Synthesis of novel superhard materials under ultrahigh pressure

Superhard materials are solids whose Vickers hardness is beyond 40 GPa. They have wide applications in industry such as cutting and polishing tools, wear-resistant coatings. Most preparations of superhard materials are conducted under extreme pressure and temperature conditions, not only for scientific investigations, but also for the practical applications. In this paper, we would introduce the recent progress on the design and preparations of novel superhard materials, mainly on nanopolycrystalline diamond, B–C–N superhard solid solutions, and cubic-Si3N4/diamond nanocomposites prepared under ultrahigh pressure and high temperature（HPHT）, using multi-anvil apparatus based on the hinged-type cubic press. Bulk materials of all these superhard phases have been successfully synthesized and are systematically tested. We emphasize that ultra-HPHT method plays an important role in the scientific research and industrial production of superhard materials. It provides the driving forces for the light elements forming novel superhard phases as well as the way for sintering high-density nanosuperhard materials.     

Nanoscale structural and electronic evolution for increased efficiency in polymer solar cells monitored by electric scanning probe microscopy

Control of blend morphology at multi-scale is critical for optimizing the power conversion efficiency （PCE） of plastic solar cells. To better understand the physics of photoactive layer in the organic photovoltaic devices, it is necessary to gain understanding of morphol- ogy and the corresponding electronic property. Herein we report the correlation between nanoscale structural, electric properties of bulk heterojunction （BHJ） solar cells and the annealing-induced PCE change. We demonstrate that the PCE of BHJ solar cells are dramatically improved （from 1.3 % to 4.6 %） by thermal annealing, which results from P3HT crystalline stacking and the PCBM aggregation for interpenetrated network. The similar trend for annealing- induced photovoltage and PCE evolution present as an initial increase followed by a decrease with the annealing time and temperature. The surface roughness increase slowly and then abruptly after the same inflection points observed for photovoltage and PCE. The phase images in electric force microscopy indicate the optimized P3HT and PCBM crystallization for interpenetrating network formation considering the spectroscopic results as well. From the correlation between surface photovoltage, blend morphology, and PCE, we propose a model to illustrate the film structure and its evolution under different annealing conditions. This work would benefit the better design and optimization of the morphology and local electric proper- ties of solar cell active layers for improved PCE.     

古本《尚书》研究的重大进展——读《古本（尚书）文字研究》

《古本〈尚书〉文字研究》的重要创获之一就是从文字学的角度对古本《尚书》文字现象进行专题研究,这在国内外尚属首创;其次,对《尚书》古写本的研究推进了一大步;再次,启发我们重新思考古书流传和孔传本古文《尚书》真伪问题;最后,将语言文字学研究和文献研究相结合,也是该书的亮点。目前,清华简中的《尚书》材料引起了学术界的广泛关注,此书之出,可谓正当其时,值得学界关注。     

黄山市幼儿体育活动现状与发展对策研究

幼儿体育是幼儿教育的重要组成部分,对促进幼儿身心全面发展具有重要作用,但目前对国内中小型城市幼儿体育现状的研究很少。本文通过对安徽省黄山市幼儿体育活动现状进行研究,分析得出制约黄山市幼儿体育活动开展的经费、师资等因素,并提出拓宽资金来源途径、加强师资建设、积极引进人才等建议,旨在为我国中小城市幼儿体育活动的进一步发展提供借鉴依据。     

实现局域网上机试的一种有效方法

通过在Novell局域网上添加特定的考试用户，实现随堂机试，自动回收，并且最大程度地限制了考试用户的作弊。     

CFRP筋预应力锚具受力性能试验

设计一套圆弧槽夹板式锚具,通过拉拔试验研究锚具的夹持性能,并研究包括施加于夹板紧固件螺栓上的总扭矩值和扭矩沿夹具纵向分布等主要参数对锚具性能的影响.结果表明,总扭矩值和扭矩分布均对锚具的性能有明显影响.当施加在夹板紧固件螺栓的总扭矩值小于200 N·m,试件最终将发生滑移破坏;当总扭矩值超过200 N·m,试件最终发生...     

助跑与起跳合理结合──决定跳远成绩最关键的技术

本文讨论了影响跳远助跑与起跳技术的几个因素，得出助跑与起跳合理结合，是决定跳远成绩最关键的技术．     

粗毛淫羊藿的引种栽培试验

报道粗毛淫羊藿的引种栽培方法，试验表明，遮阴度较高，相对湿度较大、酸性腐殖土的立地条件加上一定的栽培管理措施，是该植物的引种栽培成功的生境，对淫羊藿属其它种类的工用上种栽培了具有一定的参考价值。     

在厚积薄发中前进 ——记第二届中国术语学建设研讨会

一 精练实干的队伍 2007年8月8日,适逢北京奥运会开幕一周年倒计时,由全国科学技术名词审定委员会(以下简称全国科技名词委)和黑龙江大学联合举办的第二届中国术语学研讨会在哈尔滨开幕.这个吉祥的日子,反映了会议主办方的良好愿望--祝愿中国术语学研究兴旺发达."哈尔滨"来自满语,传说为"晒网场"之意,自然也就是"收获之乡"了.     

莆田市专业技术人才队伍现状与思考

阐述现阶段莆田市专业技术人才队伍的现状，指出存在的问题并分析相关原因，根据实际情况，从四个方面提出专业技术人才队伍建设对策。