湖北省补充耕地按等级折算系统设计与实现

保护耕地是我国的一项基本国策,国家通过制定一系列耕地保护政策来保护耕地资源,来保证国家的粮食安全。耕地占补平衡就是国家为实现耕地总量动态平衡,确保国家粮食安全而做出的重要规定。本文结合湖北省农用地分等的成果,根据湖北省补充耕地按等级折算系数计算方法从系统分析、系统总体设计、系统功能设计等方面研究湖北省补充耕地按等级折算系统的设计技术路线。由此建立耕地占补平衡体系和有效的评价和监督机制,防止耕地占补平衡的表面化和短期化,实现土地资源的可持续利用。     

Densities of Huanghe River estuary and Bohai Bay waters

The densities of 36 water samples from the Huanghe River estuary and Bohai Bay were determinedby a magnetic float densimcter under three temperatures from 15℃ to 25℃.All the measured densities ofsamples were greater than that of the values calculated from the International Equation of State of Seawater.The differences between the measured and calculated densities increased with the decrease of salinities.The dif-ferences appeared exponentially correlated with[Ca~(2+)]/s,[Mg~(2+)]/s and[SO_4~(2-)]/s,and had"s"type curverelationship with the alkalinity in all salinity range.But in the salinity ranging from 25.72 to 31.57,therelationships were all linear.The density difference can be estimated from the equation △ρ（10~3kg·m~(-3)）=（-2.79+236.5([Ca~(2+)]/s)/(-9.7464×10~（-3）+[Ca~(2+)]/s).It was the high alkalinity and[Ca~(2+)]/s that resulted in the measured densi-ties of seawaters being higher than the calculated densities in the Huanghe estuary and Bohai Bay.     

倾斜界面PS转换波速度比和倾角提取的差值谱方法

首次提出了采用差值谱同时提取转换波速度比和界面倾角的方法。对于倾斜界面的PS转换波地震数据,获取界面上介质的纵横波速度比和反射界面的倾角,是转换波地震数据后续一系列处理流程的关键。通过预设速度比和倾角抽取CCP共转换点道集,并对其进行速度比谱计算,将速度比谱中获得的速度比估算值与预设值作差,在一定范围内改变速度比和倾角值,得到多个速度比差值,最后生成分别以速度比和倾角为坐标的二维差值谱,通过分析差值谱提取纵横波速度比和界面倾角。该方法能够同时对2个未知参数进行提取,获得的结果误差较小,可以为转换波后续处理提供可靠依据。      

利用深源近震高频Ps转换波震相研究松辽盆地沉积层结构

本文利用高频深源近震地震波形数据的R/Z比来获取沉积盆地速度结构,并以2011-05-10发生在黑龙江省与吉林省交界处(131.09°E,43.32°N)的M W5.7深源地震(深度554.9 km)为例,分析位于松辽盆地沉积层内部NECESSArray中的22个台站记录到的0.5~2 Hz数据,利用沉积盆地对地震波的到时延迟效应及P波和Ps转换波的振幅信息,通过对沉积盆地底部剪切波速度与厚度进行网格搜索获得松辽盆地的速度结构。结果显示,22个台站下方的沉积层顶部剪切波速度为0.1~1.0 km/s,且盆地边缘速度较大,盆地厚度为0~6.5 km,总体呈现内部大于边缘的状态。与已有结果相比,本文结果在沉积层边缘地带较符合实际趋势,表明利用高频近震深源Ps转换波的方法可以较好地获得沉积盆地内部的速度结构。     

利用近震及远震转换波测定永清M4.3级地震的震源深度

根据近震沉积层基底界面转换波Sp震相和远震深度震相sP、pP的特征,对2018-02-12永清M4.3地震的震源深度进行分析,运用F-K波数与频率方法拟合近震理论波形、Teleseis方法拟合远震理论波形,并与实际波形对比,对震源深度进行测试。结果表明,永清地震的震源深度为16~17 km,从发震位置和震源深度分析来看,此次地震发生在中上地壳,与区域内其他地震事件类似。     

碎屑岩储层模型的转换波正演模拟波场特征及其分辨率分析

基于东部某油田物性资料,建立典型碎屑岩储层模型,利用弹性波方程交错网格有限差分正演,对模型进行多波正演模拟。
通过分析正演模拟的炮集记录、叠前偏移剖面以及振幅属性,总结了多波正演的波场特点及其分辨率。分析结果表明,转换波反射频
率比纵波的低,能量随偏移距的增加而增加,零偏移距处能量为零;转换波在地层厚度为λ/4处发生调谐效应,调谐振幅属性变化规
律与纵波变化规律一致;综合考虑该区纵波、转换波波速以及不同深度的纵波、转换波中心频率变化,可知在该区目标层深度转换波
分辨率低于纵波分辨率。      

