珠江入海口水体中多氯联苯及其归宿分析

以气质联用仪检测了珠江八大入海口水样中19种PCBs单体. 结果显示:PCBs在溶解相和颗粒相中的总含量分别为0.02～2.55和0.05～5.14 ng/L;水体PCBs的log Koc范围为4.70～5.18,与其log Kow值表现为非线性相关,表明水体溶解相与颗粒相间PCBs分配的非平衡状态;第三相胶体相吸附了滤液中2.3～52.6%的PCB单体;入海口区域的PCBs水气交换净通量约为-1.41102 ng/m2 day,PCBs表现为水体向大气的扩散,入海口水体可能是周边大气中PCBs的重要输入源.     

北海近岸海域表层沉积物中DDTs、PCBs的分布、来源与生态风险分析

为评价广西北海市近岸海域表层沉积物中滴滴涕(DDTs)和多氯联苯(PCBs)的生态风险水平,于2017年8月使用挖斗式采泥器采集北海市近岸海域17个站点的表层沉积物样品,采用气相色谱法测定样品中DDTs(pp′-DDE、op′-DDT、pp′-DDD、pp′-DDT)和PCBs(三氯联苯PCB28,四氯联苯PCB52,五氯联苯PCB101、PCB112、PCB118,六氯联苯PCB138、PCB152、PCB153,七氯联苯PCB180和八氯联苯PCB198)的含量,分析其组分特征,并对沉积物中DDTs和PCBs进行生态风险评价。结果表明:北海近岸海域表层沉积物中持久性有机污染物(Persistent Organic Pollutants,POPs)平均含量(ng·g-1,干重)为PCBs(3.08)DDTs(0.89);污染物等值线图表明近岸海域表层沉积物中的DDTs、PCBs含量高于远岸海域,DDTs含量高值区主要在北海港泊位及营盘港海域,PCBs含量高值区主要在北海港泊位、营盘海域及铁山港湾口海域。DDTs 4种同系物平均百分含量排序为pp′-DDE(46.4%)pp′-DDT(21.8%)op′-DDT(20.5%)pp′-DDD(11.3%),pp′-DDE为沉积物DDTs中的主要成分;五氯联苯PCB101和七氯联苯PCB180为沉积物中PCBs的主要成分;所有站位中DDTs、PCBs的含量平均值均低于一类标准(GB18668-2002),污染程度总体较轻;有17.6%的站位DDTs含量介于生态风险效应区间低值(Effects Range Low,ERL)和生态风险效应区间中值(Effects Range Median,ERM)间。北海市近岸海域表层沉积物中DDTs、PCBs残留水平生态风险总体较低。     

加速溶剂萃取用于贝类中多氯联苯的提取

针对分析贝类中痕量多氯联苯（PCBs）,采用加速溶剂萃取提取其中的7种PCBs（PCB28,PCB52,PCB101,PCB118,PCB153,PCB138,PCB180）,讨论了温度和循环次数对加速溶剂萃取提取效率的影响,并采用凝胶渗透色谱（GPC）和Florisil土填充的固相萃取（SPE）小柱联用净化,去除脂肪和其他杂质,通过GC-ECD分析得到回收率数据。结果表明加速溶剂萃取用于贝类中PCBs的提取,最佳温度条件为100℃,最佳循环次数为2次。采用此种前处理方法的回收率和重复性均较好,具有良好的应用价值。     

长江口表层沉积物中多氯联苯残留和风险评价

采用GC-ECD(gas chromatography-electron capture detector)对14种多氯联苯(polychlorinated biphenyls,PCBs)在长江口及东海近岸沉积物中的残留水平进行了测定,对其分布、组分特征、来源及生态风险水平进行了探讨.结果表明:多氯联苯在表层沉积物中的...     

Products Made from Nonmetallic Materials Reclaimed from Waste Printed Circuit Boards

Printed circuit boards (PCBs) are in all electronic equipment, so with the sharp increase of elec-tronic waste, the recovery of PCB components has become a critical research field. This paper presents a study of the reclaimation and reuse of nonmetallic materials recovered from waste PCBs. Mechanical proc-esses, such as crushing, milling, and separation, were used to process waste PCBs. Nonmetallic materials in the PCBs were separated using density-based separation with separation rates in excess of 95/. The re-covered nonmetals were used to make models, construction materials, composite boards, sewer grates, and amusement park boats. The PCB nonmetal products have better mechanical characteristics and dura-bility than traditional materials and fillers. The flexural strength of the PCB nonmetallic material composite boards is 30/ greater than that of standard products. Products derived from PCB waste processing have been brought into industrial production. The study shows that PCB nonmetals can be reused in profitable and environmentally friendly ways.     

