Experimental research on electric insulator damaged by chemical pollutant

As a main insulating device of power system, insulator can be damaged by chemical pollutant, which does threaten the electric system. An artificial pollution test system is utilized to study the damage mode for a suspension insulator, and the effects of concentration and existing state on damage efficiency of chemical pollutant are studied. Testing results show that the damage mode is flashover damage, whose efficiency increases with the decrease of creepage distance. The concentration of conductive particle of chemical pollution can effectively elevate damage efficiency, though it has a critical value. Unlike natural pollution, chemical pollutant can make insulator flashover damage whether in wet or dry condition. The damage process and relative results reveal the damage rule of insulator by chemical pollutant. Those studies put forward a new means to damage electric insulated device, and provide important reference to the protection design of electric insulator.

Protection of Environment from Damaged Nuclear Station and Transparent Inflatable Blanket for Cities—Protection from Radioactive Dust and Chemical, Biological Weapons

The author, in a series of previous articles, designed the “AB Dome” made of transparent thin film supported by a small additional air overpressure for the purpose of covering a city or other important large installations or sub-regions. In present article the author offers a variation in which a damaged nuclear station can be quickly covered by such a cheap inflatable dome. By containing the radioactive dust from the damaged nuclear station, the danger zone is reduced to about 2 km2 rather than large regions which requires the resettlement of huge masses of people and which stops indus-try in large areas. If there is a big city (as Tokyo) near the nuclear disaster or there is already a dangerous amount of radioactive dust near a city, the city may also be covered by a large inflatable transparent Dome. The building of a gi-gantic inflatable AB Dome over an empty flat surface is not difficult. The cover is spread on a flat surface and a venti-lator (fan system) pumps air under the film cover and lifts the new dome into place but inflation takes many hours. However, to cover a city, garden, forest or other obstacle course in contrast to an empty, mowed field, the thin film cannot be easily deployed over building or trees without risking damage to it by snagging and other complications. This article proposes a new method which solves this problem. The design is a double film blanket filled by light gas such as, methane, hydrogen, or helium - although of these, methane will be the most practical and least likely to leak. Sections of this AB Blanket are lighter than air and will rise in the atmosphere. They can be made on a flat area serving as an as-sembly area and delivered by dirigible or helicopter to station at altitude over the city. Here they connect to the already assembled AB Blanket subassemblies, cover the city in an AB Dome and protect it from bad weather, chemical, bio-logical and radioactive fallout or particulates. After assembly of the dome is completed, the light gas can be replaced by (heavier but cheaper) air. Two projects for Tokyo (Japan) and Moscow (Russia) are used in this paper for sample computation.

Oxidative DNA damages by chemical exposures at work

Oxidative DNA damage is an inevitable consequence of cellular metabolism, with a propensity for increased levels following toxic insult. Of the molecules subject to oxidative modification, DNA has received the greatest attention, with biomarkers of exposure and effect closest to validation. There are many chemicals in workplaces that could cause oxidative DNA damages such as carcinogens. This review concentrated on studies published between the years 2000 and 2012 that used to detect 8-oxodG in humans (workers), laboratory animals and in cell lines. Given the recent toxicological results from oxidative stress, it is important to review these studies to improve the current understanding of the oxidative DNA damages by chemical exposures at work. It also suggests that biomarkers may be responsible for understanding the role of oxidative DNA damage in disease, highlighting the need for further studies.

Microscopic model for chemical etchability along radiation damage paths in solids

It would be very interesting to develop a picture about removal of atoms from the radiation damaged paths or latent nuclear tracks and undamaged bulk material in track detectors. Here, theory of chemical etching is described briefly and a new model for chemical etching along radiation damaged paths in solids is developed based on basic scientific facts and valid assumptions. Dependence of chemical etching on radiation damage intensity and etching conditions is discussed. A new parameter for etching along radiation damaged paths is introduced, which is useful for investigation of relationship between chemical etchability and radiation damage in a solid. Results and discussion presented here are also useful for further development of nuclear waste immobilization.

