Effect of deteriorated microstructures on stress corrosion cracking of X70 pipeline steel in acidic soil environment

In order to investigate stress corrosion cracking （SCC） of X70 pipeline steel and its weld joint area in acidic soil environ- ment in China, two simulating methods were used： one was to obtain bad microstructures in heat affected zone by annealing at 1300 ℃ for 10 min and then, quenching in water; the other was to get different simulating solutions of acidic soil in Yingtan in south- east China. The SCC susceptibilities of X70 pipeline steel before and after quenching in the simulating solutions were analyzed using slow stain rate test （SSRT） and potentiodynamic polarization technique to investigate the SCC electrochemical mechanism of different microstructures further. The results show that SCC appears in the original microstructure and the quenched microstructure as the polarization potential decreases. Hydrogen revolution accelerates SCC of the two tested materials within the range of-850 mV to -1200 mV vs. SCE. Microstructural hardening and grain coarsening also increase SCC. The SCC mechanisms are different, anodic dissolution is the key of causing SCC as the polarization potential is higher than the null current potential, and hydrogen embrittlement will play a more important role to SCC as the polarization potential lower than the null current potential.

Could Acid Sulfate Soils Be a Potential Environmental Threat to Estuarine Ecosystems on the South China Coast?

Acid sulfate soils (ASS) contain considerable amounts of reduced sulfur compounds (mainly pyrite) which produce sulfuric acid upon their oxidation. ASS-derived environmental degradation widely occurs in the coastal lowlands around the world, especially in the tropical and subtropical areas. The presence of ASS in the South China has been recognized but their distribution may be largely underestimated because the soil survey data concerning ASS are based on unreliable methods and techniques. ASS in the South China have been traditionally used for rice cultivation and this practice has been proved sustainable if appropriate improvement measures are adopted. Recently, the rapid economic growth in the region has resulted in intensified coastal development which frequently involves activities that may disturb ASS. Construction of roads, foundations and aquaculture ponds may cause the exposure of ASS to air and bring about severe environmental acidification. There is currently insufficient awareness of the problems among the researchers, policy-makers and land managers in the South China. More atteation must be paid to the possible ASSderived environmental degradation in order to ensure a sustainable development of the coastal lowlands in the South China region.

Synthesis and Characterization of 12-Acryloyloxystearic Acid and Application in Preparing Environmentally Friendly Magnesium 12-Acryloyloxy Stearate Detergent

In this article, 12-acryloyloxystearic acid was synthesized, which was then used to prepare the magnesium 12-acryloyloxy stearate detergent. Reaction conditions for synthesizing 12-acryloyloxystearic acid, including the molar ratio of 12-hydroxystearic acid to acrylic acid, the catalyst amount, the esterification temperature, and the esterification time, were optimized. Under the optimized conditions, the 12-acryloyloxystearic acid with an acid value of 159 mg KOH/g and a melting range of between 70.4 ℃ and 71.4 ℃ was obtained. The structure of 12-acryloyloxystearic acid was confirmed by FTIR spectroscopy. Results of preparing magnesium 12-acryloyloxy stearate detergent showed the existence of acryloyloxy radical in 12-hydroxystearic acid could improve the quality of lubricant detergent greatly.

Effect of ocean environmental factors on sound absorption by boric acid relaxation in sea water

By using the expressions for the maximum absorption per wavelength (αλ),and the relaxation frequency fr of the boric acid relaxation derived previously by the author and employing the related oceanographic literatures, the effects of pressure, temperature, pH and salinity on (αλ)r and ∫r of the boric acid relaxation in sea water have been estimated. Results show that ( αλ), not only increases with pH but also increases approximately linearly with pressure and temperature, and is nearly proportional to the 1. 35 power of salinity. However, pressure, pH and salinity have negligible effect on ∫r; therefore, ∫r, can be approximately expressed as a function of temperature only. Comparisons of the predicted with the measured ( αλ)r and ∫r in different ocean areas are given.

