生物炭的环境效应及其应用的研究进展

作为新型环境功能材料,生物炭以其优良的环境效应和生态效应成为环境科学等学科研究的前沿热点.本文介绍了生物炭结构和基本特性,对其在土壤肥力改良、碳的增汇减排以及受污染环境修复的应用和机理方面的研究进展进行了综述,并扼要分析了生物炭研究的前景和方向,为生物炭技术的应用和推广提供一定的思路.     

植物排放的羰基化合物及其与大气的交换

综述了植物来源的羰基化合物的研究结果,并着重总结了植物与大气之间羰基化合物的交换研究.羰基化合物在植物与大气之间的交换包括植物本身排放羰基化合物、羰基化合物沉降到植物叶片以及植物对羰基化合物的吸收和代谢3个过程.在植物周围空气中羰基化合物的浓度与交换补偿点的关系决定交换的方向:羰基化合物是被植物排放到大气中,还是沉降到植物叶面.当其在空气中的浓度低于补偿点时,植物排放羰基化合物;而当其在空气中的浓度高于补偿点时,羰基化合物沉降到植物叶面.作者还提出,与人类生活密切相关的景观植物的排放应受到格外的重视.利用植物代谢有害污染物的能力来净化空气,是植物修复技术在大气污染环境中的应用.筛选吸收、代谢污染物强的植物种类,科学搭配种类组成,建立不同类型的人工植物群落,以实现最佳植物净化效果.将环境科学与生态学、遗传学等多学科结合起来,探索更为理想的植物修复方法是未来的主要研究方向.     

金钟藤的年轮生长量与气候因子的相互关系

分析了金钟藤(Merremiaboisiana(Gagn.)vanOoststr.)的年轮特征,并探讨了它与温度等气候因子的关系。金钟藤的年轮极不规则,有许多自然隆起和裂缝。金钟藤的年轮生长量通过格子法来估算。结果表明金钟藤年轮的年平均生长量与温度呈极显著正相关,与降水、日照时数和相对湿度相关性不显著。罗浮山地区降水和日照时数基本能够满足金钟藤的生长,结合相关研究结果推测:温度可能是金钟藤快速生长的主要驱动因子。     

有机物质的沸点与其结构的关系

本文总结了影响有机化合物沸点的主要因素, 详细地概括了沸点与有机物质结构的关系.尤其是在此基础上找到一种估算沸点的方法,并给出了估算式:Tb=Km·e(W/M). 利用该式,可以更准确地计算出许多有机物质的沸点.     

基于低碳经济的能源资源协调发展的研究

能源是经济发展的命脉。经济和能源的协调发展是社会发展的原动力。经济发展离开能源的基础,那将是无源之水,无本之木。所以,经济和能源应该协调发展,社会才能稳步前进。发展低碳经济是利用先进的技术和有效的管理方法与手段,保护资源,保护环境,实现社会和经济的可持续化发展的必由之路;是我国经济发展方式转型,产业结构调整过程中必须完成的紧迫任务之一。世界产业结构的变动,必然影响到开放度不断加大的我国,正是在这样的背景下,我国的煤炭及其他矿产品的出口不断增长。在我国融人经济全球化的过程中,要注意在接受国际产业结构调整对我国经济发展有利影响的同时,要用低碳经济的发展战略模式,避免消极影响危及我国经济的长期、根本利益。应该在这个大前提下,对我国自然资源进行有计划的开发和提高自然资源的有效利用。实现可持续发展已经成为中国社会经济发展的一个重要基本方针,可持续发展不仅要强调对环境的保护,而且应包括如何解决在人口已经高度密集,人均资源相对匮乏,自然生态环境已经十分脆弱的条件下,如何实现经济的长期高速发展,同时又要保护环境的这样一个史无前例的社会实践问题。低碳经济和能源资源的协调发展就成了解决这一问题的必经之路。能源既是重要的必不可少的经济发展和社会生活的物质前提,又是现实的重要污染来源,解决好我国的能源可持续发展战略问题,是实现我国社会经济可持续发展的重要环节。     

