完善公安标准化技术审查工作的几点措施及思考

标准化技术审查是标准制修订工作中的重要环节,也是标准在批准发布之前的最后一道技术性审查关口.本文结合日常工作实际,对公安标准化技术审查工作的现状及面临的挑战进行了分析,对近年来采取的一些应对措施作了介绍,同时还提出了进一步完善标准化技术审查工作的几点思考.     

Application of in vitro gut fermentation models to food components: A review

This review introduces recent changes regarding measurement of preferences brought about by the discovery of false preferences that occur with paired preference testing. Testing protocols are examined critically. False preferences result from a response bias elicited by factors distinct from sensory properties of products being tested that can distort results. Statistical approaches to circumventing this problem are examined. Alternative methods are being developed to eliminate false preferences based on understanding information processing in the brain. This has led to development of disruptive experimental preference testing protocols based on hypothesized use of processing subroutines in the brain to protect the central processing system from overload. These disruptive protocols suppress response bias. Paired preference testing is designed to predict consumer behavior. A paucity of studies addressing whether they do is put into perspective.     

Efficient computational method for transient EM response of large-loop source over layered earth

Calculations of the ElectroMagnetic （EM） response produced by a large horizontal loop placed over layered medium are rather complex because its integral expression contains the product of two Bessel functions and has a divergent term. In this paper, an improved fast Hankel and Gaver-Stehfest transforms are introduced to solve the strong-oscillation and slow-decay properties of the integrand, where one Bessel function in the product is substituted by a carefully chosen polynomial of high accuracy and the other used as the digital filter coefficients in the convolution integral. Comparisons prove the validity and the efficiency of the proposed method.     

季铵盐型抗静电剂的研究现状及进展

文章介绍了塑料用抗静电剂的种类以及特性。着重对国内外季铵盐型阳离子研究现状及应用进行了总结。最后对国内抗静电剂的研发提出了展望,并给出了相应的建议。     

A new boundary meshfree method for calculating the multi-domain constant coefficient heat conduction with a heat source problem

A new high-precision boundary meshfree method, namely virtual boundary meshfree Galerkin method (VBMGM), for calculating the multi-domain constant coefficient heat conduction with a heat source problem is given. In the paper, the radial basis function interpolation is used to solve the virtual source function of virtual boundary and the heat source within each subdomain. Simultaneously, the equation of VBMGM for multi-domain constant coefficient heat conduction with a heat source problem is obtained by the Galerkin method. Therefore, the proposed method has common advantages of the boundary element method, meshfree method, and Galerkin method. Coefficient matrix of this specific expression is symmetrical and the specific expression of VBMGM for the multi-domain constant coefficient heat conduction with a heat source problem is given. Two numerical examples are given. The numerical results are also compared with other numerical methods. The accuracy and feasibility of the method for the multi-domain constant coefficient heat conduction with a heat source problem are proved.     

C臂CT在经皮椎体成形术治疗骨质疏松性椎体压缩骨折中的临床应用

【摘要】 目的 探讨C臂CT技术在经皮椎体成形术（PVP）治疗骨质疏松性椎体压缩骨折（OVCF）中的应用价值。方法 自2010年1月—2013年12月期间，对110例OVCF患者实施PVP治疗，所有患者分为两组，A组48例在普通DSA引导下完成，B组62例在平板DSA C臂CT引导下完成，比较两组的术前、术后1 d和1个月的视觉模拟评分（VAS），骨水泥注入量、骨水泥填充率及骨水泥渗漏率。结果 所有病例均成功完成手术，术后两组VAS评分与术前比较差异有统计学意义（P < 0.05），同时期组间VAS评分比较差异无统计学意义（P > 0.05）。A组骨水泥渗漏率明显高于B组，而骨水泥注入量、骨水泥填充率明显低于B组，两组间比较差异有统计学意义（P < 0.05）。两组均无严重并发症发生。结论 利用C臂CT成像技术可以更直观地监测PVP中的穿刺过程，准确评判骨水泥的分布和泄漏情况，降低高龄患者手术风险。
     

Carboxymethyl sago pulp/chitosan hydrogel as an immobilization medium for activated sludge for p-nitrophenol biodegradation

In this study, carboxymethyl sago pulp (CMSP) derived from sago waste was successfully crosslinked with ferric ions in the presence of chitosan forming a novel immobilization matrix for p-nitrophenol (PNP)-acclimated activated sludge. On the basis of the shortest biodegradation time of PNP, the optimized operational conditions of immobilization were found to be: 7 w/v% CMSP, 9 g L⁻¹ of activated sludge, 0.1 M ferric ion, and 15 min of crosslinking time. Observable inhibited PNP biodegradation was exhibited by the suspended activated sludge at the initial PNP concentration of 400 mg L⁻¹. In contrast, complete mineralization was achieved by the CMSP/chitosan-immobilized activated sludge (CMSP/Ch-AS) beads. The results revealed the important role of CMSP/Ch hydrogel in protecting activated sludge from the toxicity of PNP. The CMSP/Ch-AS beads could be reused consecutively up to three and two cycles, respectively, for the biodegradation of PNP at 200 and 400 mg L⁻¹, with the attainment of more than 99% of PNP removal at each cycle. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47531.     

Effect of midblock on the morphology and properties of blends of ABA triblock copolymers of PDLA-mid-block-PDLA with PLLA

A method to overcome the brittleness of poly (l-lactic acid) (PLLA) by kinetically trapping a continuous low T_g amorphous phase is presented. This morphology is accomplished by exploiting the significant difference in the crystallization temperatures of PLLA vs its stereocomplex with the poly (d-lactic acid) (PDLA) isomer. In our studies, the D isomer is the end block of a triblock copolymer with a configuration of the form PDLAn–Soft Blockm–PDLAn. As demonstrated in this study, when blended with PLLA, the obtained morphology, and improvement in the sample toughness and flexibility, strongly depend on the miscibility of the midblock in the triblock copolymer with the matrix PLLA. The difference in the chemical nature of the midblock clearly affected the stereocomplex crystallization between the PDLA end blocks, the PLLA matrix polymer, and the morphology formed. It is found that the miscible midblock gives rise to a soft continuous amorphous phase while in the case of an immiscible midblock, a glassy phase separated amorphous phase is formed. Dramatically different physical properties can be obtained for various PLLA/triblock copolymer blends giving access to tough, yet flexible, semicrystalline PLLA blends.     

电刺激结合冷却排酸对牦牛细胞骨架蛋白(Desmin、Troponin-C、Integrin)降解影响的研究进展

本文旨在介绍电刺激在牦牛肉类工业中的应用与研究及其机理。根据电刺激对骨架蛋白Desmin、Troponin-C、Integrin降解的影响机理,在此基础上讨论电刺激结合冷却排酸对骨架蛋白降解的机理。     

Solution of laplace equation by the method of separation of variables

Abstract

The Laplace equation, which is used to describe the problem of two‐dimensional heat conduction with appropriate boundary conditions at steady state, is solved in this work by applying the method of separation of variables. The primary objective of this work involves discussing the effects of the constant value of the separation of variables (p) and the sequential order of substituting boundary conditions on the solution. Without appropriately arranging the sequential order of substituting the boundary conditions, the solution for non‐zero constant values of separation of variables (p) can not be obtained. For a zero value for the constant of the separation of variables, the solution obtained is trivial or does not exist. Solutions in different forms are obtained by using different values for the constant of the separation of variables (p) and for the sequential orders of substituting the boundary conditions.