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内蒙古农牧交错区典型黑土坡耕地土壤侵蚀空间分布特征

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水土保持研究 2025年第1期32卷 13-20页

作者：邹惠杰刘刚舒成博孙波刘亚张琼郭珍中国科学院教育部水土保持与生态环境研究中心黄土高原土壤侵蚀与旱地农业国家重点实验室中国科学院水利部水土保持研究所中国科学院大学西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室四川华标测检测技术有限公司

[目的]定量了解内蒙古典型黑土区土壤侵蚀速率，探究该区域土壤侵蚀空间分布特征，阐明土壤侵蚀坡面和区域空间分布规律，以期为区域水土流失治理提供参考。[方法]采集内蒙古农牧交错区（海拉尔区、额尔古纳市和牙克石市）典型黑土坡耕... 详细信息

[目的]定量了解内蒙古典型黑土区土壤侵蚀速率，探究该区域土壤侵蚀空间分布特征，阐明土壤侵蚀坡面和区域空间分布规律，以期为区域水土流失治理提供参考。[方法]采集内蒙古农牧交错区（海拉尔区、额尔古纳市和牙克石市）典型黑土坡耕地的土壤样品，利用137Cs示踪技术计算各采样点土壤侵蚀速率，结合小波分析的方法研究土壤侵蚀在坡面的分布特征。[结果]（1） 3个坡面所有采样点137Cs含量均小于背景值（1 984.24 Bq/m2）,表现为所有坡面土壤流失。（2） 3个地区的采样坡面平均侵蚀速率表现为：海拉尔[6 533.37 t/（km2·a）]>额尔古纳[4 174.35 t/（km2·a）]>牙克石[2 765.87 t/（km2·a）]。相同坡面的3个纵向断面的平均侵蚀速率相近，同一断面侵蚀速率的变异程度较高。（3）土壤侵蚀速率沿坡长呈强弱交替的周期性变化，但周期长度并不固定。大部分纵向断面存在周期长度为80～160 m和160～200 m的大小两个周期。部分纵向断面只存在一个周期长度为100～120 m的周期。[结论]该地区土壤侵蚀在坡面尺度表现为全坡面侵蚀且在纵向呈现周期性特征，在区域尺度呈现从东到西逐渐增加趋势。

关键词：土壤侵蚀典型黑土农牧交错带小波分析

EM Scattering from Conducting Flat Plates Coated with Thin RAM

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Wuhan University Journal of Natural Sciences 2002年第2期7卷 185-188页

作者： Yang He-lin xia Ying-qing Lu shu liu Wu Department of Physics Central China Normal UniversityWuhan 430079China School of Electronic Information Wuhan UniversityWuhan 430072China

According to the equivalence principles, high frequency approximation and boundary conditions, a method has been developed to deal with the EM scattering by a rectangular conducting flat plate coated with uniaxial anisotropic radar absorbing material (RAM). The simple and effective method is available to the system of RCS prediction in which the large complex targets modeled by facets and wedges. Numerical results show some properties of EM scattering by conducting plate coated with thin uniaxial anisotropic RAM.

关键词： EM scattering equivalence principles radar absorbing material

Efficient Estimation of Longitudinal Data Additive Varying Coefficient Regression Models

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Acta Mathematicae Applicatae Sinica 2017年第2期33卷 529-550页

作者： shu liu School of Statistics and Information Shanghai University of International Business and Economics Shanghai 201620 China School of Statistics and Management Shanghai University of Finance and Economics Shanghai 200433 China

We consider a longitudinal data additive varying coefficient regression model, in which the coef- ficients of some factors （covariates） are additive functions of other factors, so that the interactions between different factors can be taken into account effectively. By considering within-subject correlation among repeated measurements over time and additive structure, we propose a feasible weighted two-stage local quasi-likelihood estimation. In the first stage, we construct initial estimators of the additive component functions by B-spline se- ries approximation. With the initial estimators, we transform the additive varying coefficients regression model into a varying coefficients regression model and further apply the local weighted quasi-likelihood method to estimate the varying coefficient functions in the second stage. The resulting second stage estimators are com- putationally expedient and intuitively appealing. They also have the advantages of higher asymptotic efficiency than those neglecting the correlation structure, and an oracle property in the sense that the asymptotic property of each additive component is the same as if the other components were known with certainty. Simulation studies are conducted to demonstrate finite sample behaviors of the proposed estimators, and a real data example is given to illustrate the usefulness of the proposed methodology.

