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Channel estimation in space and frequency domain for MIMO-OFDM systems

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 40-44页

作者： pan pei-sheng,zheng bao-yu College of Communication and Information,Nanjing University of Posts and Telecommunications,Nanjing 210003,China College of Communication and Information Nanjing University of Posts and Telecommunications Nanjing 210003 China

Multiple-input multiple-output （MIMO） systems can be combined with orthogonal frequency division multiplexing （OFDM） systems to improve the capacity and quality of wireless communications. In this article, a channel estimation technique in both space and frequency domain for MIMO-OFDM systems is proposed. It is shown that the proposed scheme with space-frequency pilot tones achieve optimal minimum mean square error （MMSE） channel estimation. Simulation results indicate that the proposed method achieves good performance.

关键词： channel estimation MIMO OFDM space frequency pilot tones

Spatial distribution of the oxygen-18 in precipitation in China based on a new empirical model

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Journal of Mountain Science 2019年第11期16卷 2605-2614页

作者： ZHAO pei GUO zheng-sheng SHE Dong-li TANG Xiang-yu Department of Geography Shangluo UniversityShangluo 726000China Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China College of Urban and Environment Sciences Shanxi Normal UniversityLinfen 041000China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Research Center of Soil and Water Conservation and Ecological EnvironmentChinese Academy of Sciences&Ministry of EducationYangling 712100China

Modeling the oxygen-18 in precipitation based on regional topography and meteorological factors is helpful to constrain missing isotopic data in some regions that is required for many paleoclimate,eco-hydrological and atmospheric circulation ***,the relationship betweenδ18Oin precipitation(δ18OPPT)and the affecting factors need to be thoroughly *** present a model considering the combined effects of temperature,altitude,and latitude on the spatial variability of annual average of stable isotopes in precipitation across *** new model performed significantly better(P<0.05)than the widely used Farquhar and Bowen&*** model allows modelling the spatial distribution of isotopes in precipitation depending on temperature *** residuals of presented model did not significantly correlate with *** on the model and residuals,a high-resolution map of annual averageδ18Opptacross China was generated.δ18OPPTdecreased from low toward high latitudes and from low towards high altitudes *** model application provides important information forancient climate,hydrological cycle and water vapor sources studies.

关键词： Climate change Isotope hydrology Geographic information Spatial distribution

Synthesis,characterization,and tunable semiconducting properties of aza-BODIPY derived polycyclic aromatic dyes

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Science China Chemistry 2020年第9期63卷 1240-1245页

作者： Wanle sheng yu-Qing zheng Qinghua Wu Kangkang Chen Mao Li Lijuan Jiao Erhong Hao Jie-yu Wang Jian pei The Key Laboratory of Functional Molecular Solids Ministry of EducationSchool of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China Department of Chemistry BengBu Medical CollegeBengbu 233030China

Azadipyrromethene derived polycyclic aromatic complexes(HBPs)containing thirteen fused rings have been synthesized,which show highly selective intense absorption in the near infrared spectrum(NIR)region with high photo-and *** periphery alkoxy and alkyl substituents greatly affect their molecular packing structures in thin films and their thin film transistor *** the simple changes of the alkyl substituents,the packing structures changed from discrete-grain with H-aggregation type absorption to lamellar packing with J-aggregation type absorption,and the semiconducting properties were modulated from p-type to interesting ambipolar-type in solution-processed organic field effect transistors(OFETs)with hole and electron mobilities reaching to 0.42 and 0.17 cm^2 V^-1 s^-1,respectively.

关键词： aza-BODIPY polycyclic aromatic dyes near infrared field-effect transistors

Unconventional Fluorescent and Multi-responsive Polyethyleneimine with LCST and UCST Behavior:Synthesis,Characterization and Biological Applications

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Chinese Journal of Polymer Science 2024年第6期42卷 826-837页

作者： Feng-Ming Yin Li-Li Wu Shu-sheng Li Xiao-Na pan Xiao-Li Zhu Xu-bao Jiang Xiang zheng Kong College of Chemistry and Chemical Engineering University of JinanJinan250022China Shandong Institute for Product Quality Inspection Jinan250102China College of Chemical Engineering Tianjin UniversityTianjin300072China

