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Phase Residual Estimations for PCVs of Spaceborne GPS Receiver Antenna and Their Impacts on Precise Orbit Determination of GRACE Satellites

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Chinese Journal of Aeronautics 2012年第4期25卷 631-639页

作者： TU Jia gu Defeng WU yi yi Dongyun College of Science National University of Defense TechnologyChangsha 410073China

In-flight phase center systematic errors of global positioning system（GPS） receiver antenna are the main restriction for improving the precision of precise orbit determination using dual-frequency *** approach is one of the valid methods for in-flight calibration of GPS receiver antenna phase center variations（PCVs） from ground *** this paper,followed by the correction model of spaceborne GPS receiver antenna phase center,ionosphere-free PCVs can be directly estimated by ionosphere-free carrier phase post-fit residuals of reduced dynamic orbit *** the data processing of gravity recovery and climate experiment（GRACE） satellites,the following conclusions are ***,the distributions of ionosphere-free carrier phase post-fit residuals from different periods have the similar systematic ***,simulations show that the influence of phase residual estimations for ionosphere-free PCVs on orbit determination can reach the centimeter ***,it is shown by in-flight data processing that phase residual estimations of current period could not only be used for the calibration for GPS receiver antenna phase center of foretime and current period,but also be used for the forecast of ionosphere-free PCVs in future period,and the accuracy of orbit determination can be well improved.

关键词： global positioning system precise orbit determination phase center variations phase residual estimation GRACE

An approach to the capsule endoscopic robot with active drive motion

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第3期12卷 223-231页

作者： Da-qiang gu Yong zhou Department of Mechanical Engineering Zhejiang University Hangzhou 310027 China

Commercialized capsule-type endoscopes move passively by peristaltic waves (and gravity),which makes it difficult for doctors to diagnose the areas of interest more thoroughly and *** resolve this problem of passivity,it is necessary to find a special locomotion principle,which fits the gastrointestinal (GI) *** this paper,a legged locomotive mechanism with shape memory alloy (SMA) actuation based on the peristaltic principle is proposed,and then the structure of the locomotion mechanism is *** on the preliminary results,the design,modeling,and fabrication of an SMA microactuation concept for application in an endoscopic capsule are given,as well as the SMA spring and legged component design,which is the core section of the system *** used the pseudo-rigid-body model (PRBM) to analyze nonlinear and large deflections of the SMA legged ***,a prototype endoscope with an SMA spring and six legged components was designed and *** is 15 mm in diameter and 33 mm in total length,with a hollow space to house other parts needed for endoscopy such as a camera,a radio frequency (RF) module,and *** testing,the locomotive mechanism was effective in a plastic tube environment.

关键词： Capsular endoscopy Shape memory alloy (SMA) Microactuation Locomotion

Effect of Astragalus complanatus flavonoid on anti-liver fibrosis in rats

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World Journal of Gastroenterology 2005年第37期11卷 5782-5786页

作者： Chun-Yu Liu Zhen-Lun gu Wen-Xuan zhou Ci-yi guo Department of Pharmacology Medical College of Suzhou University Suzhou 215007 Jiangsu Province China Suzhou Institute of Chinese Meteria Medica Suzhou University Suzhou 215007 Jiangsu Province China The Hong Kong Association for Health Care Ltd Hong Kong China

AIM： To observe the anti-liver fibrosis effect of Astragalus complanatus fiavonoids （ACF） in rats. METHODS： The liver fibrosis model in rats was established by injecting interperitoneally 0.2 mL/100 g 0.5% dimethylnitrosamine, thrice a week. Meanwhile, the rats were administered ACF （30, 60, 120 mg/kg） or colchicine （0.1 mg/kg） once a day for 1 mo. Serum N-propeptide of type Ⅰ procollagen （PINP） and type Ⅲ procollagen （PⅢNP） was measured using ELISA. Malondialdehyde （MDA） and superoxide dismutase （SOD） in hepatic tissue were evaluated. Matrix metal protease-1 （MMP-1） mRNA expression was assayed by RT-PCR and the protein expression of tissue inhibitor of metal protease-1 （TIMP-1） was analyzed by immunohistochemistry. RESULTS： In the ACF groups, SOD activity increased and MDA content decreased in comparison to the liver fibrosis model group. The serum PINP and PⅢNP contents in ACF-2 and -3 group decreased compared to those in model group. In ACF-2 and -3 group, the expression of MMP-1 mRNA increased significantly and the protein expression of TIMP-1 decreased compared to that in model group. CONCLUSION： The antifibrotic mechanisms of ACF are associated with its influence on lipid peroxidation and collagen synthesis and degradation.

