用∑WESH图评价某涂料化工厂的可持续性

介绍了在清洁生产过程中用∑WESH图评价涂料化工厂的可持续发展的原理及方法,并进行了一个实例的评价.从该厂的∑WESH图得出该厂的水及能源的利用率高,所用的原材料的稀缺性都不大,唯一较严重的问题是二甲苯的通过量大,危害性较严重.因此建议该厂在配方上尽量减少二甲苯的使用,开发新产品.     

喷涂前处理污染源的分析及其处理措施

随着我国国民经济的快速发展和国家"节能减排"重点项目的深入开展,各种污染源的分析及其处理措施的研究备受关注.本文在充分研究若干家电企业的钢铁喷涂制件的前处理工艺(如:预脱脂、脱脂、清洗、表调、磷化等)的基础上,分析喷涂前处理过程中的污染源,研究污染源的处理措施.     

酿酒酵母细胞表达异源萜类化合物的研究进展

萜类化合物具有可观的经济价值,但是目前的生产过程复杂、产量低。酿酒酵母甲羟戊酸途径为萜类化合物的合成提供直接前体,因此酿酒酵母细胞具有合成异源萜类化合物的天然优势。对酿酒酵母甲羟戊酸途径的清晰认识是对其进行有效利用的基础,本文从代谢途径、关键酶的特点和全局调控机制3个方面对该途径进行了介绍。从代谢途径的构建和优化、模块与底盘细胞的适配、模块构建及组装方式的角度概述了酿酒酵母细胞异源合成单萜、倍半烯萜、二萜、三萜类化合物的研究进展。指出实现酿酒酵母高效合成萜类化合物所需要解决的基础问题是对酿酒酵母甲羟戊酸途径进行更为全面了解和对萜类化合物的天然代谢途径进行明确解析;另外,合成生物学的进一步发展也将为此提供应用基础。     

香叶油的研究进展

为了全面了解香叶油的研究现状,为我国香叶油的开发利用提供思路, 综述了香叶的栽培、组培技术研究、香叶油的应用、香叶油的提取及化学成分研究、香叶油调配研究等方面的现状,并对香叶品种的遗传改良提出一些有益的建议.     

胶原纤维的性能特点和作用

1胶原纤维巴西Novaprom胶原纤维是以精选的牛皮内剖层(真皮)组织提取的,它不同于明胶或明胶的衍生物。它的生产是在严格控制的时间和温度范围内进行的,从而确保其主要成分──胶原蛋白的活性不变,并以天然纤维的形式存在。它在肉制品中的结构呈纤维状而不是一般的胶冻,因而这种结构是非常稳定的,是不可逆的。它是很好的功能性动物纤维蛋白,在肉制品及鱼糜制品等相关的食品中得到广泛的应用。2胶原纤维的性能及相关指标(1)蛋白质含量:胶原纤维中的动物蛋白质(M×6.25)高达98%,含有人体必需的氨基酸。(2)吸水、持水性:胶原纤维结构良好,呈矩…     

鲜为人知的科学珍闻

有言在先,珍闻的挑选奉行以下原则:科学应该是有趣的,科学之所以好玩,部分原因在于你了解、知道这些奇谈怪论的存在。科学的伟大之处在于,它不必是教条的、有价值的实验,也不要求对所有理论进行最准确的过滤以得     

玻璃纤维拉丝池窑配合料设备研制的进展

玻璃纤维池窑拉丝生产线配合料的制备中,原料是形成优质玻璃液的基础,因此可以说配合料的稳定性、均匀性和准确性对玻璃纤维的质量起着决定的作用.生产实践证明:组分和粒度均匀的配合料,不但能强化玻璃液的熔化和澄清过程,而且还能减少或消除影响玻璃质量的各种弊病.所以认真拟定玻璃纤维原料的成分和选择玻璃纤维的种类和化学性质:严格控制进厂原料化学成分、粒度和水份;做好原料的分堆、存放、加工、称量、混合、输送是优质配合料制备不可缺少的手段,这也是做好玻璃纤维池窑配合料的基本任务.     

氢氧化镁阻燃剂的研究进展

主要论述了国内外阻燃剂的种类和发展,指出由于环境和健康的原因,无机阻燃剂是最有发展前途的,其中的氢氧化镁因其特有的性质,在无机阻燃剂中尤为突出.考虑到氢氧化镁的广泛应用的前景和其本身的缺点,对其改性成为业界的研究重点,其中主要介绍了钛酸酯、硬脂酸(盐)、镁盐晶须和胶囊化等技术,指出以后的发展方向是在改性基础上的协同作用.     

