N/S co-doped carbon nanosheet bundles as high-capacity anode for potassium-ion battery

Potassium-ion batteries(PIBs)are of academic and economic significance,but still limited by the lack of highly active electrode materials for de-/intercalation ...     

基于减损采肉的纤维化重组鱼糜及其凝胶品质

针对传统鱼糜加工过程中肌纤维破坏严重、鱼糜制品呈胶质化等问题,该文以减损采肉和纤维重组为思路,开发纤维化鱼糜并研究其凝胶品质。结果表明：采用谷氨酰胺转氨酶（transglutaminase,TG 酶）预处理会促进回收鱼肉蛋白间的交联,进而影响重组鱼糜的物性特征。其中TG 酶添加量为0.1%并处理8 h 时,纤维化鱼糜的凝胶强度超过550 g·cm,且凝胶具有较好的持水力、白度和质构特性,然而水溶性蛋白的回填会降低其凝胶强度。通过对鱼糜的纤维化程度进行评价,发现纤维化鱼糜的纤维化程度仍可保持在68%以上,进一步中试研究发现与传统鱼糜相比,纤维化鱼糜的凝胶强度保持率大于75%。     

分级加卸载条件下Q3黄土三轴蠕变特性研究

采用分级增量循环加卸载方式,利用SR-6型三联式三轴蠕变仪对陕西省泾阳县某边坡原状黄土进行了三组室内三轴固结排水蠕变试验,着重研究了黄土黏弹塑性的基本规律,以此建立了黏弹塑性九元件蠕变模型。结果表明:该地区原状黄土具有明显的流变特性,总体呈线性衰减蠕变;卸载后,土样产生衰减黏弹性回弹变形,回弹量随着卸荷量的减小,围压的增大,含水率的增大而减小;加卸载应力历史对黄土蠕变变形具有累积效应;该地区原状黄土的回弹变形不明显,黏弹性变形在蠕应变中所占比重较小;所建立的元件蠕变模型可以较好地描述该地区黄土的三轴线性蠕变特性,物理意义明确,且模型参数易得。     

Effect of Substrate Pretreatment on Controllable Growthof TiO2 Nanorod Arrays

Well-aligned TiO2 nanorod arrays(TNAs) were prepared on the pretreated quartz substrates.The effect of the pretreatment conditions on the growth of TNAs was systematically investigated by X-ray diffraction(XRD),field-emission scanning electron microscopy(FE-SEM) and high-resolution transmission electron microscopy(HRTEM).It is demonstrated that the pre-coating TiO2 crystal seeds on the substrates can greatly improve the growth orientation of TNAs.Rutile TiO2 crystal seeds induce the nucleation and growth of TNAs more preferably than the anatase TiO2 seeds.The growth density and diameter distribution of TNAs strongly depend on the TiO2 crystal seeds density.It is proved that TNAs with different morphologies can be controllably synthesized by using hydrothermal approach by pretreating substrates.The photocatalytic activity of TNAs was investigated by measuring the photodegradation rate of methyl blue aqueous solution under UV irradiation(254 nm).And the results show that TNAs with large growth density and small diameter size exhibit relatively higher photocatalytic activity.     

基于椭圆曲线密码的数据集中器通信报文混合密码算法

针对数据集中器通信的安全需求,分析了数据集中器通信受到的主动攻击和被动攻击行为,建立数据集中器通信安全需求模型,提出了一种基于椭圆曲线密码(ECC)的数据集中器通信报文混合密码算法。提出的混合密码算法能够解决单独的ECC加密算法不能实现数字签名问题和椭圆曲线数字签名算法不能实现通信报文保密的问题。研究结果表明,提出的混合密码算法符合数据集中器通信安全需求。     

Investigation of the Viscosity and Structural Properties of CaO-SiO2-TiO2 Slags

The viscosity of CaO-SiO₂-TiO₂ slags was measured via the rotating cylinder method to reveal the effect of TiO₂ on viscous flow of the slags. Furthermore, the structure of the ternary slags and the role of Ti⁴⁺ were investigated by Fourier transform infrared and Raman spectroscopy techniques. The results are beneficial for a better understanding of the behaviors of Ti-bearing silicate slags. The TiO₂ additions lowered the viscosity and apparent activation energy of the slags. However, the degree of polymerization (DOP) of silicate network was found to be enhanced with increasing the TiO₂ content, which is suggested by the increase in mole fraction of Q ³ ([SiO₄]-tetrahedra with three bridging oxygens) and the decrease in Q ⁰. The Eq. [2] Q ² ? Q ¹ + Q ³ was appropriate to express the relationship of different Q ⁿ species. The introduction of Ti⁴⁺ into the silicate network as network formers increased the DOP but weakened the strength of slag structure at the same time. Besides, a large proportion of Ti⁴⁺ exists in the slag in the form of \( TiO_{4}^{4 - } \) monomers, resulting in a decrease of viscosity with increasing TiO₂ content.     

MC34063 DC/DC转换控制电路测试方法概述

目前,DC/DC转换器广泛应用于远程及数据通信、计算机、办公自动化设备、工业仪器仪表、军事、航天等领域,涉及到国民经济的各行各业。文章以其中有一定代表性的MC34063电路为例,扼要介绍其电特性和用其构成的升压电路的测试方法,并解析其测试原理和升压电路设计中的注意事项,对DC/DC转换器的分析测试和量产测试提供一些借鉴。     

平面流铸工艺中冷却辊流场和传热三维稳态模拟

平面流铸法是一种制备非晶和纳米晶薄带的先进技术。这项技术的难点不仅在于快速冷却以抑制薄带的晶化,还在于获得高表面质量的薄带。提出了一种用三维稳态模拟模型预测工业生产中广泛应用的2种单辊冷却结构的流场和传热系数分布的新方法。利用FLUENT软件,结合能量和动量方程,计算了2种结构的流速分布。预测了2种结构的对流换热系数分布。结果表明,水槽结构的速度分布无均匀性,也无周期性;水缝结构的速度分布无均匀性,但具有周期性。2种结构的对流换热系数分布不是中心对称的,水缝结构的冷却特性更为规则。预测了水缝结构的3个对称分布的合适区域,并通过连续生产多次验证。根据热平衡原理,描述了平面流铸法工艺的传热过程。对流换热系数的均匀分布可以作为冷却辊结构设计的依据之一。     

影响热塑性聚氨酯弹性体性能的因素浅析

对影响热塑性聚氨酯弹性体性能的因素进行了分析和讨论,包括多元醇的结构和相对分子质量、异氰酸酯和扩链剂种类、扩链系数、硬段含量、氢键、催化剂等。提出在生产热塑性聚氨酯弹性体过程中要对体系配方进行科学设计。     

三相不同期合闸下变压器电磁暂态分析及对保护的影响

三相断路器经过长期运行后出现短时的三相合闸不同期,这在现实中是不可避免的。由于三相变压器三角形侧绕组的存在,使其在三相不同期合闸过程中会经历多个暂态过程,从而可能在剩磁较小的情况下也会导致铁芯的严重饱和,使差动保护误动作。在三相组式变压器模型的基础上,分析了三相不同期合闸的物理过程,对变压器合闸过程中的磁链进行了计算,并分析了产生磁链最大值的合闸情况以及漏抗对磁链的影响,发现漏抗在涌流的分析中不能忽略。分析表明,在三相不同期合闸的影响下可能出现二次谐波含量远低于传统值的情况。