均体长50.12 cm,成活率98.7%,总重1 244.6 kg,最大个体为2.3 kg.大鲵在海拔108m地区人工养殖的成功,对野生种群修复、保护及开发将起到积极的重要作用.  相似文献   
7.
以甘肃小陇山林区为对象,分析论述了该林区工业用材林基地建设的优势和前景,提出了基地建设的培育技术和发展对策。  相似文献   
8.
鄂尔多斯盆地的环境地球化学景观与水土流失分布特征与基底断裂关系密切。盆地基底断裂控制了盆地的环境地球化学景观和元素分布特征,尤其是定边—绥德断裂带和华池—大同断裂带将盆地分成两个截然不同的地球化学、地貌景观区;鄂尔多斯盆地内的基底断裂在某种程度上控制了盆地的地势、地形、地貌、新构造运动、岩石类型、岩性构造、土壤类型及其性质、浅层地下水及其性质,并间接地控制了土壤岩石后期的改造、风与水的动力条件等因素。研究盆地基底断裂与水土流失的关系,用于指导水土流失综合治理具有重要的现实意义。  相似文献   
9.
随着现代建筑功能需求的多元化,地下室成为当前城市建筑工程开发中较为常见的地下建筑结构,后浇带浇筑通常是为避免钢筋混凝土结构出现温缩或沉降裂缝而采取的施工技术工艺,受客观因素影响和制约,地下室后浇带部位通常会出现不同程度的渗漏现象,本文针对其渗漏成因及处理方法进行分析。  相似文献   
10.
文章介绍了地下室光导采光技术原理、采光系统结构;探讨了鸡西地区地下室光导采光的可行性;通过工程方案对比分析,指出了地下室应用光导采光技术的经济价值。  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