气候变化对黄河流域的影响及应对措施

分析了全球气候变化对黄河流域区域气候、水资源量、生态格局、农业牧业生产、地质灾害、文物保护的影响,阐述了应对研究的主要进展及存在的主要问题,探讨了气候变化对黄河流域影响的未来趋势,提出了进一步研究工作的建议:即统筹建设黄河流域气象、水文、环境、地质灾害观测和预报预警系统;厘清多因素影响下的流域水资源时空过程,提升流域水资源效能;调整坡耕地和生态用地,加强流域水源涵养能力;加强植物生理生态适应性研究,优化流域农业和草业布局;修订文化遗产赋存环境区划,进行预防性保护技术研发;加强流域黄土滑坡加固新材料和生态修复协同技术研究。     

Widespread adoption of Bt cotton and insecticide decrease promotes biocontrol services

Over the past 16 years, vast plantings of transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) have helped to control several major insect pests and reduce the need for insecticide sprays. Because broad-spectrum insecticides kill arthropod natural enemies that provide biological control of pests, the decrease in use of insecticide sprays associated with Bt crops could enhance biocontrol services. However, this hypothesis has not been tested in terms of long-term landscape-level impacts. On the basis of data from 1990 to 2010 at 36 sites in six provinces of northern China, we show here a marked increase in abundance of three types of generalist arthropod predators (ladybirds, lacewings and spiders) and a decreased abundance of aphid pests associated with widespread adoption of Bt cotton and reduced insecticide sprays in this crop. We also found evidence that the predators might provide additional biocontrol services spilling over from Bt cotton fields onto neighbouring crops (maize, peanut and soybean). Our work extends results from general studies evaluating ecological effects of Bt crops by demonstrating that such crops can promote biocontrol services in agricultural landscapes.     

移动热湿源廊道热环境的改善及送风参数优化

为有效改善具有移动热湿源的高温高湿廊道热环境,给工人提供舒适的工作环境。以邯郸市某铁渣转运廊道为依托,建立廊道空气与皮带表面热湿耦合传热物理模型,定性分析不同送风温度、送风风速、铁渣温度、皮带运行速度条件下廊道热环境的改善效果,定量探究其对廊道热环境的影响程度,并拟合各影响因素与廊道温度的相关经验关联式。结果表明：对廊道热环境影响程度由大到小依次为：送风温度、送风风速、铁渣温度、皮带运行速度。送风温度越低,送风风速越高,铁渣温度越低,皮带运行速度越小,越能有效改善廊道热环境。送风温度为22℃,送风风速为2 m/s,铁渣温度为65℃,皮带速度为3.0 m/s为廊道热环境改善的最优组合方式。文章研究成果将为类似廊道内选择合适的通风方式、设备调控及系统优化提供指导。     

The Technology Selection and Critical Successful Factors in the Information Technology （IT） Growth of Manufacturing Corporations in China

With the rapid development of the information technology （IT） and the more competitive environment of the corporations, IT is not only important for the enterprises tactically but also strategically, We extend the concept of the critical success factors （CSF） and Nolan＇s stages theory to identify the IT issues and measure their CSF of the manufacturers in China. We put forward the IT selection matrix based on Nolan＇s stages theory to analyze the IT application in manufacturers in Beijing based on our survey. We analyze the development of IT, IT selection strategy and the CSF influencing the IT growth of manufacturers in China.     

Brexit and Its Impact on the US Stock Market

This paper firstly analyzes the Brexit's impact on the US stock market using a novel interval methodology. The interval-valued dummy variables are proposed to measure the direction and magnitudes of the changes in the inter-day trend and the intra-day volatility of SP500 returns simultaneously. It is found that both the trend and the volatility of SP500 returns increased before the Brexit. Besides, the Brexit negatively affected SP500 returns' trend in the short term after the event,while its impact on market volatility was positive, which slowly decayed across time. Furthermore, a new interesting finding is that there are both short-term momentum effects(i.e., positive autocorrelation of trends) and volatility clustering in stock markets.     

浅析建筑工程材料造价的有效控制

文章针对工程材料造价的重要性以及目前管理中存在的问题,探讨了加强材料造价管理的有效措施,以供同行参考.     

Multiple Hierarchy Decision Analysis of Science Funds Management System

This article discusses a multiple hierarchy decision analysis in which the Analytic Hierarchy Pro     

超声对小白鼠睾丸精子发生的影响

实验用功率面密度为5W/cm~2,频率为1.10MHz 的连续聚焦超声分别对小白鼠睾丸进行5min 和10min 的照射,於照射后24,48,168和360h 取材制片,观察计数小白鼠睾丸生殖细胞中期分裂相,发现超声对小白鼠睾丸精子发生有明显的抑制作用,并且与照射时间长短有关.精原细胞、初级精母细胞和次级精母细胞对超声的反应有所不同.本文对其作用机制进行了初步讨论.     

海产无脊椎动物呼吸强度的比较

对测试的１８种海产经济无脊椎动物的呼吸强度进行的系统比较研究表明：日本和螺类，随时间的延长其呼吸强度呈逐渐下降趋势。说明对氧的含量的敏感性强；而蛤类则随时间的延长其呼吸强度呈逐渐上升趋势，说明对氧的含量的敏感性差．呼吸强度与动物的生活习性有关．习见织纹螺、短滨螺接近陆生生活，呼吸强度最强；日本呼吸强度次之；再次为一般螺类；最弱的为蛤类．     

超声峰值频率方程的理论研究

将多粒子振动系统的本征频率率和量子系统辐射能，应用到超声换能器系统中的压电陶瓷片及其在传输杆中的传播。根据假设和声子在传输杆中的传播，导出了超声峰值频率方程。