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41.
亓玲 《防灾博览》2005,(1):45-45
10月2日低温气流突袭湖北武汉,全市狂风不止气温骤降。 台湾红火蚁灾情蔓延,全台5个县市受灾。 3日泰国发现全亚洲首例狗感染禽流感病例。 5日江西一煤矿发生瓦斯爆炸事故,造成9人死亡。 7日广西出现罕见的局部严重干旱,67万亩农田出现旱情。 8日久晴不雨的湘江中游出现了秋季最低水位。 9日鹤矿集团十三化工公司雷管车间发生爆炸,13人伤亡。 10日湖北一学校发生食物中毒事件,34名学生人院治疗。 11日水资源占全国1乃的长江流域污水处理率仅为1明毛。 16日罗马尼亚一3岁雌黑熊肇事,导致l死10伤。 19日四川宝兴县发生岩体垮塌事故,死亡9人失…  相似文献   
42.
The coastal water of northeast Taiwan island, called 'Yin-Yang Hai' for its distinct yellow colour compared with blue offshore water, was investigated from 1989 to 1990 by the authors. Biological study showed the dominant species of plankton to be Copepoda, Cladocera, planktonic eggs and Diatoma. Dominant species of benthos were young crabs, Amphipoda and Annelida, with Amphipoda usually occurring in heavily polluted areas. Heavy metal data showed that the concentration of copper was high. the copper and iron concentration in algae of the intertidal zone was also high. the concentrations of iron and copper in inshore water were also higher than in offshore water. By comparison of the pH and salinity distribution of this area, we conclude that this coastal water has been polluted by acid waste water from coastal industry. the suspended solids concentration in sea water is high. Flocculation occurring at the boundary of fresh and saline water might be a reason for the distinct yellow colour of the water of this area. Further study is required.  相似文献   
43.
Adults of the sea urchin Arachnoides placenta (L.) were induced to spawn, and eggs were fertilized at 28°C in September 1989. After 5 min, eggs were transferred to 28, 31, 34, or 37°C and reared to metamorphosis. Embryos were observed at 20-min intervals during the first 2 h; larvae were observed daily. The cleavage was higher at higher temperatures. Embryos reared at 28°C were still at the 4th cleavage (16-cell stage) after 100 min, while those at 34°C had reached the 5th cleavage (32-cell stage). All embryos reared at 37°C died on the second day. Incidence of abnormality was 20 to 30% at 28 and 31°C, 48% at 34°C, and 77% at 37°C. The 8-arm stage was reached after 4 d at 28°C, 3 d at 31°C and 2 d at 34°C. Larvae displayed decreasing body length and arm length with increasing temperature. Larvae at 31°C have relatively long arms, as a result of a decrease in body length, not because of increased arm length. Incidence of metamorphosis was 43.9±1.7% (mean/plusmn;SD) at 28°C, 24.5±1.9% at 31°C, and 5.3% at 34°C. The size of metamorphosed juveniles was significantly larger at 28°C than at 31 and 34°C. Temperatures of 31°C negatively affect larvae and juveniles of the sand dollar.  相似文献   
44.
45.
氯自由基对于臭氧和二次气溶胶的生成贡献不容忽视.夜间颗粒相氯(Cl~-)可以通过与N_2O_5的复杂反应转化生成ClNO_2,其光解产生的氯自由基将显著影响大气污染的形成机制.本文以上海地区为案例,以2017年为基准年,收集了人为源活动水平数据,采用排放系数估算方法,首次建立了上海地区人为源氯化氢(HCl)和颗粒氯(Cl~-)的排放清单;并进一步结合模型计算海盐气溶胶排放的颗粒氯(Cl~-).结果表明,2017年上海市人为源和天然源排放的HCl和Cl~-分别为1207 t和820 t,其中,燃煤、工业、垃圾焚烧和秸秆燃烧产生的HCl排放量分别为327、134、722和24 t.燃煤源中的燃煤电厂和其它行业燃烧约占燃煤源排放的80%;工业源中水泥为HCl的最大排放源,约占工业源排放的51%;垃圾焚烧厂排放约占总HCl排放的60%,为最大的HCl排放源.燃煤、工业源、垃圾焚烧、秸秆焚烧、烹饪源和海盐的颗粒Cl~-排放量分别为82、153、498、47、39和0.6 t,燃煤源中的燃煤电厂占燃煤Cl~-排放的40%,供热、其他行业和家庭燃烧分别占燃煤Cl~-排放的24%、22%和14%;钢铁行业为工业源的主要Cl~-排放源,约占工业源排放的90%,垃圾焚烧厂占全部Cl~-排放的61%,烹饪源中餐饮企业为最主要排放源,占烹饪源的70%;天然源海盐的排放量极少,未占到总排放的1%.从空间分布来看,浦东新区、宝山、普陀、松江和金山排放的HCl和Cl~-占到全市人为源总排放的80%,为主要的HCl和Cl~-排放区域.本文研究建立的上海地区大气中氯化氢和颗粒氯排放源清单,对于深入研究氯化学机制对二次污染的影响提供了重要的数据参考.  相似文献   
46.
以南京江北新区分流制雨水管道沉积物为研究对象,考察不同粒径沉积物中铵态氮(NH3-N)和硝态氮(NO3--N)干期分布特征,分析其随干期长度的变化关系,并探讨沉积物理化性质及微生物菌群结构对NH3-N和NO3--N干期分布的影响.结果表明:粒径≤0.075mm的沉积物中NH3-N占比最高(交通区30.8%,商业区36.7%);交通区粒径≤0.075mm的沉积物中NO3--N占比最高(33.0%),而商业区粒径0.075~0.15mm沉积物中NO3--N占比最高(34.4%);干期长度与交通区0.075~0.15mm粒径段的沉积物中NO3--N含量及商业区粒径≥0.3mm的沉积物中NH3-N含量之间的相关性均最显著;雨水管道沉积物中NH3-N和NO3--N的干期分布与O-H和N-H等官能团、表面极性和亲水性、微观形貌等有一定关联;交通区雨水管道沉积物中Gemmobacter等反硝化优势菌种(相对丰度总和为20.15%)对NO3--N干期分布影响更显著.  相似文献   
47.
