Numerical experiments for the impacts of temperature and precipitation variation on the growth and development of winter wheat

The growth process of winter wheat was simulated by CERES-wheat model assuming the daily temperature increase -1, 0,1, 2℃ and daily precipitation increase -20, -10, -5, 0, 5, 10, and 20 percent, respectively. The case study site is Zhenjiang City of Jiangsu Province in the east China. Simulation results show that the impacts of temperature variation on winter wheat is stronger than that of precipitation. Climate warming would speed development rate and shorten phonological period. In general, the adverse effect of climate change on grain yield is greater than that of its beneficial effect, especially when the climate becoming cooler and dryer. The increase of temperature and decrease of precipitation would reduce the plant extractablc soil water content.     

化工厂、制药厂、焦化厂废水中有机污染物组成分析

对太原地区的化工厂、制药厂、焦化厂排放废水中有机污染物进行了系统检测。在太原化工厂排放废水中检测出21种有机污染物,苯酚、氯苯占排放量的32.1％;在制药厂废水中检测出23种有机污染物,氯苯、硝基乙苯占排放量的53.2％;在焦化厂排放废水中检测出43种有机污染物,11种多环芳烃占排放量的57.0％,7种酚类占排放量的21.9％。     

Fractal properties of patch perimeters in a disturbed montane landscape, Beijing, China

１ＩｎｔｒｏｄｕｃｔｉｏｎＬａｎｄｓｃａｐｅｆｒａｇｍｅｎｔａｔｉｏｎａｎｄｉｔｓｉｍｐａｃｔｓｏｎｂｉｏｌｏｇｉｃａｌｄｉｖｅｒｓｉｔｙｈａｖｅｂｅｅｎｔｈｅｈｉｇｈｌｙｃｏｎｃｅｒｎｅｄｔｏｐｉｃｓｉｎｔｈｅｒｅｃｅｎｔｙｅａｒｓｂｉｏｌｏｇｉ...     

Application of KCl-denuder for measuring gas-phase mercuric species(Hg~(2+))in atmosphere

ＡｐｐｌｉｃａｔｉｏｎｏｆＫＣｌｄｅｎｕｄｅｒｆｏｒｍｅａｓｕｒｉｎｇｇａｓｐｈａｓｅｍｅｒｃｕｒｉｃｓｐｅｃｉｅｓ（Ｈｇ２＋）ｉｎａｔｍｏｓｐｈｅｒｅＷｅｉＳｈｉｑｉａｎｇＣｏｌｅｇｅｏｆＥｎｖｉｒｏｎｍｅｎｔａｎｄＲｅｓｏｕｒｃｅｓ，Ｓｏｕｔ...     

16Mnq钢板对接焊接工艺评定

通过试验,对16Mnq钢板对接焊接工艺进行评定。     

Visual Basic(VB)在工程CAD中的应用

本文介绍了使用Visual Basic开发常用工程CAD系统的一般方法,其中包括用户界面的设计、图形信息的处理、零件特征信息的传递、数据库的访问等多方面的内容。     

基于特征和知识的精密注塑模设计和制造系统

采用先进的CAD/CAM技术对传统模具设计制造方法进行改造,是提高模具设计制造质量和效率的关键.此文提出基于特征和知识的才法构造精密注塑模设计和制造系统,并介绍了系统的总体方案和系统包含的各模块功能.这一系统是浙江省科委八五攻关项目“精密注塑模设计和制造(CAD/CAM)技术”的核心.     

锻模毛边槽楔角对充满性影响的研究

用毛边槽桥部楔角不同的几种模具进行了模锻工艺试验,结果表明楔角α在3°～15°范围内,随着α的增大,充满性提高,成形载荷下降。     

Landscape patterns and their evolutions in the suburban ecotone A case study of the eastern suburb of Beijing

Ｌａｎｄｓｃａｐｅｐａｔｔｅｒｎｓａｎｄｔｈｅｉｒｅｖｏｌｕｔｉｏｎｓ１０ｔｈｅｓｕｂｕｒｂａｎｅｃｏｔｏｎｅ──ＡｃａｓｅｓｔｕｄｙｏｆｔｈｅｅａｓｔｅｒｎｓｕｂｕｒｂｏｆＢｅｉｊｉｎｇＹａｎｇＪｕｒｏｎｇ，ＺｈａｎｇＨｏｎｇｍｅｉ，ＨｕａｎｇＹｉ...