Spatiotemporal Characteristics of Rural Labor Migration in China: Evidence from the Migration Stability under New-type Urbanization

Although the factors affecting rural-to-urban migration have been discussed and analyzed in detail, few studies have examined the spatiotemporal dynamic characteristics of rural migrants' employment and working-cities in the post-immigrate era, which is essential for the citizenization and social integration of new-type urbanization in China. This study uses survey data from rural migration laborers across the eastern, central, and western China to construct a comprehensive labor migration stability index, and compares the determinants of the migration stability of rural labor among cities and industries using Geodetector. The results are as follows: 1) Compared with the midwestern cities, eastern cities have attracted younger and more skilled rural labor, and industries with higher technical content have higher migration stability among rural laborers. 2) Rural laborers more often adapt to changes by changing employment instead of changing working-cities. 3) The individual experiences of rural laborers and urban characteristics have significant impacts on the stability of migration, and family and societal guanxi(Chinese interpersonal relationships) enhance migration stability. 4) A unified labor market and convenient transportation have somewhat slowed industrial transfers and labor backflow. This study enhances our understanding of the roles of industrial transfer and new-type urbanization in shaping the labor geography landscape and provides policy implications for the promotion of people-oriented urbanization.     

Analytical Solution for 3D Tidal Flow with Vertically Varying Eddy Viscosity

In this study, a 3D idealized model of tidal flow, in which the tidal elevation and velocities are solved analytically, is developed. The horizontal eddy viscosity is neglected, and the vertical eddy viscosity used in the study is assumed to be independent of time and only varies as a parabolic function in the vertical direction. The analytical solution is obtained in a narrow rectangular bay, with the topography varying only across the bay. The model results are compared with the field observations in the Xiangshan Bay. The results show that the influence of varying vertical eddy viscosity mainly has two aspects. On one hand, it amplifies the magnitude of the tidal elevation, particularly the amplitude near the head of the bay. On the other hand, it adjusts the axial velocity profile, resulting in an obvious frictional effect. Furthermore, the tidal elevation and velocities are more sensitive to the magnitude of the eddy viscosity near the bottom than the structure in the upper water layer.     

Remote Detection of Varying Water Storage in Relation to Surfacial Temperature of Aral Sea

Lake monitoring by remote sensing is of significant importance to understanding the lake and ambient ecological and environmental processes. In particular, whether lake water storage variation could predict lake surfacial temperature or vice versa has long fascinated the research community, in that it would greatly benefit the monitoring missions and scientific interpretation of the lake change processes. This study attempted to remotely detect the dynamics of the Aral Sea and pursue the relationships between varying lake water storage attributes and surface water temperature by using MODIS LST(Moderate-resolution Imaging Spectroradiometer Land Surface Temperature) 8-day composite products, satellite altimeter data, and actual meteorological measurements. Their associations with lake Surface Water Temperatures(SWT) were then analyzed. Results showed the lake water surface areas and elevations of the North Aral Sea tended to increasing trend from 2001(2793.0 km~2, 13.6 m) to 2015(6997.8 km~2, 15.9 m), while those of the South Aral Sea showed a decreasing trend during 2001(20 434.6 km~2, 3.9 m) and 2015(3256.1 km~2, 0.9 m). In addition, the annual daytime and nighttime lake SWT both decreased in the North Aral Sea, while only the daytime SWT in the South Aral Sea exhibited an increase, indicating a rising deviation of diurnal temperatures in the South Aral Sea during the past 15 yr. Moreover, a lower correlation was found between variations in the daytime SWT and storage capacity in the South Aral Sea(R~2 = 0.33; P 0.05), no fair correlations were tested between lake water storage and daytime SWT in the North Aral Sea nor between lake water storage and nighttime SWT in either part of the sea. These results implied that climate change, if any at least during the research period, has no significant effects on lake dynamics over the two sectors of the Aral Sea with anthropogenic disturbances. However, climate change and human activities may overlap to explain complex consequences in the lake storage variations. Our results may provide a reference for monitoring the spatiotemporal variations of lakes, increasing understanding of the lake water storage changes in relation to the lake SWT, which may benefit the ecological management of the Aral Sea region, in the effort to face the likely threats from climate change and human activities to the region.     

