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Influence of Blade Outlet Angle on Inner Flow Field of Centrifugal Pump Transporting Salt Aqueous Solution

Chinese Journal of Mechanical Engineering 2009年第6期22卷 912-917页

作者： YANG Minguan KANG can dong Xiang liu dong School of Energy and Power Engineering Jiangsu University Zhenjiang 212013 China

During transportation of salt aqueous solutions with centrifugal pump, crystallization phenomenon is frequently encountered. For this kind of two-phase flow, it is difficult to be accurately modeled since there are various medium properties and phase change characteristics. In view of experiment, several problems are hampering the implementation of precise measurement. Influences of blade outlet angle and medium temperature on crystallization rate were studied. Sodium sulfate solution was applied to simulate practical fluid in chemical industry. Particle image velocimetry（PIV） was employed to measure velocity distributions in rotating impeller. Crystallization processes in three impellers with different blade outlet angles were investigated. Relations among crystallization and flow parameters such as temperature and velocity were obtained. With the same blade wrap angle, when blade outlet angle is larger, diffusion of single flow passage gets stronger, relative velocity at blade outlet decreases and large scale vortex tends to appear near the blade working surface. For the impact of volume effect of particle phase on fluid viscosity, both liquid and solid phase velocities decrease with continual forming and growing of crystal particles. Velocity of solid phase is greater than that of liquid phase and its direction leans more closely to blade working surface. Solid particles tend to move towards blade working surface, as is more obvious in the impeller with large blade outlet angle. Therefore, collision between solid particles with stem part of blade working surface is more intensive in impeller with large blade outlet angle. Concerning transportation of salt aqueous solution, accurate PIV measurement is conducted in centrifugal impellers with different blade outlet angles. The results are useful and instructive in relevant engineering design and operation.

关键词： centrifugal pump flow with crystallization blade outlet angle particle image velocimetry(PIV)

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Low-power laser therapy for carpal tunnel syndrome:effective optical power

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Neural Regeneration Research 2016年第7期11卷 1180-1184页

作者： Yan Chen Cheng-qiang Zhao Gang Ye can-dong liu Wen-dong Xu Department of Neurology Tongji HospitalTongji University School of Medicine Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Department of Rehabilitation Medicine Tongji HospitalTongji University School of Medicine

Low-power laser therapy has been used for the non-surgical treatment of mild to moderate carpal tunnel syndrome,although its efficacy has been a long-standing *** laser parameters in low-power laser therapy are closely related to the laser effect on human *** evaluate the efficacy of low-power laser therapy,laser parameters should be accurately measured and controlled,which has been ignored in previous clinical ***,we report the measurement of the effective optical power of low-power laser therapy for carpal tunnel *** monitoring the backside reflection and scattering laser power from human skin at the wrist,the effective laser power can be *** clinical measurements from 30 cases,we found that the effective laser power differed significantly among cases,with the measured laser reflection coefficient ranging from 1.8% to 54%.The reflection coefficient for 36.7% of these 30 cases was in the range of 10–20%,but for 16.7% of cases,it was higher than 40%.Consequently,monitoring the effective optical power during laser irradiation is necessary for the laser therapy of carpal tunnel syndrome.

关键词： tunnel moderate irradiation inferred hemisphere reflecting absolute calibration Probability consent

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Picotesla fiberized diamond-based AC magnetometer

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Photonics Research 2024年第6期12卷 1250-1261页

