户内燃气集中安检综合服务模式探讨

针对用户端燃气安全存在的问题,提出户内燃气集中安检综合服务模式(实行入户安全检查、安全宣传和隐患整改三联动),探讨了户内燃气集中安检综合服务模式的内容、流程、注意事项。     

Exposure to organophosphate and polybrominated diphenyl ether flame retardants via indoor dust and childhood asthma

Although the ubiquitous detection of polybrominated diphenyl ether (PBDE) and organophosphate flame retardants (PFRs) in indoor dust has raised health concerns, only very few epidemiological studies have assessed their impact on human health. Inhalation of dust is one of the exposure routes of FRs, especially in children and can be hazardous for the respiratory health. Moreover, PFRs are structurally similar to organophosphate pesticides, which have been associated with allergic asthma. Thus, we investigated whether the concentrations of PFRs and PBDEs in indoor dust are associated with the development of childhood asthma. We selected 110 children who developed asthma at 4 or at 8 years old and 110 matched controls from a large prospective birth cohort (BAMSE – Barn, Allergy, Milieu Stockholm Epidemiology). We analyzed the concentrations of 7 PFRs and 21 PBDEs in dust collected around 2 months after birth from the mother's mattress. The abundance rank in dust was as follows: TBOEP?TPHP>mmp‐TMPP>EHDPHP~TDCIPP>TCEP~TCIPP~BDE‐209?BDE‐99>BDE‐47>BDE‐153>BDE‐183>BDE‐100. There was no positive association between the FRs in mattress dust and the development of childhood asthma. In contrast, dust collected from mattresses of the mothers of children who would develop asthma contained significant lower levels of TPHP and mmp‐TMPP. This study provides data on a wide range of PFRs and PBDEs in dust samples and development of asthma in children.     

Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish

Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine system, pathological changes in tissues and reproduction and development) and tissue residue levels of OHCs (e.g., PCBs, DDTs, CHLs, PBDEs and in a few cases perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonates (PFSAs)). Some exceptions include semi-field studies on comparative contaminant effects of control and exposed cohorts of captive Greenland sled dogs, and performance studies mimicking environmentally relevant PCB concentrations in Arctic charr. Recent tissue concentrations in several arctic marine mammal species and populations exceed a general threshold level of concern of 1 part-per-million (ppm), but a clear evidence of a POP/OHC-related stress in these populations remains to be confirmed. There remains minimal evidence that OHCs are having widespread effects on the health of Arctic organisms, with the possible exception of East Greenland and Svalbard polar bears and Svalbard glaucous gulls. However, the true (if any real) effects of POPs in Arctic wildlife have to be put into the context of other environmental, ecological and physiological stressors (both anthropogenic and natural) that render an overall complex picture. For instance, seasonal changes in food intake and corresponding cycles of fattening and emaciation seen in Arctic animals can modify contaminant tissue distribution and toxicokinetics (contaminant deposition, metabolism and depuration). Also, other factors, including impact of climate change (seasonal ice and temperature changes, and connection to food web changes, nutrition, etc. in exposed biota), disease, species invasion and the connection to disease resistance will impact toxicant exposure. Overall, further research and better understanding of POP/OHC impact on animal performance in Arctic biota are recommended. Regardless, it could be argued that Arctic wildlife and fish at the highest potential risk of POP/OHC exposure and mediated effects are East Greenland, Svalbard and (West and South) Hudson Bay polar bears, Alaskan and Northern Norway killer whales, several species of gulls and other seabirds from the Svalbard area, Northern Norway, East Greenland, the Kara Sea and/or the Canadian central high Arctic, East Greenland ringed seal and a few populations of Arctic charr and Greenland shark.     

后酯化法制备聚羧酸盐系高效减水剂的研究

通过丙烯酸与烯丙基磺酸钠的自由基共聚制备了含有羧基和磺酸基团的共聚物,然后将其与聚乙二醇单烷基醚进行酯化反应,合成了可用作高效减水剂的聚羧酸盐接枝共聚物。通过CPC、红外光谱和化学滴定等方法对接枝共聚物的结构进行了表征。在此基础上讨论了接枝共聚物主链分子量、支链长度以及羧基、磺酸基和聚氧乙烯支链三者的摩尔比等因素对减水剂性能的影响。并研究了减水剂掺量对水泥净浆和砂浆性能的影响。     

二甲醚与液化石油气的合作性竞争

分析了二甲醚(DME)替代液化石油气(LPG)的可行性,DME替代LPG的现状、MDE产业发展面临的问题、DME与LPG进行合作的可行性。提出双方应开展合作性竞争,取长补短,规范市场,分担社会责任,实现市场双赢。     

聚乙二醇缩水甘油醚对丝素蛋白膜的改性

合成了不同分子量的聚乙二醇缩水甘油醚（PEGO），用1H－NMR，红外吸收光谱对其进行了表征，并将其用于改性丝素膜，用X射线衍射法，氨基酸分析仪研究了PEGO改性丝素膜的结构，并对改性丝素膜中的溶出率以及力学性能进行了测试，结果表明，PEGO可以改变丝素膜的结构，降低丝素大分子的溶出率，改性后的丝素膜具有较好的拉伸强度和较大的断裂伸长率，得到了较为柔韧的改性丝素膜。     

纤维素醚改性水泥浆的粘度变化研究

增稠是纤维素醚对水泥基材料的重要改性效果。研究了纤维素醚掺量、粘度仪旋转速度和温度对纤维素醚改性水泥浆粘度变化的影响。结果表明:纤维素醚掺量增加,水泥浆的粘度不断增加,纤维素醚溶液和水泥浆的粘度具有"复合叠加效应";纤维素醚改性水泥浆的假塑性低于纯水泥浆,粘度仪的旋转速度越低,或纤维素醚改性水泥浆的粘度越低,或纤维素醚掺量越低,纤维素醚改性水泥浆的假塑性越明显;温度升高,由于温度和水泥水化的共同作用,纤维素醚改性水泥浆的粘度会增加或降低。纤维素醚的种类不同,其改性水泥浆的粘度变化规律存在差异。     

新型聚芳醚酮离聚物膜材料的合成及结构表征

以二氯二苯甲烷和2,6-二甲基苯酚为原料合成了含有阻碍基团的双酚单体,用此双酚单体和1,3-二(4-氟苯甲酰基苯)在无水碳酸钾存在的条件下反应制得聚芳醚酮,然后用氯磺酸磺化,控制反应条件,使磺酸基团恰好进入苯环对位,制得新型结构的磺化聚芳醚酮。用DM SO溶解,倾于干净平整的玻璃板上制得无氟质子交换膜。     

硫酸钙晶须催化合成一缩二乙二醇双甲基丙烯酸酯*

以一缩二乙二醇和甲基丙烯酸甲酯为主要原料,酯交换合成一缩二乙二醇双甲基丙烯酸酯.硫酸钙晶须对合成一缩二乙二醇双甲基丙烯酸酯具有高效催化作用,而半水和无水硫酸钙均没有催化活性.考察了甲基丙烯酸甲酯与一缩二乙二醇物质的量比、催化剂用量、阻聚剂用量等因素对收率的影响,得出了最佳反应条件:n(甲基丙烯酸甲酯);n(一缩二乙二醇)=3.5:1,反应温度为回流温度,催化剂硫酸钙晶须、阻聚剂氮氧自由基加入量分别为一缩二乙二醇质量的3%、0.1%.在此条件下合成的一缩二乙二醇双甲基丙烯酸酯的收率大于96.3%,纯度达97%.     

含氟芳香聚合物

本文介绍了一些含氟芳香聚合物的制备方法及主要特性。