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Array errors active calibration algorithm and its improvement

Science China(Information Sciences) 2010年第5期53卷 1016-1033页

作者： WANG Ding & WU Ying Institute of Information Engineering, Information Engineering University, zhengzhou 450002, China 1. Institute of Information Engineering Information Engineering University Zhengzhou 450002 China

The combined effects of mutual coupling, gain and phase errors, and sensor position errors have great negative impact on the direction-finding performance of the MUSIC algorithm. This paper investigates the calibration of the array errors induced by the three errors. Based on the array errors calibration algorithm (algorithm 1) presented by See, two improved array error-calibrating algorithms are presented. One (algorithm 2) uses the sparseness of mutual coupling matrix, and the other (algorithm 3) utilizes more special structures of mutual coupling matrix. Although the three algorithms have the same computation mode and theoretical framework, the latter two algorithms have much higher precision than the former one, as more properties of mutual coupling matrix are utilized in the two algorithms, and if the array manifold is uniform linear array or uniform circular array, algorithm 3 could have more obvious advantages. On the other hand, the three algorithms can be generalized to the situation when the calibration source azimuths have deviations. The three extended algorithms can not only calibrate the array errors, but also offset the deviations of calibration source azimuths simultaneously. Finally, the performances of the three algorithms are compared both in the absence and presence of the deviations of calibration source azimuths. Many simulation experiments demonstrate that the estimation precision of array errors can be obviously improved if more properties of mutual coupling matrix are effectively used.

关键词： array calibration mutual coupling gain and phase error sensor position errors complex symmetric banded Toeplitz matrix complex symmetric circular matrix sparse matrix

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Pharmacokinetics of lansoprazole in Chinese healthy subjects in relation to CYP2C19 genotypes

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Acta Pharmacologica Sinica 2004年第8期 12-16页

作者： Yu-rong HU, Hai-ling QIAO, Quan-cheng KAN Department of Clinical Pharmacology, School of Medicine, zhengzhou University, zhengzhou 4.0052, China.

AIM: To study the kinetic characteristics of lansoprazole in healthy Chinese subjects in relation to CYP2C19 genotype status for the individualized dose regimen of lansoprazole. METHODS: Nine homozygous extensive metabolizers (homo EMs) and 9 poor metabolizers (PMs) were recruited for the study from a total of 70 healthy Chinese volunteers, whose CYP2C19 genotype status was determined by the PCR-RFLP techniques. After a single oral dose of 30 mg lansoprazole capsule, plasma concentrations of lansoprazole were determined with HPLC method. RESULTS: In Chinese subjects, the allele frequencies of the CYP2C19ml and CYP2C19m2 mutation were 0.35 and 0.07, respectively. The concentration-time curves in the two groups were best fitted to a one-compartment model. In the homo EMs and the PMs groups, the main kinetic parameters were as follows: Tmax (2.44±0.85) and (2.33±0.94) h, Cmax(1.10±0.34) and (1.73±0.56) mg/L, Cl/F (16.55±6.38) and (3.58±1) L/h, T1/2ke(1.96±0.51) and (4.21±0.53) h, AUC were (3.23±1.0

关键词： lansoprazole pharmacokinetics human CYP2C19 protein genotype

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SURFACE STATE AND CATALYTIC ACTIVITY OF ACTIVATED AMORPHOUS Fe_(80)Zr_(12)B_8 ALLOY

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Acta Metallurgica Sinica(English Letters) 1993年第7期6卷 57-63页

作者： WANG Xike SHEN Ningfu CHEN Haisong zhengzhou Institute of Technology,zhengzhou,ChinaZHANG Haifeng Luoyang Research Institute for Ship Materials,Luoyang,ChinaGU Haicheng Xi’an Jiaotong University,Xi’an,China Professor,Research Centre for Materials,zhengzhou Institute of Technology,zhengzhou 450002,China

The depth profile of composition,chemical state of elements and morphology of as- received and activated amorphous Fe_(80)Zr_(12)B_8 alloy ribbons have been studied by means of Auger electron spectroscopy,X-ray photoelectron spectroscopy and scanning Auger microprobe combined with Ar ion *** dull and free sides of the as- received ribbons were covered with an iron oxide *** a pronounced surface segregation and oxidation of B and precipitation of microcrystalline α-Fe particles were observed on both sides of activated ribbons,B and Zr were oxidized selectively in subsurface *** both sides of ribbons,a porous surface structure formed. The BET surface area was measured to be increasing from 0.11 to 2.68 m^2/*** principal mechanism of in situ activation has been discussed.