高浸透性大分子聚酯乳液的研制

1前言 随着池窑生产的发展,原有的浸润剂在快速浸润性和快速浸透性方面无法得到满足.意大利DSM公司聚酯乳液是公认的喷射纱浸润剂最好的成膜剂.本项目的目的是研制出能工业化生产的与DSM公司产品质量相当的聚酯乳液,替代进口,节约外汇,满足我国池窑发展需要,争创良好的经济社会效益.     

宁静——使艺术深华

宁静的山是心灵的绘画,宁静的水是灵魂的诗篇,宁静的夜是精神的书籍。在这越来越充斥着物欲纵横的社会,浮躁成了现代人的代名词,而保持一颗宁静的心,尤其在艺术创作中显得尤为重要。     

Enzymes-Assisted Extraction of Plants for Sustainable and Functional Applications

The scientific community and industrial companies have discovered significant enzyme applications to plant material. This rise imparts to changing consumers’ demands while searching for ‘clean label’ food products, boosting the immune system, uprising resistance to bacterial and fungal diseases, and climate change challenges. First, enzymes were used for enhancing production yield with mild and not hazardous applications. However, enzyme specificity, activity, plant origin and characteristics, ratio, and extraction conditions differ depending on the goal. As a result, researchers have gained interest in enzymes’ ability to cleave specific bonds of macroelements and release bioactive compounds by enhancing value and creating novel derivatives in plant extracts. The extract is enriched with reducing sugars, phenolic content, and peptides by disrupting lignocellulose and releasing compounds from the cell wall and cytosolic. Nonetheless, depolymerizing carbohydrates and using specific enzymes form and release various saccharides lengths. The latest studies show that oligosaccharides released and formed by enzymes have a high potential to be slowly digestible starches (SDS) and possibly be labeled as prebiotics. Additionally, they excel in new technological, organoleptic, and physicochemical properties. Released novel derivatives and phenolic compounds have a significant role in human and animal health and gut-microbiota interactions, affecting many metabolic pathways. The latest studies have contributed to enzyme-modified extracts and products used for functional, fermented products development and sustainable processes: in particular, nanocellulose, nanocrystals, nanoparticles green synthesis with drug delivery, wound healing, and antimicrobial properties. Even so, enzymes’ incorporation into processes has limitations and is regulated by national and international levels.     

中低温煤焦油蒸馏过程中金属元素的迁移规律

以中低温煤焦油轻油和重油为实验原料,采用常压蒸馏获得170~200℃、200~240℃、240~270℃、270~300℃、300~320℃、320~340℃、340~360℃和360~390℃煤焦油馏分油;利用配有油品加氧制冷进样系统的ICP-OES测定了21种微量元素在馏分油中的含量,考察了不同馏分油中元素的分布情况。研究表明：在原煤焦油中,未发现Ag、Mg、Mo、Na、Ni、Fe、Mn、Cr及Ti元素,含量较高的元素有Sn、P、Al、Pb、Si,其中Sn元素在轻油和重油中的含量分别为11.78μg/g和14.04μg/g;在所有馏分油中,未发现Al、Mo、Fe、Mn、Cr及Ti元素,含量比较高的元素有Si、Sn、Na、Zn、Pb,特别是Si、Na、Sn、Zn、Ni、Pb及B元素可以有效富集于馏分油中。可能的原因是Ca、Fe、Mg、Al等金属以不同的盐类形态存在,在煤焦油脱水及<170℃蒸馏过程中,这些金属盐类会被部分带出,导致其在馏分油中的含量未富集或未检出;通过关联金属元素在馏分油中的分布与其组成的关系,馏分油中元素的分布可能与酚类化合物、杂环化合物和蒸馏温度等相关。酚类化合物及杂环化合物可能与Ag、B、Cu、Mo、Sn、Na、Zn、Ca、Pb等金属形成络合物或卟啉配合物,蒸馏温度一方面可以破坏Sn、Cd、Pb、Zn、Cu、Ca、Pb等元素在馏分油中的结合力,另一方面也可以促进这些元素与馏分油中的含氧、含氮等化合物更好地发生化合反应,进而影响金属元素在馏分油中的含量分布。     

Mechanisms Governing Anaphylaxis: Inflammatory Cells,Mediators, Endothelial Gap Junctions and Beyond