多媒体教学的利与弊

多媒体教学,就是利用计算机技术对文、图、声、像等多种信息进行综合处理和控制,从而形成一种全新的教学形式．运用多媒体课件辅助教学,能创设逼真的教学环境,动静结合的教学图像,生动活泼的教学氛围,可以解决常规教学难以解决的问题．但是多媒体技术在教学中并不是万能的,不要过于依赖多媒体课件,一定要正确认识到多媒体技术在教学中的辅助性的作用．参3．     

细胞膜结合的雌激素受体的特异性标记

细胞膜结合的雌激素受体(Cell membrane-bound estrogen receptor,cmER)介导了雌激素的非基因组作用,参与了乳腺癌等诸多疾病的发生,但是作用机制研究受限于能够有效区分cmER和细胞质内ER(Estrogen receptor)的标记手段.为了实现cmER的特异性标记,首先在体外分别表达含有A1、S6和ybbR三个不同短肽的谷胱甘肽S转移酶融合蛋白,比较磷酸泛酰巯基乙胺基转移酶(Phosphopantetheinyl transferase,PPTase)-AcpS和Sfp对其的识别选择性.选取识别效率较高和特异性较好的A1短肽,将其构建到雌激素受体ERα的C端(ERα-A1),结果表明该偶联并不影响ERα的蛋白质表达及其在雌激素作用下的转录.进一步研究表明,来源于大肠杆菌的PPTase-AcpS可以以辅酶A-生物素(Coenzyme A-biotin)为底物,将生物素特异性标记到ERα-A1.这些结果为进一步研究雌激素及cmER介导的非基因组调控机制提供了新的方法.     

基于jQuery框架的AJAX网站设计模式的研究

从AJAX技术出发,对实现AJAX技术常用框架ASP.NET AJAX、Dojo、DWR、Prototype、jQuery、YahooUser Interface进行讨论,重点介绍了其中较为优秀的jQuery框架,并用具体实例证明jQuery可以非常方便快捷的开发网站,并将WEB设计由原来的三层变为四层,即页面设计、前台逻辑设计、业务逻辑设计和数据库设计,它们之间相对独立,网站设计结构清晰、维护容易.图1,表1,参6.     

人工纳米材料的生物效应及其对生态环境的影响

人工纳米材料由于具有独特的物理化学性质而得到广泛的应用,其对人体健康及环境的潜在影响也已引起科学界及政府部门的关注.通过总结近年来的相关研究资料,分类归纳了目前国内外对一些常见的人工纳米材料如富勒烯、碳纳米管、量子点、二氧化钛、纳米铁材料及纳米铝材料的生物和生态效应研究,详细总结了纳米材料毒理学的研究对象、研究方法以及最新研究成果,同时分析了各种纳米材料生物毒性的可能机制,最后对纳米材料安全性今后的研究方向进行了展望.     

源于大气的氟在水稻不同器官的分布及对糙米含氟量的影响

用开顶式熏气罩熏气的方法,研究了气源氟在水稻不同器官的分布及对糙米含氟量的影响。结果表明:气源氟主要分布于水稻叶片中,根含氟量不受气源氟的影响;籽粒含氟量取决于籽粒器官形成后空气氟浓度,与籽粒器官形成前的空气氟浓度无关;糙米氟含量与水稻抽穗齐穗后所暴露的氟剂量间呈极显著线性相关关系。     

Applications of chitosan in food,pharmaceuticals, medicine,cosmetics, agriculture,textiles, pulp and paper,biotechnology, and environmental chemistry

Environmental Chemistry Letters - Chitosan is a biopolymer obtained from chitin, one of the most abundant and renewable materials on Earth. Chitin is a primary component of cell walls in fungi, the...     

