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1.
中药材原料在醇提、发酵、醇沉等环节气体间的相互反应生成的挥发性有机气体(VOCs)对环境和人体健康产生影响。本研究采用SUMMA罐采样-二级冷阱浓缩-GC/MS方法,研究了贵州省典型中药制药企业在提取、浓缩阶段VOCs的排放特征,对比分析了西药企业产排VOCs污染水平,并进行了健康风险评估。结果表明:中药、西药制药企业分别检测出64和106种挥发性有机气体,总挥发性有机气体(TVOCs)浓度为56.45~1 361.66#g/m3;中药制药企业主要物质为二氯化碳、环己烷、1,2-二氯乙烷,以烷烃、含氧有机物和恶臭类物质为主,占比76.42%,西药制药企业主要物质有二氯甲烷、丙酮、甲苯,异戊烷,烷烃和苯系物占比达到83.72%;中、西制药企业致癌风险值均介于1×10-6~1×10-4之间,具有潜在致癌风险,与西药企业相比,中药企业非致癌风险指数较小;中药制药产排VOCs的OFP在2.93~33.54#g/m3之间,芳香烃(甲苯)是中药制药产生的VOCs中对臭氧生成贡献最大的关键活性组分。  相似文献   

2.
利用苏玛罐采样、大气预浓缩-气相色谱质谱联用技术,于2016年对合肥市区大气中挥发性有机物(VOCs)进行监测,对4个不同季节的VOCs主要组成、浓度水平和变化特征进行了分析研究,并进行健康风险评价.结果表明:合肥市大气中共检出48种VOCs,主要包括烷烃、芳香烃以及卤代烃等;合肥市区TVOCs(检出VOCs化合物之和)年平均浓度(体积分数)为15.61×10~(-9),最高浓度为47.64×10~(-9);合肥市区TVOCs浓度呈明显季节变化,冬季最高,春秋次之,夏季最低,日均浓度具有早晚高、中午低的变化特征;化合物非致癌风险商值均在安全范围内,检出的苯等致癌性VOCs的致癌风险超过美国环保局给出的风险限值,存在较大的致癌风险.  相似文献   

3.
为评价珠三角某垃圾焚烧厂内工人和周边村民的二噁英健康风险,采集并分析了该垃圾焚烧厂的厂内环境(空气和飞灰)邻近敏感点(邻近村落)环境(空气和土壤)的二噁英(PCDD/Fs)质量水平,运用美国环保署(USEPA)风险评价体系和蒙特卡洛模拟(Monte Carlo simulation)对厂内工人、邻近敏感点村民(成人、青少年和儿童)在呼吸吸入、皮肤接触和经口摄入等暴露途径的健康风险进行评估.结果表明:(1)该垃圾焚烧厂固化飞灰中的PCDD/Fs毒性当量(以I-TEQ计)范围为8.99~240.00 ng TEQ/kg,环境空气中的为0.03~0.20 pg TEQ/m3,邻近敏感点土壤中的为0.81~2.04 ng TEQ/kg. (2)飞灰、厂内环境空气和邻近敏感点环境空气的PCDD/Fs单体分布特征更加接近,土壤中PCDD/Fs单体分布稍有差别. (3)厂内工人和村民(成人、青少年和儿童)的致癌风险(CR)合计第95%值范围为4.55×10-7~6.04×10-6,为可接受风险范围(<10-5);非致癌风险(HI)合计第95%值范围为4.61×10-3~4.28×10-2,远低于1,非致癌风险极低;(4)厂内工人和成人村民的CR较高, 第95%值分别占风险安全值的60%和39%.厂内工人的CR从环境空气吸入(包括在厂内和敏感点)和飞灰意外经口摄入方式占比最高,分别达55.12%和38.43%;成人村民的CR中从环境空气吸入占主导(占97.79%).建议加强对环境空气二噁英监控和飞灰经口摄入的风险管控.  相似文献   

4.
2014年7月和10月,在昆明市中心城区东风广场采样点用苏玛罐采集了大气VOCs样品,并且利用气相色谱-质谱联用仪(GC-MS)对大气中57种VOCs进行分析.结果表明:昆明夏季和秋季大气中VOCs的日平均质量浓度分别为(14.95±3.91)μg/m~3和(45.48±6.26)μg/m~3,夏季各类VOCs对臭氧生成潜势(OFP)的贡献率表现为:烷烃烯烃芳香烃,秋季各类VOCs对总OFP的贡献率表现为:芳香烃烯烃烷烃.源解析结果显示:昆明中心城区夏季大气VOCs的最主要来源为工业过程源,贡献率为40.59%,其次为交通工具尾气排放(19.33%),溶剂使用(19.19%),LPG/NG和汽油挥发(10.02%).秋季大气中VOCs最主要来源为工业过程源,其贡献率为32.34%,其次为溶剂使用源和LPG/NG挥发(27.68%),交通工具尾气排放(23.26%)和汽油挥发(8.12%).  相似文献   

