关于《工业企业厂界环境噪声排放标准》倍频带声压级结构传播固定设备室内噪声排放限值使用的探讨

根据现行国家噪声排放标准排放限值,文中从噪声危害角度根据噪声评价曲线,论证了结构传播固定设备室内噪声等效声级排放限值与结构传播固定设备室内倍频带声压级的等效关系。     

Pesticide residues in rain water from Hisar, India

Presence of pesticide residues was studied in rain water during 2002 employing multi residue analysis method by gas liquid chromatography equipped with ECD and NPD detectors and capillary columns. The presence of pesticide residues in surface aquatic system triggered the investigation of the presence of pesticides in rain water. A total of 13 pesticides were detected in rain water samples. Among the different groups of pesticides, organochlorines were present in the range of 0.041–7.060 ppb with maximum concentration of p,p’-DDT up to 7.060 μg l⁻¹. Synthetic pyrethroids were present ranging from 0.100 to 1.000 μg l⁻¹ and organophosphates in the range of 0.050–4.000 μg l⁻¹ showing maximum contamination with cypermethrin (1.000 μg l⁻¹) and monocrotophos (4.000 μg l⁻¹) of the respective groups. Almost 80% samples showed the residues above MRL of 0.5 ppb fixed for multi residues and on the basis of single pesticide, 16–50% samples contained residues above the MRL value of 0.1 ppb.     

珠海金鼎工业园地下水水质演变及其对水污染防控的提示

以珠海金鼎工业园这一典型的滨海工业园为研究对象,对比分析了工业园建成后不同时期(2005—2007与2015—2022)园区地下水环境监测数据与稳定氢、氧、氮等多种环境同位素数据,探讨了该园区浅层地下水水质时空演变特征,分析了园区地下水水质的超标问题与诱因,并识别了园区地下水、主要离子与无机氮等成分的来源,明确了该浅层含水层特征指标对海水入侵的指示,为滨海工业园区地下水污染的管控提供了科学依据。     

欧盟工业废水污染物排放限值的制定

目前欧盟废水污染物排放限值的制定,主要依据欧盟委员会公布的污染综合防治指令和水政策行动框架指令的原则来进行。限值的制定方法主要有两种：一是以技术先进、经济合理为基础的最佳可行技术法;二是通过水环境质量标准、水体稀释能力以及污水处理系统削减能力来计算的反演法。中国可借鉴欧盟的先进方法进行环境标准体系的建设和完善。     

加筋土边坡临界滑动场

在分析加筋土边坡稳定性时,将加筋材料的作用视为施加于滑面上的等效力,建立了满足力平衡的加筋土边坡安全系数的计算格式;将边坡临界滑动场数值模拟方法进行推广,提出了基于力平衡的加筋土边坡临界滑动场计算方法,可以得到形状任意的临界滑动面及边坡最小安全系数。通过算例,比较加筋前后临界滑动面和安全系数的变化,并探讨了加筋水平间距、强度、长度对加筋土边坡稳定性的影响。     

Trace Level Determination of U, Zn, Cd, Pb and Cu in Drinking Water Samples

The concentration of uranium has been assessed in drinking water samples collected from different locations in Bathinda district, Punjab, India. The water samples are taken from hand pumps and tube wells. Uranium is determined using fission track technique. Uranium concentration in the water samples varies from 2.23± 0.05 to 87.05± 0.29 μg/L. These values are compared with safe limit values recommended for drinking water. The uranium concentration in almost all drinking water samples is found to be more than the safe limit. Analysis of some heavy metals viz. Zn, Cd, Pb and Cu in water is made. The concentration of sodium, potassium, calcium, magnesium, chlorine and total hardness along with the pH value and conductivity of the water samples are measured. Some of the samples show stunningly high values of these parameters.     

