裂解汽油一段加氢催化剂的研究进展

乙烯工业副产物裂解汽油是芳烃抽提的重要原料,加氢精制是处理裂解汽油最有效、最经济的方法.文章主要介绍了裂解汽油一段加氢钯系、镍系催化荆的研究进展,同时指出裂解汽油一段加氢催化剂在工业应用上存在的问题.     

浅析继电保护微机技术应用

随着信息技术的迅速发展,微机技术在供电企业继电保护工作中得以深化应用,文章浅析了现阶段微机技术在防止继电保护"三误"事故方面的应用及未来可能的发展方向.     

太原东山地区湿陷性黄土处理方法的探讨

随着社会经济的迅速发展,高层建筑也越来越多,湿陷性黄土地区的地基湿陷处理已经引起了各方的高度关注,文章就湿陷性黄土处理方法进行了详细的探讨。     

政府在科技成果转化过程中的作用

科技成果转化是把科研前期投入转变为经济效益和社会效益的关键环节,是一项复杂的系统工程,同时也是一项风险性事业.没有政府作后盾,没有政府资助,单个个人或企业很难做到.所以,在科技成果转化过程中,政府起着重要的引导作用,是必不可少的.     

Observed increase in local cooling effect of deforestation at higher latitudes

Deforestation in mid- to high latitudes is hypothesized to have the potential to cool the Earth's surface by altering biophysical processes. In climate models of continental-scale land clearing, the cooling is triggered by increases in surface albedo and is reinforced by a land albedo-sea ice feedback. This feedback is crucial in the model predictions; without it other biophysical processes may overwhelm the albedo effect to generate warming instead. Ongoing land-use activities, such as land management for climate mitigation, are occurring at local scales (hectares) presumably too small to generate the feedback, and it is not known whether the intrinsic biophysical mechanism on its own can change the surface temperature in a consistent manner. Nor has the effect of deforestation on climate been demonstrated over large areas from direct observations. Here we show that surface air temperature is lower in open land than in nearby forested land. The effect is 0.85 ± 0.44 K (mean ± one standard deviation) northwards of 45° N and 0.21 ± 0.53 K southwards. Below 35° N there is weak evidence that deforestation leads to warming. Results are based on comparisons of temperature at forested eddy covariance towers in the USA and Canada and, as a proxy for small areas of cleared land, nearby surface weather stations. Night-time temperature changes unrelated to changes in surface albedo are an important contributor to the overall cooling effect. The observed latitudinal dependence is consistent with theoretical expectation of changes in energy loss from convection and radiation across latitudes in both the daytime and night-time phase of the diurnal cycle, the latter of which remains uncertain in climate models.     

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk

Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140?mm?Hg systolic blood pressure or ≥90?mm?Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.     

黑龙江七星河国家级湿地自然保护区生态旅游开发的SWOT分析

采用SWOT分析法较为详细地分析了七星河国家级湿地自然保护区发展生态旅游业的优势、弱势、机遇和威胁。得出黑龙江七星国家级河湿地自然保护区不仅具备景观资源独特、动植物资源丰富、旅游环境优越等开展湿地生态旅游的先决条件,而且拥有国内外生态旅游发展的有利形势和地方政策大力支持的大好机遇;但同时存在湿地保护和专业人员匮乏、旅游...     

HMCM-56分子筛催化苯酚与异丙醇烷基化反应的研究

研究HMCM-56分子筛上苯酚与异丙醇烷基化反应,探讨了反应条件包括温度,原料配比,催化剂的装填量,空速对催化剂催化性能的影响．通过X射线衍射、研究催化剂的酸性及晶相．得到最佳反应条件：T=220℃,WHSV=3．0h^-1,Catalyst Loading=0．3g,n（IPA）／n（Phenol）=0．8,苯酚的转...     

黑龙江省松嫩平原南部土地质量地球化学评价

以黑龙江省松嫩平原南部8．15万km^2范围表层土壤为研究对象,利用层次分析法、地统计学和模糊评价法从土地的肥力质量和环境质量进行评价,并利用地理信息系统（GIS）技术进一步分析研究区内地球化学质量的空间分布规律和变异性．研究结果表明,黑龙江省松嫩平原南部综合地球化学质量较好,土地的环境质量很高,土质非常清洁、安全．同...     

自然的贫困和可持续设计的未来

全球化伊始,工业文明消解了传统哲学天人合一的理念,由此引发了人口、环境和生态危机。人类必须重估生活方式,从生存论去体悟有机自然。通过溯源可持续设计,其技进于道的变动时空观源自以人为本的文化思想,在卫护人类和自然的循环利用过程中,可持续设计对生态的理性尊重将迎来一种新的文明。