海洋沉积物污染特征与生态分析

近几年,海洋沉积物中重金属含量明显升高,极大程度上危害了海洋底栖生物的生命健康。因此,为评价海洋沉积物污染特征与生态风险指数,本文以广西防城港为例,对防城港近海区设置取样监测点（A1～A10）,按照春、夏、秋、冬四季测定海水表层沉积物中重金属元素（Cu铜、Pb铅、Cd镉、Zn锌）的含量,并采用单因子指数法、综合污染指数法与潜在生态风险指数法分析沉积物的污染特征与生态风险。结果表明,第一,该海洋沉积物中Cu、Pb、Cd、Zn的年均含量分别为15.47、18.42、0.275、64.07mg/kg,沉积物综合污染指数大于10,说明海洋沉积物呈现较高污染状态。第二,该海洋沉积物中重金属对南海海域潜在生态风险属于中等水平,重金属危害大小顺序排列为Cd> Cu> Pb> Zn。     

云南省文山州南北河沉积物重金属污染特征及生态风险评价

为了解云南省文山州南北河表层沉积物中重金属的污染状况,2021年1月采集干流7个样点的沉积物样品,对沉积物中的Pb、Cd、As、Zn、Cu、Ni、Cr进行实验室检测。通过地累积指数法、潜在生态风险指数法对检测指标进行分析。结果表明：以地累积指数法评价,南北河沉积物重金属主要污染因子为As、Cd、Zn、Pb、Cu,Ni和Cr为无污染;以潜在生态危害指数法评价,南北河干流沉积物7种沉积物呈现不同生态风险,其中Cd为低生态风险—极强生态风险,As为低生态风险—中强生态风险,Pb、Zn、 Cu、 Ni、 Cr为低生态风险。As和Cd为南北河干流主要污染和生态风险来源。     

合肥市南淝河表层沉积物重金属污染评价

对合肥市南淝河表层沉积物中重金属污染状况进行采样调查,选取了8个采样点,测定了沉积物中Cr、Cd、Pb、Ni、Zn、Cu 6种重金属的含量,并采用地质累积指数法和Hakanson潜在生态风险指数法对其污染程度进行分析评价。地质累积指数评价结果表明:南淝河6种重金属的生态风险等级由强至弱依次为Cd、Zn、Cu、Ni、Pb、Cr;生态风险指数评价结果显示:在南淝河沉积物重金属中,Cd存在一定的潜在生态风险,Cr、Pb、Ni、Zn、Cu均处于轻微等级,重金属生态风险等级由强至弱依次为Cd、Cu、Ni、Pb、Zn、Cr,多数采样点的沉积物重金属综合潜在生态风险等级处于轻微级,个别采样点达到了中等甚至强生态风险等级。     

扬州古运河三湾段沉积物中重金属潜在生态风险评价及形态变化特征

扬州古运河是京杭大运河最古老的一段,为了解沉积物中重金属污染状况,采用Hakanson潜在生态风险评价扬州古运河三湾段沉积物中重金属Cr、Ni、Cu、Zn、Cd和Pb的风险水平,并对形态分布特征进行了研究。结果表明:扬州古运河六种重金属的含量均高于背景值,其中Cd含量为其背景值的13.15倍。沉积物中重金属的累积潜在生态风险指数RI高达456.55,沉积物的总体潜在生态风险等级为强。沉积物中Pb的主要赋存形态主要以铁锰氧化态存在,而Zn和Cd主要以酸可溶态形式存在,说明这三种重金属的潜在生态风险水平较高。     

淮南市泥河沉积物重金属潜在生态风险分析研究

为了了解淮南泥河沉积物中重金属污染现状和潜在环境风险,测定了泥河表层沉积物中重金属Cu、Zn、Pb、Cd、Hg和Ni的含量,并采用沉积物质量基准法(SQG)和Hankanson潜在生态风险指数评估了这几种重金属的环境风险。结果表明,泥河表层沉积物中Cu、Zn、Pb、Cd、Hg和Ni的平均含量分别为24.51 mg·kg-1、75.07 mg·kg-1、16.13 mg·kg-1、1.92 mg·kg-1、0.055 mg·kg-1和25.32 mg·kg-1。根据SQG标准,泥河表层沉积物中的重金属Cd和Ni处于中度污染水平,可能会对水域生物产生一定的负面影响。     

