用分子束外延技术按样定制半导体微观结构

在按样定制的半导体微观结构中，通过把异质结精确地植入晶体内即可定域地确定所期望的势能差。分子束外延技术用于以一个原子接一个原子的构建晶体薄膜，从而可以在微观惊工内精确地“裁剪”人工层状晶体。在ＧａＡｓ／ＡｌｘＧａ１－ｘＡｓ超晶格中各组分的周期性调制产生了新颖的电子性质，它开辟了崭新的技术用途。     

氧弹热量计智能化系统研制及应用

精密电子温差测量仪产生的温差电势经高阻抗直流放大器放大，由计算机采集和存贮数据，自动作图及处理数据，测量物质的燃烧热，实现了氧弹热量计智能化．     

可见光/Fenton光催化处理高浓度味精废水的研究

对可见光辅助Fenton试剂处理味精废水的主要影响因素进行了研究。主要考察了光照强度,二价铁离子和双氧水摩尔配比((n(H2O2)/n(Fe2+)),反应时间及初始pH值等因素对废水的CODCr去除率的影响。通过单因素实验确定影响因素最佳范围并据此设计正交实验,确定了最佳反应条件为:在功率为60W的白炽灯照射下,pH值=3.5,n(H2O2)/n(Fe2+)=20 1,反应时间t=60min,此时CODCr去除率可达98.50%,各因素对反应的影响顺序为:pH>n(H2O2)/n(Fe2+)>反应时间。     

B超监视下行疑难吸宫术与取环术21例

在B超引导下处理疑难吸宫术与取环术是一种安全、简便、快速、准确性高的好方法。本文报道了作者们在B超监视下行21例疑难吸宫术及取环术的体会。     

寒冷地区挤压机生产混凝土空心板中的问题探索

本文就混凝土空心板成型构件表面塌陷，构件超厚，保护层露筋和空心板裂缝等问题，做了一些探索，提出了参考性的解决办法。     

给定流形自适应广义同步及在保密通信中的应用

基于Lyapunov稳定性理论,研究两类给定流形的双向耦合自适应广义同步问题。在理论上给出了达到广义同步的充分而非保守的条件,应用广义同步原理,使信息信号遮掩于给定流形的混沌系统进行传输。由于预先给定流形是可以改变的,因此可使相应的混沌行为呈现多态化。数值仿真通过构造线性和非线性的给定流形的混沌和超混沌系统验证了这种理论结果是有效的。结果显示可形成多种相异的混沌动力学行为,增强信号传输的保密性。     

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.     

Comparison of the effect of hydrogen incorporation and oxygen vacancies on the properties of anatase TiO2: electronics,optical absorption,and interaction with water

Hydrogenation has been recently developed as an approach to improve the visible-light response of titanium dioxide （TiO2）; however, the effect of hydrogenation on the electronics and optical absorption of anatase TiO2 has been widely debated. In this work, the electronic structures and optical properties of hydrogenated TiO2 and its interaction with water have been studied using the density functional theory plus Hubbard model. A comparison of the effect of hydrogenation and introduction of oxygen vacancies （OVs） to TiO2 is presented. It is found that both hydrogenation and OVs can promote the absorption of visible light and strengthen the adsorption of water. Compared with OVs, hydrogen incorporation can lead to local distortion and even amorphous structures when it is heavily doped.     

第一性原理计算Fcc-Cr_(1-x)Si_xN的调幅分解

基于通过第一性原理计算方法,计算了三元固溶体Fcc-Cr1-xSixN总能,在此基础上计算了其分离能和调幅分解线.结果说明,Fcc-Cr1-xSixN是亚稳相,能够经调幅分解机制分解为Fcc-CrN和Fcc-Si N.组元相形成的应变能小于分离能,不会抑制Fcc-Cr1-xSixN的调幅分解.Fcc-Cr1-xSixN的Si含量为渗透阈值时,不会发生调幅分解.Fcc-Cr1-xSixN可能经调幅分解生成Fcc-Si N.     

21世纪基本物理学（M理论）及其哲学思考

本文在于探索M理论的哲学问题。全文分三个部分。第一，20世纪基本物理学的成就和问题；第二，M理论的重要概念；第三，M理论的哲学反思。