5.
为了更全面地识别大气中挥发性有机物(VOCs),通过建立VOCs高分辨谱库、优化匹配指数阈值、综合使用电子轰击和化学电离获取分子离子峰等步骤,采用气相色谱-静电场轨道阱高分辨质谱(GC-Orbitrap/MS)建立了环境空气中VOCs的非靶标筛查方法.结果表明,在大连市植物源和交通源采样点环境空气样品中共识别出244种化合物,其中148种的定性水平符合1级或2a级.对识别出的VOCs进行定量与半定量分析,发现交通源和植物源采样点样品的φ(TVOCs)平均值分别为(21.02±7.12)×10-9和(15.96±4.20)×10-9.应用最大增量反应活性(MIR)法评估了VOCs的臭氧生成潜势(OFP),芳香烃和含氧挥发性有机物对两类采样点样品OFP的贡献率均较高,筛查出了一些以往受关注较少的VOCs,包含这部分VOCs后估算的OFP可增加11%以上.  相似文献   

6.
基于苏州市2020年7—10月VOCs离线采样数据, 探讨苏州市VOCs的时空分布特征、来源及其臭氧生成潜势(OFP), 并与国内其他研究进行对比。结果表明, 苏州市夏季VOCs平均浓度为47.1 nL/L, OFP平均贡献为334.7 μg/m3, 芳香烃和含氧挥发性有机物(OVOCs)是VOCs 的重要组分, 对臭氧生成贡献较大, 其浓度和组分与上海市趋势相似。PMF结果表明, VOCs的6个主要浓度来源排序为液化石油气挥发源(20.7%)>有机溶剂使用源(19.5%)>工业源(17.5%)>机动车尾气排放源>其他源>燃烧源, 苏州市液化石油气挥发源高于长三角地区普遍水平。长三角地区芳香烃浓度较高, 与较高的工业和溶剂使用源贡献相关。总体来说, 芳香烃和OVOCs对苏州市大气环境影响较大, 贡献较大的是表面涂层源、加油站、道路移动源、石化与化工源, 应重点管控。  相似文献   

7.
为了解太原市PM10和PM2.5中重金属污染状况,采集了太原市春季环境空气中可吸入颗粒物(PM10)和细颗粒物(PM2.5)样品,利用等离子体发射光谱仪对样品中As和8种重金属(Mn,Cu,Zn,Pb,Cr,Ni,Co,Cd)的含量进行测定,并对As和重金属健康风险进行评价。结果显示:太原市PM10和PM2.5中均以Zn的质量浓度最大,分别为369.08ng/m3和271.74ng/m3;As的质量浓度相对较小,分别为3.41ng/m3和2.33ng/m3;各点位As、Cu、Zn、Pb、Cr和Cd元素主要显含在PM2.5中。PM10和PM2.5通过呼吸吸入途径产生的成人非致癌风险和致癌风险为儿童的3.98~4.00倍;非致癌风险总和(Hi)低于人体可接受的水平,不具有非致癌风险;PM2.5和PM10的致癌风险介于人体可接受范围,不具有致癌风险。各点位As和重金属在PM2.5和PM10中的非致癌风险比值PHi小于1;1号、3号点位致癌风险比值QR大于1,且对人体健康危害最严重的为可吸入颗粒物PM10,需引起高度重视。  相似文献   

8.
选取济南市东泺河城市汇水区为研究对象,分采暖季和非采暖季,采集30个点位的地表灰尘,测定了Cd,Cr,Cu,Pb,Zn,Hg,As等7种重金属质量分数,评估了其健康风险水平.结果表明:儿童和成人两季致癌健康风险均小于最大可接受风险值.成人两季非致癌风险均可忽略.儿童非致癌风险在非采暖季存在,采暖季可忽略.非致癌风险贡献前三位的重金属为:Cr>Pb>Cu,这3种重金属占到总非致癌风险的95%左右. Cr致癌风险占总致癌风险的99.5%以上.风险较高的区域均集中在研究区的西北方向.重金属污染来源主要为交通源和小型建材企业.  相似文献   

9.
陈晓秋  徐亚  傅彦斌  王颖 《海峡科学》2012,(6):11-13,16
在2011年10月使用挥发性有机物(VOCs)快速在线监测系统监测福州市城区VOCs日变化趋势,进行工作日与非工作日VOCs日变化特征的对比分析.结果表明:(1)工作日TVOCs在上午7:00前后和下午1 7:00前后各出现一个峰值,与人们上下班时的交通高峰期一致;而非工作日人们的作息时间发生了变化,交通状况也随之改变,使得非工作日TVOCs浓度日变化与工作日有很大的差异,在上午7:00前后和下午17:00前后没有典型的双峰,非工作日TVOCs浓度的最大值在下午出现.(2)同TVOCs对比一样,非工作日的苯和甲苯日变化趋势也与工作日不同,进一步印证了非工作日与工作日交通状况的不同造成VOCs日变化特征的差异.(3)通过对日变化研究期间风向玫瑰图分析发现,由于风速较小,在SSW风向下,TVOCs浓度最高,s和SSE风向的TVOCs浓度也较高;由于风速相对较大及从海洋上带来了洁净空气,在ENE、E、ESE风向上TVOCs浓度较低.  相似文献   

10.
 采用三级冷阱预浓缩和气相色谱质谱联用仪分析了天津市华苑居住区大气中挥发性有机物(VOCs)组成,总共检测108种物质,其中烷烃和苯系物占VOCs总量59.2%。冬春两季总挥发性有机物(TVOCs)浓度范围分别为519.4—1029.6μg/m3和299.8—463.8μg/m3,其中丙酮平均浓度最高(20.0μg/m3),正庚烷最低(1.1μg/m3)。TVOCs和单质浓度呈现出冬高春低特点,这与大气层对污染物降解和稀释能力的季节性变化存在一定关系,而另一个重要原因则是周边源产生的污染物在大气输送下对华苑地区的影响。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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