高频雷达OSMAR流速探测精度的对比验证

高频雷达探测海洋表面流与常规海流计测量海流是两种不同的测量方式。本文根据 2种观测方法所获取资料的不同特点 ,对引起 2种测量方法流速测量差异的主要误差进行了分析 ,并采用合适的方法对这些主要误差进行了量化估计。研究发现 ,2种测量方法取样的空间差异、时间差异以及仪器的观测误差等是构成高频雷达与常规海流计测量结果差异的主要因素。充分考虑这些因素对流速测量的影响能较大的提高高频雷达流速对比验证的精度     

渤海西南部潮间带沉积物中的重金属

用石墨炉原子吸收分光光度法测定了渤海潮间带沉积物中Zn,Cu,Pb,Cd,Cr和Ni。研究结果表明,渤海西南部潮间带沉积物中重金属含量基本正常,但Zn的污染较为明显,可能与油田排污有关。黄河口重金属含量从高潮带向低潮带逐渐降低。本区沉积物具有相似的地球化学特性。沉积物中重金属含量与有机质含量密切相关,它们易与有机质结合,而沉降至底质。     

5种海鱼的生态生长效率研究

在常温下进行星鳗、蛹、黑鳗、厚头平Ｙｏｕ和皱唇鲨等五种鱼类的生长实验，得出这５种鱼类摄食巢沙蚕、火枪乌贼、斑Ｊｉ（碎块）、带鱼（碎块）和玉筋鱼的生态生长效率波动于３．８￣３３．６％范围内，平均为１６．０％，相对平均日摄食量处于１．６￣１１．５％之间，另外，对饵料系数、平均日摄食量及平均体重日增长量进行了探讨。     

黄河口拦门沙与盐水楔特征及其演变

黄河口存在一个成型堆积法，称拦门沙。多次实测结果，其长度约３－７ｋｍ同蛋白质水平宽度与河宽相同，横亘于黄河尾闾与海水相连接处。随着河口延伸，拦门沙也向海推移，淤积最多的 部位是前绝急坡区。     

The role of social capital for farmers’ climate change adaptation in Lancang River basin in China

This paper distinguishes between bridging and bonding social capital to assess their roles for individual farmers’ adaptation strategies taken through technology adoption. Based on primary data collected in Langcang River (LCR) basin area in southwestern China, the paper finds: (1) adaptation measures have been widely taken by surveyed households, but non-infrastructure-based measures are more prevalent than infrastructure-based measures and (2) surveyed households have strong social capital while having weak bridging social capital. Their bonding social capital has significantly positive relationship with their adaptation decisions, but bridging social capital does not have such statistically significant relationship. It recommends that the governments contemplate carefully how to help the poor to get a good combination of bonding and bridging social capital when designing policies to help the rural poor to improve their long-term adaptive capacity and achieve sustainable rural development.     

中国人口流动重力模型回归系数的定量估算及其空间异质性研究

基于中国337个地级及以上行政区划间人口省际流动数据,对人口流动重力模型代理变量的回归系数进行实证推算。结论包括：① 在地级行政单元研究精度下,中国人口流动重力模型代理变量的回归系数呈现出明显的空间异质性,及难以预期的作用效应,因此研究精度的提升将加剧空间交互模型构建的复杂程度,同时假定重力模型回归系数的空间均质性将导致模拟结果空间差异趋势的收敛;② 中国人口省际流动距离衰减系数为1.975,337个地级及以上行政区划距离衰减系数值域为0.434~4.438。研究所展示的各省该系数值域及直辖市、省会城市结果为今后模型应用提供了基础参考数据;③ 地级行政单元下的距离衰减系数存在空间异质性与梯度特征,高值区主要分布在东北沿疆、新疆和珠三角地区,低值区主要位于中国中部和西南地区。结合以往研究成果比较,中国人口省际流动的空间衰减特征与铁路客运网络的可达性格局存在一定程度的一致性。     

