一步法二甲醚合成技术新进展

综述了一步法合成二甲醚的热力学研究、催化剂研究、动力学研究、工艺条件研究、反应器研究及工业化示范研究等关键技术的进展情况。认为一步法合成二甲醚各项技术均已基本完善 ,应当大力进行工业化研究 ,使该工艺尽快发挥效益。     

加强医学摄影研究内容系统化的新思考

医学摄影是学科,更是一个领域。因此,医学摄影的一切研究,都将纳入系统研究之中,摒弃小体系,确立标准化,才具科学性、实用性和可持续性。本文将医学摄影体系的研究、教材体系的研究、标准化的研究、组织体系的研究、多元形式的研究、设备与环境的研究、人才知识结构的研究7个方面纳入在医学摄影研究内容的大系统之中,使之更为系统化、科学化。     

上海石化PTT产业链研发和产业化进展

详细介绍了中国石化上海石化股份有限公司1,3-PDO、PTT及其产品的研发情况。具体研究内容有:1,3-PDO的研发,PTT聚合研究,包括催化剂的筛选、反应温度控制、缩聚研究、副反应研究等;PTT聚合物加工性能研究,包括非等温结晶行为研究、热稳定性研究、流变性及可纺性研究等;PTT纤维的纺织、染整研究。石化公司在研发基础上,完成了8000t/aPTT连续试验装置改造的初步设计和施工设计,并用壳牌公司切片生产了6.5t的136.7dtex/24fPTT/FDY。     

浅谈我国医药的现状及发展趋势

介绍目前我国药学研究领域、中药及中成药研究、制剂研究、新药研究、生物技术等的现状及发展趋势。     

基于文献计量学的国内堆肥微生物研究分析

堆肥原料的有机物降解依靠堆肥微生物,研究堆肥微生物可促进堆肥技术发展。本文采用文献计量学方法,对知网堆肥微生物的研究文献进行分析,主要分析堆肥微生物研究文献数量年度变化、堆肥微生物研究人员及研究机构、堆肥微生物研究热点。分析得出结论为:国内堆肥微生物研究在稳步开展、国内堆肥微生物研究协作需要加强,国内堆肥微生物研究热点为堆肥微生物技术应用领域、微生物堆肥原料、微生物堆肥工艺、微生物堆肥产品、微生物堆肥机理研究等。本文可供废弃物处理、环保等领域科研人员作为参考。     

我国创业教育研究热点与研究前沿的可视化分析--基于CSSCI来源期刊(2003-2018年)数据

以CSSCI数据库中2003-2018年创业教育相关文献为研究对象,以CiteSpace V可视化软件为研究工具,文章对近年来我国创业教育领域的研究进展进行了梳理,并通过关键词共现和突现词探测确定了创业教育领域的研究热点与研究前沿。研究结果显示,创业教育基本理论研究、创业教育教学研究、创业教育实施机构研究及创业教育对象研究是近年来我国创业教育的研究热点;创新创业教育、生态系统、美国教育、创业意愿等是我国创业教育的研究前沿。我国创业教育研究整体上发展较快,但仍需继续立足时代发展背景,扎根本土化研究,优化创业教育质量评价研究,推进创业教育生态系统等方面的研究。     

化学工程技术的几个热点与发展趋势

叙述了化学工程领域的一些研究热点及研究进展,对超临界化学反应技术、分离技术、传热过程等单元操作过程进行了分析与研究,认为化学工程技术的研究重点在过程、设备、研究对象、研究方法与手段等方面都发生了深刻的变化,化学工程技术的研究将更加注重多学科的融合,以节约能源、资源,提高环境保护水平为目标。     

热烈庆祝中国林科院建院50周年!中国林业科学研究院介绍

中国林业科学研究院（简称中国林科院）是国家林业局直属的综合性、多学科、社会公益型国家级科研机构，主要从事林业应用基础研究、战略高技术研究、社会重大公益性研究、技术开发研究和软科学研究，着重解决全国林业发展和生态建设中带有全局性、综合性、关键性和基础性的重大科技问题。     

过氧化物交联聚乙烯挤出成型研究进展

介绍了过氧化物交联聚乙烯(PEXa)的交联机理。综述了国内外挤出PEXa所用原料和工艺的研究,其中包括PEXa专用料、加工助剂(过氧化物交联剂、抗氧化剂、稳定剂等)、交联温度、时间等;分析了挤出PEXa管材设备的研究现状,包括一步法挤出PEXa装备、两步法挤出PEXa装置及配套的生产线;最后展望了PEXa的未来研究方向。指出未来技术研究主要集中在以下几个方面:螺杆挤出的专用料研究、高速度、大口径的工艺研究、二步法螺杆挤出相关机理研究。     