关键词： Astragalus complanatus, Liver fibrosis N-propeptide of typeⅠ procollagen N-propeptide of type Ⅲ procollagen Malondialdehyde Superoxide dismutase Matrix metal protease-1 Tissue inhibitor of metal protease-1

Fast and Robust Stereo Vision Algorithm for Obstacle Detection

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Journal of Bionic Engineering 2008年第3期5卷 247-252页

作者： yi-peng zhou Department of Automation Northwestern Polytechnic University Xian 710068 P. R. China

Binocular computer vision is based on bionics, after the calibration through the camera head by double-exposure image synchronization, access to the calculation of two-dimensional image pixels of the three-dimensional depth information. In this paper, a fast and robust stereo vision algorithm is described to perform in-vehicle obstacles detection and characterization. The stereo algorithm which provides a suitable representation of the geometric content of the road scene is described, and an in-vehicle embedded system is presented. We present the way in which the algorithm is used, and then report experiments on real situations which show that our solution is accurate, reliable and efficient. In particular, both processes are fast, generic, robust to noise and bad conditions, and work even with partial occlusion.

关键词： stereo vision vehicle dynamics visibility range image alignment

Semipositivity of generic ordinary fibration over a curve

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Science China Mathematics 2018年第10期61卷 1749-1758页

作者： yifei Chen yi gu Academy of Mathematics and Systems Science Chinese Academy of Sciences

Let f : X → B be a generic ordinary proper fibration over a complete curve in positive characteristics, we prove that the dual of higher direct image sheaf R^1 f_*O_X is nef. As a corollary, we show that f_*ω_(S/B) ... 详细信息

关键词： semipositivity fibrations direct image sheaf

Adversarial network embedding using structural similarity

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Frontiers of Computer Science 2021年第1期15卷 223-232页

作者： Zihan zhou Yu gu Ge YU School of Computer Science and Engineering Northeastern UniversityShenyang 110819China

Network embedding which aims to embed a given network into a low-dimensional vector space has been proved effective in various network analysis and mining tasks such as node classification,link prediction and network *** emerging network embedding methods have shifted of emphasis in utilizing mature deep learning *** neural-network based network embedding has become a mainstream solution because of its high eficiency and capability of preserv-ing the nonlinear characteristics of the *** this paper,we propose Adversarial Network Embedding using Structural Similarity(ANESS),a novel,versatile,low-complexity GAN-based network embedding model which utilizes the inherent vertex-to-vertex structural similarity attribute of the *** learns robustness and ffective vertex embeddings via a adversarial training ***,our method aims to exploit the strengths of generative adversarial networks in generating high-quality samples and utilize the structural similarity identity of vertexes to learn the latent representations of a ***,ANESS can dynamically update the strategy of generating samples during each training *** extensive experiments have been conducted on the several benchmark network datasets,and empirical results demon-strate that ANESS significantly outperforms other state-of-theart network embedding methods.

关键词： network embedding structural similarity generative adversarial network

On Subsonic and Subsonic-Sonic Flows with General Conservatives Force in Exterior Domains

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Acta Mathematicae Applicatae Sinica 2023年第1期39卷 3-16页

作者： Xumin gu Tian-yi WANG Department of Mathematics Shanghai University of Finance and EconomicsShanghai 200433China Department of Mathematics School of ScienceWuhan University of TechnologyWuhan 430070China The Institute of Mathematical Sciences the Chinese University of Hong KongShatinN.T.Hong Kong Gran Sasso Science Institute viale Francesco Crispi767100 L'AquilaItaly

In this paper, we study the irrotational subsonic and subsonic-sonic fows with general conservative forces in the exterior domains. The conservative forces indicate the new Bernoulli law naturally. For the subsonic case, we introduce a modified cut-off system depending on the conservative forces which needs the varied Bers skill, and construct the solution by the new variational formula. Moreover, comparing with previous results, our result extends the pressure-density relation to the general case. Afterwards we obtain the subsonic-sonic limit solution by taking the extract subsonic solutions as the approximate sequences.