Review on Chlorobenzoic Acids Biodegradation and Their Environmental Impacts

Chlorobenzoic Acids are toxic organic compounds largely distributed in soils and sediments. They can be degraded to various products by microorgans. This paper is a review of the literature on biodegradability of the chlorobenzoic acids. The degradation pathways, degradation genes, role of transposable elements, and construction of strains are discussed. A brief introduction is given on the environmental impacts and the pollution control.

The effects of the environmental factors on Laminaria disease caused by alginic acid decomposing bacteria

-The rot disease of Laminaria occurs often in nurseries of sporeling and commercial cultivation in the sea and results in economic loss greatly. Usually the disease outbreaks accompanied with massive multiplication of alginic acid decomposing bacteria. From the section of the decaying Lamuutria which resulted from the inoculation of alginic acid decomposing bacteria, it was observed that the bacteria invaded the epiderm of the Laminaria surface at first, then entered the ex-odermis, endodermis and pith. In addition, there were a great amount of bacteria in the intercellular region and a lot of free cells of the algae in the decaying areas. The wall of some free cells was decomposed, which led to soft tissue or disintegration. Alginic acid decomposing bacteria are normal epiphytic microorganisms growing on Lamuutria surface. These bacteria do not cause disease at normal environmental conditions. The experiments showed that the unfavourable conditions, e. g. , wounding, overcrowding, high temperature reduced the ability of antibacterial activity and made the algae more susceptible to the pathogens and favoured the multiplication of alginic acid decomposing bacteria and finally led to the disease outbreak. The unfavourable environmental factors which resulted from a variety of reasons were the main cause of the disease.

Impact of Oil and Gas Activities on Acidity of Rain and Surface Water of Niger Delta, Nigeria: An Environmental and Public Health Review

Acidic aerosols resulting from gas flaring and refinery operations in the Niger Delta are a serious environmental and public health concern. Several thousand tons of flue gas components (dust particles, SOx, CO and NOx) are released into the atmosphere by flaring billions of cubic meters of natural gas, refining and volatilizing the spilt oil. Heat wave is generated by flaring travels several meters away from flare points, destroying crops, farm lands, exotic species that are hunters delight while causing extinction of fragile soil flora and fuana. The occurrence of acid rain in the region implies that the natural receptors of the area are the final recipient of land and atmospheric pollutants. In effect, the water needs and public health of the populace are greatly impeded. Nitric and sulphuric acids are regarded as the sole contributors of nitrate and sulphate in precipitation influenced by combusted hydrocarbons: fine nitrate aerosols that dissolve in rain water are conversion products of NO2 that arise from flaring, power plants and motor vehicles. Scientific evidence has shown that rain water and surface water quality in the Niger Delta can accentuate the poor health burden, and may be perpetuated through generations unborn. Diagnostic health risk assessment has revealed that drinking nitrate contaminated water may be associated with spontaneous miscarriage, ectopic pregnancy, adult malignant lymphomas, soft tissues sarcomas, cancers and lesions with added health burden associated with heavy metals and other ions. All these pose public health emergency and may significantly entrench health risk for generations to come. Therefore, this manuscript is intended to close certain gaps that were not covered by toxicological information and available data on environmental and food contamination and human internal exposure: it will serve as a continuous reminder and a useful guide to public health policy makers, workers and community based physicians.

Preparation and Characterization of Environmental Functional Poly(Styrene-<i>Co</i>-2-[(Diethylamino)Methyl]- 4-Formyl-6-Methoxy-Phenyl Acrylate) Copolymers for Amino Acid Post Polymerization

Vanillin was used as renewable resource for preparing new monomer in two stops. The monomer has tertiary amine group which facilitates the pH change and functional aldehyde group that encourages the formation of Schiff base. It was abbreviated by DEAMVA and evaluated using chemical analysis e.g. 1H NMR, 13C NMR and FT IR all data were in logic case. Copolymerization of Styrene with 5 and 15 mol% of DEAMVA has been done by free radical polymerization and AIBN as initiator. The copolymers have been chemically and physically characterized e.g. 1H NMR, FT IR, GPC, and DSC. Post polymerization of poly (styrene-Co-DEAMVA) with 15 mol% (III b) was prepared for immobilization of tryptophan and investigated by the same methods used lately. Moreover, the sensitivity of the posted copolymer to pH has also studied by UV-vis. Spectroscopy. Scanning electron microscopy (SEM) was used to study the morphological feature of polymer surface after immobilization of tryptophan.

