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Effects of slip length and hydraulic diameter on hydraulic entrance length of microchannels with superhydrophobic surfaces

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Frontiers in Energy 2020年第1期14卷 127-138页

作者： Wenchi GONG Jun shen Wei DAI Zeng DENG Xueqiang DONG Maoqiong GONG Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

This paper investigated effects of slip length and hydraulic diameter on the hydraulic entrance length of laminar flow in superhydrophobic *** investigations were performed for square microchannels with Re ranging between 0.1 and *** is found that superhydrophobic microchannels have a longer hydraulic entrance length than that of conventional ones by nearly 26.62%at a low *** dimensionless hydraulic entrance length slightly increases with the increasing slip length at approximately Re<10,and does not vary with the hydraulic diameter.A new correlation to predict the entrance length in square microchannels with different slip lengths was developed,which has a satisfying predictive performance with a mean absolute relative deviation of 5.69%.The results not only ascertain the flow characteristics of superhydrophobic microchannels,but also suggest that super hydrophobic microchannels have more significant advantages for heat transfer enhancement at a low Re.

关键词： laminar flow hydraulic entrance length super hydrophobic surface slip length hydraulic diameter

Enhanced hydrogen storage properties of MgH_(2) with the co-addition of LiBH_(4) and YNi_(5) alloy

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Journal of Materials Science & Technology 2024年第11期178卷 90-99页

作者： Shaoyang shen Wenfang Liao zhijie Cao Jiangwen Liu Hui Wang Liuzhang Ouyang Guangdong Engineering Research Center for Advanced Energy Storage Materials School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510641China New Energy Materials Laboratory School of PhysicsNingxia UniversityYinchuan 750021China

MgH_(2),as one of the typical solid-state hydrogen storage materials,has attracted extensive ***,the slow kinetics and poor cycle stability limit its *** this work,LiBH_(4) and YNi_(5) alloy were co-added as additives to MgH_(2) via ball milling,thereby realizing an excellent dehydrogenation per-formance and good cycle stability at 300 ℃.The MgH_(2)-0.04LiBH_(4)-0.01YNi_(5) composite can release 7 wt.%of hydrogen in around 10 min at 300 ℃ and still have a reversible hydrogen storage capacity of 6.42 wt.%after 110 cycles,with a capacity retention rate as high as 90.3%based on the second dehydrogenation *** FTIR results show that LiBH_(4) can reversibly absorb and desorb hydrogen throughout the hydrogen ab/desorption process,which contributes a portion of the reversible hydrogen storage capacity to the MgH_(2)-0.04LiBH_(4)-0.01YNi_(5) *** to the small amount of LiBH_(4) and YNi_(5),the dehydro-genation activation energy of MgH_(2) did not decrease significantly,nor did the dehydrogenation enthalpy(△H)***,the MgNi3B2 and in-situ formed YH3 during the hydrogen absorption/desorption cycles is not only beneficial to the improvement of the kinetics performance for MgH_(2) but also improves its cycle *** work provides a straightforward method for developing high reversible hydrogen capacity on Mg-based hydrogen storage materials with moderate kinetic performance.

关键词： Hydrogen storage Magnesium hydride Lithium borohydride YNi5 alloy High reversible capacity

Investigation of combined degrader for proton facility based on BDSIM/FLUKA Monte Carlo methods

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Nuclear Science and Techniques 2022年第2期33卷 30-39页

作者： Man-Fen Han Jin-Xing Zheng Xian-Hu Zeng Jun-Song shen Hefei Institutes of Physical Science Chinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China

The significant advantage of proton therapy over other particle-based techniques is in the unique physical characteristics of the Bragg *** can achieve a highly conformal dose distribution and maximize the probability of tumor control by varying the irradiation *** proton facilities use cyclotrons for fixed energy beam extraction and are equipped with degrader and collimator systems for energy modulation and emittance ***,interactions between charged particles and degrader materials inevitably cause beam loss and divergence and deteriorate beam performance,which present great challenges for downstream transport and clinical *** this work,we investigate a method of energy reduction by combining boron carbide and graphite in a degrader to obtain greater beam transmission at lower *** results demonstrate that the beam size and emittance at the exit of the combined degrader diverge less than those of multi-wedge one in the energy range of 70-160 ***,the transmission efficiency after the first dipole also shows improvements of 36.26%at 70 MeV and 70.55%at 110 *** a component with a high activity level,the degrader causes additional ambient radiation during *** induced radiation even remains several hours after system *** of material activation and induced radiation based on 1 h irradiation with a 400 nA beam current shows that the combined degrader has a definite advantage in shielding despite producing more secondary *** radioactivity and average ambient dose equivalent are reduced by 50%compared with the multiwedge degrader at the important cooling time of 1 *** 12 h and 24 h of cooling,the radiation levels of degraders decrease slightly due to the presence of long half-life residual *** average dose generated from the multi-wedge degrader is still 1.25 times higher than that of the combined one.