基于PEEC方法的平面电路EMC问题分析

提出了基于部分元等效电路（PEEC）方法求解印制板电路电磁兼容问题的新方法,即将印制板电路的辐射问题分为两步：（1）用部分元等效电路的方法确定印制板导体上的场源（电流）分布;（2）将所有电流元的辐射场进行叠加求总的辐射场。文中对上述方法进行了分析,在此基础上通过一个对称电路和一个非对称电路的辐射场计算,提出了一些工程设计中减小辐射的设计准则。     

黄河头道拐段冰封期PCBs的分布特征及来源分析

以2012-2013年度黄河头道拐断面冰封期冰、水中多氯联苯的实测值为依据,剖析该断面在冰封期多氯联苯的含量分布特征,并进行来源分析。得出结论:水中ΣPCBs的质量浓度范围为10.19~53.00 ng·L-1,平均质量浓度为31.87 ng·L-1、冰中ΣPCBs的质量浓度范围为2.91~34.34 ng·L-1,平均质量浓度为15.11 ng·L-1,低氯联苯含量高于高氯联苯,这与我国曾大量生产使用低氯联苯的实际情况相符合;与2011-2012年度同期相比低氯联苯的含量增长65.7%,高氯联苯降低20.39%,总体增长28.96%。流凌期PCBs含量最大,进入冰封期阶段,PCBs含量逐步降低,融冰期有所回升。头道拐断面冰封期冰、水中PCBs的来源主要有:变压器油、油漆添加剂和造纸漂白工业。     

Levels and distribution of polychlorinated biphenyls in the atmosphere close to Chinese Great Wall Station,Antarctica: Results from XAD-resin passive air sampling

Antarctica is an important research region for assessing persistence and long-range atmospheric transport (LRAT) of persistent organic pollutants (POPs). In this study, XAD-resin passive air sampling was conducted near the Chinese Great Wall Station, Antarctica, during a one-year sampling period in 2009-2010. The air concentrations of polychlorinated biphenyls (PCBs) were at a very low level, with total PCBs in the range of 26.74-45.08 pg m 3. PCB profiles were dominated by tetra-PCBs, tri-PCBs and di-PCBs, indicating LRAT was responsible for the pollutants in the Antarctic atmosphere. The sampling site near the Chinese Great Wall Station did not show higher PCB levels than the other sites, suggesting that PCB sources associated with the Great Wall Station were negligible. PCB-11 is a non-Aroclor congener, which has specific sources compared to other Aroclor PCB congeners. PCB-11 was observed in all air samples, with an average concentration of 1.22 pg m 3. To our knowledge, this study is the first investigation of PCB levels and distribution in the atmosphere around the Chinese Great Wall Station, Antarctica.     

典型废旧家电印刷线路板热失重特性和热解动力学模型

用热重法研究了废旧电视机、电脑、手机和洗衣机4种典型家电印刷线路板的热解特性,发现在相同条件下不同印刷线路板的热解起始温度、终止温度、最大失重速率、峰温和反应时间随升温速率的变化规律一致,但总失重率存在着较大差异．建立了不定温条件下非均相反应的热解动力学模型,用Kissinger法和形状因子法求解了4种典型家用电器印刷线路板的表观动力学参数E、A和n．彩电：E=103．09kJ／mol,爿：8．17×10^8／min,n=1．73;洗衣机：E=98．15kJ／mol,A=1．50×10^8／min,H=2．73;手机：E=78．79k1／mol,A=2．48×10^7／rain,H=3．56;电脑：E=101.31kJ／mol,A=2．96×10^8／min,n=1．77．由动力学模型计算出的转化率与实验值之间能够较好地吻合．     

生物酶对五氯联苯降解的初步研究

多氯联苯（PCBs）是具有代表性的持久性有机污染物（POPs）,其氯代数目越多,降解越难。本文以分离筛选的6株PCBs降解细菌为材料,制备了含有NADH辅酶再生系统关键酶甲酸脱氢酶（FDH）的PCBs降解复合酶,研究了其对PCBs的降解效果。结果表明,Pseudomonas sp. MGB11胞内酶/FDH复合酶对五氯联苯PCB114的降解率在10 h内可达69.4%,对于高毒性、难降解的高氯PCBs的污染修复具有应用价值。     

