Toxicity screening of biodegradable polymers. I. Selection and evaluation of cell culture test methods

A screening test method for potential toxicity of biodegradable plastics on humans and the environment was selected and evaluated with samples of cellulose acetate, Bionolle, polyhydroxybutyrate-co-valerate (Biopol), and polycaprolactone (Tone polymer). Among the standardin vitro tests using animal cell cultures for the evaluation of biomedical materials, the test by direct contact and the test with extract were examined. Qualitative and quantitative determinations of the cell viability and morphology indicate that the test with extracts can be easily performed, providing reproducible and comparable results for all materials. Using the cell culture test with the extract of sterile samples, an estimation of the toxicity of a new polymeric material can be obtained within a few weeks.     

灭火泄爆门的研制（QVD）

研制了一种能够重复使用的泄爆装置──灭火泄爆门，在１５升改进型哈特曼装置中对玉米淀粉和硅钙粉作了粉尘爆炸泄爆实验。结果表明，泄爆过程中火焰完全被捕集住，泄爆门开启压力在０．００１～０．０５ＭＰａ间，可按用户的需要调节，虽然这种灭火泄爆门灭焰捕集部分体积较小，但其泄瀑效率可高达７％。     

二氧化钛光催化氧化研究进展

简要介绍了二氧化钛光催化氧化的基本原理,对影响二氧化钛光催化氧化的因素及解决途径进行了分析,综合论述了光催化在环境保护中的应用效果。研究结果表明,光催化是一项具有广阔应用前景的新型水处理技术,它不仅具有低能耗、易操作、无二次污染等特点,而且对一些特殊污染物的去除具有更佳的效果,有较好的推广价值。     

工艺安全管理的重要组成——事故调查

介绍了OSHA对事故调查基本要素的规定、事故调查程序和事故调查方法,另外,通过事故归因理论及事故原因的分析,旨在采用科学调查分析方法深入剖析事故原因,制定和落实事故预防和控制措施,吸取事故教训。实现生产企业的本质安全。     

基于VSG的微电网逆变器控制策略研究

针对微电网中的分布式电源出力的间歇性导致微电网功率不稳定的问题,基于虚拟同步发电机(Virtual Synchronous Generator,VSG)技术的控制方法,建立VSG的数学模型,设计了一种基于电流、电压和功率控制的反馈控制器,提出了一种全新的VSG控制策略,实现分布式电源动态特性对微电网中有功功率和无功功率的均分控制。并通过Matlab/Simulink仿真,验证了所提控制算法的有效性。结果表明:该控制策略对抑制因新能源发电并网导致的电网波动、提高电能质量具有重要意义。     

Response surface method for modeling the removal of carbon dioxide from a simulated gas using water absorption enhanced with a liquid-film-forming device

This paper presents the results from using a physical absorption process to absorb gaseous CO_2mixed with N_2using water by producing tiny bubbles via a liquid-film-forming device(LFFD)that improves the solubility of CO_2in water.The influence of various parameters—pressure,initial CO_2concentration,gas-to-liquid ratios,and temperature—on the CO_2removal efficiency and its absorption rate in water were investigated and estimated thoroughly by statistical polynomial models obtained by the utilization of the response surface method(RSM)with a central composite design(CCD).Based on the analysis,a high efficiency of CO_2capture can be reached in conditions such as low pressure,high CO_2concentration at the inlet,low gas/liquid ratio,and low temperature.For instance,the highest removal efficiency in the RSM–CCD experimental matrix of nearly 80%occurred for run number 20,which was conducted at 0.30 MPa,CO_2concentration of 35%,gas/liquid ratio of 0.71,and temperature of 15°C.Furthermore,the coefficients of determination,R~2,were 0.996 for the removal rate and 0.982 for the absorption rate,implying that the predicted values computed by the constructed models correlate strongly and fit well with the experimental values.The results obtained provide essential information for implementing this method properly and effectively and contribute a promising approach to the problem of CO_2capture in air pollution treatment.     