关键词： additive vary-coefficient model longitudinal data modified Cholesky decomposition withinsubject correlation

The influence of metabolic syndrome on atrial fibrillation recurrence: five-year outcomes after a single cryoballoon ablation procedure

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Journal of Geriatric Cardiology 2021年第12期18卷 1019-1028页

作者： Yu xia xiao-Feng LI Jun liu Miao YU Pi-Hua FANG shu ZHANG State Key Laboratory of Cardiovascular Disease Cardiac Arrhythmia CenterFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

BACKGROUND Metabolic syndrome(MetS)has been reported as a risk factor of atrial fibrillation(AF)recurrence after radi-ofrequency catheter *** study aimed to investigate the long-term influence of MetS on paroxysmal AF recurrence after a single cryoballoon ablation procedure,which was scarcely investigated yet in Chinese *** In total,137 paroxysmal AF patients who had successfully completed a single cryoballoon ablation procedure at Fuwai Hospital,Beijing,China from December 2013 to October 2015 were *** for patients with AF recurrence,all patients were followed up for no less than five *** predictors of AF recurrence were determined by Cox propor-tional hazards regression *** Among 137 paroxysmal AF patients,91 patients(66.4%)had successfully achieved overall five-year follow-up after a single cryoballoon ablation procedure,and 44 patients(32.1%)had *** with MetS had a significant lower incidence of freedom from AF recurrence than those without MetS(50.0%vs.74.2%,log-rank P<0.01)during the five-year ***(HR=1.95,95%CI:1.069−3.551,P=0.030)was an independent predictor of AF recurrence after adjusting for multiple *** the second year post cryoballoon ablation procedure,the recurrence rate of AF gradually increased in patients with MetS,in con-trast,decreased recurrence rate of AF in patients without *** MetS is an independent predictor for five-year AF recurrence after a single cryoballoon ablation procedure in paroxysmal AF *** therapy of AF and MetS may improve the long-term outcomes of AF patients.

关键词： balloon fibrillation atrial

Thermal stability and electrical transport properties of Ge/Sn-codoped single crystalline β-Zn4Sb3 prepared by the Sn-flux method

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Chinese Physics B 2017年第2期26卷 441-445页

作者： Hong-xia liu shu-ping Deng De-cong Li Lan-xian Shen shu-kang Deng Education Ministry Key Laboratory of Renewable Energy Advanced Materials and Manufacturing Technology Yunnan Normal UniversityKunming 650500China Photoelectric Engineering College Yunnan Open UniversityKunming 650500China

This study prepares a group of single crystalline β-Zn_4Sb_3 with Ge and Sn codoped by the Sn-flux method according to the nominal stoichiometric ratios of Zn_（4.4）Sb_3 Ge_xSn_3（x = 0–0.15）. The prepared samples possess a metallic luster surface with perfect appearance and large crystal sizes. The microscopic cracks or defects are invisible in the samples from the back-scattered electron image. Except for the heavily Ge-doped sample of x = 0.15, all the samples are single phase with space group R3c. The thermal analysis results show that the samples doped with Ge exhibit an excellent thermal *** with the polycrystalline Ge-substituted β-Zn_4Sb_3, the present single crystals have higher carrier mobility, and hence the electrical conductivity is improved, which reaches 7.48×10~4S·m^（-1） at room temperature for the x = 0.1 *** change of Ge and Sn contents does not improve the Seebeck coefficient significantly. Benefiting from the increased electrical conductivity, the sample with x = 0.075 gets the highest power factor of 1.45×10^（-3）W·m^（-1）·K^（-2） at 543 K.