统计方法在污染场地修复验收评估中的应用

为合理评估污染场地修复验收结果,运用2种统计学方法——平行样t检验和UCL(置信上限)评估方法,对修复案例场地土壤样品的检测结果进行评估. 结果表明:采用传统的逐一对比方法,有8个采样点的w(As)和1个采样点的w(Hg)超过修复目标;平行样t检验法显示,这9个超标采样点中,S48采样点w(As)和S1采样点w(Hg)略微超过修复目标,是由采样与实验室误差引起,可视为已经达到修复效果;95%UCL评估方法结果则显示,w(As)和w(Hg)的95%UCL分别为23.81和5.83mg/kg,均小于对应的修复目标值,只有S26采样点w(As)大于修复目标值的2倍,可判定该场地土壤中除S26采样点w(As)外,其他均已达标. 研究说明:①运用适当的统计分析方法对修复效果进行评估,可节省不必要的修复成本;②传统的逐一对比方法适用于修复场地面积较小、采样数量有限的情况,平行样t检验则可剔除采样过程或实验室分析误差导致的超标值的影响;③95%UCL评估方法可从整体上判断场地修复效果,适合于修复面积较大、采样数量相对较多的情况,应用时注意95%UCL应小于修复目标值,污染物含量的最高检测值应不超过修复目标的2倍且不出现局部连续超标区域.      

基于绝热火焰温度多元混合气体可燃性极限的理论预测

为了预测多元混合气体可燃性极限,通过化学平衡计算软件分析确定了气体在可燃性下限（LFL）和可燃性上限（UFL）的燃烧产物及计算绝热火焰温度（CAFT）,基于能量平衡方程和简化反应模型,分别建立了混合气体LFL和UFL预测模型。应用该预测模型对CH4、C2H4、C3H8、C3H6和CO组成的不同比例混合气体可燃性极限进行预测。结果表明:简化反应模型对于LFL和UFL预测值与文献中实验值的平均相对误差分别为2.76%和5.45%,相关系数分别为0.995和0.950;同时发现两步简化模型对含有C2H4和CO混合组分预测结果误差较大,但对于平均碳原子数大于2的混合气体,预测结果一致性较好。     

微型自动塑限仪研制初探

通过设计由搅拌装置、滚搓装置组成的塑限仪,来测定粘性土的塑限含水率.该仪器的研制与应用,将解放传统意义上的手工操作方式,达到逐渐消除试验中的人为影响,严格规范试验测定的科学性、准确性,提高试验工作效率的目的.     

Survey regarding the 0.05 blood alcohol concentration limit for driving in the United States

Background: On May 14, 2013, the National Transportation Safety Board (NTSB) proposed that states lower the blood alcohol concentration (BAC) illegal limit from 0.08 to 0.05 g/dL (also referred to as the 0.08 law and the 0.05 limit, respectively). In March 2017, this recommendation was signed into law in the State of Utah.

Objective: The objective of this survey is to investigate perceptions regarding enforcement of the 0.05 g/dL BAC limit.

Method: Opinions of law enforcement officers, prosecutors, and defense attorneys were obtained through a series of questionnaires and focus groups.

Results: Survey data were collected from 32 law enforcement officers, 20 prosecutors, and 4 defense attorneys. The participants rated the usefulness of the NHTSA's driving while intoxicated (DWI) driving cues lower for the 0.05 limit than for the 0.08 law. Some of the participants believed that training would be needed in regard to sobriety testing under the 0.05 limit. Participants also stated that adequately preparing for prosecution of drunk drivers would be more difficult under the 0.05 limit. In addition, it was believed that drunk driving cases are more likely to be withdrawn and fewer plea agreements and guilty pleas are likely under the 0.05 limit. Prosecutors were concerned that the 0.05 limit would result in poorly investigated cases and overburden the court system. Defense attorneys were concerned about the social and economic costs of a 0.05 limit.

Discussion: Overall, it appears that the 0.05 limit is viewed as enforceable and it will save lives; however, the usefulness of the NHTSA DWI Detection Guide and of the standardized field sobriety tests need to be established for lower BACs, and efforts must be made to educate people regarding the relationship between BAC and impairment and impairment and driving with the risk of injury and death.

Conclusion: Though the 0.05 limit offers promise in saving lives, the following issues associated with changing the limit to 0.05 need to be resolved prior to implementation: Validating the sobriety tests for the 0.05 limit; if needed, modifying the sobriety tests to make them effective and valid at the 0.05 limit; and training law enforcement personnel and educating the public regarding the 0.05 limit.