采用非稳相偏振滤波的DAS-VSP数据P/S波分离方法及其应用

分布式光纤声学传感(DAS)因成本低、易布设以及高密度采样等优势正成为重要的地震观测技术,尤其是越来越多地与垂直地震剖面(VSP)结合,用于主动地震勘探或被动地震监测.DAS传感器通过感知弹性波场产生的轴向应变或应变速率来观测地震波场振动.然而,目前单分量DAS-VSP数据未完整地记录地下弹性波场的三维矢量振动信号,因此如何从中分离出P波或S波用于后续地震成像与参数反演是重要且很有挑战的课题.以弹性波传播理论为基础,本文根据P波和S波的频散关系估算接收点处各自的偏振方向,通过随频率和空间位置变化的偏振滤波实现DAS-VSP数据的P/S波分离.理论模型合成数据与东海实际DAS-VSP数据实验结果表明,该方法能有效地将P波和S波信号从单分量DAS-VSP数据中分离出来,可为后续纵横波速度反演、PP与PS波成像提供关键的数据预条件处理.

基于SRTM数据的天气雷达净空环境评估研究

针对天气雷达的选址受净空环境直接影响的问题,提出基于SRTM数据的天气雷达净空环境评估研究。采用航天飞机雷达地形测绘使命高程数据,对天气雷达净空环境进行评估,并进行方位矫正和距离矫正。测试结果表明,基于航天飞机雷达地形测绘使命数据的天气雷达净空环境评估方法的方位分辨率为0.25°,测距大于260千米;与实地勘测结果之间的误差最小,具有较好的一致性;方位角的变化幅度较小,误差小。表明研究提出的方法在天气雷达净空环境评估中具有较好的应用效果,对气象检测技术的发展有一定促进作用。

Inequalities relating to L_p-version of Petty's conjectured projection inequality

Petty＇s conjectured projection inequality is a famous open problem in the theory of convex bodies. In this paper, it is shown that an inequality relating to Lp-version of the Petty＇s conjectured projection inequality is developed by using the notions of the Lp-mixed volume and the Lp-dual mixed volume, the relation of the Lp-projection body and the geometric body Г-pK, the Bourgain-Milman inequality and the Lp-Bnsemann-Petty inequality. In addition, for each origin-symmetric convex body, by applying the Jensen inequality and the monotonicity of the geometric body Г-pK, the reverses of Lp-version of the Petty＇s conjectured projection inequality and the Lp-Petty projection inequality are given, respectively.

Three-dimensional stereotactic surface projection in the statistical analysis of single photon emission computed tomography data for distinguishing between Alzheimer's disease and depression

AIM To evaluate usefulness of single photon emission computed tomography(SPECT) with three-dimensional stereotactic surface projection(3D-SSP) in distinguishing between Alzheimer's disease(AD) and depression.METHODS We studied 43 patients who presented with both depressive symptoms and memory disturbance. Each subject was evaluated using the following:(1) the Minimal Mental State Examination;(2) the Hamilton Rating Scale for Depression;(3) Clinical Global Impression-Severity scale(CGI-S); and(4) SPECT imaging with 3D-SSP.RESULTS The MMSE scores correlated significantly with the maximum Z-scores of AD-associated regions. CGI-S scores correlated significantly with the maximum Z-scores of depression-associated regions. Factor analysis identified three significant factors. Of these, Factor 1 could be interpreted as favouring a tendency for AD, Factor 2 as favouring a tendency for pseudo-dementia, and Factor 3 as favouring a depressive tendency.CONCLUSION We investigated whether these patients could be categorized as types: Type A(true AD), Type B(pseudodementia), Type C(occult AD), and Type D(true depression). The factor scores in factor analysis supported the validity of this classification. Our results suggest that SPECT with 3D-SSP is highly useful for distinguishing between depression and depressed mood in the early stage of AD.

