城市街道空气中铅污染及其对机体无机盐影响的研究

本文对兰州市不同交通路口铅污染现场监测及交警人群健康体检，结果表明各路口受汽车尾气污染严重，铅浓度在１．１６～２．６４μｇ／ｍ３之间。将１２０名交警分外勤警７０人作为污染组，内勤警及户藉警５０人作为对照组，调查结果尿中δ－氨基乙酰丙酸两组比较没有统计学差异（Ｐ＞０．０５）；污染组发铅、尿铅浓度均显著高于对照组，发锌、铜、钙及血中ＩｇＡ、ＩｇＧ、ＩｇＭ均低于对照组，并具有统计学差异（Ｐ＜０．０５，Ｐ＜０．０１）。提示街道空气铅污染对交警体内无机盐水平及机体免疫能力具有一定的影响。     

汉江上游郧县曲远河河口段全新世古洪水水文状态研究

对汉江上游河谷郧县曲远河河口剖面进行了沉积学、粒度、磁化率和烧失量的研究。结果表明：夹在古土壤中的灰白色沉积层是典型的古洪水滞流沉积物，记录了一次特大洪水事件，用地层对比法和OSL方法确定其发生时间为4 950~5 450 a B.P.。用古洪水SWD尖灭点法确定古洪水行洪水位高程为169 m，采用比降法恢复其洪峰流量为60 577 m3/s。根据2011年汉江上游洪水洪痕，用相同的方法对洪峰流量进行了反演，误差为-411％，说明用比降法恢复的古洪水洪峰流量是可靠的     

差异性区域网格化环境管理初探

差异性区域网格化环境管理是在环境状况存在明显分异区域进行环境管理的有效的方式。依托网格化管理在资源整合和信息共事方面的优势．探讨在环境状况差异明显区域构建网格化管理体系的目标、步骤与管理思路。以上海市宝山区的实践为例．根据区内环境现状差异明显的特征。将全区划分为150个网格．从中选取环境矛盾较为突出的网格．开展区域环境综合整治与环境建设．逐年逐块提升区域网格环境状况．实现区域环境网格等级的提升．初步达成区域生态、生产、生活的协调。实践表明．差异性区域网格化管理是建设环境友好型社会的一种有效的环境管理手段。     

Sedimentary Pigments and Organic Matter in Relation to Benthic Fauna in the Tan-Shui Estuary, Taiwan

The benthic ecological structure of the Tan-Shui estuary, Taiwan is changed due to long term effects of dumping of urban wastewater and of engineering actions. to monitor these changes, we sampled and analyzed benthos and sediment from 12 stations on the estuary.

The composition of the dominant species of benthos varied seasonally, with molluscan and crustacean species having greater numbers and higher frequencies of occurrence than other species. the dominant taxa during winter were Nassarius sp. and Maldanidae at two stations. Analysis using Simpson's index and Shannon's index showed the benthic community varied more in coastal areas than in offshore areas.

Physicochemical analysis showed that most of the Tan-Shui estuary consisted of sandy sediment. the variations in concentrations of organic carbon and total nitrogen at each station were small. Although the concentrations of chlorophyll-a and carotenoid at all stations were generally low, the two stations had the highest concentrations, and we concluded that the concentration of pigments in these sediments was related to the abundance of benthos. the community structure of the benthos reflected the characteristics of the sediments, and benthic species exhibited selection of and adaptation to specific sedimentary environments.     

Modelling and Prediction of Diesel Engine Performance using Relevance Vector Machine

Diesel engines are being increasingly adopted by many car manufacturers today, yet no exact mathematical diesel engine model exists due to its highly nonlinear nature. In the current literature, black-box identification has been widely used for diesel engine modelling and many artificial neural network (ANN) based models have been developed. However, ANN has many drawbacks such as multiple local minima, user burden on selection of optimal network structure, large training data size, and over-fitting risk. To overcome these drawbacks, this article proposes to apply an emerging machine learning technique, relevance vector machine (RVM), to model and predict the diesel engine performance. The property of global optimal solution of RVM allows the model to be trained using only a few experimental data sets. In this study, the inputs of the model are engine speed, load, and cooling water temperature, while the output parameters are the brake-specific fuel consumption and the amount of exhaust emissions like nitrogen oxides and carbon dioxide. Experimental results show that the model accuracy is satisfactory even the training data is scarce. Moreover, the model accuracy is compared with that using typical ANN. Evaluation results also show that RVM is superior to typical ANN approach.     

Interspecific and intraspecific identification of Dendrobium based on the psbAtrnH intergenic region sequences and the 5S rRNA gene spacer sequences北大核心CSCD

This research aimed to investigate the interspecific and intraspecific identification of Dendrobium by using the multi-locus method so as to provide a molecular basis for Dendrobium identification through the combination of chloroplast psbA-trnH intergenic region sequences and ribosome 5S rRNA gene spacer sequences. PCR direct sequencing was applied to detect the chloroplast psbA-trnH intergenic region sequences as well as the ribosome 5S rRNA gene spacer sequences of 12 Dendrobium species, while the psbA-trnH intergenic region sequences of Dendrobium denneanum dq-2 variety and dq- 5line were cloned and sequenced for single nucleotide polymorphism (SNP) analyzing. The sequences were analyzed by the software Sequencher4.14, Bioedit7.0, MEGA5.2 and Dansp5.0; the interspecific and intraspecific Kimara-2-Parameter(K2P) distances were also calculated. The phylogenetic tree (using Neighbor joining method) was constructed with Bulbophyllum odoratissimum and Bletilla striata as outgroup. The results showed an average length of chloroplast psbA-trnH gene sequences in Dendrobium as 742.3 bp, with 72 variable sites, including 33 information sites; the average length of the ribosome 5S rRNA gene spacer sequences in Dendrobium was 336.4 bp, with 213 variable sites including 139 information sites. Using psbAtrnH intergenic region sequences in combination with ribosome 5S rRNA gene spacer sequences can not only identify D. denneanum, D. hancockil, D. thysiflorum, D. devonianum, D. moniliforme, D. chrysotoxum, D. officinale, D. heterocarpum and D. nobile, but also differentiate D. officinale from different geographical populations, and distinguish the dq-2 variety and dq 5line with SNP in the multi locus of D. denneanum.     

典型喀斯特小流域水文水化学过程对旱季暴雨的响应

通过定位监测和样品跟踪采集,在旱季对喀斯特小流域连续20天无前期降雨的一场暴雨(累计降雨量64mm)水文水化学过程进行了动态监测,并分析了相关的影响因素。结果表明,小降雨事件(8.5mm)未能引起溪流水位、电导率及温度的明显变化,而当累计降雨量达到35.5mm后溪流水开始响应。此后,溪流水文水化学参数对降雨快速响应,除硝态氮外,电导率(EC)、δ18 O、Ca2+迅速降至最低值,雨水稀释作用对其水化学变化起主要作用。通过对溪流新旧水比例进行划分发现,降雨前期和后期,溪流以旧水补给为主,而在水位快速上涨阶段,新水比例达到34%左右。两次降雨过程中,在溪流水水位升高的情况下,水体中硝态氮浓度仍然表现出高于雨前浓度的趋势。该研究为该区旱季小流域水资源利用和污染物防治方面提供了一定理论依据。