量子计算模拟及优化方法综述

在处理某些大规模并行问题时,量子计算因量子位独特的叠加态和纠缠态特性,相比经典计算机在并行处理方面具有更明显的优势。现阶段,物理量子比特计算机受限于可扩展性、相干时间和量子门操作精度,在经典计算机上开展量子计算模拟成为研究量子优越性和量子算法的有效途径。然而,随着量子比特数的增加,模拟所需的计算机资源呈指数增长。因此,研究大规模量子计算模拟在保证计算准确度、精度及效率的情况下减少模拟所需资源具有重要意义。从量子比特、量子门、量子线路、量子操作系统等方面展开,阐述量子计算的基本原理和背景知识。同时总结基于经典计算机的量子计算模拟基本方法,分析不同方法的设计思路和优缺点,列举目前常见的量子计算模拟器。在此基础上,针对量子计算模拟的通信开销问题,从节点拆分和通信优化2个方面出发,讨论基于超级计算机集群的量子计算模拟优化方法。     

Defect Engineering in Earth-Abundant Cu2ZnSn(S,Se)4 Photovoltaic Materials via Ga3+-Doping for over 12% Efficient Solar Cells

The efficiency of earth-abundant Cu₂ZnSn(S,Se)₄ (CZTSSe) solar cells is considerably lower than the Shockley–Queisser limit. One of the main reasons for this is the presence of deleterious cation disordering caused by Sn_Zn antisite and 2Cu_Zn+Sn_Zn defect clusters, resulting in a short minority carrier lifetime and significant band tailing, leading to a large open-circuit voltage deficit, and hence, low efficiency. In this study, Ga-doping is used to increase the CZTSSe solar cell efficiency to as high as 12.3%, one of the highest for this type of cells. First-principles calculations show that the preference of Ga³⁺ occupying Zn and Sn sites has a benign effect on suppressing the formation of the Sn_Zn deep donor defects by upwardly shifting the Fermi level, which is further confirmed by deep-level transient spectroscopy characterization. Besides, the Ga dopants can also form defect-dopant clusters, such as Ga_Zn+Cu_Zn and Ga_Zn+Ga_Sn, which also have positive effects on suppressing the band-tailing states. The defect engineering via Ga³⁺-doping may suppress the band-tailing defect with a decreased Urbach energy, elevate the minority carrier lifetime, and in the end, enhance the V_OC from 473 to 515 mV. These results provide a new route to further increase CZTSSe-based solar cell efficiency by defect engineering.     

基于SLR数据的雷达探测精度分析方法

空间安全已成为各航天大国国家安全中的重要一环,空间目标监视技术也已成为空间技术新的制高点。雷达凭借其全天时、全天候的特点,已成为空间目标监视的骨干设备,其探测精度直接影响太空态势掌控的准确性,因此准确分析雷达探测精度有着重要意义。本文以卫星激光测距（SLR）数据为基础,首先分析了不同阶数插值算法以及滑动式内插、非滑动式内插的插值精度,而后介绍了坐标转换方式与雷达精度分析方法。仿真结果表明,滑动式九阶拉格朗日插值算法有较好的插值效果,满足雷达精度分析的需求。     

PbTiO3 as Electron‐Selective Layer for High‐Efficiency Perovskite Solar Cells: Enhanced Electron Extraction via Tunable Ferroelectric Polarization

PbTiO₃ (PTO) is explored as a versatile and tunable electron‐selective layer (ESL) for perovskite solar cells. To demonstrate effectiveness of PTO for electron–hole separation and charge transfer, perovskite solar cells are designed and fabricated in the laboratory with the PTO as the ESL. The cells achieve a power conversion efficiency (PCE) of ≈12.28% upon preliminary optimization. It is found that the PTO ferroelectric layer can not only increase the PCE, but also tune the photocurrent via tuning PTO's ferroelectric polarization. Moreover, to understand the physical mechanism underlying the carrier transport by the ferroelectric polarization, the electronic structure of PTO/CH₃NH₃PbI₃ heterostructure is computed using the first‐principles methods, for which the triplet state is used to simulate charge transfer in the heterostructure. It is shown that the synergistic effect of type II band alignment and the specific ferroelectric polarization direction provide the effective extraction of electrons from the light absorber, while minimize recombination of photogenerated electron–hole pairs. Overall, the ferroelectric PTO is a promising and tunable ESL for optimizing electron transport in the perovskite solar cells. The design offers a different strategy for altering direction of carrier transport in solar cells.     

导湿涤纶、竹纤维与棉三合一混纺纱开发

介绍了新型原料导湿涤纶、竹纤维的性能特点，以及与长绒棉三合一开发生产TC/竹／JC40／40／20 18．2tex混纺纱的纺纱工艺流程及各工序的工艺与技术措施。     

国外地下水模拟软件的发展现状与趋势

通过对目前国际上最有影响的几个地下水模拟软件的分析 ,概述了地下水模拟软件的发展现状 ,指出组件化、与GIS集成、前后处理功能强化、科学可视化的深入应用将是未来地下水模拟软件发展的主要趋势     

基于PC机的气缸定位控制系统

提出一种以PC上位机为核心,以Visual C++为开发平台的控制系统,实现气缸精确定位控制。选择参数自整定Fuzzy-PID控制算法,利用比例方向控制阀、标准气缸、位移传感器和数据采集卡等元件,建立气缸定位控制系统实验平台。利用PC强大的数据处理能力实现Fuzzy-PID控制算法,以及PC丰富的外部接口实现输入输出模块的连接,可以有效节约系统开发成本。     

基于网络的科学问题求解环境研究

科学问题求解环境以一套高效的科学计算工具集为基础,为求解科学问题提供了一个方便易用的平台。把传统的科学问题求解环境同网络的共享与协同特征相结合,为满足科学问题求解过程中普遍存在的知识复用与大规模计算的需求提供了新的机遇。该文介绍了科学问题求解环境的发展历史及存在的问题,在此基础上提出了一种解决方案——基于网络的科学问题求解环境(Grid-PSE)。     

WELL-DISPERSED NANODIAMOND AQUEOUS SUSPENSIONS ——PREPARATION, PROPERTIES AND APPLICATIONS

Well-dispersed nanodiamond(ND) aqueous suspensions in both acidic and alkaline environments is prepared by mechanochemical treatment. All the ND particles in the suspensions are smaller than 100nm in dimension with a narrow size distribution, and no destabilization phenomena were detected in a duration of more than one year. Stable. dispersion of ND in the media may attributed to the strong electrostatic repulsion between particles because of the adsorption of dispersants, while mechanical forces may strengthen this adsorption reaction. Good adaptability and applicability of the suspensions to the change of ND concentration and surrounding temperature are observed, and improved performances of ND diamonds are obtained when used in uhrafine polishing and composite plating.