基于BIM+B/S的水库工程数字化展示平台的构建

针对水库工程在初步设计阶段仍以二维图纸作为成果交付,缺少对工程整体情况、投资估算等关键信息直观展示的问题,将BIM数字信息建模、BIM数据文件优化处理、B/S前后端分离、跨平台访问等技术应用于新建岔河水库工程,建立岔河水库枢纽BIM模型,创建实现平台功能的数据文件并构建岔河水库枢纽工程数字化展示平台。研究结果表明:构建的岔河水库工程数字化展示平台可以高效、流畅、跨平台地在电脑端和手机端,向参建各方展示待建枢纽工程的基本情况和地理位置,建筑物三维信息模型,单体工程的施工模拟动画,以及枢纽工程投资估算关键信息。研究结果深化BIM技术应用程度,可为其他水利工程信息化提供重要参考和借鉴价值。

Review of the Relocation of General Zhang Fei’s Temple in View of the Three Gorges Dam Project

As a national cultural property,General Zhang Fei’s Temple is the largest ancient architectural complex in the Three Gorges of the Yangtze River.It was built in the Han Dynasty and has a long history of nearly 2,000 years.In 1994,the Chinese government launched the Three Gorges Dam project at the Yangtze River and implemented the largest relocation project for the General Zhang Fei Temple to prevent it from being submerged.The temple was relocated 32 kilometers upstream along with the local people of Yunyang County,and the historic environment was rebuilt on the opposite side of the migrant city of New Yunyang County.The temple was restored successfully and the tradition of offering sacrifices to General Zhang Fei continued in the local community.The relocation project lasted for 8 years and became the largest cultural heritage conservation project of the People’s Republic of China at the end of the 20th century.This paper comprehensively summarizes and reviews the project goals,implementation process,and project highlights of this relocation,so as to provide an important case reference for heritage conservation projects in the future.

Analysis of debris flow control effect and hazard assessment in Xinqiao Gully,Wenchuan M_(s)8.0 earthquake area based on numerical simulation

Xinqiao Gully is located in the area of the 2008 Wenchuan M_(s)8.0 earthquake in Sichuan province,China.Based on the investigation of the 2023"6-26"Xinqiao Gully debris flow event,this study assessed the effectiveness of the debris flow control project and evaluated the debris flow hazards.Through field investigation and numerical simulation methods,the indicators of flow intensity reduction rate and storage capacity fullness were proposed to quantify the effectiveness of the engineering measures in the debris flow event.The simulation results show that the debris flow control project reduced the flow intensity by41.05%to 64.61%.The storage capacity of the dam decreases gradually from upstream to the mouth of the gully,thus effectively intercepting and controlling the debris flow.By evaluating the debris flow of different recurrence intervals,further measures are recommended for managing debris flow events.

Present Situation and Projection of Tibet's Population

The following is up-to-date inform at ion about Tibet's Population.In 1995,there was a population about 2.43 million in the region,according to my estima-tion based on data from the 1990 census and annual sam-pling surveys.The birth rate was 28 per thousand,the death rate ten per thousand and the natural increase rate 18 per thousand.

An Equivalent Form of S-L Projection Learning

Learning a mapping between an input space and an output.space from training data canbe viewed as a problem of function approximation,which means that different criteria result in learningapproaches of different abilities.Among them,projection criterion proposed by one of the authors aimsdirectly at optimal generalization.The projection idea leads to three specific learning approaches,projection learning,partial projection learning,and averaged projection learning,and a framework of afamily of projection learning called S-L projection learning is established to discuss infinite kinds oflearning.S-L projection learning has a different form from the three methods,and it is not easy to analyzetheir relationship.This paper focuses on an equivalent form of S-L projection learning,which shows thatit is a transformed version of partial projection learning.