Non-aromatic fluorescent and multi-responsive materials,exhibiting inherent fluorescence emission and controlled phase change,have garnered significant attention in recent ***,the underlying interaction between their fluorescent properties and phase transition remains *** this study,we synthesized a series of catalyst-free aza-Michael addition-based polyethyleneimine(RFpei)materials by reacting polyethyleneimine(pei)with N-isopropyl acrylamide(NIPAM).The resulting RFpei was comprehensively characterized,and demonstrated dual-phase transition behavior(LCST and UCST)in water,which could be finely tuned by adjusting its composition or external factors such as ***,upon UV irradiation(365 nm),RFpei exhibited strong fluorescence *** further investigated the effects of NIPAM grafting percentage to pei,polymer concentration,and pH on the LCST/UCST and fluorescent properties of RFpei aqueous ***,we showcased the great potential of RFpei as a versatile tool for physiological cell imaging,trace detection,and controlled release of *** study presents a novel class of stimuli-responsive fluorescent materials with promising applications in the field of biomedicine.

关键词： Polyethyleneimine Multi-responsiveness Intrinsic fluorescence emission Cell imaging Controlled drug release

DIFFUSING OF AN AMMONIA MOLECULE IN WATER IN A VERY SHORT TIME PERIOD

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Journal of Hydrodynamics 2012年第6期24卷 969-970页

作者： sheng Nan TU yu-song GUO pan WAN Rong-zheng FANG Hai-ping Shanghai Institute of Applied Physics Chinese Academy of Science University of the Chinese Academy of Sciences Institute of Systems Biology Shanghai University

The diffusion of an ammonia molecule （NH3） in water was investigated by molecular dynamic simulations. It is found that the diffusion shows negative correlation with its dipole orientation.

关键词： diffusion ammonia correlation

Lentiviral vector-mediated down-regulation of IL-17A receptor in hepatic stellate cells results in decreased secretion of IL-6

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World Journal of Gastroenterology 2012年第28期18卷 3696-3704页

作者： sheng-Chu Zhang Yi-Hu zheng pan-pan yu Tan Hooi Min Fu-Xiang yu Chao Ye yuan-Kang Xie Qi-yu Zhang Department of General Surgery The First Affiliated Hospital of Wenzhou Medical College Wenzhou 325000 Zhejiang Province China Stem Cell Center Lurid University 22184 LundSweden Department of Infectious Disease Binjiang Hospital of Hangzhou Hangzhou 310051 Zhejiang Province Ctaina

AIM: To investigate the mechanism of interleukin (IL)-6 secretion through blocking the IL-17A/IL-17A recepto (IL-17RA) signaling pathway with a short hairpin RNA (shRNA) in hepatic stellate cells (HSCs) in vitro . METHODS: HSCs were derived from the livers of adul male Sprague-Dawley rats. IL-6 expression was evalu ated using real-time quantitative polymerase chain reaction and enzyme linked immunosorbent assay. The phosphorylation activity of p38 mitogen activated pro tein kinases (MAPK) and extracellular regulated pro tein kinases (ERK) 1/2 upon induction by IL-17A and suppression by IL-17RA shRNA were examined using Western ***: IL-6 expression induced by IL-17A was significantly increased compared to control in HSCs (P < 0.01 in a dose-dependent manner). Suppression of IL17RA using lentiviral-mediated shRNA inhibited IL-6 expression induced by IL-17A compared to group with only IL-17A treatment (1.44 ± 0.17 vs 4.07 ± 0.43, P < 0.01). IL-17A induced rapid phosphorylation of p38 MAPK and ERK1/2 after 5 min exposure, and showed the strongest levels of phosphorylation of p38 MAPK and ERK1/2 at 15 min in IL-17A-treated HSCs. IL-6 mRNA expression induced by IL-17A (100 ng/mL) for 3 h exposure was inhibited by preincubation with specific inhibitors of p38 MAPK (SB-203580) and ERK1/2 (PD-98059) compared to groups without inhibitors preincubation (1.67 ± 0.24, 2.01 ± 0.10 vs 4.08 ± 0.59, P < 0.01). Moreover, lentiviral-mediated IL-17RA shRNA 1 inhibited IL-17A-induced IL-6 mRNA expression compared to random shRNA in HSCs (1.44 ± 0.17 vs 3.98 ± 0.68, P < 0.01). Lentiviral-mediated IL17RA shRNA 1 inhibited phosphorylation of p38 MAPK and ERK1/2 induced by 15 min IL-17A (100 ng/mL) exposure. CONCLUSION: Down-regulation of the IL-17RA receptor by shRNA decreased IL-6 expression induced by IL-17A via p38 MAPK and ERK1/2 phosphorylation in HSCs. Suppression of IL-17RA expression may be a strategy to reduce the inflammatory response induced by IL-17A in the liver.

