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Broadband beam steering for misaligned multi-mode OAM communication systems

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Journal of Systems Engineering and Electronics 2021年第4期32卷 779-788页

作者： TIAN Zhengjuan chen rui LONG Wenxuan ZHOU Hong MORETTI Marco School of Communication Engineering Xidian UniversityXi’an 710071China Department of Information Engineering University of PisaPisa 56126Italy

Orbital angular momentum(OAM)at radio frequency(RF)has attracted more and more attention as a novel approach of multiplexing a set of orthogonal OAM modes on the same frequency channel to achieve high spectral efficiency(SE).However,the precondition for maintaining the orthogonality among different OAM modes is perfect alignment of the transmit and receive uniform circular arrays(UCAs),which is difficult to be satisfied in practical wireless communication ***,to achieve available multi-mode OAM broadband wireless communication,we first investigate the effect of oblique angles on the transmission performance of the multi-mode OAM broadband system in the non-parallel misalignment ***,we compare the UCA-based RF analog and baseband digital transceiver structures and corresponding beam steering *** analysis and numerical simulations validate that the SE of the misaligned multi-mode OAM broadband system is quite low,while analog and digital beam steering(DBS)both can significantly improve the SE of the ***,DBS can obtain higher SE than analog beam steering especially when the bandwidth and the number of array elements are large,which validates that the baseband digital transceiver with DBS is more suitable for multi-mode OAM broadband wireless communication systems in practice.

关键词： orbital angular momentum(OAM) uniform circular array(UCA) broadband wireless communication misalignment beam steering

Influence of Operating Parameters on NO_(x)and SO_(2)Emissions in Circulating Fluidized Bed with Post-Combustion

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Journal of Thermal Science 2023年第5期32卷 1858-1867页

作者： WANG Chao SONG Guoliang chen rui JIANG Yu LYU Qinggang School of Engineering Science University of Science&Technology of ChinaHefei 230026China Institute of Engineering Thermophysics Chinese Academy of ScienceBeijing 100190China University of Chinese Academy of Science Beijing 100049China Dalian National Laboratory for Clean Energy Dalian 116023China

Post-combustion technology of circulating fluidized bed can largely reduce the emission of nitrogen oxides(NOx)in the process of combustion and succeed in meeting the ultra-low NO_(x)standard for some fuels like Shenmu *** the potential of synergistic control of the emissions of NO_(x)and sulphur dioxide(SO_(2))under post-combustion technology has become a direction that needs further *** experiments were conducted on a 0.1 MW(thermal)circulating fluidized bed(CFB)test platform,composed of a CFB main combustor and post-combustion chamber(PCC).The paper focuses on the effects of air distribution ratio and temperature in CFB and limestone addition on NO_(x)and SO_(2)*** experimental results showed that compared with traditional CFB combustion,post-combustion technology can reduce NO_(x)emission largely,but lead to a slight increase in SO_(2)*** higher SO_(2)emissions at post-combustion can lead to less NO_(x)*** the decrease inλ_(CFB),NO_(x)emission first decreased and then increased;by contrast,SO_(2)emission withλ_(CFB)first increased and then *** post-combustion,whenλ_(CFB)was 0.9,NO_(x)emission was the minimum,while the SO_(2)emission was the *** temperature and limestone addition has less adverse effects on NO_(x)emission under post-combustion,compared with traditional CFB *** injection into the furnace is applicable under post-combustion,and the sulfur removal efficiency under post-combustion is very high,almost equivalent to that under traditional combustion.

关键词： circulating fluidized bed post-combustion NO_(x) SO_(2) synergistic control

A modified rheological model of natural debris flows

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Chinese Science Bulletin 2000年第8期45卷 743-748页

作者： WANG Yuyi FEI Xiangjun chen rui chengdu Institute of Mountain Hazards and Environment Chinese Academy of SciencesDongchuan Debris Flow Observation and Research StationChinese Academy of SciencesChengdu 610041China Department of Hydraulics Qinghua UniversityBeijing 100083China

The two coefficients of the linear dimensionless viscous-dispersive mixture model have been modified according to their rheological properties of different types of viscous debris flows based on the observation and experimental data of debris flows and their slurries in the field, and then a rheological model of hyperconcentrated debris flows has been derived. The modified coefficients are the exponent of A which is modified by the highly-viscous slurry medium, and the maximum density which is modified by the volume concentration of original debris flows with heterogenous grain size.

关键词： debris flow Theological properties rheological model.

