Preparing Technique of Super High StrengthHigh Performance Concrete with Superfine Sand

With the understanding that there will be a great demand for superhigh performance concrete (SHPC) in the future construction engineering,while the resources of coarse and intermediate sand commony used for SHPC are scarce,so it is very important to replace coarse and intermediate sand by plentiful superfine one; First in China and abroad as well a superfine sand superhigh performance concrete with max. slump 255mm and max.28d compressive strength 126.8 MPa was prepared.It was compared with superhigh performance concrete with intermediate sand.     

温度和光强对金钗石斛吸收磷素的影响

应用３２Ｐ研究了温度和光强对金钗石斛吸收磷素的影响。结果表明,２５℃和４０℃处理,植株吸磷量分别为１０℃处理的２．３和２．５倍。２５℃处理,茎中３２Ｐ放射性比活度最高。在中度光（２×１０４Ｌｘ）和高光强（５×１０４Ｌｘ）下,植株吸磷量分别较弱光（５×１０３Ｌｘ）下增加７４％和２３％。在中度光下,茎中３２Ｐ放射性比活度最高。     

不同化肥品种对春小麦营养元素的吸收、土壤磷素的释放及其产量的影响

试验结果表明,不同处理的春小麦各生育期的氮磷吸收趋势是一致的.植株的氮素相对含量苗期最高,抽穗期最低,灌浆期逐渐提高,每个时期与对照几乎相同.而绝对含量各时期是逐渐上升的,且明显高于对照;植株磷素相对和绝对含量苗期最低,拔节期急速上升.不同处理的相对含量与对照接近,绝对含量明显高于对照;同时,合理施用氮肥,不仅能促进磷素的吸收,而且能促进土壤磷的释放,改变土壤磷的形态.通过F值测定,不同氮肥品种间产量差异不显著.氮磷配合处理间差异极显著.且以尿素和硫铵组合的处理增产效果最佳.同时,在人工灌溉条件下,施肥各     

联合国推进世界林业发展的综合战略

本文以联合国粮农组织林业委员会第9届会议材料为基础,结合以前几次会议内容,分析了联合国粮农组织及其它国际组织推进世界林业发展的综合战略。内容主要包括世界林业的长期发展战略、积极推行《热带林业行动计划》、全面发展林业的新的政策观点、促进国际林业合作、联合国际社会各方面力量推动各国政府林业工作,并协调林业发展政策、组织信息交流、提供咨询、宣传出版、培训人员等。     

Proximate Composition and Antioxidant Properties of Orange Mud Crab,Scylla olivacea

The proximate composition and antioxidant properties of the muscle tissues of Scylla olivacea are reported herein. The carbohydrate content was in the range of 1.52% to 3.07%, while protein varied from 13.30% to 17.28%. Meanwhile, the fat content for S. olivacea was found to be ranging from 0.20% to 0.57%. The moisture content in S. olivacea was 60.00%. Generally, no significant differences were observed in both male and female tissues of S. olivacea regarding its total phenolic content, 2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) scavenging, and superoxide dismutase activities. However, significant differences were observed for the total flavonoid content and activity of catalase. The present results revealed the nutritional information and enzymatic and nonenzymatic antioxidant status of the tissues of S. olivacea.     

多功能森林经营:理论与实践

开展森林经营是提高中国森林质量的根本举措。阐述了森林经营的定义、意义、基本原则、分类和森林作业法,介绍了近自然林业的基本理论和森林抚育的主要措施。     

黑龙江省山地地区农作制度现状分析

利用2008年统计数据,分析了黑龙江省山地地区的农作制各要素的现状和特点,认为黑龙江省山地地区农作制存在的问题是农业产业结构不合理;林业内部结构不合理;产业链短.该地区农作制的发展趋势为:调整农业产业结构,加快发展林业产业;调整林业内部结构,加快林产品发展和林木的培育,促进农业可持续发展;引进龙头企业、加快产业链的建立...     

人工种子的制作及应用前景

人工种子是利用组织培养的方法,培养出胚状体,这些具有种子的性能胚状体,可以直接进行播种,论述了人工种子的概念和特点,以及人工种子的制作方法和应用前景。