基于地图视角的北极海洋权益现状研究

明确各国北极海洋权益现状是我国未来北极活动的基础。本研究根据相关文献及图集资料,基于地图视角,对环北极国家的专属经济区划界、外大陆架申请、海洋保护区建立等方面进行定量化、空间化的分析,以此反映北冰洋海洋权益基本情况。结合《联合国海洋法公约》《公海公约》《大陆架公约》《领海及毗连区公约》等相关法律政策,预测北极海洋权益未来发展趋势并探究其对我国未来北极活动的影响,为我国未来北极策略制定提供参考。结果表明,沿岸国家对北冰洋活动的限制程度具有一定的规律性:在经向上,呈现出显著的纬度地带性,即限制程度随着纬度增高而逐渐减弱;在深度方向,对大陆架的控制范围大于对其上覆水域的控制范围。     

Impacts of Two Types of El Ni o on the MJO during Boreal Winter

The features of the MJO during two types of El Ni no events are investigated in this paper using the daily NCEP-2reanalysis data, OLR data from NOAA, and Real-time Multivariate MJO index for the period 1979–2012. The results indicate that the MJO exhibits distinct features during eastern Pacific(EP) El Ni no events, as compared to central Pacific(CP) El Ni no events. First, the intensity of the MJO is weakened during EP El Ni no winters from the tropical eastern Indian Ocean to the western Pacific, but enhanced during CP El Ni no winters. Second, the range of the MJO eastward propagation is different during the two types of El Ni no events. During EP El Ni no winters, the MJO propagates eastwards to 120?W, but only to 180?during CP El Ni no winters. Finally, the frequency in eight phases of the MJO may be affected by the two types of El Ni no. Phases 2 and 3 display a stronger MJO frequency during EP El Ni no winters, but phases 4 and 5 during CP El Ni no winters.     

Performance of a pickax

Summary Single and multiple impact tests were conducted with a commerically available 3.58 kg pickax with a 60° conical tip and a 30° wedge tip in the input energy range from 1.01 to 59.4 J. Five target materials were employed: (1) 2024-0 aluminum, (2) diorite, (3) sandstone, (4) cement-sand, and (5) green shale. Force and penetration data were collected using strain gages and a non-contact displacement probe. It was found that when the impact process involves cracking and chipping, the maximum penetration was linearly proportional to the input energy and the forcepenetration relation exhibited non-linear characteristics. When the impact process does not involve cracking or chipping, the penetration was related to the square root of the input energy and the force-penetration relation exhibited a nearly linear relation. Thus, empirical models involving a linear spring resistive force or a constant resistive force were found to reasonably describe the penetration and input energy data. In addition, an analytical model involving a pickax mass inertia term and a piecewise linearized force-penetration function was constructed that portrayed the force and penetration histories. Good results were obtained for both conicaland wedge-tip cases. From the multiple impact tests it was found that the efficiency of the pickax operation decreases by about 50 to 60 percent after ten impacts, suggesting that the impact point be moved in order to obtain an improved performance.     

Investigation of crack formation during loading of brittle rock

Conclusions The response of elastic/brittle targets to loading by conical-, wedge-and hemispherical-indenter shapes representing jackhammer bit tips was analyzed. Theoretical predictions of crack extent and direction are based on values of the maximum principal strains and the associated extension strain criterion in the target assuming a semi-infinite, homogeneous and isotropic solid.Corresponding static experiments using an MTS machine and dynamic percussive tests involving an encased circular target disk of Sierra granite have been conducted. The damage pattern consisting of a crater, a crushed zone, a region of multiple minor cracks as well a some longer fissures has been delineated. Comparison with theoretical predictions indicate that cracks are produced by maximum tensile strain, with their directions predicted well by the present theory. The upper bound predictions of the crack extent are also in reasonable accord. Deviations are due to the presence of inhomogeneities and anisotropies in the tests specimens.