污染地域环境水文地质勘查技术应用浅探

随着时代的发展,科技水平的不断进步,社会对水文地质勘察技术的关注程度越来越高,其应用范围也越来越广。     

利93区块钻探技术

我公司通过对利93区块所钻井的研究,在总结以往钻井经验的基础上,认真消化和吸收国内同行业的先进钻探技术,结合的利93断地质特点,总结出了一套适应该区块安全快速钻进的实用技术,提高了该区块的钻井速度与钻井质量,取得了良好的社会效益与经济效益。     

大股东地位、产权属性与控制权利益获取——基于大宗股权交易视角的分析

文章利用2006-2010年发生的大宗股权交易事件,对大股东获取控制权利益行为进行分析。研究结论表明,大股东在所有权结构中的控制能力越强,能够获取的控制权利益水平就越高,但是与非控股大股东相比,处于控股地位的大股东更倾向于以私有收益的方式实现控制权利益;与非国有股东相比,国有性质的股东更倾向于以私有收益的方式实现控制权利益;较好的市场环境能够有效抑制获取控制权私利行为,尤其是对控股大股东和国有性质股东获取私利行为的作用程度和效果更明显。     

高海拔地区TM遥感数据信息的提取与DEM获取研究

本研究以Landsat TM遥感数据为研究对象,以杂谷脑河流域为例,从遥感数据的几何校正、最佳波段选择、图像融合、图像裁剪、土地分类和图像的解译角度进行了处理.之后,将校正后的数据进行了矢量化并得到DEM,在DEM的基础上进行了高程、坡度、坡向方面的分析,得到了有利于LUCC分析的可靠数据.     

Dynamic land use and land cover changes and their effect on forest resources in a coastal village of Matemwe,Zanzibar, Tanzania

Recent land cover change estimates show overall decline of tropical forests at the regional and global scales caused by multiple social, cultural and economic factors. There is an overall concern on the prevailing land use practices, such as shifting cultivation and extraction of forest materials as agents of forests losses, but also new, emerging land uses are threatening tropical forests. Understanding of the long-term development and driving forces of forest changes are needed, especially at local levels where many decisions on forest policies and land uses are made. This paper addresses the importance of such information for improved estimates of forest dynamics by studying local level land cover and land use changes during the last 50–70 years in the Eastern African tropical island of Zanzibar, Tanzania. The paper discusses the role of traditional and new land uses mainly subsistence farming, tourism and government interference through tree planting, in the long-term development of the forests at the village level. The material for the study is gathered from the interpretation of archival maps and aerial photographs combined with contemporary digital aerial photographs. The analyses are based on the mapping, spatial sampling and spatio-temporal change trajectory analysis (LCTA) of forest land cover, forest land uses and settlement patterns with GIS and statistics. Six distinct forest land cover change trajectories were identified and these illustrate dynamic and heterogeneous nature of the forests. Closed forest cover has dominated throughout due to cyclical land use patterns, but over 70% of the land area has been continuously transforming between closed, semi-open and open land cover conditions. Land use turnover rates indicate that hardly any forest areas are left untouched from the forces, which remove and re-establish forest vegetation in the long run. Land cover and land use change trajectories are spatially fragmented in the studied landscape. Majority of forest loss-gain dynamics is caused by shifting cultivation, while forest losses are most dramatic along the coast, where traditional and new land uses meet and land uses pressures are highest. The study suggests that landscape change trajectory analyses, where contemporary and historical information on land uses and land cover changes are spatially linked, can provide valuable aspects into local level forest land use planning and management strategies. For the case study, the findings suggest the following key forest management strategies for consideration: (1) establishment of a protected forest/scrubland in participation with the local stakeholders, especially the farmers, (2) promotion of areas for permanent agricultural practices, while simultaneously introducing management controls in the traditional slash-and-burn farming areas, and (3) promoting new livelihood opportunities for the farmers, who have traditionally been dependent on forest resources, meanwhile introducing alternatives for fuel wood for cooking.     

一种针对压缩域信号的新型锁相环技术

针对通信信号压缩采样获得的压缩域信号频率、相位提取问题,提出了一种基于压缩感知的新型锁相环技术。通过深入研究压缩域的信号估计问题,提出了压缩域锁相环路,可以直接在压缩域同步跟踪信号频率和相位变化,不再需要高复杂度的信号重构处理。分析了环路模型及其估计性能,并针对该锁相环可行性和性能分别进行了仿真实验。仿真结果不仅验证了压缩域锁相环的可行性,同时表明该环路能够实现高动态信号的高精度频率提取。压缩域锁相环的应用潜力较大,例如可以作为压缩感知通信接收机的同步解调方法。     

最优化理论与方法在油田产量优化研究中的改进

结合油田生产实际对最优化理论与方法在油田产量优化中的应用作了切实的改进,提出了新的模型设计,并以某油田的数据参数为例对改进后的优化模型进行了实证分析,取得了较好的模拟效果。     

基于图形小波变换的遥感图像表示与去噪

离散小波变换（Discrete Wavelet Transform,DWT）通常用于图像的表示。然而,对于具有不规则形状边缘的图像,尤其是对于纹理和细节信息较多的遥感图像,DWT却很难有效表示,进而影响后续去噪效果。针对该问题,提出了一种基于图形小波变换（Graphic Wavelet Transform,GWT）的图像去噪方法。首先,将图像表示为图形信号,并通过该图形信号的谱表示构造相应的变换矩阵;然后,设计了一种改进自适应阈值的图像去噪方法,在GWT变换域内对图像去噪。实验结果表明,与常用的图像去噪方法相比,所提算法能够提供更好的图像主观质量。采用均方根误差（Root Mean Square Error,RMSE）和峰值信噪比（Peak Signal-to-Noise Ratio,PSNR）作为客观指标,结果表明,采用所提方法得到的重建图像客观质量更优。     

基于卷积神经网络自编码器结构的空时分组传输方案

为提高现有端到端通信系统的泛化能力和可靠性,提出了一种基于卷积神经网络的空时分组码（Space-Time Block Coding,STBC）多输入多输出通信系统物理层方案。该方案将通信系统物理层表述、调制和解调过程联合起来形成端到端自编码器系统,引入多层一维卷积层,分别构建发射机和接收机,并扩展为多天线模式。为进一步提高系统可靠性,合理规划网络结构和参数,联合信号的调制和编码方案,优化了系统模型。仿真实验表明,针对瑞利相关衰落下多输入多输出（Multiple-Input Multiple-Output,MIMO）信道应用场景,训练模型可以实现传统STBC系统的误码性能,两发两收系统在发送端相关系数为0和0.9时分别优于传统系统0.5 dB和1 dB。此外,经过优化后的系统可获得采用卷积编码的性能改善效果,其两发两收不同工作方式优于传统1/2码率卷积编码STBC系统1~3 dB。     

核心企业主导的供应链金融模式风险机理研究

在核心企业主导的供应链金融模式中,核心企业的主导作用会产生依赖性垄断,推动风险的发生,导致中小企业融资中屡屡出现欺诈和套取现金等不良行为。通过对供应链金融模式演变和供应链金融风险等相关分析,提出不同供应链金融模式下核心企业参与的可能性风险,并基于复杂系统理论和共生理论构建了核心企业主导的供应链金融网络拓扑结构及依赖共生模型。进一步揭示了该模式风险产生的机理及原因,完善了供应链金融风险的相关理论。最后提出引入区块链技术的分布式存储、时间戳及智能合约功能实现与供应链金融的融合,达到"去核心化"的目的,从根本上杜绝风险的产生。