关键词： steady fow homentropic irrotation subsonic fow subsonic-sonic limit

Melatonin protects liver from intestine ischemia reperfusion injury in rats

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World Journal of Gastroenterology 2008年第48期14卷 7392-7396页

作者： Jian-yi Li Hong-Zhuan yin Xi gu Yong zhou Wen-Hai Zhang yi-Min Qin The Fifth Department of General Surgery Shengjing Affiliated Hospital of China Medical University Shenyang 110004 Liaoning Province China The Second Department of General Surgery Shengjing Affiliated Hospital of China Medical University Shenyang 110004 Liaoning Province China The Sixth Department of General Surgery Shengjing Affiliated Hospital of China Medical University Shenyang 110004 Liaoning Province China Department of General Surgery The First People's Hospital of Shenyang Shenyang 110004 Liaoning Province China

AIM: To investigate the protective effect of melatonin on liver after intestinal ischemia-reperfusion injury in rats. METHODS: One hundred and fifty male Wistar rats, weighing 190-210 g, aged 7 wk, were randomly divided into melatonin exposure group, alcohol solvent control group and normal saline control group. Rats in the melatonin exposure group received intraperitoneal (IP) melatonin (20 mg/kg) 30 min before intestinal ischemia-reperfusion (IR), rats in the alcohol solvent control group received the same concentration and volume of alcohol, and rats in the normal saline control group received the same volume of normal saline. Serum samples were collected from each group 0.5, 1, 6, 12, and 24 h after intestinal IR. Levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured with an auto-biochemical analyzer. Serum TNF-α was tested by enzyme-linked immunosorbent assay (ELISA). Malondialdehyde (MDA) in liver was detected by colorimetric assay. Pathological changes in liver and immunohistochemical straining of ICAM-1 were observed under an optical microscope. RESULTS: The levels of ALT measured at various time points after intestinal IR in the melatonin exposure group were significantly lower than those in the other two control groups (P < 0.05). The serum AST levels 12 and 24 h after intestinal IR and the ICAM-1 levels (%) 6, 12 and 24 h after intestinal IR in the melatonin exposure group were also significantly lower than those in the other two control groups (P < 0.05). CONCLUSION: Exotic melatonin can inhibit the activity of ALT, AST and TNF-α, decrease the accumulation of MDA, and depress the expression of ICAM-1 in liver after intestinal IR injury, thus improving the liver function.

关键词： Melatonin Intestinal ischemia-reperfusion injury Liver TNF-α

Ultrasonic enhancement of persulfate oxidation system governs emerging pollutants decontamination

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Green Energy & Environment 2024年第11期9卷 1666-1678页

作者： Yanpan Li Yanbo zhou yi zhou National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical ProcessEast China University of Science and Technology130 Meilong RoadShanghai200237China Shanghai Engineering Research Center for Multi-media Environmental Catalysis and Resource Utilization East China University of Science and Technology130 Meilong RoadShanghai200237China Shanghai Institute of Pollution Control and Ecological Security Shanghai200092China

Emerging contaminants (ECs) are widely present in aquatic environments, posing potential risks to both ecosystems and human health. Theultrasound-assisted persulfate oxidation process has attracted considerable attention in the degradation of ECs due to its ability to generate bothsulfate radicals and cavitation effects, enhancing degradation effects. In this paper, the principle of ultrasonic synergistic Fenton-like oxidationsystem for degrading organic pollutants was reviewed, divided into homogeneous system, non-homogeneous system, and single-atom system toexplore the synergistic effect of ultrasound-enhanced persulfate technology in three aspects, and the effects of environmental factors such asultrasonic frequency and power, system pH, temperature, and initial oxidant concentration on the system's decontamination performance werediscussed. Finally, future research on ultrasonically activated persulfate technology is summarized and prospected.

关键词： Ultrasound Persulfate Emerging contaminants Reaction mechanism Synergistic effects