Anaphylaxis is a severe, acute, life-threatening multisystem allergic reaction resulting from the release of a plethora of mediators from mast cells culminating in serious respiratory, cardiovascular and mucocutaneous manifestations that can be fatal. Medications, foods, latex, exercise, hormones (progesterone), and clonal mast cell disorders may be responsible. More recently, novel syndromes such as delayed reactions to red meat and hereditary alpha tryptasemia have been described. Anaphylaxis manifests as sudden onset urticaria, pruritus, flushing, erythema, angioedema (lips, tongue, airways, periphery), myocardial dysfunction (hypovolemia, distributive or mixed shock and arrhythmias), rhinitis, wheezing and stridor. Vomiting, diarrhea, scrotal edema, uterine cramps, vaginal bleeding, urinary incontinence, dizziness, seizures, confusion, and syncope may occur. The traditional (or classical) pathway is mediated via T cells, Th2 cytokines (such as IL-4 and 5), B cell production of IgE and subsequent crosslinking of the high affinity IgE receptor (FcεRI) on mast cells and basophils by IgE-antigen complexes, culminating in mast cell and basophil degranulation. Degranulation results in the release of preformed mediators (histamine, heparin, tryptase, chymase, carboxypeptidase, cathepsin G and tumor necrosis factor alpha (TNF-α), and of de novo synthesized ones such as lipid mediators (cysteinyl leukotrienes), platelet activating factor (PAF), cytokines and growth factors such as vascular endothelial growth factor (VEGF). Of these, histamine, tryptase, cathepsin G, TNF-α, LTC₄, PAF and VEGF can increase vascular permeability. Recent data suggest that mast cell-derived histamine and PAF can activate nitric oxide production from endothelium and set into motion a signaling cascade that leads to dilatation of blood vessels and dysfunction of the endothelial barrier. The latter, characterized by the opening of adherens junctions, leads to increased capillary permeability and fluid extravasation. These changes contribute to airway edema, hypovolemia, and distributive shock, with potentially fatal consequences. In this review, besides mechanisms (endotypes) underlying IgE-mediated anaphylaxis, we also provide a brief overview of IgG-, complement-, contact system-, cytokine- and mast cell-mediated reactions that can result in phenotypes resembling IgE-mediated anaphylaxis. Such classifications can lead the way to precision medicine approaches to the management of this complex disease.     

Recent advances in synthesis, physical properties and applications of conducting polymer nanotubes and nanofibers

This article summarizes and reviews the various preparation methods, physical properties, and potential applications of one-dimensional nanostructures of conjugated polyaniline (PANI), polypyrrole (PPY) and poly(3,4-ethylenedioxythiophene) (PEDOT). The synthesis approaches include hard physical template method, soft chemical template method, electrospinning, and lithography techniques. Particularly, the electronic transport (e.g., electrical conductivity, current-voltage (I-V) characteristics, magnetoresistance, and nanocontact resistance) and mechanical properties of individual nanowires/tubes, and specific heat capacity, magnetic susceptibility, and optical properties of the polymer nanostructures are presented with emphasis on size-dependent behaviors. Several potential applications and corresponding challenges of these nanofibers and nanotubes in chemical, optical and bio-sensors, nano-diodes, field effect transistors, field emission and electrochromic displays, super-capacitors and energy storage, actuators, drug delivery, neural interfaces, and protein purification are also discussed.     

松香基表面活性剂研究进展

松香是一类产量丰富、价格低廉的可再生林产资源,被广泛地应用于食品、农业、橡胶、油墨、涂料等领域。松香的三环二萜结构具有超强的疏水性,通过催化异构、Diels-Alder加成等手段引入亲水基团可制备高附加值、易生物降解的绿色表面活性剂。本文从阴离子、阳离子、非离子和两性离子表面活性剂4个大类对松香基表面活性剂应用的文献及专利进行综述,重点分析了羧酸盐、磺酸盐、硫酸盐和磷酸盐4种阴离子型表面活性剂和季铵盐阳离子型表面活性剂,多元醇型和聚氧乙烯型非离子表面活性剂,以及甜菜碱型和氧化胺型两性离子表面活性剂。剖析松香基表面活性剂产业化开发的新技术及新产品概况,提出松香基表面活性剂替代传统表面活性剂的潜在应用领域。同时,对松香基表面活性剂的研究发展与产业化发展进行了评价与展望。     

High-Performance Polymers for Separation and Purification Processes: An Overview

Separation and purification techniques are applied in many important fields, such as in the medical, chemical, metallurgical, environmental, and pharmaceutical industries. Recent advances in separation science and the urgent need for highly selective purification have necessitated a rapid progress with respect to the reagents, chemicals, and surfactants used in separation processes to attain a high efficiency and selectivity. Polymeric materials have attracted considerable interest, and they have been widely used as extractants, catalysts, and modifiers, in separation and purification processes. This review outlines the recent advances in the use of novel polymers, natural and synthetic, in different separation and purification techniques. Various separation techniques such as chromatography, crystallization, precipitation, distillation, electrophoresis, filtration, and mineral processing methods are discussed, and the polymers used in each method are described in terms of their properties, structure, and function. The application of polymers shows great promise in achieving a highly efficient separation, especially in the areas of membrane separation and water purification. The rational design of new multifunctional polymers with triggered functions presumably presents new opportunities for the development of advanced separation methods.     