多氯联苯类化合物分子结构的理论研究

采用Gaussian-98软件包中ab initio分子轨道法（HF/6-31G）对多氯联苯PCBs28、PCBs52、PCBs101、PCBs103、PCBs118、PCBs138、PCBs153、PCBs180和PCBs204等9种物质的分子结构进行了计算,并通过分析计算所得的结构参数：键长、键角、二面角、能量值以及偶极矩揭示了该9种物质的结构特征,比较了PCBs同族体在结构上的微小差别,探讨了多氯联苯分子结构与毒性的关系,理论计算结果与实验结果基本一致,同时所得的PCBs同族体的结构参数对研究PCBs同族体的环境行为具有重要的参考价值。     

基于灰度信息的PCB板精确定位

利用模板匹配法在待测PCB图像中建立坐标系,采用基于边缘灰度幅度的轮辐法检测定位圆,由幅度排序相关搜索算法检测出最佳圆;提出PCB板角度定位的3种算法,比较了不同算法在检测精度、速度和稳定性上的差异,实证了轮辐法可实现PCB板的精确快速定位.     

热提羊栖菜多糖对黑腹果蝇生长的影响

【目的】研究经热提醇沉得到的羊栖菜多糖(SFPs)对黑腹果蝇生长的影响。【方法】采用85℃热水煮提,乙醇沉淀,氯化钙去除褐藻淀粉等多种工序提取羊栖菜多糖,并分析其化学性质;以黑腹果蝇为实验对象,研究羊栖菜多糖浓度对黑腹果蝇幼虫体型、体重和羽化的影响。【结果】经热提醇沉得到的羊栖菜多糖纯度较高,总糖含量高达81.93%,分子量和单糖组成较稳定。与对照组相比,经羊栖菜多糖处理后,黑腹果蝇在体型和体重上均有增加。实验组0.1%♀和1.5%♀与对照组CK♀存在显著差异(P0.05),0.5%♀组与对照组CK♀存在极显著差异(P0.01);实验组0.1%♂、0.5%♂、1.5%♂与对照组CK♂存在显著差异,但实验组之间并没有显著差异,其中1.5%♂组增重最为明显。实验组与对照组在幼虫孵化率上存在显著差异;对照组黑腹果蝇从卵至羽化为5~8d,0.1%和0.5%组为6~9d,1.5%组为6~10d。0.1%♀、1.5%♀、0.1%♂组与相对应的对照组相比,羽化数量存在显著差异;对比羽化成虫雌雄比例,只有1.5%组与CK组存在显著差异。【结论】经热提醇沉法提取的羊栖菜多糖性质稳定,能降低黑腹果蝇幼虫羽化率,延长幼虫羽化时间,对果蝇后代的雌雄比例略有影响,同时可以增大成虫体型,增加成虫体重。     

Research progress of the endocrine disrupting activities of polychlorinated biphenyls

Polychlorinated biphenyls (PCBs) arc global persistent organic pollutants. Almost all commercial PCBs mixtures, single PCB congener, and their metabolites possess endocrine disrupting activities. They can disrupt the estrogen/androgen system, thyroid hormone system and other endocrine systems by interfering with the synthesis, transport, storage, metabolism, and feedback regulation of hormones. The newest data related to the endocrine disrupting activities of PCBs and their mechanisms arc reviewed and the research perspectives arc also discussed.     

Electrocatalytic dechlorination of 2,4,5-trichlorobiphenyl using an aligned carbon nanotubes electrode deposited with palladium nanoparticles

Palladium loaded carbon nanotubes cathode with well-aligned nanotubes array was successfully fabricated on a titanium foil (Pd/CNTs/Ti) using a chemical vapor deposition technique and subsequent electrochemical deposition method. Pd particles were well dispersed on CNTs wall surfaces with average sizes no more than 20 nm, in most cases around 10 nm. Experiments for dechlorination of 2,4,5-trichlorobiphenyl (PCB 29) in methanol/water solution were carried out for the first time using Pd/CNTs/Ti cathode for investigation of its performance in electrocatalytic dechlorination of PCBs. Results show that Pd/CNTs/Ti presented better dechlorination efficiency (up to 90% in 6 h) than Pd/Ti and Pd/graphite cathodes owing to unique properties owned by CNTs, which benefited enhanced dechlorination of PCB 29. Complete dechlorination for PCB 29 was observed and biphenyl was identified to be final dechlorination product. The amount of Pd loading, cathode potential, and electrolytes were found to be key factors influencing dechlorination performance.     