三相逆流化床的研究进展与展望

三相逆流化床(TPIFB)作为一种新型的流化床反应器,具有诸多优点及巨大的应用前景。本文首先介绍了TPIFB的结构、原理和特点,综述了TPIFB基础研究和应用研究。基础研究的阐述主要包括:流型、压力降、最小流化速度、相含率、停留时间分布、气泡行为、传质和传热等流体力学特性的重要性;操作条件和流体物性对这些流体力学特性的影响规律;一些重要流体力学特性参数的数学模型及数值模拟研究等。TPIFB应用研究主要介绍了其在装置优化、含油废水处理及其他工业废水处理等方面的研究进展和主要成果。最后指出TPIFB瞬态和微观研究较少、实验研究方法单一、实验结论缺少定量关系、实验模型和方法存在局限性、应用性研究少而分散等是目前阻碍TPIFB工业化应用的主要问题,并展望了其今后的主要研究方向,包括反应器装置设计和开发、数值模拟结合实验考察TPIFB瞬态和微观特征、过程优化机理模型与反应器模型的建立、反应器放大及应用性研究。     

树脂基复合材料成型工艺研究进展

主要综述了树脂基复合材料的几种成型工艺,包括RTM、VARTM、CRTM、LRTM、RFI、VARI、SCRIMP、SRIM、TERM,各自的发展现状、成型原理、特点等.     

Potential of Polyvinylidene Fluoride/Carbon Nanotube Composite in Energy,Electronics, and Membrane Technology: An Overview

Polyvinylidene fluoride (PVDF) is a semicrystalline thermoplastic and electroactive polymer with piezoelectric and pyroelectric properties, thermal stability, elasticity, and chemical resistance. PVDF exits in five different phases (α, β, δ, γ, and ε-phase). Unique properties of this polymer enhances its use in chemical, biomedical, and electronic industries such as supercapacitors, transducers, actuators, and batteries. Carbon nanotube (CNT) is used as reinforcement to exploit full potential of PVDF in energy, electronics, and membrane technology. The nanofiller affects morphology, piezoelectric, pyroelectric, electrical, dielectric, thermal, and mechanical properties of PVDF-based nanocomposite. CNT content and chemical modification influence properties as well as application of PVDF.     

2004～2005年国外塑料工业进展

收集了2004年7月-2005年6月国外塑料工业的相关资料，介绍了2004年～2005年国外塑料工业的发展情况。提供了世界几大区域塑料的产量、增长率及所占份额；美国、德国、日本、韩国、法国、比利时、印度、西班牙、中国台湾、加拿大、巴西、英国等国家和地区的不同树脂的产量及消费量；各国、各地区塑料原料的产量、进出口量、国内消费量和人均消费量；日本塑料原料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮、聚砜）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

A review of ZrO2 nanoparticles applications and recent advancements

The many branches of nanoscience have made significant strides and advancements during the past ten years, as has the entire scientific community. Zirconia nanoparticles have several uses as adsorbents, nanosensors, nanocatalysts, and other types of nanomaterials. Their outstanding biomedical uses in dental care and drug delivery, as well as their intriguing biological characteristics, such as their anti-cancer, anti-microbial, and antioxidant activity, have further encouraged researchers to investigate their physicochemical properties using various synthetic pathways. Due to the popularity of zirconia-based nanomaterials, the current research comprehensively examines several synthesis techniques and their effects on the composition, dimensions, forms, and morphologies of these nanomaterials. In general, there are two methods for creating zirconia nanoparticles: chemical synthesis, which uses hydrothermal, solvothermal, sol-gel, microwave, solution combustion, and co-precipitation processes; and a greener method, which uses bacteria, fungi, and plant components. The aforementioned techniques have been evaluated in the present review for achieving particular phases and shapes. A thorough analysis of zirconia-based nanomaterial's uses is also included in the review. Furthermore, comparisons with their equivalent composites for various applications as well as the influence of particular phases and morphologies have been added. The final portion includes the summary, future outlook, and potential application.     

Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined.     

Electrospinning jets and polymer nanofibers

In electrospinning, polymer nanofibers are formed by the creation and elongation of an electrified fluid jet. The path of the jet is from a fluid surface that is often, but not necessarily constrained by an orifice, through a straight segment of a tapering cone, then through a series of successively smaller electrically driven bending coils, with each bending coil having turns of increasing radius, and finally solidifying into a continuous thin fiber. Control of the process produces fibers with nanometer scale diameters, along with various cross-sectional shapes, beads, branches and buckling coils or zigzags. Additions to the fluid being spun, such as chemical reagents, other polymers, dispersed particles, proteins, and viable cells, resulted in the inclusion of the added material along the nanofibers. Post-treatments of nanofibers, by conglutination, by vapor coating, by chemical treatment of the surfaces, and by thermal processing, broaden the usefulness of nanofibers.     