作者： SHAO-CHUN ZHANG YONG liu LONG-KUN SHAN XUE-dong GAO JIA-QI GENG CUI YU YANG dong XIANG-dong CHEN GUANG-can GUO FANG-WEN SUN CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China National Key Laboratory of ASIC Hebei Semiconductor Research InstituteShijiazhuang 050051China Electric Power Quantum Sensing Joint Laboratory of Anhui Province State Grid Anhui Electric Power Research InstituteHefei 230601China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Portable quantum sensors are crucial for developing practical quantum sensing and metrology *** nitrogen-vacancy(NV)centers in diamonds have emerged as one of the most promising candidates for compact quantum ***,due to the difficulty of coherently controlling the ensemble spin and noise suppression in a large volume,it often faces problems such as reduced sensitivity and narrowed bandwidth in integrated lensless ***,we propose a fluorescence signal treatment method for NV spin ensemble manipulation by the exponential fitting of spin polarization processes,instead of integrating the photon *** enables spin state readout with a high signal-to-noise ratio and applies to the pulse sensing protocols for large-volume NV *** on this,we further developed a fiberized diamond-based AC *** an XY8-N dynamical decoupling pulse sequence,we demonstrated a T_(2)-limited sensitivity of 8pT/√Hz and T_(1)-limited frequency resolution of 90 Hz over a wide frequency band from 100 kHz to 3 *** integrated diamond sensor leverages quantum coherence to achieve enhanced sensitivity in detecting AC magnetic fields,making it suitable for implementation in a compact and portable endoscopic sensor.

关键词： magnetometer quantum ensemble

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Modeling urban scale human mobility through big data analysis and machinelearning

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Building Simulation 2024年第1期17卷 3-21页

作者： Yapan liu Bing dong Department of Mechanical&Aerospace Engineering Syracuse University263 Link HallSyracuseNY 13244USA

In the United States,the buildings sector consumes about 76%of electricity use and 40% of all primary energy use and associated greenhouse gas *** behavior has drawn increasing research interests due to its impacts on the building energy ***,occupant behavior study at urban scale remains a challenge,and very limited studies have been *** an effort to couple big data analysis with human mobility modeling,this study has explored urban scale human mobility utilizing three months Global Positioning System(GPS)data of 93,o00 users at Phoenix Metropolitan *** research extracted stay points from raw data,and identified users'home,work,and other locations by Density-Based Spatial Clustering ***,daily mobility patterns were constructed using different types of *** propose a novel approach to predict urban scale daily human mobility patterns with 12-hour prediction horizon,using Long Short-Term Memory(LSTM)neural network *** shows the developed models achieved around 85%average accuracy and about 86%mean *** developed models can be further applied to analyze urban scale occupant behavior,building energy demand and flexibility,and contributed to urban planning.

关键词： urban human mobility big data analysis urban scale occupant behavior recurrent neural networks

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Bipolar Thermally Activated Delayed Fluorescence Emitter with Balanced Carrier Transport for High-Efficiency Nondoped Green Electroluminescent Devices

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CCS Chemistry 2024年第9期6卷 2346-2357页

作者： Yuchao liu Zhagen Miao Haikuo Gao Shian Ying can Gao Shouke Yan Huanli dong Zhongjie Ren Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-PlasticsSchool of Polymer Science and EngineeringQingdao University of Science and TechnologyQingdao 266042 National Laboratory for Molecular Sciences Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190 Department of Chemistry University of Chinese Academy of SciencesBeijing 100049 Shandong Engineering Research Center of Aeronautical Materials and Devices College of Aeronautical EngineeringBinzhou UniversityBinzhou 251900 State Key Laboratory of Chemical Resource Engineering College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029

High-efficiency electroluminescent devices featuring simplified architecture have received considerable attention due to significant advantages in construction procedures and commercialized ***,there still remains a critical challenge with regard to the lack of organic semiconductors that simultaneously possess high luminescent efficiency and balanced carrier-transporting ***,we design a thermally activated delayed fluorescence(TADF)emitter 4-(9,9-dimethyl-9,10-dihydroacridine)-4′-triphenylphosphineoxide-benzophenone(DMAC-BPTPO)by incorporating triphenylphosphine oxide into the donor–acceptor *** accessional electrontransporting moiety,rod-like dimer,and horizontally packing model synergistically enable DMAC-BP-TPO which possesses an excellent photoluminescence quantum yield of nearly 90%with a reverse intersystem crossing rate constant of 2.0×106 s−1,horizontal dipole ratio of 89%,and a balanced electron and hole mobilities with a small constrast ratio of ***,simplified electroluminescent devices including organic lightemitting diodes(OLEDs)and organic light-emitting transistors(OLETs)incorporating DMAC-BP-TPO-based nondoped film are demonstrated due to their superior integrated optoelectronic properties along with preferable horizontal dipole orientation.A record-high external quantum efficiency value of 21.7%and 4.4%are finally achieved in the simplified nondoped OLED and OLET devices,which are among the highest values in the related research *** work provides a new avenue to develop a high-efficiency bipolar TADF emitter to advance the simplified electroluminescent devices.