Numerical Simulation of Thermo-Hydro-Mechanical-Chemical Response Caused by CO_(2)Injection into Saline Geological Formations:A Case Study from the Ordos Project,China

Thermo-hydro-mechanical-chemical(THMC)interactions are prevalent during CO_(2)geological sequestration(CGS).In this study,a sequential coupling THMC numerical simulation program was constructed,which can be used to explore the following issues of CGS:fluid and heat flow,solute transport;stresses,displacements and rock failures related to geo-mechanical effects;equilibrium and kinetic chemical reactions;chemical damage to mechanical properties of the rock.Then,the coupling program was applied to the Ordos CGS Project to study the formation response under the multifield interaction caused by CO_(2)injection.The simulation results show that the mechanical process dominates the short CO_(2)injection period.Specifically,the formation’s permeability near the injection well increases by 43%,due to the reduction of effective stress,which significantly promotes the lateral migration of CO_(2).When the injection rate exceeds 0.15 million tons per year,the cohesion of the reservoir rock is not enough to resist the shear force inside the rock and rock failure may occur.During the subsequent long-term sequestration period(200 years),the influence of mineral reactions gradually increases.Due to calcite dissolution,the shear modulus of caprock is predicted to decrease by 7.6%,which will to some extent increase the risk of rock failure.

Analysis of Damaged Silicon Rubber Hose

Recently, there have been many reports of silicon rubber (SR) hoses becoming brittle in juice factory within one month of purchase. The damage is a new phenomenon, and its cause is unknown. We have collected the damaged hoses attached to UHT sterilizer (ultra-high-temperature) in juice factory and examined them for chemical changes. In addition, we have analyzed the hose-washing chemicals (NaOH and HNO333) and the exposure UTH temperature have direct effect on the brittleness of the silicon hose in juice factory.

高地应力-化学侵蚀耦合作用下炭质板岩蠕变试验及非线性蠕变损伤模型

为克服高程障碍并降低施工风险,可采用长大隧道穿越崇山峻岭,但这些隧道往往处于深埋高地应力环境,并受到化学侵蚀影响。为了解决此问题,以丽江—香格里拉炭质板岩大变形隧道为研究对象,采用室内试验和理论推导,研究深埋炭质板岩隧道受化学侵蚀作用下的围岩变形特性。在Poyting-Thomson体蠕变体的基础上,根据模型元件的力学特性,叠加了损伤元件、化学损伤元件和非线性元件,提出高地应力-化学侵蚀耦合作用下炭质板岩非线性蠕变损伤本构关系。研究结果表明:1)炭质板岩试样受化学侵蚀影响显著,侵蚀90 d试样所产生的轴向蠕变应变为侵蚀0 d试样的2.02倍,侵蚀60 d试样所产生的径向蠕变为侵蚀0 d试样的1.85倍;2)受侵蚀的炭质板岩试样在三轴压缩状态下破裂以斜向贯通裂隙为主,并产生一定的滑移错动裂隙,且沿轴线的拉伸劈裂破坏受围压作用抑制明显,未产生竖向贯通裂隙。

利用电化学和显色检测法分级评估316L不锈钢钝化膜完整性

针对核电和航天工程不锈钢设备服役在高温高盐海洋环境中钝化和损伤的质检评估,提出显色检测图像分析钝化膜完整性分级的方法。以不同钝化及其损伤状态的316L不锈钢为研究对象,通过显色检测的红色色度图像分析与电化学腐蚀行为检测,建立显色色度与耐蚀性的关系,并获得分级范围。结果表明,显色色度随钝化膜损伤程度增加而增大,随自钝化时间的延长而减小;二次局部损伤在直方图中具有双峰特征;色度百分比和面积百分比呈现双对数线性二阶段特征;动电位极化和阻抗表明,点蚀电位和界面反应阻抗随损伤程度的增加而减小;耐蚀性随显色色度的增加而下降;最终获得了316L不锈钢钝化膜完整性的三个色度等级范围。这可为不锈钢钝化膜质检分级评估提供理论基础。