磁改性生物质炭渣对酸性矿山废水中Cu^(2+)、Pb^(2+)的吸附研究

针对酸性矿山废水(Acid Mine Drainage, AMD)中Cu^(2+)和Pb^(2+)含量过高,生物质炭渣吸附能力有限等问题,以工业固体废弃物生物质炭渣为原材料,采用高锰酸钾和硫酸亚铁对生物质炭渣进行磁改性,制备生物质炭渣负载MnFe_(2)O_(4)的复合磁性材料(BC-MF),并将BC-MF作为去除酸性矿山废水环境中Cu^(2+)和Pb^(2+)的吸附剂。基于单因素试验方法,探究pH值、温度、初始质量浓度、吸附时间、共存金属离子等因素对BC-MF吸附Cu^(2+)和Pb^(2+)性能的影响,并将吸附动力学、吸附热力学、吸附等温线与扫描电子显微镜(Scanning Electron Microscopy, SEM)、X射线衍射(X-ray Diffraction, XRD)、傅里叶变换红外光谱(Fourier Transform Infrared Spectroscopy, FT-IR)、磁滞回线测试(Vibrating Sample Magnetometer, VSM)、Zeta电位(Zeta potential)等表征方法结合,研究MnFe_(2)O_(4)磁改性生物质炭渣吸附Cu^(2+)、Pb^(2+)的机理。结果显示,改性后的BC-MF对Cu^(2+)和Pb^(2+)的去除率均提升20百分点以上,且吸附饱和质量比分别为18.04 mg/g和24.98 mg/g。表征结果显示:MnFe_(2)O_(4)磁性颗粒成功负载到BC-MF上,并使之具有磁性;BC-MF对Cu^(2+)和Pb^(2+)吸附过程均符合Langmuir等温吸附方程和准二级动力学模型,吸附过程是为化学吸附为主的单层均相吸附;热力学结果表明该吸附过程属于自发进行的熵增过程。

不同产地及品种牡丹籽油脂肪酸和角鲨烯含量的比较分析

旨在为油用牡丹的品种选育、牡丹籽油的营养评价和产地溯源提供参考信息,采用气相色谱-质谱法对4个油用牡丹主产地(河南洛阳、山东菏泽、安徽亳州和甘肃兰州)的凤丹牡丹籽油和紫斑牡丹籽油的脂肪酸组成和角鲨烯含量进行检测,并对牡丹籽油的脂肪酸及角鲨烯含量与环境因子的相关性进行分析。结果表明:牡丹籽油中含有11种脂肪酸,以α-亚麻酸、油酸和亚油酸为主;8个牡丹籽油样品中的脂肪酸相对含量及角鲨烯含量存在差异,其中相同产地的凤丹牡丹籽油中的油酸相对含量均显著低于紫斑牡丹籽油的(p<0.05),亚油酸相对含量除河南洛阳产地外均显著高于紫斑牡丹籽油的(p<0.05);甘肃兰州牡丹籽油的亚油酸相对含量显著低于其他产地的(p<0.05),可作为对兰州牡丹籽油进行鉴别的指标之一;牡丹籽油中角鲨烯含量、油酸和α-亚麻酸相对含量,均随着年降雨量的增加、年平均气温的升高而减少,随着海拔的增加而增加,且牡丹籽油中的角鲨烯含量随着油酸、α-亚麻酸相对含量的增加而增加,随着亚油酸相对含量的增加而减少。综上,品种、产地及环境因子的不同均会造成牡丹籽油脂肪酸及角鲨烯含量的差异。

