蚀变岩型金矿床地球化学新模型

以山东招远河东金矿为例，系统采集地表＋54m至－80m七个不同标高中段的地球化学样品，详细研究了包括碱性元素在内的20余种常、微量元素在蚀变岩中的分布特征，重新建立了典型蚀变岩型金矿床找矿评价的元素组合模式、物化探异常模式和地球化学分带模型，指出了深部找矿方向和探采工作应注意的问题。     

声屏障用于室内降噪的技术与经济问题

根据室内声屏障的降噪原理及影响因素,论述了室内声屏障降噪效果的评价与测量方法。通过固定式及活动式声屏障的设计,分析了室内声屏障的技术特点和经济效益。     

短缺资源类型与供需趋势分析

短缺资源是指在一定时空范围和一定技术经济条件下,因需求量大于供给量而产生明显缺口的资源。按照短缺资源的分类,中国战略性短缺资源主要有石油、耕地和淡水,三者对国家安全和社会经济发展具有全局性和长远性影响。中国非战略性短缺资源主要有森林、富铁矿、铬铁矿、铜矿和钾盐等。随着经济的发展,人口的继续增长,从本世纪初到本世纪中叶,上述各种短缺资源的短缺数量增加,短缺程度趋于加剧。解决中国短缺资源的供需矛盾,需要从多种途径综合考虑:①多元化利用国外资源,弥补国内资源短缺;②建立战略资源储备体系,应付突发危机;③节约、替代和综合利用降低资源消耗;④强化资源保护,提高资源再生能力;⑤依靠科技进步,寻求解决短缺资源的新途径。     

链条式刮油刮泥机在治理含油污水中的应用

在平流隔油池安装山东省新泰市石油化工机械厂生产的ＧＴ－１型链条式刮油刮泥机，操作简单，运行稳定，收油效果良好，除油效率由以前的７３．４９％提高到８３．０６％，出水含油可控制在５０ｍｇ／Ｌ以下，每年增加经济效益１３．６万元     

湘东北燕山晚期花岗岩构造环境判别

在湘东北中生代多期陆内花岗岩浆活动中 ,燕山晚期花岗岩占有重要地位 ,燕山晚期大规模花岗岩侵入代表一种特殊的构造环境。本文通过湘东北主要燕山晚期花岗岩的岩石化学和微量元素来判别成岩构造环境 ,认为该期花岗岩属于富碱质的钙碱性花岗岩 ,为陆内拉张环境下的产物 ,进一步进行构造环境分类 ,判别其属于后造山PA型花岗岩 ,形成于造山作用后期的拉张环境 ,与陆内裂谷长期拉张的构造环境明显不同。在区域构造演化分析的基础上 ,提出湘东北燕山晚期花岗岩形成于印支—燕山早期陆内挤压 走滑剪切造山作用后期的构造松弛阶段拉张环境 ,燕山晚期PA型花岗岩的出现标志着陆内活化由挤压向拉张的构造转折 ,同时也反映湘东北的陆内活化至少经历了陆内挤压和陆内拉张两个演化阶段。     

Prenatal diagnosis of distal arthrogryposis type I by ultrasonography

Two consecutive pregnancies in a woman with initially undiagnosed type I distal arthrogryposis (DA) are reported. A prenatal diagnosis of the condition was made by ultrasound in the 17th week of gestation in one of the pregnancies, whereas in the subsequent pregnancy the disorder was excluded as early as 13 weeks' gestation. The diagnoses were verified at birth. The feasibility of prenatal diagnosis of DA type I in the second trimester is thus confirmed and its possibility in the late first trimester is suggested.     

