杭嘉湖蚕桑区主要大气氟污染源及治理现状

对杭嘉湖蚕桑区大气氟主要污染源——砖瓦厂氟的排放状况及各种含氟烟道废气治理装置的治理效果进行了较为深入的调查分析,认为砖瓦厂含氟废气不经烟道排放较为严重。目前砖瓦厂所采用的各种含氟废气治理装置中,旋流板塔装置除氟效率较佳,可使废气氟的排放浓度降至5mg/m~3以下,基本上能消除下风向300m以远的大气氟污染对蚕桑的严重危害。     

流动注射分光光度法测定水中铝的含量

以桑色素作显色剂,采用流动注射分光光度法测定水中铝的含量。在桑色素质量浓度为0．8g／L、聚氧乙烯辛基苯基醚体积分数为1．0％、进样环体积为400μL、检测波长420nm的条件下,采用流动注射分光光度法对水中铝的含量进行测定,本方法的线性范围为2～300μg／L,检出限（信噪比为3）为0．124μg／L,相对标准偏差为2．9％,加标回收率为96．4％～101．8％。     

盐析分相微萃取—高效液相色谱法测定水中含氯除草剂

采用盐析分相微萃取—高效液相色谱法同时测定水中3种含氯除草剂,建立并优化了反相离子对液相色谱条件,考察了萃取剂种类、盐析剂的种类和加入量及试样pH对萃取效果的影响。对氯苯氧乙酸、2,4-二氯苯氧乙酸和2,4-滴丁酯的质量浓度在0.1~100.0mg/L内与色谱峰面积呈良好的线性关系,相关系数不低于0.9992。平均回收率分别为96.29%、79.16%和70.21%,相对标准偏差小于5.3%。该方法操作简便、绿色环保,适合于水中含氯除草剂的测定。     

浅埋衬砌隧道-邻近建筑地震动力相互作用IBEM模拟

采用高精度间接边界元方法(IBEM)考察地震波入射下隧道-邻近建筑物二维地震动力相互作用的规律。结果表明:建筑物与邻近隧道存在着明显的相互作用,整体动力反应规律取决于隧道,建筑物之间的空间位置关系、隧道埋深、入射波的频率和角度等因素。隧道位于建筑物正下方时,刚性衬砌隧道(相对围岩)对上部结构主要表现为隔震效应;隧道位于建筑物两侧时,隧道对建筑顶部位移有明显放大效应,最大可放大约40%。同时隧道应力也明显增大,最大可放大约43%。因此实际中需根据隧道-建筑物的空间位置关系,适当调整衬砌隧道与沿线建筑物的抗震设防水平。     

土壤侵蚀信息系统的结构设计

本文介绍了黄土地区土壤侵蚀信息系统的建造原理与方法。分析探讨了土壤侵蚀各因子计算机自动提取的算法，以及土壤侵蚀预测模型的构造方法，并用灰色控制系统的原理确定了模型的参数。并以山西省离石县王家沟流域羊道沟为例进行了试验研究。     

Social media and disasters: a functional framework for social media use in disaster planning,response, and research

A comprehensive review of online, official, and scientific literature was carried out in 2012–13 to develop a framework of disaster social media. This framework can be used to facilitate the creation of disaster social media tools, the formulation of disaster social media implementation processes, and the scientific study of disaster social media effects. Disaster social media users in the framework include communities, government, individuals, organisations, and media outlets. Fifteen distinct disaster social media uses were identified, ranging from preparing and receiving disaster preparedness information and warnings and signalling and detecting disasters prior to an event to (re)connecting community members following a disaster. The framework illustrates that a variety of entities may utilise and produce disaster social media content. Consequently, disaster social media use can be conceptualised as occurring at a number of levels, even within the same disaster. Suggestions are provided on how the proposed framework can inform future disaster social media development and research.     