基于随机森林模型与SHAP算法的渝东北烟区土壤交换酸含量影响因素分析研究

【背景和目的】土壤交换酸含量在农业生产中对于指导施肥和调节土壤pH具有重要作用,研究环境因子(气候、地形、成土母岩)和种植年限对土壤交换酸(Exchangeable Acidity, EA)含量的影响。【方法】以重庆市东北烟区为研究区,对该区中483个采样点的土壤交换酸数据进行统计分析,构建随机森林(Random Forest, RF)模型并结合Shapley Additive exPlanations(SHAP)算法,探讨影响土壤交换酸含量的主控因素。【结果】(1)研究区土壤交换酸含量在1.56~27.50 cmol/kg之间,与降水、日照时数、坡向、种植年限呈极显著负相关性。二叠系石灰岩发育的土壤交换酸含量显著高于三叠系石灰岩发育的土壤。(2)RF模型可解释土壤交换酸含量空间变异的64%,影响因子对土壤交换酸含量的重要性为气候>成土母岩>种植年限>地形。(3)SHAP算法揭示了土壤交换酸含量在不同气候条件下存在明显的阈值效应。当年均降水量、日照时数和均温分别超过1250 mm、1290 h和12℃时,会导致土壤交换酸含量的减少,反之则会促使其增加。【结论】气候是影响土壤交换酸含量变异最重要的环境因素,其中降水和日照时数是最重要的气候因子,研究结果可为烟田土壤酸化管理调控提供参考。

核酸等温扩增技术在病毒检测中的应用

病毒是引发人类疾病的主要病原体之一.传统的聚合酶链式反应(PCR)技术虽然被广泛应用于病毒分子诊断,但其对温度的要求较为严格,限制了其在现场诊断中的应用.为了满足现场快速诊断的需求,核酸等温扩增技术得到快速发展,其无需热循环,可以在恒定温度下实现核酸扩增,可适应不同的应用场景.本文综合评述了等温扩增技术在病毒检测领域的最新进展,从病毒样本采集、核酸提取、等温扩增检测等几个方面分别进行阐述,探讨了酶辅助等温扩增技术、无酶等温扩增技术以及与多体系串联的级联扩增技术的原理、关键参数及其病毒检测应用,并对比了市场上相关试剂盒的特点.此外,讨论了当前核酸等温扩增技术在病原体检测应用中面临的一些难题,如提取效率、稳定性和成本等,提出了未来的发展方向,为进一步改善现场诊断效率提供了新的思路.

邻苯二甲酸二(2-乙基己基)酯(DEHP)诱发小鼠胆汁淤积和肝损伤的作用机制

目的探讨邻苯二甲酸二(2-乙基己基)酯(DEHP)诱发小鼠胆汁淤积和肝损伤机制研究。方法体内实验:将成年雌性ICR小鼠随机分为对照组(玉米油)、DEHP组(200 mg·kg^(−1)·d^(−1)),共灌胃4周,建立胆汁淤积模型。收集所有小鼠血液与肝组织,生化仪检测血清、肝脏总胆汁酸(TBA)水平,酶标仪检测ALP、GGT;HE染色观察肝组织病理变化;实时定量PCR检测肝脏炎症因子IL-1β、IL-6和TNF-α的表达水平;液相色谱-三重四级杆质谱仪(LC-MS/MS)检测小鼠肝脏胆汁酸谱。体外实验:培养小鼠肝细胞AML-12,使用DEHP(250μmol/L)以及去氧胆酸(DCA)(125μmol/L)和鹅去氧胆酸(CDCA)(125μmol/L)处理细胞24 h,实时定量PCR检测细胞炎性因子IL-1β、IL-6和TNF-α的mRNA水平。计量资料两组间比较采用成组t检验,多组间比较采用单因素方差分析,进一步两两比较采用LSD-t检验。结果体内实验显示:与对照组相比,DEHP组小鼠肝体比,血清TBA、ALP、GGT及肝脏TBA均显著升高(t值分别为−4.396、−5.109、−8.504、−3.792和−7.974,P值均<0.05)。与对照组相比,肝脏胆汁酸谱中胆酸(CA)、CDCA、牛磺鹅去氧胆酸(TCDCA)、DCA及熊去氧胆酸(UDCA)均显著升高(t值分别为−2.802、−3.177、−2.633、−2.874和−2.311,P值均<0.05)。DEHP组小鼠肝脏HE染色显示为汇管区扩大、胆管变形、胆管周围伴有炎性细胞浸润,且肝脏炎症因子IL-1β、IL-6和TNF-αmRNA水平均显著升高(t值分别为−2.539、−2.823和−4.636,P值均<0.05)。体外实验显示:0~1000μmol/L DEHP处理后肝细胞活力实际数值相差不超过15%,分别使用125、250以及500μmol/L的DEHP刺激后,肝细胞的炎症因子IL-1β、IL-6和TNF-αmRNA水平均明显升高(P值均<0.05)。与单独使用DEHP刺激相比,CDCA联合DEHP刺激上调了细胞炎症因子IL-1βmRNA水平(P<0.01);DCA与DEHP联合刺激可显著增加细胞炎症因子IL-1β和IL-6的mRNA水平(P值均<0.01)。结论DEHP暴露导致小鼠胆汁淤积肝病的发生并诱发肝脏炎症,这可能与其促进有毒胆汁酸的产生进而加剧炎性因子分泌有关。