球栅阵列封装板级跌落试验与有限元分析

通过板级跌落试验研究球栅阵列(BGA)封装在冲击脉冲下的动态响应和失效模式,并运用有限元软件ABAQUS对跌落过程进行模拟。模拟计算结果与实验结果一致,应力最大值出现在最外围拐角焊点与印刷电路板PCB侧焊盘的连接处,剥离应力是导致焊点裂纹萌生、扩展最终完全断裂的主要原因。此外,研究了外围尺寸相同的3种不同焊点分布对PCB挠度和最外围拐角焊点剥离应力的影响,结果表明:焊点分布对PCB挠度影响较小;外围焊点分布密度显著影响最外围拐角焊点的剥离应力。     

Reproductive failure in common seals feeding on fish from polluted coastal waters

The population of common seal Phoca vitulina in the westernmost part of the Wadden Sea, The Netherlands, has collapsed during the past few decades. Between 1950 and 1975 the population dropped from more than 3,000 to less than 500 animals. Comparative studies of common seal populations from different parts of the Wadden Sea reveal that pup production has declined sharply only in the western (Dutch) part. A comparative toxicological study on the levels of heavy metals and organochlorines in tissues of seals from the western and northern parts of the Wadden Sea shows that only the polychlorinated biphenyl (PCB) levels differ significantly. This is predominantly a result of PCB pollution from the river Rhine, which mainly affects the western (Dutch) part. PCBs are thought to be responsible for the low rate of reproduction in Dutch common seals on the basis of epidemiological and experimental data on the ability of PCBs to interfere with mammalian reproduction. Here I report that reproductive failure in common seals from the Dutch Wadden Sea is related to feeding on fish from that polluted area. This is the first demonstration of a causal relationship between naturally occurring levels of pollutants and a physiological response in marine mammals.     

多氯联苯的正辛醇—空气分配系数与分子结构信息的关系研究

以多氯联苯分子的范德华体积、偶极矩、平均分子极化率和分子椭圆度等分子结构信息为基础,通过线性多元回归建立了它们与正辛醇—空气分配系数K OA的定量结构—性质关系(QSPRs),预测了一些多氯联苯的K OA。同时研究了分子结构数据对K OA的影响,结果表明对K OA影响最大的是范德华体积和平均分子极化率。苯环上氯原子数越多,对-log K OA的影响越大,非邻位氯取代的多氯联苯分子的-log K OA较大,其次是单邻位取代的多氯联苯分子的-log K OA,双邻位取代的多氯联苯分子的-log K OA较小。     

递增负荷运动对运动员血睾酮及皮质醇含量的影响

研究递增负荷运动对运动员血睾酮及皮质醇含量的影响;随机选择某体育学院自愿参加本实验的大学生20名,将其划分成实验组和对照组,令实验组受试者进行16 d、4个阶段的递增负荷跑步运动,每天运动1次,4次一个阶段,对照组不进行任何运动。第三阶段实验组体重、体脂百分比低于对照组,去脂体重高于对照组,差异显著(P0.05),BMI、体脂百分比和体脂含量低于对照组,差异非常显著(P0.01);实验组第三阶段体重低于实验前,差异非常显著(P0.01),体脂百分比、BMI、体脂百分比和体脂含量低于实验前,去脂体重高于实验前,差异显著(P0.05);第四阶段实验组各身体成分指标和对照组及实验前相比差异非常显著(P0.01)。和实验前相比,实验组受试者四个阶段血睾酮浓度逐渐降低,第三阶段较实验前有显著性差异(P0.05),第四阶段较实验前有非常显著性差异(P0.01);实验组第三阶段血睾酮含量较对照组更低,有显著性差异(P0.05),第四阶段也低于对照组,有非常显著性差异(P0.01)。实验组第一阶段唾液和血清皮质醇含量高于对照组和实验前,差异呈非常显著性(P0.01),第二阶段唾液皮质醇含量高于对照组和实验前,差异呈显著性(P0.05)。实验过程中随着负荷的逐渐增加,实验组血睾酮含量/皮质醇逐渐增加。递增负荷运动能够降低运动员血睾酮含量,使皮质醇含量先增加后降低,说明递增负荷运动能够使机体分解代谢保持平衡。     

草地藏系绵羊贾洛类群生产性能研究

通过对150不同性别各年龄段贾洛羊的体尺、体重测定,以及对成年公羊（n=4）成年羯羊（n=6）的屠宰测定,结果得出：成年公羊的屠宰率为63．75±3．59％净肉率为35．00±0．82％,胴体重为37．33±5．05kg,肉骨比3．91．成年羯羊屠宰率为67．17±2.32％,净肉率为40．83±1．17％,胴体重为32．17±3．25kg,肉骨比5．15．成年贾洛羊的宰前活重X与净肉重Y的回归方程为y=1．761x＋23．915．