Momentum as Translations at Conformal Infinity

Although General Relativity is the classic example of a physical theory based on differential geometry, the momentum tensor is the only part of the field equation that is not derived from or interpreted with differential geometry. This work extends General Relativity and Einstein-Cartan theory by augmenting the Poincaré group with projective (special) conformal transformations, which are translations at conformal infinity. Momentum becomes a part of the differential geometry of spacetime. The Lie algebra of these transformations is represented by vectorfields on an associated Minkowski fiber space. Variation of projective conformal scalar curvature generates a 2-index tensor that serves as linear momentum in the field equations of General Relativity. The computation yields a constructive realization of Mach’s principle: local inertia is determined by local motion relative to mass at conformal infinity in each fiber. The vectorfields have a cellular structure that is similar to that of turbulent fluids.

Origin of Magnetic Fields of Stellar Objects in the Universe Based on the 5D Projection Theory

Beginning with a 5D homogeneous universe [1], we have provided a plausible explanation of the self-rotation phenomenon of stellar objects previously with illustration of large number of star samples [2], via a 5D-4D projection. The origin of such rotation is the balance of the angular momenta of stars and that of positive and negative charged e-trino pairs, within a 3D ⊗1D?void of the stellar object, the existence of which is based on conservation/parity laws in physics if one starts with homogeneous 5D universe. While the in-phase e-trino pairs are proposed to be responsible for the generation of angular momentum, the anti-phase but oppositely charge pairs necessarily produce currents. In the 5D to 4D projection, one space variable in the 5D manifold was compacted to zero in most other 5D theories (including theories of Kaluza-Klein and Einstein [3] [4]). We have demonstrated, using the Fermat’s Last Theorem [5], that for validity of gauge invariance at the 4D-5D boundary, the 4th space variable in the 5D manifold is mapped into two current rings at both magnetic poles as required by Perelman entropy mapping;these loops are the origin of the dipolar magnetic field. One conclusion we draw is that there is no gravitational singularity, and hence no black holes in the universe, a result strongly supported by the recent discovery of many stars with masses well greater than 100 solar mass [6] [7] [8], without trace of phenomena observed (such as strong gamma and X ray emissions), which are supposed to be associated with black holes. We analyze the properties of such loop currents on the 4D-5D boundary, where Maxwell equations are valid. We derive explicit expressions for the dipolar fields over the whole temperature range. We then compare our prediction with measured surface magnetic fields of many stars. Since there is coupling in distribution between the in-phase and anti-phase pairs of e-trinos, the generated mag-netic field is directly related to the angular momentum, leading to the result that the magnetic field can be expressible in terms of only the mechanical variables (mass M, radius R, rotation period P)of a star, as if Maxwell equations are “hidden”. An explanation for the occurrence of this “un-expected result” is provided in Section (7.6). Therefore we provide satisfactory answers to a number of “mysteries” of magnetism in astrophysics such as the “Magnetic Bode’s Relation/Law” [9] and the experimental finding that B-P graph in the log-log plot is linear. Moreover, we have developed a new method for studying the relations among the data (M, R, P) during stellar evolution. Ten groups of stellar objects, effectively over 2000 samples are used in various parts of the analysis. We also explain the emergence of huge magnetic field in very old stars like White Dwarfs in terms of formation of 2D Semion state on stellar surface and release of magnetic flux as magnetic storms upon changing the 2D state back to 3D structure. Moreover, we provide an explanation, on the ground of the 5D theory, for the detection of extremely weak fields in Venus and Mars and the asymmetric distribution of magnetic field on the Martian surface. We predict the equatorial fields B of the newly discovered Trappist-1 star and the 6 nearest planets. The log B?−?log P graph for the 6 planets is linear and they satisfy the Magnetic Bode’s relation. Based on the above analysis, we have discovered several new laws of stellar magnetism, which are summarized in Section (7.6).

