Quantum Mechanics and Computation

In quantum computation non classical features such as superposition states and entanglement are used to solve problems in new ways, impossible on classical digital computers.We illustrate by Deutsch algorithm how a quantum computer can use superposition states to outperform any classical computer. We comment on the view of a quantum computer as a massive parallel computer and recall Amdahls law for a classical parallel computer. We argue that the view on quantum computation as a massive parallel computation disregards the presence of entanglement in a general quantum computation and the non classical way in which parallel results are combined to obtain the final output.     

现有防疫通风措施及基于先进气流组织的源头控制技术应用

新冠疫情暴发后,如何应对呼吸道传染病的传播这一难题再次摆在了人们面前.通风是最重要的工程防疫措施,ASHRAE、REHVA、SHASE以及中国的相关机构、学会就如何利用暖通空调系统有效防控COVID-19的传播相继出台了指导性文件.总结和分析系列指导性文件中有关通风量和气流组织方面的内容,发现现有工程防疫措施尚存在诸多...     

基于BMP图像边缘跟踪的飞秒激光微加工技术研究

针对复杂结构和图案的飞秒激光微加工, 提出了一种基于BMP图像边缘跟踪的飞秒激光微加工方法. 介绍了采用该方法实现复杂图形飞秒激光微加工的总体思路, 讨论了加工路径的提取、优化、跟踪和加工过程的反馈, 以及在此基础上开发的飞秒激光微加工数控程序等. 并利用此技术成功制备出二维微纳图案. 研究结果表明, 利用该技术可实现微米至亚微米级特征尺寸复杂图案和微纳结构的飞秒激光数控加工.     

基于最小化系统功率的多小区蜂窝中继波束成形研究

为了减少小区间干扰给用户通信带来的不利影响,研究了多小区通信系统协作传输技术.提出了一种联合优化多小区基站和中继波束成形权重的迭代优化策略,在用户信干噪比限制下达到了最小化系统总功率的目标.利用半正定放松技术把上述优化问题转化为半正定规划问题,从而通过内点法得到最优解.仿真结果表明,提出的多小区基站和中继波束成形权重的迭代优化策略只需要有限的几次迭代就可达到最优的性能,并给出了在性能与基站天线和中继数目之间的折中,从而利用最少的系统资源,达到降低相邻小区用户干扰,保证用户的正常通信质量的目标.     

Subcellular trafficking of the substrate transporters GLUT4 and CD36 in cardiomyocytes

Cardiomyocytes use glucose as well as fatty acids for ATP production. These substrates are transported into the cell by glucose transporter 4 (GLUT4) and the fatty acid transporter CD36. Besides being located at the sarcolemma, GLUT4 and CD36 are stored in intracellular compartments. Raised plasma insulin concentrations and increased cardiac work will stimulate GLUT4 as well as CD36 to translocate to the sarcolemma. As so far studied, signaling pathways that regulate GLUT4 translocation similarly affect CD36 translocation. During the development of insulin resistance and type 2 diabetes, CD36 becomes permanently localized at the sarcolemma, whereas GLUT4 internalizes. This juxtaposed positioning of GLUT4 and CD36 is important for aberrant substrate uptake in the diabetic heart: chronically increased fatty acid uptake at the expense of glucose. To explain the differences in subcellular localization of GLUT4 and CD36 in type 2 diabetes, recent research has focused on the role of proteins involved in trafficking of cargo between subcellular compartments. Several of these proteins appear to be similarly involved in both GLUT4 and CD36 translocation. Others, however, have different roles in either GLUT4 or CD36 translocation. These trafficking components, which are differently involved in GLUT4 or CD36 translocation, may be considered novel targets for the development of therapies to restore the imbalanced substrate utilization that occurs in obesity, insulin resistance and diabetic cardiomyopathy.     

System waste in education and research: A Delphi study in India

A concept of system waste has been developed, and reported in the literature, to focus explicitly on waste and its reduction. In this study, which is a part of the authors' ongoing research on system waste, an attempt has been made to estimate current and future system waste in education and research (EDR) in India. The concept of system waste, which is defined as “any unnecessary input to and/or any undesirable output from any system,” is complex, multifaceted, subjective and not generally clearly understood. Its study is a fit case for the use of qualitative group problem-solving techniques. Delphi is the technique which has been used here to learn about system waste. A two-round Delphi study was conducted in 1990 in EDR in which teachers, educational administrators, planners, and parents participated. The paper describes the study and its results.     

Equilibrating metal-oxide cluster ensembles for oxidation reactions using oxygen in water.

Although many enzymes can readily and selectively use oxygen in water-the most familiar and attractive of all oxidants and solvents, respectively-the design of synthetic catalysts for selective water-based oxidation processes utilizing molecular oxygen remains a daunting task. Particularly problematic is the fact that oxidation of substrates by O2 involves radical chemistry, which is intrinsically non-selective and difficult to control. In addition, metallo-organic catalysts are inherently susceptible to degradation by oxygen-based radicals, while their transition-metal-ion active sites often react with water to give insoluble, and thus inactive, oxides or hydroxides. Furthermore, pH control is often required to avoid acid or base degradation of organic substrates or products. Unlike metallo-organic catalysts, polyoxometalate anions are oxidatively stable and are reversible oxidants for use with O2 (refs 8,9,10). Here we show how thermodynamically controlled self-assembly of an equilibrated ensemble of polyoxometalates, with the heteropolytungstate anion [AIVVW11O40]6- as its main component, imparts both stability in water and internal pH-management. Designed to operate at near-neutral pH, this system facilitates a two-step O2-based process for the selective delignification of wood (lignocellulose) fibres. By directly monitoring the central Al atom, we show that equilibration reactions typical of polyoxometalate anions keep the pH of the system near 7 during both process steps.