关键词： amorphous Fe_(80)Zr_(12)B8 alloy surface state catalytic activity in situactivation

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The Stability of Nonlinear Time-Delay Discrete Systems

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Systems Science and Systems Engineering 1999年第1期9卷 27-39页

作者： XIAO Hui-min(Dept. of Info.Henan University of Finance & Economics, zhengzhou 4.0052, China)YUAN Fu-Shun(Dept. of System Science and Mathematics, zhengzhou University, zhengzhou 4.0052, China)

In this paper, the stability of nonlinear time-delay discrete systems is investigated bymeans of the Gauss-Seidel iteration method. Some algebraic criteria of the stability are obtained. Theconstruction of Lyapunov fu... 详细信息

关键词： noalinear time-Delay discrete systems gauss-seidel iteration mothod stability

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Conformal Deformations for Prescribing Scalar Curvature on Riemannian Manifolds with Negative Curvature

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Acta Mathematica Sinica,English Series 1998年第3期14卷 361-370页

作者： Hu Zejun Postdoctoral Station of Mathematics, Hangzhou University, Hangzhou, 310028, China Department of Mathematics, zhengzhou University, zhengzhou 4.0052, China

We study the conformal deformation for prescribing scalar curvature function on Cartan-Hadamard manifold M^n(n≥3) with strongly negative curvature. By employing the super- subsolution method and a careful construction for the supersolution, we obtain the best possible asymptotic behavior for near infinity so that the problem of complete conformal deformation is solvable. In more general cases, we prove an asymptotic estimation on the solutions of the conformal scalar curvature equation.

关键词： Conformal deformation Scalar curvature Complete metric Super-subsolution method

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A　DEVELOPMENT　STUDY　OF　CAST　COPPER　ALLOYWITH　HIGH　STRENGTH　AND　HEAT－RESISTANCE

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Acta Metallurgica Sinica(English Letters) 1996年第3期9卷 217-222页

作者： WANG Zheng REN Chenxing and WANG Suying(Department of Materials Science, zhengzhou Institute of Technology, zhengzhou 450002, China)

By means of Precipitation hardening, a cast copper alloy with high strength and heatresistance named Cu-6Ti-Cr-Al has been developed. This alloy has good castability. After water quenching at 860℃ for 1 h and aging at 450℃ for 4 h, the tensile strength, σ_b, is greater than 890MPa and the compressive strength, σ_(bc), reaches 1300MPa, while the ratio of compression, ε_c, is maintained at 20%. When the environmental temperature is raised to 450℃, the mechanical properties do not show any appreciable loss. These copper alloy castings have been used on the roll sleeves of rubber formers and the journal bearings of sheet mills. The results have shown that the service life of these parts is much longer than that of aluminium bronze and 904alloy castings. In the present work, the microstructure, mechanical properties and strengthening mechanism were investigated.

关键词： cast copper alloy mechanical properties microstructure precipitation hardening

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Surgical treatment of Budd-Chiari syndrome:analysis of 221 cases

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Hepatobiliary & Pancreatic Diseases International 2011年第4期10卷 435-438页

作者： Xiao-Wei Dang,Pei-Qin Xu,Xiu-Xian Ma,Da-Qian Xu,Yan-Ju Zhu and Yong-Shuai Zhang Division of Hepatobiliary and Pancreatic Surgery,First Affiliated Hospital,zhengzhou University,zhengzhou 4.0052,China Division of Hepatobiliary and Pancreatic Surgery First Affiliated Hospital Zhengzhou University Zhengzhou 450052 China

BACKGROUND:Budd-Chiari syndrome (B-CS) refers to post-hepatic portal hypertension and/or inferior vena cava hypertension caused by obstruction of blood flow at the portal cardinal hepatic *** treatments of B-CS include operations on pathological membrane lesions,shunting and combined *** have shown that China,Japan,India and South Africa have a high incidence of *** China,the Yellow River Basin in Henan,Shandong,Jiangsu and Anhui Provinces also have a high incidence,around 10 per 100 ***:The clinical data of 221 B-CS patients were analyzed *** focused on pathological types,surgical methods,effectiveness and complications of treatment,and ***:Based on imaging findings such as color ultrasonography,angiography or magnetic resonance angiography,the 221 patients were divided into 3 types (five subtypes):type Ia (72 patients),type Ib (20),type II (72),type IIIa (33),and type IIIb (24).Surgical procedures included balloon membranotomy with or without stent (65 patients),improved splenopneumopexy (18),radical resection of membrane and thrombus (17),inferior vena cava bypass [29,with cavocaval transflow (13) and cavoatrial transflow (16)],mesocaval shunt (41),splenocaval shunt (25),splenoatrial shunt (12),splenojugular shunt (6),and combined methods (8).The complication rate was 9.05% (20/221) and the perioperative death rate was 2.26% (5/221).All of the patients were followed up from 6 months to 5 *** success rate was 84.6% (187/221),and the recurrence rate was 8.9% (9/101) and 13.5% (13/96) after 1-and 5-year follow-up,***:The rational choice of surgical treatment based on B-CS pathological typing may increase the success rate and decrease the recurrence.

