Centimeter-Sized Molecular Perovskite Crystal for Efficient X-Ray Detection

Molecular perovskites have demonstrated great potential for ferroelectrics and nonlinear optics; however, their charge transport properties for optoelectronics have rarely been explored. Here, understanding of charge transport behavior of molecular perovskite under X-ray excitation based on centimeter-scale TMCM-CdCl₃ (TMCM⁺, trimethylchloromethyl ammonium) single crystal is demonstrated. The crystal is fabricated from an aqueous solution and exhibits a large bandgap of 5.51 eV, with the valence band maximum mainly dominated by the Cl-p/Cd-d states and the conduction band minimum primarily by Cd-s/Cl-p states. Charge mobility exceeding 40 cm² V⁻¹ s⁻¹ and mobility–lifetime (µτ) product on the order of 10⁻⁴ cm² V⁻¹ for the crystal are observed. These excellent optoelectronic properties translate to an efficient photoresponse under X-ray excitation, with the sensitivity reaching 128.9 ± 4.64 µC Gy_air⁻¹ cm⁻² [fivefold higher than that of the commercialized amorphous selenium (α-Se)] and a low detection limit of 1.06 μC Gy_air⁻¹ s⁻¹ (10 V bias). This work pioneers a superior metal-based molecular perovskite single-crystal based paradigm for optoelectronic investigation, which may lead to the discovery of a new generation of X-ray detection and imaging materials.     

供电企业多元化用工的一体化管理模式研究

随着供电企业的不断发展壮大,劳动用工已从传统的用工模式转向多元化用工。多元化用工作为一种新型的用工方式,为供电企业的发展提供了人力支持,但在管理过程中也存在一些问题。本文从管理的实践出发,分析了供电企业多元化用工的现状及存在的问题,并针对这些问题提出了解决的对策。     

基于多安全机制的Linux应用沙箱的设计与实现

文章设计了一个具有自己独立工作目录的Linux应用沙箱,可为用户对不信任的应用程序提供一个独立和安全的运行环境,应用程序在沙箱中所做的操作对主机不会造成任何影响。该沙箱提供了文件系统隔离、系统资源隔离、物理资源隔离、权能限制和强制访问控制(Mandatory Access Control,MAC)等策略,添加了地址随机化、不可执行页保护等内存保护安全策略。与已有沙箱对比,文章设计的沙箱增加了多种安全机制,提高了系统的安全性,保护了系统的数据安全和用户的个人隐私等。     

MR-DBSCAN： a scalable MapReduce-based DBSCAN algorithm for heavily skewed data

DBSCAN （density-based spatial clustering of ap- plications with noise） is an important spatial clustering tech- nique that is widely adopted in numerous applications. As the size of datasets is extremely large nowadays, parallel process- ing of complex data analysis such as DBSCAN becomes in- dispensable. However, there are three major drawbacks in the existing parallel DBSCAN algorithms. First, they fail to prop- erly balance the load among parallel tasks, especially when data are heavily skewed. Second, the scalability of these al- gorithms is limited because not all the critical sub-procedures are parallelized. Third, most of them are not primarily de- signed for shared-nothing environments, which makes them less portable to emerging parallel processing paradigms. In this paper, we present MR-DBSCAN, a scalable DBSCAN algorithm using MapReduce. In our algorithm, all the crit- ical sub-procedures are fully parallelized. As such, there is no performance bottleneck caused by sequential process- ing. Most importantly, we propose a novel data partitioning method based on computation cost estimation. The objective is to achieve desirable load balancing even in the context of heavily skewed data. Besides, We conduct our evaluation us- ing real large datasets with up to 1.2 billion points. The ex- periment results well confirm the efficiency and scalability of MR-DBSCAN.     

Ti基非晶复合材料的强韧化机理研究

采用水冷铜坩埚磁悬浮熔炼-铜模吸铸法在真空及高纯氩气保护条件下制备了直径3mm的(Ti_0.5Ni_0.48M_0.02)₈₀Cu₂₀ (M=Fe、Ce、Zr)合金,研究了Fe、Ce、Zr对合金凝固组织中形状记忆晶相析出的变化规律,分析了该合金的室温力学行为与强韧化机理。研究发现,(Ti_0.5Ni_0.48M_0.02)₈₀Cu₂₀ (M=Fe、Ce、Zr)合金铸态结构均为非晶+形状记忆晶相(B2过冷奥氏体和B19_’热致马氏体)的复合结构,其中M=Fe的合金B2相体积分数析出最多,M=Zr的合金B19_,相体积分数最多。在室温压缩过程中,合金均表现出良好的综合力学性能,其中以M=Ce 的合金性能最优,断裂强度,屈服强度,塑性应变分别达到2645Mpa,1150Mpa和12.2%。合金在受压应力断裂后,组织中奥氏体相体积分数减小,马氏体相体积分数增加,同时在屈服后均表现出强烈的加工硬化行为。加工硬化速率和瞬时加工硬化速率随真应变的变化分为三个阶段,合金内部在压应力的作用下B2向B19_,相转变是合金强韧化的主要动力。M=Fe的合金加工硬化速率、平均加工硬化指数、瞬时加工硬化指数最大,加工硬化能力最强,M=Ce的合金次之,M=Zr的合金最弱。     

砂带基布的生产和处理加工技术

本文简要介绍用于生产高档砂带纯棉基布的生力技术,重点叙述基布的特殊质量要求和特殊的后整理技术.     

无线电波在矿井巷道中传播的探讨

介绍了无线电波在巷道中的应用情况及实验结果。结合理论分析,指出无线电波在井巷中引起电波衰减的主要原因是波的折射与反射,而不是巷壁的吸收。提出井下实验应不仅把注意力放在长波、中波频段,还应放在超短波频段,认为在超短波频段孕育着希望。最后,提出了改进无线电波在井巷中使用效果的几点建议。     

Online balancing of the rotor-bearing unit of the flywheel energy storage system

采用SB-7700型动平衡仪对400 kW/10 MJ飞轮储能系统轴系进行了本机动平衡,依据动平衡结果,提出了增加平衡工艺飞轮的修改设计.采用两平面方法进行本机动平衡后,飞轮储能机组达到额定3600 r/min的高速稳定运行.振动测试表明,充电,放电状态振动特性有所差别,放电功率对共振区振动幅频特性有显著影响,这反映了永磁电机电磁力对同步振动的作用.     

"三新三化"的成功实践

中国海洋石油总公司为降低油田开发投资,提高经济效益,提出“三新三化”,即：新思想、新技术、新方法;简易化、标准化、国产化。中海石油有限公司湛江分公司在进行涠１１－４油田东区的开发工程中,围绕这一精神采用多项新技术并实行新管理方法,使油田投资少、建设周期短,取得了明显的经济效益,本文对油田开发过程中的新技术、新的管理方法进行简要总结。     

SiC_p/ZL201复合材料的力学性能

研究了ＳｉＣｐ尺寸、含量及热处理工艺对铸造ＳｉＣｐ／ＺＬ２０１复合材料的室温和高温力学性能的影响。随ＳｉＣｐ含量的提高和粒子尺寸的增大,复合材料的室温抗拉强度呈下降趋势。随温度升高,基体合金的抗拉强度急剧下降,而复合材料的则下降较小。当温度大于２４０℃时复合材料的抗拉强度高于基体合金,表明ＳｉＣｐ的加入显著提高了基体合金的高温抗拉强度。