新疆盐渍化土壤氮肥氨挥发损失特征初步研究

在室温下应用“静态吸收法”,研究不同盐渍化程度的盐化土壤和碱化土壤上氮肥氨挥发损失特征。结果表明:(1)除碱土外碱化土壤上氮肥氨挥发量随时间延长呈现下降趋势,在盐化土壤上氨挥发量随时间呈现先上升后下降趋势。(2)供试9个典型盐渍化土壤样品上氮肥氨挥发量(Y)与时间(t)关系均符合Y=at2 bt c动力学方程,相关性呈极显著水平。(3)氨挥发总量(Y)、氨挥发速率(Yi)与土壤含盐量(x)呈极显著正相关;氨挥发持续时间随着盐渍化程度的增加而延长。(4)氨挥发总量、挥发速率与盐渍土pH相关性未达到显著水平;盐渍土上pH值对氨挥发的影响需要进一步研究。以上结果表明,盐渍化耕作土壤上氮肥氨挥发的控制要依据盐渍化类型的不同而制定相应的措施。     

Ecological effects of reactivation of artificially stabilized blowouts in coastal dunes

In an inner dune area in the Dutch coastal dunes several artificially stabilized blowouts were reactivated. The purpose was to investigate whether these reactivated blowouts could remain active despite the increased atmospheric deposition of nutrients, how much area would be affected by sand from the blowouts, whether the vegetation would respond to the deposition of sand, and whether the reactivation of blowouts could be a measure against the effects of acidification and eutrophication. This paper presents the results of the first years of minitoring the changes in the blowout morphology and the response of the vegetation. In the monitoring period (1991–1994) the blowouts remained active and grew slowly in size and depth. The area which receives more than 1 cm of calcareous sand from the blowout in three years was up to six times the area of the blowouts. Moss vegetation responded to the accumulation of sand:Campylopus introflexus was sparse within the deposition area whereasTortula ruralis was found near the contour of 1 cm deposition in 3 yr. No indications were found that shrubs or marram grass were adversely affected by the deposition of sand. The experiment forms part of a programme to test measures aimed at mitigating the effects of air pollution on natural landscapes. From the viewpoint of the programme the experiment is a success.     

Alternative Non-market Value-Elicitation Methods: Are the Underlying Preferences the Same?

We advocate a more formal structural approach for comparing WTP for non-market or pre-test-market goods conveyed by fundamentally different preference elicitation mechanisms. Seven independent samples of respondents were asked to value the identical good. Elicitation methods include one actual purchase and six widely used hypothetical choice formats. Using a common underlying indirect utility function (and stochastic structure) allows data for different elicitation methods to be used independently, compared pair-wise (as in much of the earlier literature) or pooled across all samples in one unified model with heteroscedasticity across elicitation methods. Our differences in estimated WTP for the individual models are typical of earlier findings. However, pooled-data models that allow for heteroscedasticity reveal that while there are substantial differences in the amount of noise in the different samples, a common underlying systematic component of the preference structure cannot be rejected for at least four (and possibly five) of these seven elicitation methods.     

Evidence of an Edge Effect on Avian Nest Success

Abstract:  Habitat fragmentation may modify ecological patterns by increasing the importance of edge effects, including elevating rates of predation on avian nests. Conventional wisdom suggests an increased rate of predation along habitat edges, and previous reviews support this view. These reviews did not apply recent statistical approaches, however, and some were based on a small number of studies. In our meta-analysis of 64 nest-predation experiments, our results supported prior reviews of the general pattern of increased nest predation along habitat edges (  p < 0.01). We separated studies into ecologically relevant categories and found the following patterns: (1) Edge effects were more pronounced in North America and northwestern Europe than in central Europe or Central America. This result may be biased, however, by the different habitats studied in the regions. (2) Marshes and deciduous forests had significant edge effects, whereas edge effects were not apparent in coniferous forests, tropical forests, or fields. (3) Ground and natural nest studies were more likely to exhibit edge effects. (4) Edge effects were detected in studies that used quail eggs and real eggs. (5) Edge effects were not significant when artificial nests were exposed for typical incubation periods, but were significant for shorter exposures. Three alternative hypotheses may explain increased nest predation along edges. The edge-effects hypothesis states that increased nest losses along edges are the result of the habitat discontinuity. The landscape-structure hypothesis states that more fragmented landscapes are more heavily depredated by nest predators. The human-disturbance hypothesis states that near anthropogenic edges increased nest predation is related to human activities. Nest-predation experiments should be placed in a landscape context to reveal differences between the hypotheses.