Petrography and geochemistry of the Middle Devonian coal from Luquan, Yunnan Province, China

Coals from Luquan, Yunnan Province, China, have high contents of cutinite and microsporinite, with an average of 55 and 33.5 vol%, respectively, (on a mineral-free basis). The coals are classified as cutinitic liptobiolith, sporinite-rich durain, cutinite-rich durain, and sporinitic liptobiolith. These four liptinite-rich coals are often interlayered within the coal bed section and vary transversely within the coal bed. The vitrinite content varies from as low as 1.6-20.5% (mineral-free basis), and it is dominated by collodetrinite, collotelinite, and corpogelinite. The maceral composition may be attributed to the type of the peat-forming plant communities. Moreover, the Luquan coals are characterized by high contents of volatile matter, hydrogen, and oxygen, and the high values of the atomic hydrogen to carbon ratio as a result of the maceral composition. As compared with the common Chinese coals and the upper continental crust, the Luquan coals are enriched in Li, B, Cu, Ga, Se, Rb, Mo, Ba, Pb, Bi, and U, with averages of 99.9, 250, 111, 24.4, 4.55, 130, 58.8, 1276, 162, 3.85, and 34.1 μg/g, respectively. The SEM-EDX results show that V, Cr, Ga, and Rb occur mainly in clay minerals, and Cu and Pb are associated with clay minerals and pyrite, and Mo and U are mainly in clay minerals and organic matter. Barite and clay minerals are the main carrier of barium. The high B and U contents are probably resulted from deep seawater influence during coal formation.     

Perspectives on additives for polymers. 1. Aspects of stabilization

Since the earliest discovery and subsequent developments in the world of polymers associated problems and increasing applications have resulted in the rapidly expanding field of “additives.” In this context, the term additive is very generalized in that it encompasses many facets associated with ever growing needs. Of the most important are antioxidants (primary and secondary), light stabilizers, processing aids, metal deactivators, flame retardants, biocides, nucleating agents, antistatic compounds, fillers, dyes, pigments (nano, micro, and macro) to name but only a few each serving a particular function and not necessarily all at the same time in the one package. This article presents a general perspective on the type, mode of action, properties, uses, and problems (and circumvention) based on some of the more important key additives. The properties and behavior of many additives in this regard relates very much to the initial incorporation and formulation and in turn is often a major controlling factor in end use performance from a physical, esthetic, structural, mechanical, and chemical point of view. Indeed, with many polymers like PVC, for example, one enters a highly complex world of interactions which can in many cases destroy or even enhance the activity of functional processing additives. Some of these will be highlighted and hopefully the aim being here to enthuse the polymer and additive manufacturers and technologists in the processing laboratories to become more aware of potential issues and problems.     

Laccases and Tyrosinases in Organic Synthesis

Laccases (Lac) and tyrosinases (TYR) are mild oxidants with a great potential in research and industry. In this work, we review recent advances in their use in organic synthesis. We summarize recent examples of Lac-catalyzed oxidation, homocoupling and heterocoupling, and TYR-catalyzed ortho-hydroxylation of phenols. We highlight the combination of Lac and TYR with other enzymes or chemical catalysts. We also point out the biological and pharmaceutical potential of the products, such as dimers of piceid, lignols, isorhamnetin, rutin, caffeic acid, 4-hydroxychalcones, thiols, hybrid antibiotics, benzimidazoles, benzothiazoles, pyrimidine derivatives, hydroxytyrosols, alkylcatechols, halocatechols, or dihydrocaffeoyl esters, etc. These products include radical scavengers; antibacterial, antiviral, and antitumor compounds; and building blocks for bioactive compounds and drugs. We summarize the available enzyme sources and discuss the scalability of their use in organic synthesis. In conclusion, we assume that the intensive use of laccases and tyrosinases in organic synthesis will yield new bioactive compounds and, in the long-term, reduce the environmental impact of industrial organic chemistry.