关键词： Budd-Chiari syndrome intervention shunt transflow

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Weighted estimates for the multilinear singular integral operators with non-smooth kernels

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Science China Mathematics 2011年第3期54卷 587-602页

作者： HU GuoEn1 & LU ShanZhen2 1Department of Applied Mathematics, zhengzhou Information Science and Technology Institute, zhengzhou 450002, China 2Department of Mathematics, Beijing Normal University, Beijing 100875, China 1. Department of Applied Mathematics Zhengzhou Information Science and Technology Institute Zhengzhou 450002 China2. Department of Mathematics Beijing Normal University Beijing 100875 China

In this paper, by sharp function estimates and certain weak type endpoint estimates, the authors establish some weighted norm inequalities with Ap weights for the multilinear singular integral operators with non-smoot... 详细信息

关键词： approximation to the identity weighted norm inequality singular integral operator non-smooth kernel Calderón-Zygmund decomposition

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准噶尔盆地侏罗系煤岩气成藏条件及勘探潜力

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中国石油勘探 2024年第4期29卷 31-43页

作者：毛新军李艳平梁则亮朱明姚卫江李树博潘拓胡正舟汪洋中国石油新疆油田公司勘探开发研究院中国石油新疆油田公司勘探事业部

准噶尔盆地侏罗系西山窑组、八道湾组两套煤层广覆式分布,煤系地层气资源十分丰富。但作为一个全新的天然气领域,盆地煤岩气基础研究薄弱、成藏特征、富集规律及资源规模不清。为探索深部煤岩的含气性,2020年钻探风险探井CT1H井,测试获... 详细信息

准噶尔盆地侏罗系西山窑组、八道湾组两套煤层广覆式分布,煤系地层气资源十分丰富。但作为一个全新的天然气领域,盆地煤岩气基础研究薄弱、成藏特征、富集规律及资源规模不清。为探索深部煤岩的含气性,2020年钻探风险探井CT1H井,测试获最高日产气5.7×10^(4)m^(3),试采日产气量稳定在2×10^(4)m^(3),证实煤岩气领域具备高产稳产能力。通过对深部煤岩岩石学特征、煤岩储集性能、演化特征、煤岩气成藏控制因素等系统研究,明确了盆地煤岩演化程度低,属于中—低阶煤,西山窑组煤岩以中—大孔为主,八道湾组煤岩以微—小孔为主;构建了盆地煤岩气古生中储与自生自储两类成藏模式;结合烃源岩、构造、煤岩储层特征及气测异常响应等多种控藏因素对盆地煤岩气潜在领域进行了分类评价,优选了滴南—白家海、齐古两大煤岩气勘探有利区,计算二者2000~4000m埋深煤岩气资源量超万亿立方米。

关键词：准噶尔盆地侏罗系煤岩气成藏模式勘探潜力

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Modification ratio estimation for a category of adaptive steganography

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Science China(Information Sciences) 2010年第12期53卷 2472-2484页

作者： LUO XiangYang 1 , LIU FenLin 1 , YANG ChunFang 1 & LIAN ShiGuo 2 1 zhengzhou Information Science and Technology Institute, zhengzhou 450002, China 2 France Telecom R&D Beijing, Beijing 100080, China 1. zhengzhou Information Science and Technology Institute Zhengzhou 450002 China2. France Telecom R&D Beijing Beijing 100080 China

This paper investigates the detection of adaptive image steganography. Firstly, the sample pair analysis model of multiple least-significant bits (MLSB) replacement is analyzed, and the conditions under which the adaptive steganography can be detected via this model are given. For the category of adaptive steganography satisfying these conditions, a general quantitative steganalysis method is presented based on specific areas and sample pair analysis. Then, for a typical adaptive steganography, some concrete methods are proposed to select specific areas and trace sets of sample pairs, and estimate the stego modification ratios. Experimental results show that the proposed methods can estimate the stego modification ratio accurately. This verifies the validity of the proposed general quantitative steganalysis method.

关键词： adaptive steganography steganalysis MLSB (multiple least significant bits) sample pair analysis modification ratio

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