关键词： thermoelectric materials β-Zn4Sb3 flux method electrical transport properties

Gas flow characteristics of argon inductively coupled plasma and advections of plasma species under incompressible and compressible flows

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Chinese Physics B 2018年第12期27卷 348-360页

作者： shu-xia Zhao Zhao Feng Physics Department Dalian University of Technology

In this work, incompressible and compressible flows of background gas are characterized in argon inductively coupled plasma by using a fluid model, and the respective influence of the two flows on the plasma properties is specified. In the incompressible flow, only the velocity variable is calculated, while in the compressible flow, both the velocity and density variables are calculated. The compressible flow is more realistic; nevertheless, a comparison of the two types of flow is convenient for people to investigate the respective role of velocity and density variables. The peripheral symmetric profile of metastable density near the chamber sidewall is broken in the incompressible flow. At the compressible flow, the electron density increases and the electron temperature decreases. Meanwhile, the metastable density peak shifts to the dielectric window from the discharge center, besides for the peripheral density profile distortion, similar to the incompressible *** velocity profile at incompressible flow is not altered when changing the inlet velocity, whereas clear peak shift of velocity profile from the inlet to the outlet at compressible flow is observed as increasing the gas flow rate. The shift of velocity peak is more obvious at low pressures for it is easy to compress the rarefied gas. The velocity profile variations at compressible flow show people the concrete residing processes of background molecule and plasma species in the chamber at different flow rates. Of more significance is it implied that in the usual linear method that people use to calculate the residence time, one important parameter in the gas flow dynamics, needs to be rectified. The spatial profile of pressure simulated exhibits obvious spatial gradient. This is helpful for experimentalists to understand their gas pressure measurements that are always taken at the chamber outlet. At the end, the work specification and limitations are listed.

关键词： gas flow inductively coupled plasma compressible flow fluid model

Commuting Dual Toeplitz Operators on the Polydisk

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Acta Mathematica Sinica,English Series 2007年第5期23卷 857-868页

作者： Yu Feng LU shu xia SHANG Department of Applied Mathematics Dalian University of Technology Dalian 116024 P. R. China

On the polydisk, the commutativity of dual Toeplitz operators is studied. We obtain characterizations of commuting dual Toeplitz operators, essentially commuting dual Toeplitz operators and essentially semi-commuting ... 详细信息

关键词： dual Toeplitz operators polydisk Bergman space commute maximal ideal space

Multiple Solutions for a Fourth-order Asymptotically Linear Elliptic Problem

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Acta Mathematica Sinica,English Series 2006年第4期22卷 1121-1126页

作者： Ai xia QIAN shu Jie LI Department of Mathematics Qufu Normal University Qufu 273165 P. R. China Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 P. R. China

Under simple conditions, we prove the existence of three solutions for a fourth-order asymptotically linear elliptic boundary value problem. For the resonance case at infinity, we do not need to assume any more condit... 详细信息

关键词： Fourth-order elliptic boundary value problem Mountain Pass theorem Morse theory

Stroma-epithelium crosstalk in prostate cancer

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Asian Journal of Andrology 2009年第1期11卷 28-35页

作者： Yi-Nong Niu shu-Jie xia Department of Urology Beijing Chaoyang Hospital Capital Medical University Beijing 100020 China Department of Urology Shanghai First People＇s Hospital Shanghai Jiao Tong University Shanghai 200080 China

The critical role played by stroma-epithelium crosstalk in carcinogenesis and progression of prostate cancer has been increasingly recognized. These interactions are mediated by a variety of paracrine factors secreted by cancer cells and/or stromal cells. In human prostate cancer, reactive stroma is characterized by an increase in myofibroblasts and a corresponding amplification of extracellular matrix production and angiogenesis. Permanent genetic mutations have been reported in stromal cells as well as in tumour cells. Transforming growth factor-J3, vascular endothelial growth factor, platelet-derived growth factor and fibroblast growth factor signalling pathways are involved in the process of angiogenesis, whereas hepatocyte growth factor, insulin-like growth factor-l, epidermal growth factor, CXC12 and Interleukin-6 play active roles in the progression, androgen-independent conversion and distal metastasis of prostate cancer. Some soluble factors have reciprocal interactions with androgens and the androgen receptor （AR）, and can even activate AR in the absence of the androgen ligand. In this article, we review the complex interactions between cancer cells and the surrounding microenvironment, and discuss the potential therapeutic targets in the stromal compartment of prostate cancer.

关键词： angiogenesis metastasis paracrine growth factors prostate prostatic neoplasm stroma