伊通河城区段表层沉积物中重金属污染风险评价

伊通河有长春市"母亲河"的称号,河流表层沉积物中重金属污染对河流生态健康有重要影响。现对伊通河城区段3个典型断面进行划分,分析河流表层沉积物中5种重金属元素含量,采用单一重金属潜在生态风险对表层沉积物重金属污染程度进行评价及分析。结果表明,河流表层沉积物中重金属除Cr外,Cu、Zn、Cd和Pb平均含量均超过省内土壤背景值;根据单一重金属潜在风险指数表明,重金属Cu、Zn、Cr和Pb生态风险因子评价为轻微,属于低污染状态,中游段重金属Cd相较上游段及下游段风险因子高。     

引江济太沿程小型过水湖泊典型重金属富集特征及潜在生态风险

为明晰引江济太沿程上小型过水湖泊漕湖中典型重金属的富集特征和潜在生态风险，通过对河湖系统表层沉积物中9种重金属(Cr、Co、Ni、Cu、Zn、Cd、Pb、Sb和Hg)的含量分析，研究和分析了重金属的富集程度、生态风险和潜在来源。结果表明，除Co、Cr和Pb外，其余6种金属的平均含量均超过江苏省土壤背景值，Cd约是背景值的12.38倍，污染最为严重；重金属空间分布上主要集中在漕湖入湖口、圩区口、东西向中线附近以及支流口(CH11)处。地累积指数和潜在风险指数表明Cd为中污染，Zn、Sb和Hg表现为低污染水平；Cd作为主要的环境风险因子，表现为极高生态风险，表层沉积物中重金属污染整体表现为高风险水平。漕湖沉积物中重金属的富集受周边工业和农业活动的影响较大，Cd的污染与工业生产、引水和农业面源等关联较大。     

舟山长白岛邻近海域沉积物重金属污染及生态风险

对舟山长白岛邻近海域表层沉积物中7种重金属含量进行了分析。结果表明,该海域表层沉积物中Cu、Pb、Zn、Cd、Cr、Hg和As平均含量分别为15、25、51、0.053、35、0.047、7.7 mg/kg,均不高于全国海岸带重金属的背景值。单因子污染指数法评价结果表明,7种重金属均符合《海洋沉积物质量》一类标准,各重金属平均污染指数大小排序为Cu=CrPbAsZnHgCd。潜在生态风险评估表明,长白岛邻近海域潜在生态风险指数等级为"较低",海洋生态环境状况较好。     

南四湖沉积物重金属含量水平与生态风险

本论文研究了南四湖沉积物中重金属的含量及生态风险;结果表明沉积物重金属Cd、Cr、Cu、Pb、Zn、Ni、Co的含量为0.08~1.12、58.92~135.62、38.09~78.65、24.51~53.95、110.51~235.36、11.30~65.40、4.12~20.14 mg/kg,均值顺序Zn Cr Cu Pb Ni Co Cd;重金属生态风险评价结果表明,Cd和Zn的相对富集因子明显高于其它元素,且某些点这两种元素的富集程度较高。因此,在南四湖环境污染防控中,应该关注沉积物中的Cd、Zn的污染。     

湘江株洲段河流沉积物的重金属污染评价

测定了湘江株洲段河流沉积物中重金属的含量,运用了地累积指数法和潜在生态危害指数评价法对重金属污染进行了评价。数据表明:株洲段Cr、Cd、Pb、As和Hg含量的平均值分别为71. 27、10. 06、87. 66、158. 69、0. 21 mg·kg-1,分别是长株潭地区底泥背景值的1. 19、20. 12、3. 51、10. 58、0. 85倍,除Hg外均超过长株潭地区底泥背景值。根据潜在生态危害系数法的计算结果,湘江株洲段沉积物中重金属污染程度为CdAsHgPbCr;而地累积指数法则表明其污染程度为CdAsPbCrHg。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997