纳米塑料颗粒在饱和多孔介质中的迁移规律

针对纳米塑料颗粒在饱和多孔介质中的迁移及其影响因素, 以纳米聚苯乙烯(PSNPs)作为典型纳米塑料颗粒, 通过实验和理论相结合的方法研究纳米塑料颗粒的迁移规律。以经典DLVO理论计算出PSNPs与石英砂颗粒之间的相互作用能, 分析预测PSNPs与石英砂之间的吸附、聚沉。在柱实验中, 以石英砂作为多孔介质填充到砂柱中, 让PSNPs在一维饱和砂柱中迁移, 研究不同条件下PSNPs的迁移行为和影响因素。结果表明, 当离子强度由1 mmol/L增至50 mmol/L(电解质为NaCl), PSNPs与石英砂颗粒之间的相互作用能的势垒则从215.13 KT逐渐降低至45.9 KT使得PSNPs更易于吸附在石英砂介质表面, 从而降低PSNPs在多孔介质中的迁移能力, PSNPs的穿透率由62.16%降至3.65%。当离子强度由0.1 mmol/L增至5 mmol/L(电解质为CaCl₂)时, 势垒则由33.72 KT降至14.03 KT, PSNPs的穿透率从82.46%降至4.27%。这些实验现象说明增加离子强度对PSNPs的穿透起到抑制作用, 且Ca2+比Na+具有更强的电荷屏蔽作用。同时提高PSNPs的初始浓度、流速和介质粒径均可增大PSNPs的穿透率, 而大粒径PNSPs颗粒的穿透率则较小。研究中构建了PSNPs实际运移与理论之间的关系, 进一步推进PSNPs的环境行为和机理研究, 为系统全面评价纳米塑料颗粒在土壤-地下水中的环境风险和生态安全提供科学依据。      

湖光岩玛珥湖浮游植物、浮游细菌生物量与可培养细菌数量的周年变化

采用丙酮萃取分光光度法、荧光显微计数法、平板计数法分别研究湖光岩玛珥湖5个站位表层水体浮游植物生物量、浮游细菌生物量、可培养细菌数量的周年变化。结果表明,湖光岩玛珥湖浮游植物生物量(以碳C计)和浮游细菌生物量(以C计)、可培养细菌数量周年波动范围分别为84.17~243.64 mg/m3、20.53~43.60 mg/m3、0.10×103~3.63×103 m L-1。三者的周年变化趋势呈规律性同步增减,峰值均出现在3月份,且在5个采样站位间差异无统计学意义(P0.05)。与主要生态因子的相关分析显示,浮游植物与浮游细菌生物量均与总氮呈显著正相关(P0.05),而可培养细菌数量与氨氮呈显著正相关(P0.05),与溶解性氮和磷酸盐呈显著负相关(P0.05),但三者与多数调查的生态因子之间相关性无统计学意义(P0.05)。浮游植物的初级生产可能是调控细菌周年变化潜在的主导因素。     

无级比例尺信息提取技术在北京城镇道路中的应用研究

文中所叙述的无级比例尺信息提取技术,是基于GIS空间处理技术、空间分析模型、空间查询方法并结合AHP层次分析数学方法,进行模型研究并最终在集成开发环境下模拟并实现了信息提取的过程.本模型的研究是以北京市城区道路为基础研究数据.在DOTNET语言环境下结合ArcEngine9.0组件技术建立信息提取模型,在实验中反复修改模型参数,在保持北京市城镇道路整体轮廓的同时,最终形成了城镇道路的无级比例尺信息提取模型.     

笼养密度对九孔鲍生长的影响

在室内水池内以五层笼摞叠养殖方式,试验了入笼时平均壳长21.2 mm(平均体重1.1 7 g)、37.0 mm(平均体重5.43 g)、51.8 mm(平均体重16.08 g)小、中、大3种规格的九孔鲍的不同放养密度对其生长的影响.笼子大小为40 cm×30 cm×12 cm.小规格设每笼放养量为25、30、35、40、45与50只6种密度;中为25、30、35、40、与45只5种密度;大为20、25、30与40只4种密度.经60 d试验,结果表明(1)小个体组以30只/笼生长最快,平均160μm/d,33 mg/d;(2)中个体组以25只/笼生长最快,平均123um/d,62 mg/d;(3)大个体组以20只/笼生长最快,平均95 μm/d,116 mg/d.     

早期华夏先民到达美洲的考究

1910年印第安人殷福布族所指的“浮桥岛”即现在的白令海峡。该海峡两岸最窄处为86km,晴天雨后可以隔海相望,水深只有30～50m,中间还有2个小岛(大、小代奥米德岛)。这时先民们徒徙到美洲与古海平面变迁,即第四纪晚期大陆冰川不断溶化,海平面不断上升有关。大约距今14000年左右,海平面回升到-100m,从亚洲到美洲在白令海峡确实存在阿拉斯加陆桥；到了距今12000年最后一次冰期结束,海平面上升到-60m时,该陆桥仍然存在；到了距今9000年左右,海平面上升到-25m时,陆桥开始沉没,但水很浅,特别是冬季结冰,两岸徒徙也并非难事；到距今7000年以后,处于人类文明的前夜时,海平面至少比现在低5～6m,只要依靠简单工具如“筏”、“独木舟”就可以到达美洲,因此,中国许多先民从这时开始到达了美洲,这在中国古书也都有专门的记载和描述。足见,中国很早以前也是一个航海大国。     

