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1.
食品保鲜膜应用广泛,影响面大,"致癌保鲜膜"问题在我国掀起轩然大波;介绍食品保鲜膜的主要材质:聚乙烯(PE)、聚氯乙烯(PVC)、聚偏二氯乙烯(PVDC);分析哪些保鲜膜不安全;增塑剂DEHA是否致癌物,为什么有比较安全的PE保鲜膜,商家还要使用存在安全隐患的PVC保鲜膜;为什么有其他合法增塑剂不用,还要用违反国标的DEHA;不加增塑剂的保鲜膜是否绝对安全;保鲜膜能否放在微波炉里加热;有人不敢用保鲜膜,改用塑料袋、微波炉塑料容器了,是否保险.  相似文献   

2.
董文茂 《环境》2007,(7):50-50
东临风光迤逦的松山湖,北靠同沙自然保护区,西南依大岭山森林公园,倚山傍湖,生成了大岭山镇的天生丽质.近年来,大岭山镇委、镇政府将建设"依山傍湖的现代生态新城"作为新时期战略目标,在"创建省卫生镇"等一系列工作上,获得喜人成绩.  相似文献   

3.
打破僵局     
"我们拔了18吨,仍不见动静,请领导拿意见."4月13日,当河南油田井下作业二部副经理靳水生和工艺人员赶到L1256井场时,201修井队技术员范红禅立即向他们汇报拔钻解卡情况. "好,再拔拔看!"听到指令,司机汪佳柱启动30吨斜井作业机,一手扶离合器手柄,一手握刹把,脚踩油门,两眼紧盯指挥手势.作业机吼叫着,掐着油管的"脖子"使劲往上拽,那架势如同一场拔河比赛.压力器指针指向了18吨,油管还是一动不动.  相似文献   

4.
随着生产力水平的不断提高和世界经济一体化趋势的快速发展,国际河流已成为有关国家开发的热点,国际河流的生态保护与生态安全是国家维护自身生态安全的前沿.界河--黑龙江流域可持续发展,对边境地区的稳定.防止流域生态退化和保护黑龙江流域森林、黑土地、湿地等资源具有重要意义.界河沿岸地区的自然保护区在保护该地区的生态环境,生物多样性、生态系统功能和国土安全方面起到了非常重要的作用.文章介绍了界河沿岸地区自然保护区的发展状况以及数量、面积、类型、分布和管理等现状,分析了制约自然保护区发展的主要因素提出了因地制宜的建设该地区自然保护区的有效措施及发展方向.  相似文献   

5.
直面冷峻的环境现状,每一个有理性与责任感的公民无不忧心如焚.蔽日的烟云、腥臭的污河、毒化的农田和振聋发聩的噪音一刻不歇地疯狂考验和鞭笞着人们从心灵到生理的忍耐极限.本文使用大量详实的数据还原出天津环保的真相,社会各界的高度关注、积极参与和成效卓著的努力让我们对天津山清水秀的明日充满了期待.  相似文献   

6.
2006年起,广西壮族自治区地震局把做好政务信息工作摆上了重要议事日程,安排了专人负责,落实了措施,落实了专项经费,政务信息工作发生了质的飞跃.特别是信息管理员制度和激励机制从根本上改观了政务信息往日的面貌.本文介绍了广西壮族自治区地震局电子政务信息工作在事业发展中的定位、主要做法、成效和经验,意在抛砖引玉,加强学习和交流.  相似文献   

7.
上海市交通干道空气中挥发性有机物冬季污染特征研究   总被引:2,自引:0,他引:2  
2004年冬季对上海市交通干道附近空气中的挥发性有机物进行了连续6天的监测.采用GC-MS定性检出28种物质,芳香烃和烷烃分别占32%和25%.在检出物中有8种属于美国EPA优先控制的有毒有害物质.GC-FID定量表明,芳香烃中含量最高的是苯系物(BTEX)苯、甲苯、乙苯、二甲苯,其中甲苯浓度最高.苯系物的浓度与一氧化碳和二氧化氮的良好相关性说明苯系物的来源与机动车尾气密切相关,而且都受风速和车流量的影响.  相似文献   