基于矿物溶解理论的砂岩化学损伤动态模型

酸腐蚀环境下岩石物理力学性质的劣化本质上由岩石矿物的溶解引发的孔隙微裂隙的扩展贯通所致。为研究酸性环境下砂岩矿物的溶解特性,选择pH=1、3的盐酸溶液为腐蚀环境,借助X射线衍射试验鉴定砂岩矿物成分及含量,测试不同浸泡周期下溶液的pH值、阳离子浓度、岩样的质量及其纵波波速,并通过矿物溶解理论与化学动力学原理,建立反映整个腐蚀过程的砂岩化学损伤动态模型。研究结果表明:酸性环境下砂岩的损伤主要由长石和方解石的溶解所致,矿物溶解反应分为界面吸附、界面交换、解吸附三个步骤,且步骤最慢者对整个反应起控制作用。矿物溶解速率与H+浓度的n次幂成正比,且0<n≤1,其数值与矿物自身特性和溶液pH值有关。酸-岩反应具有较强的时间依赖性,其速率随腐蚀时间的延长逐渐减小而后趋于稳定,且溶液pH值越小,腐蚀时间越长,砂岩劣化越严重。pH=1、3的盐酸溶液作用下,通过化学损伤模型得到的砂岩孔隙度与通过纵波波速得到的孔隙度随腐蚀时间的变化规律具有较好的一致性,验证了模型的有效性与合理性。研究结果可为酸化学环境下岩体工程的安全性评估与灾害防治提供理论参考。

层状灰岩酸蚀化学-力学损伤演化机制研究

为研究酸性水对碳酸盐岩溶蚀-力学特性的影响,在固定时间、常温常压状态下,将不同倾角层理的灰岩岩样分别放在pH=3、4、5的酸液中进行固定流速溶蚀试验,并对溶蚀试验后的岩样进行单轴压缩、声发射(AE)及电镜扫描试验(SEM),获得岩样酸蚀前后质量、波速、Ca^(2+)/Mg^(2+)浓度、峰值强度、弹性模量、声发射振铃计数等指标的变化规律,分别采用溶蚀前后波速变化、声发射累积振铃计数表征岩样的化学溶蚀损伤和力学损伤,建立灰岩全变形过程的化学-力学损伤演化方程。试验结果表明,溶液酸性强度与岩样溶蚀率成正比,与宏观力学强度成反比,并且层理倾角对溶蚀的影响程度为90°>0°>45°。在酸性环境中,灰岩内部晶体被溶解,矿物联结减弱,从而引起宏观力学参数的改变,研究结果可以为废弃矿山岩体稳定评价提供参考。

化学侵蚀作用下花岗岩力学特性研究

为了研究化学侵蚀条件下花岗岩力学损伤特性,文章针对不同酸碱溶液侵蚀时间下集安地区花岗岩,开展了一系列单轴压缩试验。评价了化学侵蚀对花岗岩物理力学损伤机制与开裂失效的影响,并量化分析了化学侵蚀时间对力学参数的影响关系。研究发现:花岗岩抗压强度、弹性模量与侵蚀时间成反比;侵蚀时间与单轴抗压强度、弹性模量、孔隙率、波速之间的相关系数分别为-0.96、-0.98、0.91、-0.95;经过酸碱侵蚀后的花岗岩裂缝数量有所增加且无贯穿裂缝出现。

Local chemical ordering and its impact on radiation damage behavior of multi-principal element alloys

