尼龙细筛与复频筛在工业试验中的对比分析

复频筛是一种新型高效的筛分设备,具有电磁振动、高频率、设备处理能力大、筛分效率高等优点。工业试验表明,利用该设备代替原高频振动尼龙细筛,可及时筛出合格细粒级,大大提高筛分效率,降低再磨系统的循环量,稳定选别流程,提高精矿质量。     

Probing Distinctive Electron Conduction in Multilayer Rhenium Disulfide

Charge carrier transport in multilayer van der Waals (vdW) materials, which comprise multiple conducting layers, is well described using Thomas–Fermi charge screening (λ_TF) and interlayer resistance (R_int). When both effects occur in carrier transport, a channel centroid migrates along the c‐axis according to a vertical electrostatic force, causing redistribution of the conduction centroid in a multilayer system, unlike a conventional bulk material. Thus far, numerous unique properties of vdW materials are discovered, but direct evidence for distinctive charge transport behavior in 2D layered materials is not demonstrated. Herein, the distinctive electron conduction features are reported in a multilayer rhenium disulfide (ReS₂), which provides decoupled vdW interaction between adjacent layers and much high interlayer resistivity in comparison with other transition‐metal dichalcogenides materials. The existence of two plateaus in its transconductance curve clearly reveals the relocation of conduction paths with respect to the top and bottom surfaces, which is rationalized by a theoretical resistor network model by accounting of λ_TF and R_int coupling. The effective tunneling distance probed via low‐frequency noise spectroscopy further supports the shift of electron conduction channel along the thickness of ReS₂.     

Effect of carrier screening on ZnO-based resistive switching memory devices

The carrier screening effect occurs commonly in dielectric materials. It reduces the electric potential gradient, thus negatively affecting the functionality of resistive random access memory (RRAM) devices. An Au/ZnO film/Al-doped ZnO device fabricated in this work exhibited no resistive switching (RS), which was attributed to the carrier screening effect. Therefore, annealing was used for alleviating the screening effect, significantly enhancing the RS property. In addition, different on/off ratios were obtained for various bias values, and the screening effect was accounted for by investigating electron transport mechanisms. Furthermore, different annealing temperatures were employed to modulate the free carrier concentration in ZnO films to alleviate the screening effect. The maximal on/off ratio reached 10⁵ at an annealing temperature of 600 °C, yielding the lowest number of free carriers and the weakest screening effect in ZnO films. This work investigates the screening effect in RS devices. The screening effect not only modulates the characteristics of memory devices but also provides insight into the mechanism of RS in these devices.

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赖氨酸高产菌株的选育

赖氨酸作为一种重要的饲料用氨基酸,需求量一直在不断增长。传统的赖氯酸生产菌株都是多年来是经过多轮随机突变和筛选得到,而近年来随着基因重组技术的发展及对生物代谢过程的了解,人们已经能够通过基因重组技术,改变代谢途径,提高赖氨酸产量。目前有不少成功将野生菌株改造为高产菌株的案例,他们都可以作为合理设计代谢途径并结合各种组学进行微生物代谢途径改造的基础。本文主要描述通过代谢途径改造并结合高通量筛选技术,快速得到赖氨酸高产菌株的方法。     

中央维护计算机系统中的故障处理技术

针对飞机故障的产生逻辑和处理方法,详细分析了中央维护计算机系统故障数据处理模块的主要功能,建模思想和处理流程;再现了故障信息产生、级联效应删除、重复故障合并以及飞机驾驶舱效应与维护信息关联的全过程。并以国外先进机型为例,对基于逻辑方程的故障隔离技术进行了深入分析,使得系统设计思路与机载故障诊断模型相结合;随着CMCS技术的不断发展和成熟,必将对商用飞机传统维护模式和运营模式产生深远的影响。     

调水工程系统风险评价体系研究

根据调水工程事故的特点和结构系统受损害的严重程度,以Pate—Cornell系统风险计算公式为基础,在调水工程结构系统的模糊失效概率的计算和调水工程事故后果模糊综合评判的基础上,系统地提出了调水工程结构系统的风险评估体系。     

制造型企业物流分析与优化

针对制造型企业的物流优化,研究物流分析技术在设施布置中的应用。主要包括四种基本方式:工艺原则布置、产品原则布置、单元式布置和模块化布置,最后介绍计算机仿真技术在制造型企业的初步探索。     

长寿命产品退化筛选试验方法研究

 传统的可靠性筛选方法以产品是否失效为筛选判据,对于高可靠长寿命产品,必须将产品长时间置于筛选应力下,对于一批产品中的合格品会产生较为严重的不良影响.针对退化失效型产品,研究了不合格品与合格品的性能退化规律:在筛选应力下,相对于合格品,不合格品性能参数的变化速率相对较快,从而使得性能参数在试验检测过程中形成明显的双峰分布.论文提出了基于产品性能退化特性的可靠性筛选技术,在保证筛选成品率和产品可靠度的前提下,通过合理选取筛选试验持续时间和筛选阈值,实现了缩短试验时间和减少筛选应力对合格品的不良影响的目的,最后通过实例说明了方法的有效性.     

物联网信息安全整体保护实现技术研究

随着物联网技术的飞速发展,其安全问题越来越引起重视。本文首先通过对物联网的基本概念、技术的阐述并结合互联网的特点,探讨了物联网的安全需求;其次提出一种物联网整体防护体系结构,该体系结构以访问控制、可信接入、安全封装等技术为基础,从六个方面提升物联网整体防护水平;最后简单介绍了可信接入与安全封装技术的基本原理,为整体防护技术实现提供借鉴。     

β-淀粉样多肽自聚集抑制剂的电化学筛选方法研究

β-淀粉样多肽（Amyloidbeta,Aβ）的聚集物具有神经细胞毒性,可导致神经元凋亡,从而诱导阿尔茨海默症（Alzheimer’s disease,AD）的发生。能够抑制AB自聚集行为的化合物称为AB自聚集抑制剂。该抑制剂可抑制Aβ有毒聚集物的产生,从而降低Aβ所引起的神经细胞毒性,对AD病有一定的治疗效果。因此。筛选AB自聚集抑制剂对于AD的治疗有着重要的意义。在数以千万计的化合物中,要筛选出对Aβ自聚集有抑制效果的化合物需要借助众多的仪器和研究方法。该文总结了筛选AB自聚集抑制剂的几种方法．重点综述了几种低成本、快速、灵敏的电化学筛选方法。Aβ自聚集抑制剂的筛选对临床上AD病的治疗提供了理论基础,为治疗AD病这一复杂科学问题的研究起到了促进作用。