关键词： Proton therapy Degrader Boron carbide Transmission efficiency Radionuclide Ambient dose equivalent

Pretreatment neutrophil-to-lymphocyte and platelet-to- lymphocyte ratios do not predict survival in patients with cervical cancer treated with neoadjuvant chemotherapy and radical hysterectomy

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Chinese Medical Journal 2013年第8期126卷 1464-1468页

作者： WANG Dan WU Ming FENG Feng-zhi HUANG Hui-fang YANG Jia-xin shen Keng XIANG Yang Department of Obstetrics and Gynecology Peking Union McdicalCotlege Hospital Peking Union Medical College and ChineseAcademy of Medical Sciences Beijing 100730 China

Background A few inflammatory markers were studied to evaluate their possible prognostic roles in various cancers. The neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio are hypothesized to reflect the systemic inflammation. The objective of the present study was to investigate whether or not the pretreatment neutrophil-to-lymphocyte ratio or platelet-to-lymphocyte ratio can predict the survival of patients with cervical cancer treated with neoadjuvant chemotherapy and radical hysterectomy. Methods We performed a retrospective study on cervical cancer patients （FIGO stage Ib2-11b） who had undergone neoadjuvant chemotherapy and radical hysterectomy at Peking Union Medical College Hospital between January 1999 and December 2010. Data on demographics, clinical prognostic markers and histopathology were collected and analyzed. Univariate and multivariate analyses for prognostic factors were performed. Results A total of 111 patients were identified. The median neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios were 2.4 and 142.2, respectively. Overall survival and progression-free survival were neither significantly different between patients with high and low neutrophil-to-lymphocyte ratio （P=0.149 and P=0.108） nor in high and low platelet-to-lymphocyte ratio （P=0.336 and P=0.510）. On multivariate analysis, lymph node status （P=O.O00 and P=-O.O07） and lymphovascular space involvement （P=0.001 and P=0.001） were independent prognostic factors of progression-free survival and overall survival. Conclusions Lymph node status and lymphovascular space involvement were found to be independent prognostic factors for patients with cervical cancer who underwent neoadjuvant chemotherapy and radical hysterectomy. The pretreatment neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios seemed not to predict the survival of patients with cervical cancer treated with neoadjuvant chemotherapy and radical hysterectomy.

关键词： cervical cancer, neoadjuvant chemotherapy radical hysterectomy neutrophil-to-lymphocvte ratio:plutclet-to-lymphcyte ratio

Effects of the dispersed droplet sizes on the critical behavior of pseudobinary microemulsion

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Chinese Science Bulletin 2007年第8期52卷 1139-1141页

作者： CAI HongLan AN XueQin shen WeiGuo Department of Chemistry Lanzhou University Lanzhou 730000 China College of Chemistry and Environment Science Nanjing Normal University Nanjing 210097 China Department of Chemical Engineering East China University of Science and Technology Shanghai 200237 China

The critical behavior of pseudobinary microemulsion systems{water/sodium di(2-ethylhexyl)sulfo- succinate(AOT)/n-decane}with various droplet sizes was studied by measurements of refractive index. It was found that the critical exponentsβfor all systems approach 0.327 in a region sufficiently close to the critical temperature,which is consistent with 3D-Ising universality *** critical temperatures linearly decrease as the dispersed droplet sizes *** critical amplitude almost linearly in- creases with increasing the dispersed droplet sizes.

关键词：伪二元微乳液分散微滴大小临界行为振幅

LATTICE BGK MODEL SIMULATION OF ASYMMETRIC FLOW INSIDE A CONTINUOUS SLAB CASTING MOLD

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Journal of Hydrodynamics 2006年第4期18卷 431-435页

作者： ZHANG Xiao-jun shen Hou-fa Key Laboratory for Advanced Manufacturing by Materials Processing Technology Department of Mechanical Engineering Tsinghua University Beijing 100084 China

The incompressible lattice Bhatnager-Gross-Krook （BGK） model of computational fluid dynamics, from which the unsteady incompressible Navier-Stokes equations can be exactly derived with the limit of small Mach number, was established in continuous casting mold. An asymmetric flow pattern in the two-dimensional central plane of continuous slab casting mold was simulated, and the flow pattern is not stationary but changes over frequently if the Reynolds number is larger than 3000 or so. The results are found to be in excellent agreement with previous experimental results.

关键词： lattice Bhatnager-Gross-Krook (BGK) method incompressible Navier-Stokes equation continuous slab casting mold

A verifiable privacy-preserving data collection scheme supporting multi-party computation in fog-based smart grid

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Frontiers of Computer Science 2022年第1期16卷 143-153页

作者： Zhusen LIU Zhenfu CAO Xiaolei DONG Xiaopeng ZHAO Haiyong BAO Jiachen shen Shanghai Key Laboratory of Trustworthy Computing East China Normal UniversityShanghai200062China Cyberspace Security Research Center Peng Cheng LaboratoryShenzhen518055China School of Computer Science and Information Engineering Zhejiang Gongshang UniversityHangzhou310018China

