乳液法制备聚合物纳米复合材料研究进展

介绍了近年来国内外学者采用微乳液聚合、常规乳液聚合、种子乳液聚合 ,核壳乳液聚合、辐射乳液聚合、可聚合的乳化剂和聚合物乳化剂聚合等多种乳液聚合法制备聚合物纳米材料所作的研究工作。     

国外丙烯酸类增稠剂合成方法

综述了国外80年代以来丙烯酸类增稠剂的合成方法,主要包括普通乳液聚合、溶液聚合、反相乳液聚合、无皂乳液聚合、核壳乳液聚合及反相乳液聚合等。     

乳液聚合技术最新研究进展

在简单介绍乳液聚合特点的基础上,重点对近几十年来乳液聚合中发展的新技术,如核/壳乳液聚合、互穿网络聚合、微乳液聚合、无皂乳液聚合以及其它的一些新型乳液聚合方法进行了综述。     

微乳液聚合在钻井液中的研究进展

概述了微乳液的结构,形成机理以及微乳液聚合的基本原理。简单介绍了正相微乳液聚合、反相微乳液聚合以及双连续相微乳液聚合的研究,综述了微乳液聚合产品在钻井液中的应用。探讨了微乳液聚合存在的一些问题,并对今后的发展前景进行了展望。     

乳液聚合新进展

对近十年来乳液聚合中的规乳液聚合,微乳液聚合,反相乳液聚合以及以无皂乳液聚合等几个方面的研究进展进行了综述。     

微乳液聚合研究进展

简要综述了微乳液聚合与乳液聚合的区别、聚合机理和微乳液聚合体系的改进 ,介绍了微乳液合成的共聚物及微乳液聚合的应用。     

乳液聚合新方法简介——递变进料和高聚物表面活性剂

本文简要地回顾了一些非经典的乳液聚合方法,重点介绍了两种较新颖的乳液聚合技术:递变进料乳液聚合和用高聚物表面活性剂的乳液聚合。     

水性丙烯酸酯乳液聚合方法的研究进展

综述了近几年来乳液聚合制备丙烯酸酯乳液的研究进展,主要包括无皂乳液聚合、种子乳液聚合、微乳液聚合、细乳液聚合和辐射乳液聚合等不同方法与特点.另外,对不同丙烯酸酯乳液体系的乳液性能也做了详细阐述.最后对新一代水性丙烯酸乳液产品体系发展前景作了展望.     

丙烯酸酯乳液聚合研究进展

综述了近几年来丙烯酯乳液聚合方法新进展,包括反应性乳化剂存在下的乳液聚合、超浓乳液聚合、Reversible addition fragmentation chain transfer(RAFT)种子乳液聚合、辐射及氧化还原引发的乳液聚合等。另外,对不同丙烯酸酯乳液体系的动力学研究也做了详细阐述。     

有机硅改性丙烯酸酯最新乳液聚合方法研究进展

综述了几种有机硅改性丙烯酸酯复合乳液的聚合新方法,包括传统乳液聚合法、核壳乳液聚合、无皂乳液聚合、微乳液聚合以及细乳液聚合,详细介绍了各种聚合方法的特点和优势,最后指出了有机硅改性丙烯酸酯乳液的前景和发展方向。     

A Simulation Model for Heat Pump Dryer Plants for Fruits and Roots.