8.
闫琨  周康根 《云南环境科学》2008,27(Z1):103-106
详细介绍了电石渣在生产建材,治理环境污染,生产化工产品等方面的利用,并对它们在处理效果,创造的经济效益及实际应用过程中遇到的问题进行了分析.提出了一种处理电石渣的有效方法--生产具备高附加值的纳米碳酸钙,在实现经济效益的同时,还能创造良好的环境效益及社会效益.  相似文献   

9.
每天的17:30分,我们乘坐的班车在下班号响后会准时驶出厂门,出了厂门的右侧有个站,这儿是机关干部的上车点. 由于班车从我们车间始发,近水楼台先得月,我便有了固定的座位,一个位于车尾,靠窗的单座.而每天经过厂门口停站时,总会上来一个人,站在我边上,伸出一只毛茸茸的手抓住扶手.从那一身将校呢的制服上,我了解到他是厂武装部长,姓王,今年初刚转业到我们厂工作.  相似文献   

10.
一次,我国一家工厂想接一位德商的棉布袋订单.对方要求,棉布袋的材料必须是本色棉布,两面的图案须用6种颜色印刷,而且对袋子的尺寸和提手的针脚都作了严格的规定.德商没有当场与这家工厂的厂长签约,而是提出在做出符合标准的样品后,再谈今后的合作.  相似文献   

11.
A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p < 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.  相似文献   

12.
The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.  相似文献   

13.
To demonstrate the existence of light thresholds in plant growth and to examine the effects of elevated CO2 on the shade tolerance of a tree species, an experiment consisting of a completely randomized design for a total of 96 yellow birch (Betula alleghaniensis Britton) seedlings was conducted with 3 light levels (2.9%, 7.7%, 26.1% of full sunlight)×2 CO2 levels (350 and 700±10 ppm) with 4 replications in a phytotron. The study proved that thresholds exist and they vary in different plant organs. In ambient CO2, the thresholds were 13.3%, 18.7%, 15.0%, 15.2%, and 15.6% of full sunlight for stem, leaf, root, total plant biomass, and the averaged value, respectively. In 700 ppm CO2, the corresponding thresholds were 16.7%, 21.3%, 18.1%, 21.7% and 19.5% for stem, leaf, root, total plant biomass, and the averaged value, respectively. The lowest threshold in the stem is an indicator of the minimal light intensity for regular growth for seedlings of this species. Below this threshold, light-stressful growth occurs. The result of a paired t-test indicated that the thresholds in elevated CO2 were significantly higher than in ambient CO2. This suggests that yellow birch will lose its moderate shade tolerance, evolutionally becoming a shade-intolerant species, and that it may become more difficult to naturally regenerate in the future.  相似文献   

14.
应用电子显微探针元素分析技术,对背角无齿蚌(Anodonta woodiana)的贝壳(棱柱层和珍珠层)进行了19种元素(Ag、Al、Au、Ca、Co、Cu、Fe、Hf、Mg、Mn、Mo、Na、Re、Se、Sn、Sr、Tl、V、Zn)分布特征的初步研究.元素面分布分析和定量线分析结果均直观而明显地表明:贝壳中Ca含量最高,Hf、Re、Mn、Al、Co、Fe、Sr、Cu和Na的含量较低,而Au、Mg、Tl、Zn、Sn、Ag、V、Mo和Se的含量甚少.Mn在珍珠层的分布高于棱柱层,壳顶区域的珍珠层的含量(0.087±0.045)%显著高于棱柱层(0.030±0.025)%(P<0.05),腹缘区域的珍珠层的含量(0.072±0.055)%亦显著高于棱柱层(0.044±0.025)%(P<0.05),而其余元素在贝壳中均匀分布.  相似文献   