Maternal Reproductive Toxicity of Some Essential Oils and Their Constituents

Even though several plants can improve the female reproductive function, the use of herbs, herbal preparations, or essential oils during pregnancy is questionable. This review is focused on the effects of some essential oils and their constituents on the female reproductive system during pregnancy and on the development of the fetus. The major concerns include causing abortion, reproductive hormone modulation, maternal toxicity, teratogenicity, and embryo-fetotoxicity. This work summarizes the important studies on the reproductive effects of essential oil constituents anethole, apiole, citral, camphor, thymoquinone, trans-sabinyl acetate, methyl salicylate, thujone, pulegone, β-elemene, β-eudesmol, and costus lactone, among others.     

A review of liquid silicone rubber injection molding: Process variables and process modeling

Liquid silicone rubber (LSR) is an elastomer molded into critical performance components for applications in medical, power, consumer, automotive, and aerospace applications. This article reviews process behavior, material modeling, and simulation of the (LSR) injection molding process. Each phase of the LSR injection molding process is discussed, including resin handling, plastication, injection, pack and hold, and curing; and factors affecting the molding process are reviewed. Processing behavior of LSR is marked by transient interactions between curing, shear rate, temperature, pressure, and tooling. Therefore, current LSR models for curing, viscosity, pressure, and temperature are discussed. Process dynamics and material modeling are combined in LSR injection molding simulations with applications in mold design, troubleshooting process-induced defects, and management of shear stress and non-uniform temperatures between LSR and substrates during overmolding. Finally, case studies using commercial simulation software are presented, which have shown cavity pressure and flow front advancement within 3% of experimental values. Optimization of LSR materials, data collection, model fitting, venting, and bonding remain areas of continued interest.     

新型碳材料与聚烯烃复合材料研究进展

最近二十多年,由于新型碳材料（包括富勒烯、碳纳米管和石墨烯等）在很多方面具有优异的性能,开辟了诸多新颖的应用领域。本文综述了碳纳米管和石墨烯在聚烯烃树脂中的应用,通过物理共混和原位合成法形成复合材料,提高了聚烯烃材料的力学性能、结晶和熔融性能、热稳定性和导电性等,复合材料在场发射显示器件、储氢材料、电池、超强超韧复合材料、显微镜探头、超级电容器、电子枪、纳米电子器件、传感器等诸多领域已取得了较大的突破。     

Profiling of Phytosterols, Tocopherols and Tocotrienols in Selected Seed Oils from Botswana by GC–MS and HPLC

The phytosterol, tocopherol, and tocotrienol profiles for mkukubuyo, Sterculia africana, manketti, Ricinodendron rautanenni, mokolwane, Hyphaene petersiana, morama, Tylosema esculentum, and moretologa-kgomo, Ximenia caffra, seed oils from Botswana have been determined. Normal-phase HPLC analysis of the unsaponifiable matter showed that among the selected oils, the most abundant tocopherol and tocotrienol were γ-tocopherol (2232.99 μg/g) and γ-tocotrienol (246.19 μg/g), detected in manketti and mkukubuyo, respectively. Mokolwane oil, however, contained the largest total tocotrienol (258.47 μg/g). Total tocol contents found in manketti, mokolwane, mkukubuyo, morama, and moretologa-kgomo oils were 2238.60, 262.40, 246.20, 199.10, and 128.0 μg/g, respectively. GC–MS determination of the relative percentage composition of phytosterols showed 4-desmethylsterols as the most abundant phytosterols in the oils, by occurring up to 90% in moretologa-kgomo, mkukubuyo, and manketti seed oils, with β-sitosterol being the most abundant. Mokolwane seed oil contained the largest percentage composition of 4,4-dimethylsterols (45.93%). Besides 4-desmethylsterols (75%), morama oil also contained significant amounts of 4,4-dimethylsterols and 4-monomethylsterols (15.72% total). GC–MS determination of the absolute amounts of 4-desmethylsterols, after SPE fractionation of the unsaponifiable matter, confirmed that β-sitosterol was the most abundant phytosterol in the test seed oils, with manketti seed oil being the richest source (1326.74 μg/g). The analysis showed total 4-desmethylsterols content as 1617.41, 1291.88, 861.47, 149.15, and 109.11 μg/g for manketti, mokolwane, mkukubuyo, morama, and moretologa-kgomo seed oils, respectively.