海城市范家堡子滑石矿床外围找矿预测

简单地介绍了矿床地质特征,详细地分析了矿床的构造特征,推测矿区为一北北东向—倒转向斜的一部分,在F2断层的东侧已控制矿体的下部倒转向斜的核部和另一翼为本区的找矿方向。     

人卫激光测距仪接收与伺服系统改造及近地靶校准

本文介绍了房山人卫站近期在人卫激光测距系统完善和改造工作中的一些进展 ,特别是对接收系统进行了重新设计 ,对主镜、副镜、 4 5°反射镜镀多层介质膜以及安装调度。伺服系统和近地靶校准的改造工作。从2 0 0 4年 1月份的观测情况统计可以看出 ,改造后的系统在观测数量和测距能力方面均有明显的提高     

地基处理方案的模糊判别选择

采用何种地基处理方法,直接影响到地基处理的效果和造价,长期以来选择地基处理方案都是根据经验确定.文章采用层次分析法试图建立起地基处理方案选择评价体系,通过对比,在实际应用中达到优化选择地基处理方案的目的.     

Sodium fluoroacetate (1080) residues in longfin eels,Anguilla dieffenbachii,following exposure to contaminated water and food

Captive longfin eels (Anguilla dieffenbachii) were exposed to the vertebrate pesticide sodium fluoroacetate (1080) in the water column and through the ingestion of cereal pellet baits or possum muscle and gut tissue that contained 1080 residue. No mortality or unusual behaviour (in comparison with the controls) occurred in eels that were exposed to 1080. However, significantly greater weight loss occurred in eels exposed to 1080 compared with those eels that were not. No residue was detected in tissues of eels exposed to 1080 cereal baits through ingestion and direct (dermal and respiratory) absorption, or through direct absorption only. Low concentrations of 1080 were detected in muscle tissue of eels that consumed contaminated possum muscle (x = 0.0174 μg/g) or gut (x = 0.0306 μg/g) tissue. The primary factors affecting the concentration of 1080 detected in eel tissue included the dose of 1080 (mg/kg) that each eel" receiveddate="and number of days since the eel last fed on contaminated tissue. Based on the 1080 concentrations measured in eels in this study, the risk of acute poisoning to humans from eating contaminated eel flesh is considered extremely low. Even so, national and international perceptions and food safety standards have the potential to limit eel exports and/or close an eel fishery if 1080 residue was discovered in tissue.     

测井技术在地震目标追踪应用中的方法探讨

目前常见测井-地震综合应用技术主要是测井约束地震反演技术,该技术存在两方面的研究精度问题.一是初始模型等因素影响反演的精度和分辨率,二是波阻抗的多解性难免造成反演的多解性.由于存在以上原因,有必要探索其他方式的"井震结合"研究思路,根据测井、地震信息具有地质背景成因一致的特点,提出寻找二者具有的、可相互辨识的共同地质属性的分析方法,研究认为,测井、地震共同地质属性的辨识可表现在两方面,一是测井、地震信息在地质界面上下地质成因相同.深入研究两者可相互辨识的地质属性信息,可提供地质界面的识别与追踪依据;二是对于一个具体的地质事件或地质体,也理应找到具有同一成因基础的、可相互辨识的信息响应依据.利用该方法对羊二庄某区的实践表明,在测井、地震信息成因一致性分析手段的基础上,开展测井-地质共同地质属性的辨识、追踪研究,对复杂油气区有利目标的追踪具有有效性,该研究成果被钻井结果证实.     

RC框架结构抗震目标性能水平确定方法研究

在基于性能抗震设计中,要求实现多级设防,目的是使结构抗震设计不仅要保护生命安全,同时也要控制因结构破坏而带来的经济损失,使结构在整个生命周期内费用达到最小。但由于结构抗震设计中存在着大量的不确定因素,使得实现每个性能水平都是不确定的,因此,每个性能水平的目标可靠度究竟取多高才能达到设计要求,是目前抗震设计的一个基本问题。针对这一问题,将地震作用、自重荷载、材料强度等看作随机变量,分析了结构造价与失效概率之间的近似关系,明确了不同性能水平失效概率之间的合理比例关系,采用"投资-效益"准则,且控制人员伤亡率小于社会可接受水平,来确定结构的目标性能水平。以两个钢筋混凝土框架结构为例,说明了该方法的应用。     

The targets of management rules for marine mammal populations require justification: A reply to

The management of anthropogenic impacts on marine mammal populations involves the setting of targets that are built on assumptions and choices. Scientific methods can be used to investigate the implications of management actions, but the choice of overall objectives and priorities lies outside science. A recent paper (Potential biological removal and other currently used management rules for marine mammal populations: A comparison in Marine Policy), summarised the characteristics of the main approaches currently used to set conservation management targets for marine mammal populations in order to provide a basis for discussion of the targets they contain. Cooke et al. (Management rules for marine mammal populations: A response to Lonergan in Marine Policy) responded, giving some important additional information about these management rules. However most of that paper's criticisms were incorrect or misplaced. Specifically, it erroneously treated an example of how PBR could be reworked, to make its abundance explicit, as a proposal to ignore uncertainty in managing populations. This paper addresses Cooke's main criticisms, and suggests that explicit justifications should be an important part of the process of setting targets for the management of marine mammal populations.     

基于卫星的水下载体实时水声定位模型

为适应水下载体高精度实时导航定位的需求,提出了基于卫星导航定位的浮标水声定位系统定位模式,主要讨论了长基线固定浮标定位系统和超短基线单体智能浮标系统的工作原理和点位计算模型,分析了水声定位系统定位的准确度和误差源,对促进全球海域实现全天候高精度完全水下自主定位具有一定的指导意义。     

侧扫声纳系统在海底障碍物扫测中的应用

针对海道测量中侧扫声纳位置精度低的问题,利用GPS定位数据、单波束水深数据和侧扫数据,研究侧扫声纳扫海测量中海底障碍物信息精化问题。海上试验数据表明：文中提出的多源水声测量信息联合扫测海底障碍物的方法,可改善单一侧扫系统目标探测的精度,对海底目标物扫测具有较好的适用性。     

地面三维激光扫描点云拼接影响因素分析

在地面三维激光扫描仪进行三维建模过程中,需要对不同测站的点云进行拼接。为了提高不同测站点云拼接精度,本文开展了球形标靶表面扫描点数量、标靶的分布和数量及扫描距离4个因素对三维激光扫描仪不同测站下点云拼接精度的影响研究。采用法如（FOCUS）三维激光扫描仪开展了不同扫描分辨率、不同标靶数量、不同标靶分布和不同距离下的点云拼接试验,并采用SENCE软件对点云进行了拼接精度分析。试验结果表明,选择两测站的标靶表面的扫描点数量大致相等,并将4个标靶作为连接点,且放置在不同高度不规则排列时,点云拼接的精度最优。