15.
综述了近年来国内外有关河湖沉积物中邻苯二甲酸酯类物质(PAEs)的分析方法和污染特征研究进展。详细阐述了索氏提取法、超声提取法、微波辅助萃取法、加速溶剂萃取法及被动采样技术等沉积物PAEs前处理方法,柱层析法、固相萃取法2种净化方法和气相色谱、气相色谱-质谱、气相色谱-三重四极杆质谱、高效液相色谱等仪器分析方法,并对比分析了上述方法的优缺点,以期为更高效提取河湖沉积物中PAEs提供参考依据;同时总结了近年来国内外河湖沉积物中PAEs污染特征的研究进展,相比欧美等发达国家,我国沉积物PAEs污染较严重,潜在生态风险较高,主要污染物为DBP和DEHP等。  相似文献   

16.
IntroductionAswangovernorate ,Egypt ,isfamousforbymonuments (Ancient,CopticandIslamic) .Thefoundationareofthefirstimportanceandcareshouldbetakentoseethattheyareconsolidatedandprotectedasforaspossiblefromtheinfiltrationofwater.Waterisamajorcauseofdamage ,no…  相似文献   

17.
Earthworm toxicity tests are useful tools for terrestrial risk assessment but require a hierarchy of test designs that differ in effect levels (behavior, sublethal, lethal). In this study, the toxicity of chlorpyrifos contaminated soil on earthworms was assessed. In addition to the acute and chronic tests, an avoidance response test was applied. Earthworms were exposed to sublethal and lethal concentration of chlorpyrifos, and evaluated for acute toxicity, growth, fecundity and avoidance response after a certain exposure period. The test methods covered all important ecological relevant endpoints (acute, chronic, behavioral). Concentration of 78.91 mg/kg, chlorpyrifos caused significant toxic effects in all test methods, but at lower test concentrations, only significant chronic toxic effects could be observed. In the present study, chlorpyrifos had adverse effect on growth and fecundity in earthworm exposed to 5 mg/kg chlorpyrifos after eight weeks. The avoidance response test, however, showed significant repellent effects concentration of 40 mg/kg chlorpyrifos. For chlorpyrifos, concentration affecting avoidance response was far greater than growth and fecundity, it seemed likely that earthworms were not able to escape from pesticide-contaminated soil into the clean soil in field and hence were exposed continuously to elevated concentrations of pesticides.  相似文献   

18.
为探究青岛近海不同天气下气溶胶中金属元素的浓度分布特征,于2012年4~5月,2012年8月~2013年3月在青岛近海采集了总悬浮颗粒物(TSP)样品,利用电感耦合等离子体质谱法(ICP-MS)和电感耦合等离子体原子发射光谱法(ICPAES)分析了主要微量金属元素.结果表明,Al、Ca、Fe、Na、K和Mg是TSP中主要的金属元素,质量浓度占所测元素总浓度的94.2%.TSP及金属元素浓度月变化明显,Fe、Al、K、Ca、Mg、Zn、Ba、Mn、Ti、Sr和Li均在11月和1月浓度最高,Be、Sc、Co、Ni和Cr在1月最高,Na在8、11和2月较高,12月最低,Pb在1月和2月最高,8月和12月最低.富集因子表明Be、Co、Al、Ca、Fe、K、Mg、Mn、Sr和Ti主要受自然源影响,Li、Cr、Ni、Zn、Ba和Na除受自然源外,还受部分人为源影响,Pb主要来自人为源.不同天气状况对TSP及其金属元素浓度影响较大,除Ti外,所测元素浓度均在烟雾天最高.与晴天相比,烟雾天除Ti外,其余元素均升高,增幅为1~4倍,雾天Li、Be、Cr、Ni、Al、Fe、Mg和Mn变化不大,Pb和Na升高较多,Co、Ca和Ti降低较多,霾天Cr、Co和Ti降低,其余元素浓度升高,增幅为1~3倍.大部分元素在晴天富集因子最小,雾天富集因子最大.Ni、Zn、Ba、K、Na、Pb和Sr富集因子为晴<霾<烟雾<雾,Fe和Mn为晴<烟雾<霾<雾,Al和Mg为晴<雾<霾<烟雾,其余金属不同天气下富集因子的变化规律各不相同.  相似文献   