区域人口迁移时空溢出效应与动力机制分析

区域人口迁移流的规模不仅取决于迁出地与目的地的“双边”要素,也与前期迁移流和周边迁移流息息相关。传统重力模型揭示了区域人口迁移过程的“推-拉”机制,但受制于对时空维度的忽视,无法有效表达迁移流之间的时空依赖关系,因而难以度量区域要素变化对迁移流产生的时空溢出效应。本文引入多种形式的时空依赖结构,构建迁移流时空重力模型,并采用贝叶斯马尔可夫链蒙特卡洛（MCMC）方法进行估计。在此基础上,结合时空效应框架量化区域要素对迁移流的影响,定量分析人口迁移过程的时空溢出效应与动力机制。本文以1985-2015年中国省际人口迁移为例,通过与非空间的动态重力模型估计结果比较,初步表明时间依赖、空间依赖以及时空扩散依赖在区域人口迁移过程中不容忽视;时空维度上,区域要素变化在初期对迁移网络的溢出效应超过对该区域迁移流的直接影响;逐渐衰减的时空溢出效应维持了区域人口迁移规模发展的相对稳定,与动态重力模型估计结果形成了鲜明对比。区域人口规模、人均GDP水平及其时空溢出效应共同驱动中国省际人口迁移系统的发展。耦合时空维度依赖关系的时空重力模型能更好地理解区域人口迁移过程的演化特征,为促进区域人口均衡发展提供科学的决策依据。     

基于相似数据聚合与变K值KNN的短时交通流量预测

短时交通流量预测是交通控制和诱导涉及的关键技术问题,由于短时交通流量存在不确定性和时变性,其预测难度较大,是相关研究领域与工程实践中亟待解决的难题。为提高短时交通流量预测的准确性,本文设计与实现了基于相似数据聚合和变K值KNN(KNN-SDA)的短时交通流量预测算法。该算法首先采用互信息法在经过预处理的交通流量数据集提取交通流量序列最佳延迟时间信息,生成状态向量,并构建交通流量历史数据库;然后以本文所提出的相似数据聚合方法完成历史数据的聚合与清洗得到训练数据集;最后通过交叉验证确定每个时刻的最优K近邻数,完成算法实现。实验结果表明,本文提出的变K值KNN-SDA算法在保证执行效率的同时能明显提高短时交通流量的预测精度。     

黄土高原沟壑区原状土壤氮素迁移

以中国生态系统研究网络CERN长武王东沟实验站的坡耕地和塬耕地为供试土壤,研究了黄土高原沟壑塬区旱耕地原状土壤氮素迁移和时空变异。结果表明:耕作土壤NO3--N为23.1~33.8 mg/kg,NH4+-N为0.23~0.50mg/kg,DOC为9.17~13.38 mg/kg,P为0.18~0.23 mg/kg;坡耕地和塬耕地的NO3--N和NH4+-N主要集中在0~20 cm的上层土壤,中下层土壤NO3--N和NH4+-N起源于上层淋溶迁移和累积;高含量时养分淋溶溶出呈指数衰减型;NO3--N、NH4+-N、DOC向下层的迁移塬耕地慢于坡耕地。     

Withdrawing from Agrarian Livelihoods: Environmental Migration in Nepal

Although about two-thirds of Nepalese families depend on agriculture as their major source of income, the agriculture is mostly rain-fed and it has been adversely affected by water hazards and the subsequent degradation of resources. Based on case studies from three different geographical regions in Nepal, this research examines how environmental factors cause decreasing crop production and push people to abandon agriculture and accept emigration for employment. The research findings suggest a chain of push factors starting from drought or erratic rainfall causing water hazards, which impacts on depletion of crops and livestock, losses in income and employment and increased human mobility and emigration. The paper argues that the Government of Nepal and development partners can be more effective in enabling agrarian families to cope with the water hazards and shocks by formulating pro-poor mitigation and adaptation policies and strategies,focusing both on ‘rapid-onset' and ‘slow-onset' water hazards.     

MiniGUI在S3C2410中的移植与应用

在嵌入式产品开发中,除操作系统之外,开发人员关注最多的一个系统软件组件就是图形支持系统.只要是面向人机交互的嵌入式产品,就涉及到文字或者图形的输出.通过比较各种嵌入式Linux平台上的GUI系统的结构和特点,最终选定了MiniGUI作为研究对象.重点研究并实现了MiniGUI在嵌入式Linux上的移植以及Thttpd的GUI控制界面的实现方法及过程,最终在MagicARM2410开发板上成功实现了Thttpd的GUI控制界面.通过GUI界面能够实现对Thttpd的启动、停止、重新启动的功能,实现了GUI控制界面的用户登录限制而且允许用户在登录后更改用户密码.     

聚落遗址迁移最优路径模拟

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