Incorporation of fog computing with low latency,preprocession(e.g.,data aggregation)and location awareness,can facilitate fine-grained collection of smart metering data in smart grid and promotes the sustainability and efficiency of the ***,much attention has been paid to the research on smart grid,especially in protecting privacy and data ***,most previous works do not focus on privacy-preserving data aggregation and function computation query on enormous data simultaneously in smart grid based on fog *** this paper,we construct a novel verifiable privacy-preserving data collection scheme supporting multi-party computation(MPC),named VPDC-MPC,to achieve both functions simultaneously in smart grid based on fog ***-MPC realizes verifiable secret sharing of users’data and data aggregation without revealing individual reports via practical cryptosystem and verifiable secret sharing ***,we propose an efficient algorithm for batch verification of share consistency and detection of error reports if the external adversaries modify the SMs’***,VPDC-MPC allows both the control center and users with limited resources to obtain arbitrary arithmetic analysis(not only data aggregation)via secure multi-party computation between cloud servers in smart ***,VPDC-MPC tolerates fault of cloud servers and resists *** also present security analysis and performance evaluation of our scheme,which indicates that even with tradeoff on computation and communication overhead,VPDC-MPC is practical with above features.

关键词： smart grid fog computing data aggregation verifiable secret sharing error detection secure multi-party computation secure function query privacy-preserving

Improved Stiffness Modeling for An Exechon‑Like Parallel Kinematic Machine(PKM)and Its Application

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Chinese Journal of Mechanical Engineering 2020年第3期33卷 130-141页

作者： Nanyan shen Liang Geng Jing Li Fei Ye Zhuang Yu Zirui Wang Shanghai Key Laboratory of Intelligent Manufacturing and Robotics Shanghai UniversityShanghai 200444China School of Mechatronic Engineering and Automation Shanghai UniversityShanghaiChina.

Hole drilling or contour milling for the large and complex workpieces such as automobile panels and aircraft fuselages makes a high combined demand on machining accuracy,stiffness and workspace of machining ***,a 5-DOF(degrees of freedom)parallel kinematic machine(PKM)with redundant constraints is *** on the kinematics analysis of the parallel mechanism using intermediate variables,the kinematics problems of the PKM are solved through equivalent kinematics *** structural stiffness matrix method is adopted to model the stiffness of the parallel mechanism of the PKM,where the stiffness of each joint and branch component is obtained by stiffness formula and finite element *** the stiffness model of the parallel mechanism is improved by correction coefficient matrix,each element of which is constructed as a polynomial function of three independent end variables of the parallel *** terminal stiffness matrices obtained by simulation result are used to determine the coefficients of polynomial function by least square fitting to describe the correction coefficient over the workspace of the parallel mechanism *** experiment results prove that the modification method can greatly improve the stiffness model of the parallel *** enhance the machining accuracy of the PKM,the proposed kinematics model and the improved stiffness model are utilized to optimize the working stiffness of parallel machine by searching the best relative position of parallel machine and workpiece.A plate workpiece taken as example is examined in the case study section,which demonstrates the effectiveness of optimization method.

关键词： PKM 5-DOF Equivalent kinematics model Intermediate variables Stiffness correction coefficient Optimal working stiffness

Phenotype and metabolism alterations in PCB-degrading Rhodococcus biphenylivorans TG9^(T) under acid stress

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Journal of Environmental Sciences 2023年第5期127卷 441-452页

作者： Aili Li Jiahui Fan Yangyang Jia Xianjin Tang Jingwen Chen Chaofeng shen Department of Environmental Engineering College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China MOE Key Lab of Environmental Remediation and Ecosystem Health College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China

Environmental acidification impairs microorganism diversity and their functions on substance *** is a ubiquitously distributed genus for contaminant detoxification in the environment,and it can also adapt a certain range of *** work interpreted the acid responses from both phenotype and metabolism in strain Rhodococcus biphenylivorans TG9^(T)(TG9)induced at pH *** phenotype alterations were described with the number of culturable and viable cells,intracellular ATP concentrations,cell shape and entocyte,degradation efficiency of polychlorinated biphenyl(PCB)31 and *** number of culturable cells maintained rather stable within the first 10 days,even though the other phenotypes had noticeable alterations,indicating that TG9 possesses certain capacities to survive under acid *** metabolism responses were interpreted based on transcription analyses with four treatments including log phase(LP),acid-induced(PER),early recovery after removing acid(RE)and later recovery(REL).With the overview on the expression regulations among the 4 treatments,the RE sample presented more upregulated and less downregulated genes,suggesting that its metabolism was somehow more active after recovering from acid *** addition,the response mechanism was interpreted on 10 individual metabolism pathways mainly covering protein modification,antioxidation,antipermeability,H+consumption,neutralization and ***,the transcription variations were verified with RT-qPCR on 8 genes with 24-hr,48-hr and 72-hr acid *** together,TG9 possesses comprehensive metabolism strategies defending against acid ***,a model was built to provide an integrate insight to understand the acid resistance/tolerance metabolisms in microorganisms.

关键词： Environmental acidification Rhodococcus biphenylivorans Contaminant degradation Phenotypic response Transcription analysis Metabolism pathway Mechanism model