The Kinematic Effects of the Defects in Liquid Crystal Dynamics

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Communications in Computational Physics 2016年第6期20卷 234-249页

作者： rui chen Weizhu Bao Hui Zhang Institute of Applied Physics and Computational Mathematics Beijing 100088P.R.China Department of Mathematics National University of SingaporeSingapore119076 School of Mathematical Sciences Beijing Normal UniversityLaboratory of Mathematics and Complex SystemsMinistry of EducationBeijing 100875P.R.China

Here we investigate the kinematic transports of the defects in the nematic liquid crystal system by numerical *** model is a shear flow case of the viscoelastic continuummodel simplified fromthe Ericksen-Leslie *** numerical experiments are carried out by using a *** on these numerical experiments we find some interesting and important relationships between the kinematic transports and the characteristics of the *** present the development and interaction of the *** results are partly consistent with the observation from the *** this scheme illustrates,to some extent,the kinematic effects of the defects.

关键词： Nematic liquid crystals kinematic effects finite differencemethod defects

List of 85 typical catastrophic landslides from March 2004 to February 2024

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China Geology 2024年第2期7卷 369-370页

作者： rui-chen chen Yong-shuang Zhang School of Engineering and Technology China University of GeosciencesBeijing 100083China Institute of Geosafety China University of GeosciencesBeijing 100083China

Landslides are one of the most dangerous natural hazards that cause significant property damage and loss of *** often destroy farmland,villages,houses,factories,schools,roads and other facilities,injuring humans and ***,entire towns are devastated by *** to their pervasiveness,varied triggering factors,and sudden occurrence,landslides are currently one of the most challenging natural disasters to prevent and mitigate.

关键词： stated farmland catastrophic

Different timing for abdominal paracentesis catheter placement and drainage in severe acute pancreatitis complicated by intraabdominal fluid accumulation

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 134-142页

作者： rui chen Hua-Qiang chen rui-Die Li Hui-Min Lu Department of General Surgery Chengdu Sixth People’s HospitalChengdu 610058Sichuan ProvinceChina West China Center of Exellence for Pancreatitis Institute of Integrated Traditional Chinese and Western MedicineWest ChinaDivision of Pancreatic SurgeryDepartment of General SurgeryWest China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina HospitalSichuan University

BACKGROUND Non-surgical methods such as percutaneous drainage are crucial for the treatment of patients with severe acute pancreatitis(SAP).However,there is still an ongoing debate regarding the optimal timing for abdominal paracentesis catheter place-ment and *** To explore the influence of different timing for abdominal paracentesis catheter placement and drainage in SAP complicated by intra-abdominal fluid *** Using a retrospective approach,184 cases of SAP complicated by intra-abdominal fluid accumulation were enrolled and categorized into three groups based on the timing of catheter placement:group A(catheter placement within 2 d of symptom onset,n=89),group B(catheter placement between days 3 and 5 after symptom onset,n=55),and group C(catheter placement between days 6 and 7 after symptom onset,n=40).The differences in progression rate,mortality rate,and the number of cases with organ dysfunction were compared among the three *** The progression rate of group A was significantly lower than those in groups B and groups C(2.25%vs 21.82%and 32.50%,P0.05).At postoperative day 3,the levels of C-reactive protein(55.41±19.32 mg/L vs 82.25±20.41 mg/L and 88.65±19.14 mg/L,P<0.05),procalcitonin(1.36±0.51 ng/mL vs 3.20±0.97 ng/mL and 3.41±0.98 ng/mL,P<0.05),tumor necrosis factor-alpha(15.12±6.63 pg/L vs 22.26±9.96 pg/L and 23.39±9.12 pg/L,P<0.05),interleukin-6(332.14±90.16 ng/L vs 412.20±88.50 ng/L and 420.08±87.65ng/L,P<0.05),interleukin-8(415.54±68.43 ng/L vs 505.80±66.90 ng/L and 510.43±68.23ng/L,P<0.05)and serum amyloid A(270.06±78.49 mg/L vs 344.41±81.96 mg/L and 350.60±80.42 mg/L,P<0.05)were significantly lower in group A compared to those in groups B and group *** length of hospit

关键词： Abdominal paracentesis catheter drainage Timing Severe acute pancreatitis Intra-abdominal fluid Application value

An Fe-N/S-C hybrid electrocatalyst derived from bimetal-organic framework for efficiently electrocatalyzing oxygen reduction reaction in acidic media

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Journal of Energy Chemistry 2021年第1期30卷 291-300,I0010页

作者： Shuqin Song Mingmei Wu Junwei chen Zhuohua Mo rui chen Kun Wang Tongwen Yu The Key Lab of Low-carbon Chemistry&Energy Conservation of Guangdong Province School of Materials Science and EngineeringSchool of ChemistrySchool of Chemical Engineering and TechnologySun Yat-sen UniversityGuangzhou 510275GuangdongChina