砷黄铁矿生物氧化影响因素及控制方法

砷黄铁矿的生物氧化是产生含砷酸性矿山废水的主要原因,为了更好地研究含砷酸性矿山废水控制技术,综述砷黄铁矿生物氧化的关键环境影响因素和源头控制技术的研究现状。介绍砷黄铁矿的理化性质、化学和生物氧化特性,了解其在矿山环境中的氧化行为。深入阐述微生物、共存离子、有机物、伴生矿物等环境因素对砷黄铁矿生物氧化的影响及其作用机制,揭示砷黄铁矿生物氧化过程中的关键步骤和反应。环境中砷黄铁矿的氧化和砷的释放主要是由水、氧气和微生物3种成分驱动,可以通过隔绝其中任何一种成分来抑制其氧化,因此,着重介绍氧屏障法、杀菌剂法、混合碱性矿物处置法以及钝化涂层法等源头控制方法的机理并探讨其优缺点和适用性。在此基础上,还展望了该领域可行的研究方向,为评估和抑制砷黄铁矿导致的含砷酸性矿山废水提供理论基础。

四种环境材料单施对煤矿区土壤结构和性状的影响研究

为解决煤矿区土地复垦中表层土壤结构差、持水能力低和养分贫瘠等问题,通过土壤培养模拟试验,研究了单施聚丙烯酸钾、黑矾、生化腐植酸和煤基腐植酸等4种材料对土壤改良的效果,并确定了适宜的施用量。结果表明:与对照(CK)相比,4种材料中聚丙烯酸钾能显著降低土壤容重,提高孔隙度和田间持水量,其添加量5 g·kg^(-1)施用7 d时,容重较CK降低了14.02%,孔隙度、田间持水量分别提高了28.31%、54.32%;黑矾能降低土壤pH和速效养分,当添加量5 g·kg^(-1)施用25 d时,pH、有效磷、碱解氮和速效钾较CK分别降低了0.21、30.24%、56.81%、9.77%;两种腐植酸对土壤容重、田间持水量、pH、速效养分均有影响,添加8 g·kg^(-1)生化腐植酸作用25 d时,有效磷和碱解氮较CK提高了15.18%、55.83%,pH降低了0.38,而添加5 g·kg^(-1)煤基腐植酸时,有效磷、碱解氮和速效钾较CK分别提高了12.38%、28.72%、11.47%。研究表明,4种材料能不同程度改善土壤结构、提升水分保持能力、增加速效养分含量。

血站核酸检测实验室环境消毒监测结果与分析

目的 通过监控及监测本站核酸检测实验室环境消毒结果,确保血液核酸检测结果的准确性与稳定性。方法 收集2021年6月至2023年6月本站核酸检测实验室3个工作区域25次监测结果,评估核酸检测实验室空气、设备、地面、物体表面的消毒方法对消毒效果的影响。结果 采集的25次环境监测结果中2021年10月标本处理、标本制备区移动车台面乙型肝炎病毒核酸(HBV DNA)阳性,复检后仍呈阳性,消毒后重新取样,结果为阴性,其余24次环境监测合格率均为100%。Pearson相关性分析结果显示,环境监测合格率与核酸检测结果的拆分阳性率无相关性(P>0.05)。结论 本站核酸检测实验室环境消毒措施能有效确保检测质量。同时,监测结果中偶发的HBV DNA阳性结果系设备污染,未对检测实验室造成不良影响,但日常工作中应高度重视并加强实验室的清洁消毒及评估,确保实验室检测结果的准确和环境、人员等安全。