利用干湿法结合工艺实现废弃SCR脱硝催化剂中Ti、V和W元素的高效分离和浸出,提出成套废弃SCR脱硝催化剂中Ti、V和W的回收技术。以废弃SCR脱硝催化剂为研究对象,优选Ti、V和W元素最佳浸出工况,研究硫酸溶解法回收TiO2和有机萃取法回收V2O5和WO3的回收率与纯度。结果表明:酸浸还原浸钒最优工艺条件为温度140℃,液固比30∶1;钠化焙烧浸钨最优工艺条件为煅烧温度750℃,反应物与Na2CO3配比(质量比)为1∶1.5,在以上条件下V、W浸出率分别达到97.6%、93.6%。利用硫酸溶解法回收得到的TiO2产物主要以锐钛矿晶型存在形式,在最佳焙烧温度750℃下,TiO2回收率达到97.17%,纯度为95.35%。利用有机萃取法回收得到的V2O5和WO3产物的回收率和纯度分别为72.47%、75.43%和93.25%、78.26%。  相似文献   
48.
Glycine(Gly) is ubiquitous in the atmosphere and plays a vital role in new particle formation(NPF).However,the potential mechanism of its on sulfuric acid(SA)-ammonia(A)clusters formation under various atmospheric conditions is still ambiguous.Herein,a(Gly)_x·(SA)_y·(A)_z(z≤x+y≤3) multicomponent system was investigated by using density functional theory(DFT) combined with Atmospheric Cluster Dynamics Code(ACDC) at different temperatures and precursor concentrations.The results show that Gly,with one carboxyl(-COOH) and one amine(-NH_2) group,can interact strongly with SA and A in two directions through hydrogen bonds or proton transfer.Within the relevant range of atmospheric concentrations,Gly can enhance the formation rate of SA-A-based clusters,especially at low temperature,low [SA],and median [A].The enhancement(R) of Gly on NPF can be up to 340 at T=218.15 K,[SA]=10~4,[A]=10~9,and [Gly]=10~7 molecules/cm~3.In addition,the main growth paths of clusters show that Gly molecules participate into cluster formation in the initial stage and eventually leave the cluster by evaporation in subsequent cluster growth at low [Gly],it acts as an important "transporter" to connect the smaller and larger cluster.With the increase of [Gly],it acts as a "participator" directly participating in NPF.  相似文献   
49.
PM_(2.5) separator directly affects the accuracy of PM_(2.5) sampling.The specification testing and evaluation for PM_(2.5) separator is particularly important,especially under China's wide variation of terrain and climate.In this study,first a static test apparatus based on polydisperse aerosol was established and calibrated to evaluate the performance of the PM_(2.5) separators.A uniform mixing chamber was developed to make particles mix completely.The aerosol concentration relative standard deviations of three test points at the same horizontal chamber position were less than 0.57%,and the particle size distribution obeyed logarithmic normal distribution with an R~2 of 0.996.The flow rate deviation between the measurement and the set point flow rate agreed to within ± 1.0% in the range of -40 to 50℃.Secondly,the separation,flow and loading characteristics of three cyclone separators(VSCC-A,SCC-A and SCC112) were evaluated using this system.The results showed that the 50% cutoff sizes(D_(50)) of the three cyclones were 2.48,2.47 and 2.44 μm when worked at the manufacturer's recommended flow rates,respectively.The geometric standard deviation(GSD) of the capture efficiency of VSCCA was 1.23,showed a slightly sharper than SCC-A(GSD = 1.27),while the SCC112 did not meet the relevant indicator(GSD = 1.2 ± 0.1) with a GSD = 1.44.The flow rate and loading test had a great effect on D_(50),while the GSD remained almost the same as before.In addition,the maintenance frequency under different air pollution conditions of the cyclones was summarized according to the loading test.  相似文献   
50.
This study profiled the bacterial community variations of water from four water treatment systems, including coagulation, sedimentation, sand filtration, ozonation-biological activated carbon filtration (O3-BAC), disinfection, and the tap water after the distribution process in eastern China. The results showed that different water treatment processes affected the bacterial community structure in different ways. The traditional treatment processes, including coagulation, sedimentation and sand filtration, reduced the total bacterial count, while they had little effect on the bacterial community structure in the treated water (before disinfection). Compared to the traditional treatment process, O3-BAC reduced the relative abundance of Sphingomonas in the finished water. In addition, ozonation may play a role in reducing the relative abundance of Mycobacterium. NaClO and ClO2 had different effects on the bacterial community in the finished water. The relative abundance of some bacteria (e.g. Flavobacterium, Phreatobacter and Porphyrobacter) increased in the finished water after ClO2 disinfection. The relative abundance of Mycobacterium and Legionella, which have been widely reported as waterborne opportunistic pathogens, increased after NaClO disinfection. In addition, some microorganisms proliferated and grew in the distribution system, which could lead to turbidity increases in the tap water. Compared to those in the finished water, the relative abundance of Sphingomonas, Hyphomicrobium, Phreatobacter, Rheinheimera, Pseudomonas and Acinetobacter increased in the tap water disinfected with NaClO, while the relative abundance of Mycobacterium increased in the tap water disinfected with ClO2. Overall, this study provided the detailed variation in the bacterial community in the drinking water system.  相似文献   
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