单道扫描电感耦合等离子发射光谱的内标元素选择的灰色关联分析再研究(英文)

应用动态灰色模型（ＧＭ）的灰色关联分析（ＧＩＡ）为单道扫描（ＳＣＳ）电感偶合等离子发射光谱（ＩＣＰＯＥＳ）选择内标（ＩＳＴＤ）。经发射强度序列的ＧＩＡ计算和关联度序列优化后,Ｇｅ ２１９．８７ 被指定为内标。应用内标法和无内标法对中华人民共和国标样ＧＢ０７２３２ 的各元素的分析结果的相对百分误差范围分别为：０．８％ ～７．５％ 和２．５％ ～１７．５％ 。变更系数（ＣＶ）范围分别为：０．７％ ～２．９％ 和２．０％ ～５．８％ 。对内标选择与平均关联度的关系,Ｇｅ ２１９．８７ 特征的某些具体问题及统计相关分析与灰色关联分析在内标选择计算中的不可替代性问题,亦进行讨论     

高血压病发病率预报的人工神经网络方法研究

通过统计分析，选取影响银川地区高血压病发病率的主要气象因素，将其作为输入变量经多层前馈型神经网络的BP(Back Propagation)算法进行学习训练，建立了疾病发病率的人工神经网络(ANN，Artifical Neural Net)预报模型。结果表明：该方法计算简便、误差较小，为疾病发病率预报提供了一种新的预报方法。     

花粉浓度等级划分探讨

随着环境气象服务的拓展,开展花粉预报的省市地区逐年增加,但花粉预报等级在国内尚无统一标准,影响服务效果。为了使花粉浓度预报客观化规范化,根据全国29个省市花粉调查数据,按华北、东北、华东等七大区域进行了花粉季节变化规律分析。利用天津市2001—2005年、武汉市1994—1995年花粉观测资料和同期花粉过敏患者病例,进行了花粉浓度与发病率的相关分析,依据不同种类植物花粉致敏性的强弱,分别按木本植物和草本植物进行了花粉浓度等级划分,共分为低、较低、中等、较高、高5个级别。结果表明花粉浓度与发病率等级有较好的一致性。虽然用花粉浓度的高低不能精确地表示发病率的高低,但基本可以表征花粉症的发病趋势。此等级标准在实际应用中既方便而且又非常有实际意义。     

State dynamics of a double sandbar system

A 9.3-year dataset of low-tide time-exposure images from Surfers Paradise, Northern Gold Coast, Australia was used to characterise the state dynamics of a double sandbar system. The morphology of the nearshore sandbars was described by means of the sequential bar state classification scheme of Wright and Short [1984. Morphodynamic variability of surf zones and beaches: a synthesis. Marine Geology 56, 93-118]. Besides the two end members (the dissipative (D) and the reflective (R) states) and the four intermediate states (longshore bar and trough (LBT), rhythmic bar and beach (RBB), transverse bar and rip (TBR) and low tide terrace (LTT)), we identified two additional intermediate bar states. The erosive transverse bar and rip (eTBR) state related to the dominant oblique angle of wave incidence at the study site and the rhythmic low tide terrace (rLTT) related to the multiple bar setting. Using the alongshore barline variability and alongshore trough continuity as morphological indicators enabled the objective classification of the inner and outer bar states from the images. The outer bar was mostly in the TBR state and generally advanced sequentially through the states LBT-RBB-TBR-eTBR-LBT, with occasional transitions to the D state. Wave events led to abrupt state transitions of the outer bar, but, in contrast to expectations, did not necessarily correspond to upstate transitions. Instead, upstate (downstate) transitions coincided with angles of wave incidence θ larger (smaller) than 30°. The upstate TBR-eTBR-LBT sequence during high-angle events highlights the role of alongshore currents in bar straightening. The outer bar was found to govern the state of the inner bar to a large extent. Two types of inner bar behaviour were distinguished, based on the outer bar state. For intermediate outer bar states, the alongshore variability of the dominant inner rLTT state (52% in time) mainly related to that of the outer bar, implying some sort of morphological coupling. For dissipative outer bar states, however, the more upstate inner bar frequently separated from the shoreline and persistently developed rip channels as TBR became the most frequent state (60% in time).     