Contamination by selected chlorinated pesticides in surface waters in Hanoi, Vietnam

Fifteen insecticides, which were banned in Vietnam in the period from 1990 to 1998, were chosen for the investigation of surface water samples in Hanoi and its surroundings. The investigation was focused on an area of approximately 30 by 20 km. Thirty water samples, in total were analysed: 11 samples from the Red river, seven from the Duong river, four from various lakes (West lake, Thuyen Quang, Bay Mau, Ba Mau), six from irrigation canals and two samples from wells. The procedure was repeated in November 1998 and in August 1999. The results showed that the contamination of the banned pesticides was highest in the rivers and then in the irrigation canals, followed by the lakes and wells. These pesticides could hardly be determined in just two drinking water samples (wells) and their concentrations rarely exceeded detection limits (0.05-0.25 ng l(-1)). The mean concentrations of sigmaHCHs (alpha, beta, gamma, delta-HCH) and sigmaDDTs (2,4'-, 4,4'-DDE; 2,4'-, 4,4'-DDD; 2,4'-, 4,4'-DDT) in the rivers were 17.2 +/- 71.8 and 43.7 +/- 79.9 ng l(-1) in the dry season (DS, November 1998), 29.3 +/- 117 and 56.1 +/- 65.6 ng l(-1) in the rainy season (RS, August 1999), respectively. However, the highest concentration of DDTs detected in a river sample (DS): 0.324 microg l(-1) was much lower than their allowable limit of concentration in surface waters, which is accorded with Criteria of Vietnam (1995) (DDTs < 10 microg l(-1)). Moreover, endrin, heptachlor, aldrin were also detected in most of water samples with considerable mean concentrations in rivers: 25.3 +/- 40.5, 17.4 +/- 23.8, 11.0 +/- 9.02 ng l(-1) in the DS and 18.5 +/- 23.2, 19.3 +/- 29.0, 12.8 +/- 8.44 ng l(-1) in the RS, respectively. Heptachlor epoxide (isomer A) and dieldrin were detected in some water samples with lowest concentrations.     

石化行业开展健康企业建设思路探讨

通过对石化行业面临的主要健康风险进行分析,识别影响员工健康的主要危险因素,结合科学研究,提出技术支撑建议,为石化行业开展健康企业建设提供思路。     

不同排放标准下的燃煤电厂烟囱高度与落地浓度关系研究

燃煤电厂全面实施超低排放后,烟气污染物排放浓度及落地浓度得到较大程度降低,是否仍需采用高烟囱排放已引起各方关注.以西北某电厂为例,采用SCREEN3估算模式,对烟气污染物执行超低排放、特别排放及一般排放限值时,不同烟囱高度对应的最大落地浓度及落地距离进行预测.结果表明,执行超低排放限值后,SO2、NO2和PM10的最大落地浓度均显著降低,落地距离不发生变化;最大落地浓度受烟囱高度的影响较小,通过增加烟囱高度降低污染物落地浓度的效益不显著.     

重要生态功能区干旱时空演变特征及对关键资源的影响:以黄河流域为例

基于温度-植被-降水的综合干旱指数（TVPDI）、地表径流、植被净初级生产力和粮食产量等数据,利用数据空间化方法、Slope趋势分析及Pearson相关分析等方法,探究了黄河流域从2001~2020年这20年间干旱时空变化特征以及对水资源、粮食资源和植被资源的影响,试图探究干旱与关键资源之间的相互影响.结果表明:①黄河流域干旱空间分布由东南向西北呈阶梯状加重,全流域有60.6 %的区域处于干旱状态;从变化看全流域干旱整体上呈逐年下降趋势,有94 %的区域由干旱逐渐向湿润转变,从春季到冬季干旱呈现先减轻后加重的趋势.②从流域重要资源的时空变化看,起关键作用的地表径流量有53 %的区域呈现增加趋势,且主要分布在流域西南地区;表征植被资源的植被净初级生产力（NPP）及表征粮食资源的粮食产量亦呈增长趋势.③干旱与3类资源呈现显著的空间关联度,干旱程度越高对地表径流量、植被生产力和粮食产量产生的影响越显著,但近年来变湿的地区,其重要资源并未显著增加,这说明干旱对3类重要资源的影响具有时间滞后性,且其滞后性在空间分布上具有显著差异性和地域分异规律.研究对于黄河流域农业生产和抗旱减灾、生态保育具有重要理论意义.