Invasion in a diversity hotspot: exotic cover and native richness in the Californian serpentine flora

Exotic species have been observed to be more prevalent in sites where the richness of native species is highest, possibly reflecting variation among sites in resources, propagule supply, heterogeneity, or disturbance. However, such a pattern leaves unclear whether natives at species-rich sites are subject to especially severe impacts from exotics as a result. We considered this question using path models in which relationships between exotic cover and native richness were evaluated in the presence of correlated environmental factors. At 109 sites on serpentine soils across California, USA, exotic cover was positively correlated with total native herbaceous richness and was negatively correlated with the richness of both serpentine-endemic and rare native herbs. However, in path models that accounted for the influences of soil chemistry, disturbance, overstory cover, and regional rainfall and elevation, we found no indication that exotic cover reduced any component of native herb richness. Rather, our results indicated similarities and differences in the conditions favoring exotic, native, endemic, and rare species. Our results suggest that, in spite of some localized impacts, exotic species are not exerting a detectable overall effect on the community richness of the unique native flora of Californian serpentine.     

7种农药对管氏肿腿蜂的毒性及初级风险评价

为评估农药对寄生类自然天敌昆虫的安全性,选择管氏肿腿蜂(Scleroderma guani Xiao et Wu)作为受试生物,采用管测药膜法测定了3种杀虫剂、2种除草剂、2种杀菌剂对其致死效应,并根据田间推荐剂量计算暴露量,采用风险商值HQ对杀虫剂进行风险评估。结果显示,与空白对照比较,3种杀虫剂均具明显毒性作用,其中丁硫克百威、吡虫啉和呋虫胺对管氏肿腿蜂的24 h半致死量(24 h-LR50)分别为5.11、2.92和0.06 g a.i.·ha-1,农田内风险商值分别为60.23、16.64和3 105。除草剂和杀菌剂在3倍最大田间推荐剂量作用下,24 h管氏肿腿蜂死亡率均小于50%。上述结果表明,在田间推荐用量下,3种杀虫剂对管氏肿腿蜂的初级风险评价为存在高风险,建议进一步开展高级阶段风险评估或者采取合理的风险管理措施来降低风险;除草剂和杀菌剂对管氏肿腿蜂的风险可接受。     

The fungicide difenoconazole alters mRNA expression levels of human CYP3A4 in HepG2 cells

The fungicide difenoconazole has been frequently detected in agricultural products, soils and surface waters, causing increasingly public concern due to toxicological properties. Although systemic triazole fungicides can inhibit the enzymatic activity of many CYP450 isozymes, how difenoconazole affects the human CYP3A4 still remains largely unknown. We thus investigated the effect of difenoconazole on normal mRNA expression and protein expression of human CYP3A4 by real-time quantitative PCR and western blot, respectively. Results show that the exposure to difenoconazole from 0.01 to 0.5 μM for 24 h down-regulates mRNA expression levels of human CYP3A4 in HepG2 cells. We also found that difenoconazole could inhibit the enzymatic activity of human CYP3A4 in a concentration-dependent mode. The IC₅₀ of difenoconazole for inhibition of CYP3A4 activity is 0.41 µM, showing a stronger inhibitor in comparison with ketoconazole. Overall, our findings indicate the potential risk of difenoconazole for the disruption of human CYP3A4.     

Testing the feasibility of a hypothetical whaling‐conservation permit market in Norway

A cap‐and‐trade system for managing whale harvests represents a potentially useful approach to resolve the current gridlock in international whale management. The establishment of whale permit markets, open to both whalers and conservationists, could reveal the strength of conservation demand, about which little is known. This lack of knowledge makes it difficult to predict the outcome of a hypothetical whale permit market. We developed a bioeconomic model to evaluate the influence of economic uncertainty about demand for whale conservation or harvest. We used simulations over a wide range of parameterizations of whaling and conservation demands to examine the potential ecological consequences of the establishment of a whale permit market in Norwegian waters under bounded (but substantial) economic uncertainty. Uncertainty variables were slope of whaling and conservation demand, participation level of conservationists and their willingness to pay for whale conservation, and functional forms of demand, including linear, quadratic, and log‐linear forms. A whale‐conservation market had the potential to yield a wide range of conservation and harvest outcomes, the most likely outcomes were those in which conservationists bought all whale permits.