Dryer design requires food properties, drying rate and mass-heat transfer coefficients. These values change continuously during drying due to changes in food fractions, particularly the water fraction. The high energy demand and costs allied to inefficient devices, creates a great need for new processing equipment. Along these guide-lines, several heat pump drying research projects were established at the Norwegian University of Science and Technology. The heat pump dryer provides high quality final product as its drying conditions can be controlled. Its efficiency and non-polluting operation come from closed air-refrigerant circuits and from its ability to fully recover the latent heat of moist air as it exits the drying chamber. Most of the above features are quite the opposite of the conventional dryer characteristics. Several experiments were made on heat pump drying of fruits and roots at temperatures from -22.5 to 40°C to obtain data and correlations on thermophysical properties, specific enthalpy and rehydration. Also, tests were done on drying rate, moisture content, drying constant, effective mass diffusivity and heat and mass transfer equations. The next important phase is the development of a simulation model to predict the performance and characteristics of the heat pump dryer plant. The objectives of the present work are to develop and lo test a heat pump dryer simulation model. The simulation provides results on the characteristics of both plant and components which are integrated by heat and mass transfer equations. The program has menus with click-on icons, input and output pop-up dialogue boxes. The usual commands such as, file-open, file-save, edit-delete are available in this program simply called Hpdryer. The model contains moist air psychrometric. natural and conventional refrigerant property libraries. Ammonia is a time-tested, self-alarming and natural refrigerant. It has been used extensively in the past, and it has better thermodynamic and transport properties than halocarbons. Safety is easily attained by design and its restrictive standards have helped increase its use in several countries. There are 36 ammonia installations in Norway and in the United Kingdom, including a drying plant. Ammonia has zero Odp, zero Gwp and the recent R&D has led to viable small-sale heat pump plants. Ammonia and dichlarodifluoromethane refrigerants were used in the test cases simulated by Hpdryer madel.     

木质素/热塑性塑料复合材料界面增容的研究进展

将木质素作为一种有机颗粒填料添加到热塑性塑料中,可解决造纸黑液资源化利用、石油原料日渐紧张以及环境污染加剧等严峻问题。而木质素与热塑性塑料之间相容性直接影响木质素在塑料工业中的应用与发展。首先简要概述了木质素结构与性质和木质素/热塑性塑料复合材料的性能分析,然后系统地阐述国内外研究木质素/热塑性塑料复合材料界面增容方法及其原理;增容方法按添加相容剂、改性木质素和改性塑料进行归类,并对3种增容方法进行比较分析;接着综述了木质素复合材料中增容方法的交叉复合使用;最后对未来木质素/热塑性塑料复合材料界面增容的研究方向以及思路进行了展望。     

2,3,6-三甲基苯酚一步氧化制备2,3,5-三甲基-1,4-苯醌研究进展

2,3,6-三甲基苯酚一步氧化制备2,3,5-三甲基-1,4-苯醌相对于传统的磺化-氧化法具有产品收率高、过程简单、条件温和以及环境友好等特点。本文针对2,3,6-三甲基苯酚一步氧化制备2,3,5-三甲基-1,4-苯醌的均相催化氧化和非均相催化氧化工艺进行了综述,对两种工艺的发展过程及研究现状进行了评价及总结。详细讨论了不同方法和路线在催化活性、选择性以及产品分离和催化剂回收等方面的优缺点,简要分析并总结了2,3,6-三甲基苯酚一步氧化研究的发展规律和最新动态,展望了以非均相催化反应机制为重点的微观机理研究和以提高催化剂循环稳定性、降低制备成本为重点的工业化探索两个潜在的发展方向。     

Characterization of chlorophyll pigments present in canola seed,meal and oil

Chlorophyll pigments present in canola seed, meal and crude and degummed oils were analyzed by high-performance liquid chromatography (HPLC) with a fluorescence detector. Chlorophylls a and b, low levels of pheophytin a, and occasionally traces of pheophorbide and its methyl ester were present in canola seed. Meals and oils contained magnesium-deficient chlorophyll pigments such as pheophorbide a, methylpheophorbide a, pheophytins a and b, and pyropheophytins a and b but not chlorophyll a or b. The amounts of chlorophyll pigments were oil > seed >> meal. Both crude and degummed oils contained pheophytin a and pyropheophytin a as main components, but the ratio of pyropheophytin a to pheophytin a was markedly higher in degummed oils. No pheophorbides were detected in degummed oils. These results suggest that oil processing steps such as extraction and degumming affect the composition of chlorophyll pigments. Publication No. 678 Canadian Grain Commission.     

A Simulation Model for Heat Pump Dryer Plants for Fruits and Roots.