19.
通过大气环流向海洋大气边界层传输的人为源和陆源物质,明显改变了海洋气溶胶中痕量金属的组成.但基于开阔海域岛屿连续观测研究海洋气溶胶中痕量金属元素组成及其来源的研究较少.2010年3—5月在我国台湾北部东海海域彭佳屿岛采集了60个TSP(总悬浮颗粒物)样品,采用电感耦合等离子体质谱仪(ICP-MS)分析了19种痕量金属(Al、Fe、Ti、Y、Mn、Ba、Sr、Co、Cr、V、Ni、Tl、Zn、Sn、Pb、As、Cd、Sb、Se)的质量浓度.基于TSP中Al浓度、气团后向轨迹分析和美国国家宇航局CALIPSO卫星星载激光雷达扫描图像,将采集的TSP分为非沙尘TSP(不受沙尘影响的TSP)和沙尘TSP(受沙尘影响的TSP).沙尘TSP中所有痕量金属的浓度都高于非沙尘TSP,表明沙尘对彭佳屿岛TSP中痕量金属有贡献.结合富集因子、相关性分析和PMF模型研究结果表明,彭佳屿岛春季非沙尘TSP中Al、Fe、Ti和Y主要来源于地壳矿物,Mn、Ba、Sr、Co和Cr同时受地壳矿物和人为源的影响;沙尘TSP中Al、Fe、Ti、Y、Mn、Ba、Sr、Co和Cr主要来源于地壳矿物.V和Ni在彭佳屿岛春季非沙尘TSP中主要来源于燃料油燃烧,而在沙尘TSP中同时受燃料油燃烧和地壳矿物的影响.非沙尘TSP和沙尘TSP中,Tl、Zn、As、Sn、Pb、Cd、Sb和Se的来源相似.Tl主要源于交通和煤燃烧,Zn、Sn、Pb、Cd和Sb同时来源于交通、煤和燃料油燃烧,As主要来源于煤燃烧,Se则主要来源于煤和燃料油燃烧.研究显示,人为源释放到大气中的Tl、Zn、As、Sn、Pb、Cd、Sb和Se可以通过大气环流长距离传输至开阔海域.   相似文献   

20.
Bioaccumulation of heavy metals in fishes from Taihu Lake, China   总被引:9,自引:0,他引:9  
The Cr,Zn,Cu,Cd,Pb contents were determined in Cyprinus carpio Linnaeus,Carassius auratus Linnaeus,Hypophthalmichthys molitrix and Aristichthys nobilis,which were caught from Meiliang Bay,Taihu Lake,a large,shallow and eutrophic lake of China.The results showed that:(1)the Cr,Cu,Pb,Cd contents in the edible parts of the four fish species were much lower than Chinese Food Health Criterion(1994),but the Zn contents were higher than the Criterion;(2)Cd contents were the highest in the liver of fish,Pb contents were almost the same in all organs of fish,Cr contents mainly enriched in the skin and gonads,Zn contents were the highest in the gonad(♀),and Cu contents were the highest in the liver;(3)the total metal accumulation was the greatest in the liver and the lowest in the muscle.The total metal accumulation was the highest in C.auratus L.This investigation indicated that fish products in Taihu Lake were still safe for human consumption,but the amount consumed should be controlled under the Chinese Food Health Criterion to avoid excessive intake of Zn.  相似文献   

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