Multi-principal element alloys(MPEAs)have attracted much attention as future nuclear materials due to their extraordinary radiation resistances.In this work,we have elucidated the development of local chemical orderings(LCOs)and their influences on radiation damage behavior in the typical CrFeNi MPEA by hybrid-molecular dynamics and Monte Carlo simulations.It was found that considerable LCOs consist-ing of the Cr-Cr and Ni-Fe short-range orders existed in the ordered configuration with optimized system energy.Through modeling the accumulation cascades up to 1000 recoils,we revealed that the size of de-fect clusters and dislocation loops is smaller in the ordered configuration than those in the random one,although the former formed more Frenkel pairs(i.e.,self-interstitials and vacancies).In addition,the dis-tribution of dislocation loops is relatively more dispersed in the ordered configuration,and the stair-rod dislocations related to irradiation swelling are also smaller,implying that the existence of LCOs is con-ducive to enhancing radiation damage tolerance.To understand the underlying mechanism,the effects of LCOs on the formation and evolution of defects and radiation resistance were discussed from the aspects of atomic bonding,migration path,and energy of defect diffusion,which provides theoretical guidance for the design of MPEAs with enhanced radiation resistance.

内分泌干扰物对男性生殖功能损伤的研究进展

内分泌干扰物(EDCs)是一类外源性干扰人体内分泌激素作用的化合物,广泛存在于在环境中,且不易降解,人们无法避免地持续暴露于其中。许多研究表明在子宫内暴露于抗雄激素EDCs,特别是在胎儿睾丸发育的敏感时期,将会扰乱睾丸的发育并影响其功能,而成年男性暴露于各种环境EDCs也会造成生殖功能障碍,这与近年来男性生殖能力的下降有一定的关联。本文将针对几种常见EDCs对男性生殖系统的损伤及其相关机制进行总结概述。

盐水干湿循环作用下红砂岩损伤及蠕变声发射试验研究

为研究水化学溶液作用下红砂岩的损伤劣化机制,在Na2SO4溶液和NaOH溶液两种盐溶液环境下进行了干湿循环试验和蠕变声发射试验。结果表明:红砂岩的初始损伤随着干湿循环次数的增加而逐渐累积,砂岩在酸性Na2SO4溶液中的损伤劣化程度大于在NaOH溶液中的损伤劣化程度;随着干湿循环次数的增大,砂岩的初始损伤越来越严重,蠕变声发射信号逐渐从高频高幅值向低频低幅值转变,声发射累计事件数逐渐减小;相同干湿循环次数下,Na2SO4溶液中砂岩的声发射累计事件数低于NaOH溶液中砂岩的声发射累计事件数;声发射b值呈“降低-动态稳定-突降-增大”四个变化阶段,突降出现在加速蠕变阶段前后,可作为砂岩即将发生蠕变失稳破坏的前兆;声发射b值随着干湿循环次数的增加而逐渐增大,水化学损伤软化现象越严重,蠕变过程中小尺度的破坏占比越大。

Effect of chemical composition on zircon radiation damage dating:Implications for low-temperature thermochronology

Zircon radiation damage dating is a low-temperature thermochronological method that can reveal the cooling histories of magmatic intrusions and discriminate sedimentary provenance in combination with other dating methods.This method has broad application prospects because of its advantages of nondestructive,high efficiency,and capable of double(or multiple)dating,involving only multiple measurements by Raman spectrometer and laser ablation-inductively coupled plasma-mass spectrometry.However,several factors,such as zircon chemical composition and the non-uniformity of radiation damage annealing kinetics,can cause poor precision when using this method and thus restricts its wide application.This study examined the effect of chemical composition(P,Ti,Dy,Th,U,and Hf)on Raman spectra using synthetic zircon crystals grown in a lithium-molybdate flux.The results show that the full width at half-maximum(FWHM)of the v_(3)(SiO_(4))band has positive linear correlations with the concentrations of P,Ti,Dy,Th,and U in decreasing order of influence,while the FWHM is unaffected by Hf at concentrations<1 wt.%but increases at concentrations>10 wt.%.Furthermore,the Raman shift is negatively correlated with Th,U,and Dy concentrations,positively correlated with Hf,and shows no obvious correlation with Ti and P.Thus,our study shows that chemical composition is a non-ignorable factor for calculating zircon radiation damage age using Raman spectroscopy,especially for zircon with relatively high concentrations of P,rare earth elements(REEs),Th,U,and Hf.The obtained multiple linear regression equation provides a potential means for estimating the FWHM at zero dose and implication for improving the dating precision of this method.In addition,the observed effects of REEs,Th,U,and Hf on the Raman shift of the v_(3)(SiO_(4))band indicate that chemical composition in zircon might affect the estimation of the P-T conditions of geological processes when using entrapped zircon inclusions in host minerals or the field of zircon as an in situ pressure sensor in hydrothermal experiments.Our study suggests that zircon radiation damage dating,excluding geochemical effects,will be more accurate for addressing lower-temperature geological processes.