ABSTRACT

Dryer design requires food properties, drying rate and mass-heat transfer coefficients. These values change continuously during drying due to changes in food fractions, particularly the water fraction. The high energy demand and costs allied to inefficient devices, creates a great need for new processing equipment. Along these guide-lines, several heat pump drying research projects were established at the Norwegian University of Science and Technology. The heat pump dryer provides high quality final product as its drying conditions can be controlled. Its efficiency and non-polluting operation come from closed air-refrigerant circuits and from its ability to fully recover the latent heat of moist air as it exits the drying chamber. Most of the above features are quite the opposite of the conventional dryer characteristics. Several experiments were made on heat pump drying of fruits and roots at temperatures from -22.5 to 40°C to obtain data and correlations on thermophysical properties, specific enthalpy and rehydration. Also, tests were done on drying rate, moisture content, drying constant, effective mass diffusivity and heat and mass transfer equations. The next important phase is the development of a simulation model to predict the performance and characteristics of the heat pump dryer plant. The objectives of the present work are to develop and lo test a heat pump dryer simulation model. The simulation provides results on the characteristics of both plant and components which are integrated by heat and mass transfer equations. The program has menus with click-on icons, input and output pop-up dialogue boxes. The usual commands such as, file-open, file-save, edit-delete are available in this program simply called Hpdryer. The model contains moist air psychrometric. natural and conventional refrigerant property libraries. Ammonia is a time-tested, self-alarming and natural refrigerant. It has been used extensively in the past, and it has better thermodynamic and transport properties than halocarbons. Safety is easily attained by design and its restrictive standards have helped increase its use in several countries. There are 36 ammonia installations in Norway and in the United Kingdom, including a drying plant. Ammonia has zero Odp, zero Gwp and the recent R&D has led to viable small-sale heat pump plants. Ammonia and dichlarodifluoromethane refrigerants were used in the test cases simulated by Hpdryer madel.     

振动丝法测定常压和加压下液体的黏度和密度

介绍了自行研制的高温高压振动丝黏度密度仪的构造和测定原理,并以正戊烷作为实验流体对仪器的可靠性和准确性进行了测试.测定了环己烷在323.15～413.15 K温度范围内、正辛烷在313.15～393.15 K温度范围内、苯在303.15～445.15 K温度范围内压力分别为常压和6.10 MPa、正庚烷和异辛烷在298.15～403.15 K温度范围内压力分别为常压和5.10 MPa下的黏度与密度,并分别对不同压力下的黏度、密度数据进行了关联.     

Biosorption: critical review of scientific rationale,environmental importance and significance for pollution treatment

Biosorption may be simply defined as the removal of substances from solution by biological material. Such substances can be organic and inorganic, and in gaseous, soluble or insoluble forms. Biosorption is a physico‐chemical process and includes such mechanisms as absorption, adsorption, ion exchange, surface complexation and precipitation. Biosorption is a property of both living and dead organisms (and their components) and has been heralded as a promising biotechnology for pollutant removal from solution, and/or pollutant recovery, for a number of years, because of its efficiency, simplicity, analogous operation to conventional ion exchange technology, and availability of biomass. Most biosorption studies have carried out on microbial systems, chiefly bacteria, microalgae and fungi, and with toxic metals and radionuclides, including actinides like uranium and thorium. However, practically all biological material has an affinity for metal species and a considerable amount of other research exists with macroalgae (seaweeds) as well as plant and animal biomass, waste organic sludges, and many other wastes or derived bio‐products. While most biosorption research concerns metals and related substances, including radionuclides, the term is now applied to particulates and all manner of organic substances as well. However, despite continuing dramatic increases in published research on biosorption, there has been little or no exploitation in an industrial context. This article critically reviews aspects of biosorption research regarding the benefits, disadvantages, and future potential of biosorption as an industrial process, the rationale, scope and scientific value of biosorption research, and the significance of biosorption in other waste treatment processes and in the environment. Copyright © 2008 Society of Chemical Industry     

The Emerging Roles of Chromogranins and Derived Polypeptides in Atherosclerosis,Diabetes, and Coronary Heart Disease