关键词： Interleukin 17A Interleukin 6 Hepatic stellate cells Liver fibrosis

Microstructural evolution and abrasive resistance of WC7Co ceramic particle-reinforced Ti6Al4V composite coating prepared by pulse laser cladding

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Journal of Iron and Steel Research International 2020年第2期27卷 228-237页

作者： Li-jing Yang Shao-peng Wang pei Wang Huan Li Hai-yu Yang yuan-sheng Ye zheng-xian Li Northwest Institute for Non-ferrous Metal Research.Xi'an 710016 ShaanxiChina

WC7Co/Ti6Al4V composite coatings are deposited on the pure Ti substrate by pulse laser cladding(LC).During the laser melting process,the decomposition of WC7Co particles will lead to the evolution of microstructure and phases,which is directly related to the wear resistance and mechanism of composite *** microstructural evolution,phase compositions and interface reaction of WC7Co/Ti6Al4V composite coating were examined by scanning electron microscopy,energydispersive spectrum and X-ray diffraction(XRD).The hardness of different structures and abrasive resistance of composite coating were *** results show that the typical microstructure of LC WC7Co/Ti6Al4V composite coating can be classified into dissolved WC7Co composite structure and un-dissolved WC7Co *** to XRD results,there are Ti solid solution,W,TiC,VC,Co3W3C and secondary W2C in composite *** eutectic structure formed by the dissolved WC7Co particles consisted of W,W2C,TiC and P-Ti solid *** mean hardness of different structures exhibits a significant gradient distribution in composite coating.A reaction layer composed of TiC,W and W2C is also generated onto the interface between un-dissolved WC7Co particles and Ti6Al4V alloy *** abrasive mechanisms of WC7Co/Ti6Al4V composite coating are mainly adhesive wear and oxidation wear during the dry sliding process.

关键词： Laser cladding WC ceramic powder Titanium alloy Wear resistance Composite coating

Intravesical explosion during transurethral resection of bladder tumor:A case report

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World Journal of Clinical Cases 2022年第29期10卷 10689-10694页

作者： Chuan-Bing Xu Dong-sheng Jia zheng-sheng pan Department of Urology Zibo Central HospitalZibo 255036Shandong ProvinceChina

BACKGROUND Intravesical explosion during transurethral resection of bladder tumor(TUR-BT)is a very rare complication,and it may result in rupture of the bladder,which usually requires surgical correction and causes a potential threat to the patient’s *** SUMMARY This paper reports a case of intravesical explosion during *** with the literature review,the risk factors are analyzed and measures of prevention and treatment are *** Although rare,intravesical explosions can cause serious consequences,and the loud explosion can also lead to a profound psychological shadow on the *** must be aware of this potential *** operative techniques and special precautions can reduce the risk of this complication.

关键词： Transurethral resection of bladder tumor Intravesical explosion Vesical rupture Case report

Numerical simulation of flow field characteristics and the improvement of pressure oscillation of rotating detonation engine

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Defence Technology（防务技术） 2023年第8期26卷 191-202页

作者： Xin-pei Han Quan zheng bao-xing Li Qiang Xiao Han Xu Fang Wang Hao-long Meng Wen-kang Feng Chun-sheng Weng National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China Xi'an Modern Chemistry Research Institute Xi'an710065China

Due to the inherent working mode of rotating detonation engine(RDE),the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss,which makes it difficult to design nozzle and improve propulsion ***,in order to improve the characteristics of detonation flow field,the three-dimensional numerical simulation of annular chamber and hollow chamber is carried out with premixed hydrogen/air as fuel in this paper,and then tries to combine the two chambers to weaken the oscillation characteristics of detonation flow field through the interaction of detonation flow field,which is a new method to regulate the detonation flow *** results show that there are four states of velocity vectors at the outlet of annular chamber and hollow chamber,which makes RDE be affected by rolling moment and results in the loss of axial kinetic *** the external flow field of combined chamber,the phenomenon of cyclic reflection of expansion wave and compression wave on the free boundary is observed,which results in Mach disk ***,the pressure monitoring points are set at the external flow *** pressure signal shows that the high-frequency pressure oscillation at the external flow field of the combined chamber has been greatly *** to the annular chamber,the relative standard deviation(RSD) has been reduced from 14.6% to5.6%.The results thus demonstrate that this method is feasible to adjust the pressure oscillation characteristics of the detonation flow field,and is of great significance to promote the potential of RDE and nozzle design.

关键词： Detonation flow field Combined chamber Pressure oscillation Velocity vector