碳酸盐岩溶蚀效应及力学特性

针对不同赋存环境下溶蚀对碳酸盐岩力学特性的影响,采用自主研发的岩石动水压力溶蚀试验设备,开展多因素影响下碳酸盐岩溶蚀及单轴抗压强度试验,研究碳酸盐岩溶蚀效应、力学性质劣化规律及化学损伤。试验结果表明,不同赋存环境下岩样出现了不同程度的力学损伤,其抗压强度和弹性模量在溶解后有所下降,溶蚀率越高,峰值应力和弹性模量越低,进而提出劣化度拟合关系式,得到影响岩样抗压强度敏感度的各因素,依次为pH值、温度、时长、流速、动水压力及溶蚀后岩样的微观结构和矿物成分组成。

延长油田套损井化学封堵凝胶制备与应用

针对延长油田套损井日益增多的问题,通过室内实验自制了适用于延长油田套损井的封堵凝胶体系,并优化了聚合物和交联剂,进一步通过填砂管驱替实验评价了凝胶封堵性能,并将凝胶体系进行了矿场套损井治理试验。结果表明,聚合物GX-ZSD-04具有良好的耐温和耐盐性能,优化的体系配方为:3000 mg/L聚合物GX-ZSD-04+200 mg/L交联剂XT-5-ZSD-01;制备的凝胶体系突破压力为5.02 MPa,突破压力梯度为18.59 MPa/m。优化的凝胶体系封堵后套损试验井含水率由100%降至81.01%,封堵效果良好。该研究可为延长油田和同类油田在套损井凝胶封堵技术的应用与推广提供依据。

果园鸟害的综合防治技术

鸟害是影响果树产量和经济效益的重要因素之一。该文综述了果园鸟害的特点、发生规律和常用的防治技术,分析了生态防治、物理隔离、声波防治、视觉防治和化学药剂防治等不同防治方法的特点,可供广大果农、合作社和企业合理选择。

Chemical Defense of Soft Coral Sinularia polydactyla from the Red Sea Against Marine Biofilm-Forming Bacteria

Soft corals are an important group of organisms that live in reef ecosystems. In this study, the chemical defense of soft coral Sinularia polydactyla against biofilm-forming bacteria was assessed. The soft coral S. polydactyla was collected from the Obhur creek of the Red Sea and the bioactive compounds were extracted under different conditions using methanol and hexane as solvents. Results revealed that the bioactive compounds produced by the soft coral S. polydactyla were active against the growth, hydrophobicity and extracellular polymeric substances production of the biofilm-forming bacteria. However, the damage or injury in soft coral tissue caused a decrease in the activity against biofilm-forming bacteria. GC-MS analysis revealed that sesquiterpenes were abundant in normal coral sample extract while cembranoids were abundant in damaged coral sample extracts. In general, the results indicated that the soft corals either under stress or with damage may not have a strong chemical defense against the colonizing marine organisms and competitors.

高功率固体激光装置负载问题研究进展

高功率固体激光装置的负载问题是制约装置建设与运行的瓶颈问题。在高通量紫外纳秒激光辐照下,熔石英后表面的损伤不断产生和增长,严重限制了装置的负载能力。在提升熔石英抗损伤性能的基础上修复既有损伤,循环使用光学元件,是现阶段提升装置负载能力的主要手段。主要介绍了国内外近年来在熔石英损伤的规律与机制、光学元件循环处理的支撑技术以及提升负载能力的新材料与新技术方面所取得的重要进展。