空分设备运行中的危险因素及其防范措施

介绍了空分设备运行中主要危险因素的危害和来源。根据危险因素存在空分设备中位置的不同,分为设备外部和设备内部危险因素,而设备内部危险因素按爆炸性质的不同分为化学性爆炸和物理性爆炸危险因素,化学性爆炸危险因素按爆炸条件分为可燃物、助燃物和引爆源危险因素,并结合实际情况提出相应的预防措施及相关建议。     

水的化学污染

正水体因某种物质的介入而导致其化学、物理、生物及放射性等方面的特性改变,从而影响水的有效利用,危害人类健康,破坏生态平衡,造成水质恶化的现象称为水污染。水污染按性质可以划分为化学性、物理性和生物性污染三大类。物理性污染是由于向水体排放污染物造成的,     

实验室的水污染及治理

实验室产生的废水主要有物理性、化学性、生物性、放射性废水,可采取物理法、化学法、生物法进行处理。     

实验室的水污染及治理

实验室产生的废水主要有物理性、化学性、生物性、放射性废水,可采取物理法、化学法、生物法进行处理。     

拟除虫菊酯农药的降解研究

拟除虫菊酯类农药具有用量低、药效好、杀虫谱广等优点,近年来被人们广泛应用在农林害虫、家用卫生、畜禽养殖、粮食储存等领域,由此产生的农药残留问题逐渐显现。综述了影响此类农药降解转化的因素,主要包括物理性吸附、化学性降解、生物降解以及其他因素(铜离子、氮元素、重金属、秸秆堆肥和人工湿地等),并对拟除虫菊酯降解方法进行了展望。     

NHD脱硫溶液的污染问题及处理措施

从物理性污染和化学性污染两方面分析了NHD脱硫溶液污染的原因;指出了溶液污染对系统长周期运行所造成的多种影响;对比了沉降法、过滤法、精制法处理溶液污染的效果;提出了预防溶液污染的建议和措施。     

各种水污染指标之意义及影响

表示水污染程度之水质指标，依性质大致可分为物理性、化学性及生物性三类，分别释述如下：     

发质损伤的基础研究对发用类产品发展趋势的影响

城市环境的污染、紫外线辐射、烫发剂、漂白剂以及头发的整理(洗发、吹风和梳理)等均会造成头发不同程度的损伤。头发损伤的基础研究就是研究不同物理和化学因素对头发造成损伤的作用机理、了解头发损伤与头发结构与组分的相互关系 ,并从保护头发免受损伤的角度出发探讨发用类产品的发展趋势。     

沸腾炉为什么会爆炸

据了解,自五十年代中期我国开始应用沸腾炉以来,直至1981年底为止,大、小型硫酸厂中都曾发生过沸腾炉爆炸事故,有时甚至造成人身伤亡。现根据某些实例,对爆炸事故进行分析。爆炸是物质在一定条件下,在瞬间以机械功的形式放出大量能量的现象。根据引起爆炸的物质变化的性质,可分为物理性爆炸和化学性爆炸两类。就沸腾炉的爆炸事例来看,有些是属于物理性爆炸,有些则属于化学性爆炸,今分述如下。     

植物“精油”的护发功效解析

植物"精油"相对于矿物油、硅油,在防御物理损伤、改善头发强韧性、维护头发健康光泽等方面具有更明显的优势。本文从发干护理和头皮护理两方面,解析了植物"精油"护发功效的机理。     

Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.     

Molecular Hydrogen as a Potential Clinically Applicable Radioprotective Agent

Although ionizing radiation (radiation) is commonly used for medical diagnosis and cancer treatment, radiation-induced damages cannot be avoided. Such damages can be classified into direct and indirect damages, caused by the direct absorption of radiation energy into DNA and by free radicals, such as hydroxyl radicals (•OH), generated in the process of water radiolysis. More specifically, radiation damage concerns not only direct damages to DNA, but also secondary damages to non-DNA targets, because low-dose radiation damage is mainly caused by these indirect effects. Molecular hydrogen (H₂) has the potential to be a radioprotective agent because it can selectively scavenge •OH, a reactive oxygen species with strong oxidizing power. Animal experiments and clinical trials have reported that H₂ exhibits a highly safe radioprotective effect. This paper reviews previously reported radioprotective effects of H₂ and discusses the mechanisms of H₂, not only as an antioxidant, but also in intracellular responses including anti-inflammation, anti-apoptosis, and the regulation of gene expression. In doing so, we demonstrate the prospects of H₂ as a novel and clinically applicable radioprotective agent.     