关键词： organic light-emitting diode organic lightemitting transistor bipolar thermally activated delayed fluorescence nondoped active layer

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Combustion characteristics of millimeter-sized aluminum particles in fluidized bed under various O_(2)/CO_(2)/H_(2)O atmospheres Author links open overlay panel

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Particuology 2024年第8期91卷 315-322页

作者： Jialing Zhou Rui Zhang dong liu Key Laboratory of Thermal Control of Electronic Equipment Ministry of Industry and Information TechnologyNanjing210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing210094China

Aluminum is an attractive alternative fuel,but it burns very inefficiently due to the formation of a dense Al_(2)O_(3)layer which prevents O_(2)from diffusion to the surface of Al *** previous experiments,the combustion of millimeter-sized Al(mAl)particles in the fluidized bed has achieved a substantial increase in the combustion efficiency,but further improvements are still *** this study,the effects of reaction atmosphere on the fluidized combustion of mAl particles were *** experiments with different O_(2)/H_(2)O/CO_(2)concentrations were *** experimental results indicate that the combustion efficiency of mAl particles in fluidized bed increases as the mole fraction of O_(2),H_(2)O or CO_(2)increases,and the highest combustion efficiency can reach 38.7%.After the analysis of the oxide film on the surface of aluminum particles,it was found that it is easier to generate the unstableθ-Al_(2)O_(3)under CO_(2)atmosphere,and it is easier to generate the unstableγ-Al_(2)O_(3)andθ-Al_(2)O_(3)under H_(2)O *** unstable Al_(2)O_(3)film is more likely to be abraded in the fluidized bed,which leads to the effective improvement of the combustion efficiency.

关键词： Al combustion Fluidized bed Atmosphere Combustion efficiency

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Estrogen restores disordered lipid metabolism in visceral fat of prediabetic mice

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World Journal of Diabetes 2024年第5期15卷 988-1000页

作者： Su-Huan liu Zhao-Shui Shangguan Paiziliya Maitiaximu Zhi-Peng Li Xin-Xin Chen can-dong Li Research Base of Chinese Medicine Syndrome Fujian University of Traditional Chinese MedicineFuzhou 350122Fujian ProvinceChina Research Center for Translational Medicine The First Affiliated Hospital of Xiamen UniversitySchool of MedicineXiamen UniversityXiamen 361003Fujian ProvinceChina

BACKGROUND Visceral obesity is increasingly prevalent among adolescents and young adults and is commonly recognized as a risk factor for type 2 ***[17β-estradiol(E2)]is known to offer protection against obesity via diverse me-chanisms,while its specific effects on visceral adipose tissue(VAT)remain to be fully *** To investigate the impact of E2 on the gene expression profile within VAT of a mouse model of *** Metabolic parameters were collected,encompassing body weight,weights of visceral and subcutaneous adipose tissues(VAT and SAT),random blood glucose levels,glucose tolerance,insulin tolerance,and overall body *** gene expression profiles of VAT were quantified utilizing the Whole Mouse Genome Oligo Microarray and subsequently analyzed through Agilent Feature Extraction *** and pathway analyses were conducted employing Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses,*** Feeding a high-fat diet(HFD)moderately increased the weights of both VAT and SAT,but this increase was mitigated by the protective effect of endogenous ***,ovariectomy(OVX)led to a significant increase in VAT weight and the VAT/SAT weight ratio,and this increase was also reversed with E2 ***,OVX diminished the expression of genes involved in lipid metabolism compared to HFD feeding alone,signaling a widespread reduction in lipid metabolic activity,which was completely counteracted by E2 *** study provides a comprehensive insight into E2's local and direct protective effects against visceral adiposity in VAT at the gene *** In conclusion,the present study demonstrated that the HFD-induced over-nutritional challenge disrupted the gene expression profile of visceral fat,leading to a universally decreased lipid metabolic status in E2 deficient mice.E2 treatment effectively reversed this condition,shedding light on the mechanistic role and thera