花粉预报服务社会经济效益估算分析

研究花粉预报服务经济效益评估方法,对认识专业预报服务的公众价值及其潜在的社会效益有着积极的意义.主要使用的估算方法为,针对影响天津花粉预报服务经济效益的4个重要因素,花粉预报准确率、预报服务时效性、预报服务信息的覆盖率和花粉敏感人群的预防能力,设定预报准确率(Af)、预报时效率(Tf)、信息覆盖率(Ic)和患者的预防能...     

A note on wave-induced set-up by obliquely incident waves

Water level variations due to obliquely incident, shoaling and breaking waves on a plane sloping beach were discussed recently by Hsu et al. (Coastal Engineering, 53, 865–877, 2006). An inconsistency in this work with respect to the set-down, and its implications to circulation offshore of the breakpoint, was pointed out by Shi and Kirby (Coastal Engineering, 55, 1246 – 1249, 2008). Here we extend that discussion to include the surfzone momentum balance and wave-induced set-up. We discuss some remaining inconsistencies in the approximation of the surfzone momentum balance, derive and present a consistent approximation, and validate the new approximation through numerical comparison to a more exact model.     

Scattering of obliquely incident water waves by partially reflecting non-transmitting breakwaters

In the present paper, analytic solutions are derived for scattering of water waves obliquely incident to a partially reflecting semi-infinite breakwater or breakwater gap. In order to examine the correctness of the derived solutions, they are compared with the solutions derived by McIver (1999) and Bowen and McIver (2002) for a semi-infinite breakwater and a breakwater gap, respectively, in the case of perfect reflection. The derived analytic solutions are used to investigate the effect of reflection coefficient of the breakwater and wave incident angle upon the tranquility at harbor entrance. The tranquility is deteriorated by the reflected waves as the reflection coefficient increases and as waves are incident more obliquely.     

高面板坝地震动非一致输入响应规律

在多点输入方法和等价黏弹性模型的基础上,采用半解析的波函数组合法实现了面板堆石坝在非一致输入下的动力计算。从频域散射角度对计算方法的合理性进行了验证。对比了非一致输入与一致输入下高面板堆石坝的动力响应,发现在采用基岩自由表面点的振动过程相同的对比标准下,非一致输入的整体动力响应较小;在面板坝防渗系统相对薄弱的止水结构附近,非一致输入的动拉应力最大值比一致输入的结果更大;非一致输入下大坝动力响应值的分布相比一致性输入呈现出中间小、周边大的特性。并基于波动理论进一步分析了不同种类地震波入射角度对高面板堆石坝动力响应的影响,揭示了P波、SV波和SH波入射下高面板堆石坝动力响应规律：随着入射角的增大,SH波入射时,高面板坝动力响应强度基本不变; SV波入射时,存在一个临界角,当入射角在临界角左右时高面板坝动力响应强度急剧增大和减小,之前基本不变,之后一直减小;P波入射时,存在一个特征角度,在入射角小于特征角度时高面板坝动力响应强度基本不变,大于特征角度时高面板坝动力响应强度减小。     

Absolute S-velocity estimation from receiver functions

We present a novel method to recover absolute S velocities from receiver functions.
For a homogeneous half-space the S velocity can be calculated from the horizontal slowness and the angle of surface particle motion for an incident P wave. Generally, the calculated S velocity is an apparent half-space value which depends on model inhomogeneity and P -waveform. We therefore, suggest to calculate such apparent half-space S velocities from low-pass filtered (smoothed) receiver functions using a suite of filter-parameters, T . The use of receiver functions neutralize the influence of the P -waveform, and the successive low-pass filterings emphasize the variation of S velocity with depth.
We apply this   V _{S ,app.}( T )  technique to teleseismic data from three stations: FUR, BFO and SUM, situated on thick sediments, bedrock and the Greenland ice cap, respectively. The observed   V _{S ,app.}( T )  curves indicate the absolute S velocities from the near surface to the uppermost mantle beneath each station, clearly revealing the different geological environments. Application of linearized, iterative inversion quantify these observations into   V _S ( z )  models, practically independent of the S -velocity starting model. The obtained models show high consistency with independent geoscientific results. These cases provide also a general validation of the   V _{S ,app.}( T )  method.
We propose the computation of   V _{S ,app.}( T )  curves for individual three-component broad-band stations, both for direct indication of the S velocities and for inverse modelling.     

二维横向各向同性介质界面上地震波传播角度的研究

本文通过传播矩阵法，确定地震波在横向各向同性介质中传播的水平慢度垂直慢度，进而用解析式给出入射角、透射角、转换角及折射角。