不锈钢水冷器应力腐蚀开裂原因的再探讨

通过对引进的13套大化肥装置中不锈钢水冷器设备损坏的情况分析,指出了不锈钢水冷器的损坏与设备制造过程中的残存应力,运行时的热应力,水冷器中水的走向,换热管的壁温,循环冷却水中氯离子的含量均有关系,氯离子并不是水冷器应力腐蚀的决定因素.     

加氢精制反应器的腐蚀与防护

由于加氢精制装置操作条件的特殊性,加氢精制反应器有可能出现一些如氢脆、氢腐蚀、不锈钢堆焊层的剥离等特殊的损伤现象。为避免这些破坏性损伤的产生,加氢精制反应器必须要有正确的设计与选材,并且合理使用,从而保证设备的使用安全。     

DAMAGE OF FABA BEAN SEEDS DURING DRYING

Experiments have been carried out to determine a relation between mechanical properties, microstructure and drying conditions of faba bean seeds and their damages during single-stage drying. Results showed that physical damages of beans strongly depend on drying parameters, i.e.drying time and temperature, air flow rate and variety of seeds. It was revealed that some seed parts: the hilum and embryonal axis play a special role in the cracking mechanism of seeds.     

DAMAGE OF FABA BEAN SEEDS DURING DRYING

ABSTRACT

Experiments have been carried out to determine a relation between mechanical properties, microstructure and drying conditions of faba bean seeds and their damages during single-stage drying. Results showed that physical damages of beans strongly depend on drying parameters, i.e.drying time and temperature, air flow rate and variety of seeds. It was revealed that some seed parts: the hilum and embryonal axis play a special role in the cracking mechanism of seeds.     

HMX基PBX的温度环境适应性

对HMX基PBX进行了-40～+75℃温度循环试验和温度冲击试验,采用超声波参量检测方法对炸药的内部损伤进行了分析和表征。并对环境试验前后炸药的力学性能和破坏方式进行了实验研究。结果表明,温度循环试验和温度冲击试验将导致HMX基PBX产生热损伤,使HMX基PBX压缩强度轻微下降,而对拉伸强度影响不大。     

Increased Circulatory Asymmetric Dimethylarginine and Multiple Organ Failure: Bile Duct Ligation in Rat as a Model

Bile duct ligation (BDL)-treated rats exhibit cholestasis, increased systemic oxidative stress, and liver fibrosis, which ultimately lead to liver cirrhosis. Asymmetric dimethylarginine (ADMA) is a competitive inhibitor of nitric oxide synthase that can decrease the synthesis of nitric oxide. BDL rats have higher plasma and hepatic ADMA levels, which may be due to increased hepatic protein arginine methyltransferase-1 and decreased dimethylarginine dimethylaminohydrolase expression. BDL rats also exhibit renal and brain damage characterized by increased tissue ADMA concentrations. The increased plasma ADMA levels and multiple organ damages seen here are also observed following multiple organ failures associated with critical illness. This review discusses the dysregulation of ADMA in major organs in BDL rats and the role of increased ADMA in multiple organ damages.     

治理南平市水葫芦污染对策探讨

介绍南平市受外来入侵物种“水葫芦”破坏的水环境现状，分析造成危害的成因，指出水葫芦对生态、社会和人类生活带来的危害。提出了治理水葫芦的措施，以及综合防治水葫芦的对策和建议．     

Evaluation of galvanic corrosion of a Zn alloy in alcohol fuel

Galvanic corrosion of zamak was evaluated in alcohol fuel and in some alcoholic solutions that contained ionic impurities. Also, the effect of corrosive process on the quality parameters of ethanol was investigated. The results showed that corrosion of zamak mainly occurred in solutions with high levels of water and impurities. After the assays, the increasing of both pH and conductivity of the alcohols was observed. Therefore, the results showed that the contact between zamak and some materials must be avoided and the quality control of alcohol fuel must be assured as a way of avoiding damages on engines and storage-transportation fuels systems.