关键词： Estrogen Obesity,Visceral adiposity Energy metabolism Type 2 diabetes

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Sensitivity analysis of modeling parameters to soot and PAHs prediction in ethylene inverse diffusion flame

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Science China(Technological Sciences) 2024年第2期67卷 486-498页

作者： WU BingKun LI TianJiao liu dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and Technology Nanjing 210094China

The soot formation model based on inverse ethylene diffusion flames was performed to study the sensitivity of the soot formation process to the prediction *** effects of efficiency parameters such as soot inception,surface growth and coagulation on the simulation results were studied by using the adjustable efficiency *** addition,the reversible soot model and conjugate heat transfer(CHT)model were also introduced to explore their *** indicated that,among adjustable efficiency parameters,the nucleation efficiency had the greatest influence on the predicted soot and PAHs distributions,while the Habstraction-C2H2-addition(HACA)process and PAH adsorption surface growth efficiencies impacted *** adjustable efficiency parameters had a significant effect on the concentration of soot gaseous precursors and soot particles,but their effects on temperature,gas phase molecules,and intermediate species were not *** the nucleation efficiency increased from 2×10^(-6)to 1×10^(-4),the predicted value of the integrated soot was increased by nearly 50%,and the maximum primary particle number density and the number of aggregates were increased by an order of *** maximum concentration of BAPYR was ***,the peak temperature along the axial direction increased by only 3.5 *** the reversible soot model,the approximation results of the adjustable efficiency parameters could be modified,which showed the feasibility of the *** use of the CHT model promoted pyrolysis of the fuel below the outlet of the fuel tube,with high-temperature zones,soot zones,and PAHs zones moving towards higher flame ***,when using the reversible model and the CHT model,the maximum soot volume fraction decreased by 39%compared with the basic efficiency parameters,while the concentration of BAPYR increased by 162%,and the concentrations of gas phase species were decreased.

关键词： inverse diffusion flames soot formation soot model ethylene

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An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality

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Science China Chemistry 2024年第9期67卷 2998-3003页

作者： Qi liu Xue-dong Li Liang Cheng Li liu Beijing National Laboratory for Molecular Sciences(BNLMS) CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which provides efficient methods for the preparation of axially chiral ***,developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination *** this work,we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent *** addition,the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis *** methodology provided a straightforward and sustainable access to a broad range of biaryl-2-carboxylic acid and in excellent yields(up to 92%)and excellent central-to-axial chirality conversion(up to 99%conversion percentage).This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization.

关键词： br?nsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion

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A Degree Condition for Graphs Having All(a,b)-parity Factors

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 656-664页

作者： Hao-dong liu Hong-liang LU School of Mathematics and Statistics Xi'an Jiaotong UniversityXi'an 710049China

Let a and b be positive integers such that a≤b and a≡b(mod 2).We say that G has all(a,b)-parity factors if G has an h-factor for every function h:V(G)→{a,a+2,…,b-2,b} with b|V(G)| even and h(v)≡b(mod 2) for all v∈V(G).In this paper,we prove that every graph G with n≥2(b+1)(a+b) vertices has all(a,b)-parity factors if δ(G)≥(b^(2)-b)/a,and for any two nonadjacent vertices u,v ∈V(G),max{d_(G)(u),d_(G)(v)}≥bn/a+***,we show that this result is best possible in some sense.

关键词： degree condition all(a,b)-factors

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