Chromogranin A (CgA), B (CgB), and C (CgC), the family members of the granin glycoproteins, are associated with diabetes. These proteins are abundantly expressed in neurons, endocrine, and neuroendocrine cells. They are also present in other areas of the body. Patients with diabetic retinopathy have higher levels of CgA, CgB, and CgC in the vitreous humor. In addition, type 1 diabetic patients have high CgA and low CgB levels in the circulating blood. Plasma CgA levels are increased in patients with hypertension, coronary heart disease, and heart failure. CgA is the precursor to several functional peptides, including catestatin, vasostatin-1, vasostatin-2, pancreastatin, chromofungin, and many others. Catestatin, vasostain-1, and vasostatin-2 suppress the expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 in human vascular endothelial cells. Catestatin and vasostatin-1 suppress oxidized low-density lipoprotein-induced foam cell formation in human macrophages. Catestatin and vasostatin-2, but not vasostatin-1, suppress the proliferation and these three peptides suppress the migration in human vascular smooth muscles. Chronic infusion of catestatin, vasostatin-1, or vasostatin-2 suppresses the development of atherosclerosis of the aorta in apolipoprotein E-deficient mice. Catestatin, vasostatin-1, vasostatin-2, and chromofungin protect ischemia/reperfusion-induced myocardial dysfunction in rats. Since pancreastatin inhibits insulin secretion from pancreatic β-cells, and regulates glucose metabolism in liver and adipose tissues, pancreastatin inhibitor peptide-8 (PSTi8) improves insulin resistance and glucose homeostasis. Catestatin stimulates therapeutic angiogenesis in the mouse hind limb ischemia model. Gene therapy with secretoneurin, a CgC-derived peptide, stimulates postischemic neovascularization in apolipoprotein E-deficient mice and streptozotocin-induced diabetic mice, and improves diabetic neuropathy in db/db mice. Therefore, CgA is a biomarker for atherosclerosis, diabetes, hypertension, and coronary heart disease. CgA- and CgC--derived polypeptides provide the therapeutic target for atherosclerosis and ischemia-induced tissue damages. PSTi8 is useful in the treatment of diabetes.     

Social behavior and chemical communication in reindeer (Rangifer t. tarandus L.)

The social interactions of captive reindeer were observed for one year. The seasonal changes of agonistic behavior, the social rank order, social affinity during rest, social sniffing and licking, solitary sniffing and licking, hindleg-head contact, and other motor patterns involving head and antlers are described. Social sniffing and licking correlated more with sex than with social rank. Olfactory responses during encounters and tracking were investigated experimentally. Chemical communication is particularly important in sexual and maternal behavior and during encounters.     

Chemical Interactions of Brachiaria plantaginea with Commelina bengalensis and Acanthospermum hispidum in Soybean Cropping Systems

Previous results obtained in soybean-wheat rotations under no-tillage conditions showed reductions in the seedbank of the weed species Commelina benghalensis, but no alteration in the seedbank of Acanthospermum hispidum in areas infested with Brachiaria plantaginea. Analyses of the soluble fraction of B. plantaginea indicated the predominance of aconitic acid (AA) among the aliphatic acids and ferulic acid (FA) among the phenolic acids. Laboratory bioassays using C. benghalensis and A. hispidum were carried out to evaluate phytotoxic effects of pure organic acid solutions and dilute extracts of B. plantaginea on seed germination, root development, and fungal germination. Solutions of AA and FA were prepared at 0.25, 0.50, and 1.0 mM. Extracts of B. plantaginea were diluted to obtain concentrations of AA similar to those in the prepared solutions. Seeds were sown on 0.5% agar (containing AA, FA, or diluted extract) in plastic-covered receptacles and maintained in a germination chamber for 10 days. AA and FA solutions and the B. plantaginea extract reduced germination and root length, mainly of C. benghalensis. AA also stimulated the development of endophytic fungi (Fusarium solani), which had complementary adverse effects on C. benghalensis germination. FA and AA may play important roles in reducing the seedbank of some weed species, acting directly on germination and development and, indirectly, by stimulating endophytic fungi that alter germination.