Seaweed for climate mitigation,wastewater treatment,bioenergy, bioplastic,biochar, food,pharmaceuticals, and cosmetics: a review

The development and recycling of biomass production can partly solve issues of energy, climate change, population growth, food and feed shortages, and environmental pollution. For instance, the use of seaweeds as feedstocks can reduce our reliance on fossil fuel resources, ensure the synthesis of cost-effective and eco-friendly products and biofuels, and develop sustainable biorefinery processes. Nonetheless, seaweeds use in several biorefineries is still in the infancy stage compared to terrestrial plants-based lignocellulosic biomass. Therefore, here we review seaweed biorefineries with focus on seaweed production, economical benefits, and seaweed use as feedstock for anaerobic digestion, biochar, bioplastics, crop health, food, livestock feed, pharmaceuticals and cosmetics. Globally, seaweeds could sequester between 61 and 268 megatonnes of carbon per year, with an average of 173 megatonnes. Nearly 90% of carbon is sequestered by exporting biomass to deep water, while the remaining 10% is buried in coastal sediments. 500 gigatonnes of seaweeds could replace nearly 40% of the current soy protein production. Seaweeds contain valuable bioactive molecules that could be applied as antimicrobial, antioxidant, antiviral, antifungal, anticancer, contraceptive, anti-inflammatory, anti-coagulants, and in other cosmetics and skincare products.

     

Lead,cadmium, copper,zinc, iron,and calcium in human hair as a function of gender,age, smoking,and hair dyeing

Hair samples were collected randomly from 110 subjects (55 male and 55 female) ranging in age from (<15–60) years. Each subject was asked to complete a personal questionnaire describing his/her sex, age, general health, smoking, use of hair dyes, occupational area, and living habits. Concentrations of Pb, Cd, Cu, Zn, Fe, and Ca in human hair samples were evaluated using atomic absorption spectrometry. Results indicated that concentrations of Pb, Cd, Cu, and Zn in the hair of smokers were higher than those in the hair of non-smokers, whereas, Fe and Ca concentrations in hair of smokers were lower than those in hair of non-smokers. Moreover, the concentrations of these elements are higher in dyed hair compared with undyed hair.     

Metal passivity as mechanism of metal carcinogenesis: Chromium,nickel, iron,copper, cobalt,platinum, molybdenum

For the transition metals chromium, nickel, iron, copper, cobalt, platinum, and molybdenum, mechanisms of stable bonding in biochemistry (emphasis on carcinogenic mechanisms), chemistry, industrial chemistry, as well as epidemiological, occupational, orthopedic (implant devices) effects related to carcinogenesis, were reviewed. Hypothetically, the propensity to stable bonding (inertness), which ensures the metals’ performance capacity for consumers and industrial application, relates to their carcinogenicity. For chromium, a relationship between industrial/chemical and biological reactivity was noted for the tendency of Cr(III) ions to cause hydrolysis previous to stable bonding, as occurs during anodic passivation, leather tanning, and as indicated in biochemical studies pertaining to a mechanism of DNA condensation, which was suggested as a carcinogenic mechanism. The involvement of metal hydrolysis in both anodic passivation and biochemistry was noted also for nickel, iron, and platinum; the DNA interaction of platinum (cis-platin) is known to depend on hydrolysis. For nickel, issues of potential (V) were found important in both passivation and carcinogenicity. Comparably, the passivity behavior of cobalt and copper was found atypical, and their carcinogenicity yet unclear. Molybdenum, contained in passivated metallic implants, may relate to implant-associated carcinogenesis. Occupational carcinogenic effects were indicated for chromium, nickel, iron, and cobalt as caused by both reactive and passivated metal species. Exposure to acids and chronic respiratory irritation/infection/inflammation in workers were important cofactors in metal carcinogenesis. For wood and leather workers exposed to dust, the assumed presence in dust of metal particles abraded from alloys (sawing or cutting blades) may be a carcinogenic exposure hazard.     

Concentrations of V,Cr, Mn,Fe, Ni,Co, Cu,Zn, As and Cd in mesopelagic crustaceans from the North East Atlantic Ocean

Specimens of oceanic decapods, mysids and euphausiids, collected from the North East Atlantic Ocean during July 1985, were analysed for V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As and Cd. Measurement of the metals was carried out using two techniques: inductively-coupled plasma-source mass spectrometry (ICP-MS) and atomic absorption (AAS). With the exception of the iron data, good agreement was observed between the data from the two techniques. Baseline-metal data are presented for the species measured, along with any effects of animal size on metal concentration. The data presented for oceanic animals from different trophic levels are important in studies of metal fluxes and for the assessment of markers within the food web in the oceans.