建立土壤硫释放过程的人工神经网络模型

以温度、土壤含水率、胱氨酸添加量和土壤pH值作为土壤释放挥发性含硫化合物的主要影响因素,采用正交实验方法分析这些因素与土壤硫释速率的关系,利用BP神经网络算法对实验结果建模,并用模型对不同影响因素下的土壤硫释放情况进行预测。结果表明,网络模型对学习过的样本有较高预测精度,预测结果相对误差在2％以下,对未学生过的样本,误差为10％左右,表明人工神经网络方法建立的模型适用于土壤硫释放预测。     

草原生态环境监测数据建库方法初探

该文系统地介绍了草原生态环境监测数据库的一般方法，在建立图像，图形，多媒体及数据子库的前提下，同时提出了宏观遥感监测数据与地面定位监测数据的结合方式，可操作性较强。     

海洋环境责任保险

随着海洋环境问题日益尖锐，可能影响海洋环境的作业者，一旦造成海洋环境污染必将面对巨额的责任赔偿与罚款，作业者为降低自己的风险损失，政府为增强其治理及控制污染的能力，作业者不得不购买海洋环境责任保险，本文着重分析了海洋环境责任保险的发展历史，依法强制实行环境责任保险的必要性及海洋环境责任保险的责任范围。     

Sex-dependent obesogenic effect of tetracycline on Drosophila melanogaster deteriorated by dysrhythmia

Antibiotics have been identified as obesogens contributing to the prevalence of obesity. Moreover, their environmental toxicity shows sex dependence, which might also explain the sex-dependent obesity observed. Yet, the direct evidence for such a connection and the underlying mechanisms remain to be explored. In this study, the effects of tetracycline, which is a representative antibiotic found in both environmental and food samples, on Drosophila melanogaster were studied with consideration of both sex and circadian rhythms (represented by the eclosion rhythm). Results showed that in morning-eclosed adults, tetracycline significantly stimulated the body weight of females (AM females) at 0.1, 1.0, 10.0 and 100.0 µg/L, while tetracycline only stimulated the body weight of males (AM males) at 1.0 µg/L. In the afternoon-eclosed adults, tetracycline significantly stimulated the body weight of females (PM females) at 0.1, 1.0 and 100.0 µg/L, while it showed more significant stimulation in males (PM males) at all concentrations. Notably, the stimulation levels were the greatest in PM males among all the adults. The results showed the clear sex dependence of the obesogenic effects, which was diminished by dysrhythmia. Further biochemical assays and clustering analysis suggested that the sex- and rhythm-dependent obesogenic effects resulted from the bias toward lipogenesis against lipolysis. Moreover, they were closely related to the preference for the energy storage forms of lactate and glucose and also to the presence of excessive insulin, with the involvement of glucolipid metabolism. Such relationships indicated potential bridges between the obesogenic effects of pollutants and other diseases, e.g., cancer and diabetes.     

Effectiveness evaluation of water-sprinkling in controlling urban fugitive road dust based on TRAKER method: A case study in Baoding, China

Fugitive road dust (FRD) contributes a great deal to urban rainwater and air pollution and is commonly controlled by water-sprinkling in most Chinese cities. However, there is a lack of information on its effectiveness. We used the Testing Re-entrained Aerosol Kinetic Emissions from Roads (TRAKER) method to monitor different types of roads in Baoding city before and within 1 hr after water-sprinkling and obtained the road dirtiness index (a) and PM concentration in the road environment ($T_{\mathrm{T}}^{*}$), to evaluate the removal efficiency for PM deposited on the road surface (${\eta }_a$) and the reduction efficiency for the PM concentration in the road environment (${\eta }_{\text{PM}}$). The results give that the ${\eta }_a$ for three types of roads is ranked: branch road (87%-–100%) > major arterial road (80%-83%) > minor arterial road (68%-77%), and the ${\eta }_{\text{PM}}$ ranked: minor arterial road (70%) > branch road (46%-58%) > major arterial road (37%-53%). The ${\eta }_a$ and ${\eta }_{\text{PM}}$ varied non-linearly with time and presented a quadratic curve. The average effective control time (${\eta }_{\mathit{a}}$> 0) was 62 min on the major and minor arterial roads, and much longer than 1 hr on branch roads. The ${\eta }_{\text{PM}}$ values diminished completely by 72 min on average from the end of sprinkling for the three types of roads. Water-sprinkling can remove PM₁₀ particles from the road surface and reduce their concentration in the road environment more thoroughly than PM_2.5. Our findings could be helpful for controlling urban FRD emissions more efficiently and precisely.     

纸张消费激增拷问可持续发展对策

每个人每天都要用纸.如今,各类纸产品五花八门,在生活和工作的各个角落无所不在.但是有多少人知道,正是市场上日益丰富、琳琅满目的纸产品和消费者快速增加的需求,带来了中国南方海南、广西、云南、广东等省区经济发展模式的一场激烈争论.     

我校学生体育行为的调查研究

本文通过对我校03、04级学生的问卷调查，就我校学生的体育兴趣、体育课现状的态度、学校体育设置地满意程度、对教师工作的满意度等方面进行了调查分析；同时也对学生的体育行为进行了分析；并在调查研究的基础上对我国高校的体育指导思想和体育教学形式进行了反思，提出了以学生为本设计高校体育的教学形式及内容。     

拯救天堂雨林

5月初,刘芳又回到了这个“人又多又吵”的北京.一个月的雨林生活让她感觉恍如隔世,但在雨林中留下的各种淤青伤痕和蚊虫叮咬的痕迹,依旧勾起了她对那个真实的雨林世界的牵挂.     

城市污水厂污泥堆肥中试实验研究

城市污水厂污泥由于产生量大且成分复杂，如何对它进行稳定化、无害化处理已越来越受到人们的关注。本研究基于好氧发酵仓式堆肥系统，研究了城市污泥处理过程中温度、含水率、pH、有机质、水溶性有机碳、总氮和发芽指数等指标参数的变化规律。研究结果表明：当物抖初始含水率控制在65％左右时，在强制通风量112．5m^3／12hr，搅拌频率30min/24hr的工艺条件下，堆肥过程可以实现顺利升温并在55℃以上维持3天，满足杀灭致病茵要求的条件；14天反应用期结束时，物抖含水率、水溶性有机碳和有机质含量显著降低，堆肥产品腐熟，卫生学指标达到了美国EPA污泥产品A类标准；得列的污泥产品成为性质优良的土壤质量调节荆。     

银硫离子选择电极测定工业废水中的硫化物

本法用Ag/S离子选择电极测定废水中的硫化物,测定浓度范围0.1～1000.0mg/l,方法精密度为4.3％,回收率为P2.5％,检出限为0.1mg/l。大多数离子不干扰测定,该法简便快速,适用于例行监测。