污酸石膏渣的环境稳定性与金属释放特性研究

为探究火法炼铜过程产生的污酸石膏渣的环境风险,通过解析污酸石膏渣性质,采用模拟堆存、静态侵蚀、半动态侵蚀的方法研究污酸石膏渣的长期稳定性与重金属释放特性。结果表明,污酸石膏渣中As、Cd浸出浓度超标,分别为1488.66、22.98 mg/L。其中,As的酸可提取态达87.55%,Cd的有效态超90%,存在严重环境风险。模拟堆存结果表明,污酸石膏渣为严重生态风险等级,应做好防淋失、防扬尘等措施。在静态与半动态侵蚀下,污酸石膏渣表面附着的As、Cd在化学反应、扩散等作用下大量浸出,使浓度均处于较高水平。其中,模拟填埋场环境各元素浸出浓度远高于其他模拟环境,需重点关注。

东太平洋多金属结核勘探合同区表层沉积物脂肪酸分布及其物源指示意义

为丰富东太平洋多金属结核勘探合同区环境基线数据并解析底栖生物营养物质来源,本研究以气相色谱-质谱法,测定了中国大洋第45、50航次于东太平洋克拉里昂-克利珀顿区采集的表层沉积物中的脂肪酸组成,分析其分布特征及物源指示意义,探讨东太平洋多金属结核勘探合同区及周边区域表层沉积物生物群落结构的空间分布特征。结果表明,研究区域表层沉积物的脂肪酸组成主要包括以C11:0、C14:0 anteiso、C16:0为主的饱和脂肪酸、以C17:1ω7c为主的单不饱和脂肪酸、以C18:3ω6c(6,9,12)为主的多不饱和脂肪酸,其来源主要是细菌和真菌等生物。聚类分析及主成分分析结果表明,中国大洋矿产资源研究开发协会多金属结核勘探合同区KW1区块与中国五矿集团有限公司多金属结核勘探合同区A1、A2、A6、A8区块的脂肪酸组成类型较为相似,但后者各区块脂肪酸组成呈现出东西向的梯度差异。海底深度与颗粒有机碳通量的空间差异可能是造成脂肪酸组成具有地理差异的主要原因。此外,底层流和微地形等可能也会对沉积物脂肪酸空间分布产生影响。

儿童环保颜料聚乳酸纤维原液着色综合性能研究

为开发更为环保的儿童专用颜料,尝试以聚乳酸纤维为基础制备一种儿童专用的环保颜料,聚乳酸纤维具有较强的生态环保性,将其应用于儿童颜料中可以有效降低颜料本身给儿童带来的健康威胁。对儿童环保颜料聚乳酸纤维原液的制备思路进行分析,以实验方式对这种原液的着色综合性能进行研究。结果表明,该原液母粒着色性能、着色效果、着色稳定性等均较为理想,与一般市售颜料原液相比可以提供更好的综合着色性能。

Corrosion behavior and characteristics of the product film of API X100 steel in acidic simulated soil solution

The short-term corrosion behavior of API X100 steel in an acidic simulated soil was investigated by electrochemical measurements and soaking experiments,followed by corrosion morphology observations and X-ray photoelectron spectroscopy analyses.The results show that X100 steel exhibits an obvious pitting susceptibility in an acidic soil environment.Pits nucleate after approximately 10 h of immersion.Along with the nucleation and growth of the pits,the charge-transfer resistance and open-circuit potential first increase sharply,then decrease slowly,and eventually reach a steady state.The maxima of the charge-transfer resistance and open-circuit potential are attained at approximately 10 h.The evolution of the electrochemical process is confirmed by the analysis of the product film.The product film exhibits a porous and loose structure and could not protect the substrate well.The product film is primarily composed of ferrous carbonate and ferrous hydroxide（Fe（OH）2）.The concentration of Fe（OH）2 in the product film increases from the inside to the outside layer.