Heteroatoms doped Fe-N-C electrocatalysts have been widely acknowledged as one of the most promising candidates to replace Pt-based materials for electrocatalyzing oxygen reduction reaction(ORR).However,the complicated synthesis method and controversial catalytic mechanism represent a substantial impediment as of ***,a very facile strategy to prepare Fe-N/S-C hybrid through pyrolyzing Zn and Fe bimetallic MOFs is rationally *** electrocatalytic ORR performance shows a volcanotype curve with the increment of added Fe *** half-wave potential(E1/2) for ORR at optimized Fe-N/S-C-10%(10%=n(Fe)/(n(Fe)+n(Zn)),n(Fe) and n(Zn) represent the moles of Fe2+ and Zn2+ in the precursors,respectively) shifts significantly to the positive direction of 19.6 mV with respect to that of Pt/C in acidic media,as well as a high 4 e selectivity and methanol *** 10,000 potential cycles,E1/2 exhibits a small negative shift of-27.5 mV at Fe-N/S-C-10% compared favorably with Pt/C(~141.0 mV).This can be attributed to:(ⅰ) large specific surface area(849 m^(2)/g) and hierarchically porous structure are favorable for the rapid mass transfer and active sites exposure;(ⅱ) the embedded Fecontaining nanoparticles in porous carbon are difficult to be moved and further agglomerated during the electrochemical accelerated aging test,further improving its stability;(ⅲ) there exist small Fecontaining nanoparticles,uniformly doped N and S,abundant Fe-N as efficiently active *** work represents a breakthrough in the development of high-efficient non-precious-metal catalysts(NPMCs)to address the current Pt-based electrocatalysts challenges.

关键词： Bimetallic MOFs Fe-N/S-C Oxygen reduction reaction Acidic media

Ultrasound-assisted Extraction of Kamebakaurin from Rabdosia excisa by Response Surface Methodology

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Chemical Research in Chinese Universities 2013年第6期29卷 1072-1077页

作者： TANG Jian MA rui-li LI Qian-qian JIANG Chun-bao chen rui OUYANG Zhen chen Hai-sheng School of Pharmacy Jiangsu University Zhenjiang 212013 P.R.China School of Pharmacy Second Ministry Medical University Shanghai 200433 R R. China College of Material Chemistry and Chemical Engineering Hangzhou Normal University Hangzhou 310036 P. R. China

For the efficient extraction of kamebakaurin（KA）, the ultrasound-assisted extraction（UAE） of KA from Rabdosia excisa（R, excisa） via response surface methodology（RSM） was investigated with high-performance liquid chromatography（HPLC）. Effects of the experimental parameters such as extraction solvent, ratio of liquid to plant material, extraction time and extraction temperature on the extracting efficiency of KA from R. excisa were evaluated, and the purity of KA in residual was calculated. The optimized conditions were 65.5%（volume fraction） acetone, 35 ℃, time of 24.6 min with ultrasound of 80 W/L, 40 kHz, ratio of liquid to plant material at 30：1（mL/g）. The maximum yield of KA is 0.708 mg/kg, with mean purity of 6.09%, indicating that ultrasound-assisted extraction is a feasible and useful method for extracting KA from R. excisa.

关键词： Ultrasound-assisted extraction Kamebakaurin Rabdosia excisa Response surface methodology

Image-denoising algorithm based on improved K-singular value decomposition and atom optimization

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CAAI Transactions on Intelligence Technology 2022年第1期7卷 117-127页

作者： rui chen Dong Pu Ying Tong Minghu Wu College of Information&Communication Engineering Nanjing Institute of TechnologyNanjingChina College of Electric Power Engineering Nanjing Institute of TechnologyNanjingChina Hubei Key Laboratory for High-efficiency Utilization of Solar Energy and Operation Control of Energy Storage System Hubei University of technologyWuhanChina

The traditional K-singular value decomposition(K-SVD)algorithm has poor imagedenoising performance under strong *** image-denoising algorithm is proposed based on improved K-SVD and dictionary atom ***,a correlation coefficient-matching criterion is used to obtain a sparser representation of the image *** dictionary noise atom is detected according to structural complexity and noise intensity and removed to optimize the ***,non-local regularity is incorporated into the denoising model to further improve image-denoising *** of the simulated dictionary recovery problem and application on a transmission line dataset show that the proposed algorithm improves the smoothness of homogeneous regions while retaining details such as texture and edge.

关键词： singular value smoothness