B/S架构在工程结算管理信息系统中的应用

随着信息技术的飞速发展,B/S架构因其轻量化的客户端、高效的资源共享与全球连通性以及对于现代Web技术栈的充分利用,已成为现代信息系统开发的重要范式。文中概述了B/S架构的定义与特征,详细介绍了该架构在工程结算管理信息系统中的技术组成、系统设计、功能模块划分及技术选型策略,最后通过用户交互设计、数据处理与分析、系统安全与维护等方面的举措,展示了B/S架构如何在实际应用中发挥其先进性和灵活性。

基于B/S架构的建筑工程项目智慧工地信息管理平台设计

常规建筑工程项目智慧工地信息管理平台多采用云计算技术,信息管理效率偏低。为此,文章提出了基于B/S架构的建筑工程项目智慧工地信息管理平台设计;选取温湿度传感器与热成像传感器作为平台的信息采集模块的应用硬件;引入B/S架构建立平台的数据库,并通过添加数据索引表提升信息的查询速率,实现平台的信息管理功能。测试结果表明,所设计的平台能够提高施工信息的管理效率,管理效果较好。

基于Web Mercator投影的几何精校正及精度分析

Google Earth遥感影像图具有直观、免费、时效性强等特点,已逐渐应用于工程领域。分析了几何精校正的原理和方法;探讨了Web Mercator投影以及ArcGIS、ENVI用于GE遥感影像精校正的具体实施步骤和精度,以期为GE用于工程实践提供思路与方法。

PROJECTIVELY FLAT FINSLER METRICS WITH ALMOST ISOTROPIC S-CURVATURE

This article characterizes projectively fiat Finsler metrics with almost isotropic S-curvature.

Current Situations of Competitive Scientific Research Projects for Agri-scientific Research Institutions: A Case Study of Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agricultural Sciences

This paper collected and arranged competitive scientific research projects undertaken by Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agricultural Sciences in 2003-2014. Through statistical analysis on quantity of projects,funded amount,age of person responsible,professional title of person responsible,academic degree of person responsible,research object,it discussed relevant characteristics and rules. Finally,it came up with pertinent measures and recommendations,in the hope of providing services for decision-making and scientific and technological management.

A Comparative Overview of Three Gorges Project's Sediment Handling

Water projects’ sediment deposition problems always cause widespread concerns. The gravity of them varies in accordance not only with reservoirs’ natural and socio-economic characteristics but also with their modes of operation. The unique characteristics, configuration and mode of operation of Three Gorges Project (TGP) reservoir are compared with those of several existing large reservoirs in this paper. As many reservoirs are troubling environment by gradually extending coarse sediment deposition at the uppermost end of fluctuating backwater region toward upstream, Gezhouba reservoir on Yangtze and Danjiangkou reservoir on Hanjiang have shown no trace of such upstream extension of sediment deposition in relevant prototype observation data for the past 20 and more years. TGP reservoir’s in-coming flow sediment conditions and configuration in plane are almost the same as those of Gezhouba reservoir, and TGP reservoir’s mode of operation(usually keeping a very low pool level for flood control in flood season and storing up in-coming flow only thenceafter) is similar to that of Danjiangkou reservoir. New findings of sediment research and prototype flow sediment investigations as well as new agenda of large hydro projects’ construction on Jinshajiang in nearest future assure the prospects of TGP sediment handling.

Controllable precision of the projective truncation approximation for Green's functions

Recently, we developed the projective truncation approximation for the equation of motion of two-time Green's functions(Fan et al., Phys. Rev. B 97, 165140(2018)). In that approximation, the precision of results depends on the selection of operator basis. Here, for three successively larger operator bases, we calculate the local static averages and the impurity density of states of the single-band Anderson impurity model. The results converge systematically towards those of numerical renormalization group as the basis size is enlarged. We also propose a quantitative gauge of the truncation error within this method and demonstrate its usefulness using the Hubbard-I basis. We thus confirm that the projective truncation approximation is a method of controllable precision for quantum many-body systems.

Von Neumann’s Theory, Projective Measurement, and Quantum Computation

We discuss the fact that there is a crucial contradiction within Von Neumann’s theory. We derive a proposition concerning a quantum expected value under an assumption of the existence of the orientation of reference frames in N spin-1/2 systems (1 ≤ N to a new constant . It may be said that a new type of the quantum theory early approaches Newton’s theory in the macroscopic scale than the old quantum theory does. We discuss how our solution is used in an implementation of Deutsch’s algorithm.