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Ethylene Evolution Changes in Tilted Fraxinus mandshurica Rupr. var. japonica *** in Relation to Tension Wood Formation

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Journal of Integrative Plant Biology 2009年第7期51卷 707-713页

作者： Sha Jiang Ke Xu Na Zhao shu-xin zheng Yan-Ping Ren Yu-Bao Gao Song Gu College of Life Sciences Nankai University Tianjin 300071 China

The effects of ethylene on tension wood formation were studied in 3-year-old Fraxinus mandshurica Rupr. var. japonica Maxim. seedlings in two separate experiments. In experiment 1, ethylene evolution of buds and stems was measured using gas chromatography after 0, 2, 4, 7, 14, and 21 d of treatment; in experiment 2, both aminoethoxyvinylglycine （AVG） and AgNO3 were applied to the horizontally-placed stems, and the cell numbers on sites of applications were measured after 40 d. Ethylene evolution from buds was found to be much greater in tilted seedlings than in upright ones. The cell numbers of wood fibers in shoots and 1-year-old stems were reduced in treatments with 12.5×10^-7μmol/L AVG, 12.5×10^-8μmol/L AVG, and 11.8×10^-8μmol/Lmol/L AgNO3; whereas the horizontal and vertical diameters were reduced by treatment of 12.5×10^-7μmol/L AVG. Ethylene evolutions of shoots and 1-year-old stems were inhibited greatly in comparison with the control by applying 12.5×10^-7μmol/L AVG. The formation of a gelatinous layer of wood fibers was affected by neither AVG nor AgNO3 application. These results suggest that ethylene regulates the quantity of wood production, but does not affect G-layer formation in F. mandshurica Rupr. *** Maxim. seedlings.

关键词： ethylene evolution Fraxinus mandshurica inhibitors tension wood formation

Single-atom-mediated electron islands boost photocatalytic CO_(2)chemical fixation

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Science China Chemistry 2024年第7期67卷 2292-2299页

作者： shu Shang Lei Li xin He Hui Wang Lirong zheng Wei Shao Xiaodong Zhang Yi Xie Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China Institute of Energy Hefei Comprehensive National Science CenterHefei 230031China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Chemistry and Chemical Engineering Hefei Normal UniversityHefei 230031China

Photocatalytic cycloadditions of CO_(2)with epoxides are emerging as a significant platform for the green synthesis of valuable carbonates,where efficient catalytic systems with spatially separated charge carriers are ***,a single p-block metal atom is proposed to be a candidate for photogenerated electron localization on a metal oxide *** taking the Bi single-atom supported on ZnO nanosheet(Bi1/ZnO)as an example,we show that the Bi atom plays the role of an electron island in the sea of delocalized holes within ***,the as-formed electron island could readily promote the rate-determining ring-opening process of cycloaddition *** from the unique spatially separated electrons and holes,the Bi1/ZnO achieves a high yield of cyclic carbonates with almost 100%*** study provides a pioneering strategy for enhancing the performances of photocatalytic CO_(2)chemical fixation.

关键词： electron islands CO_(2)photofixation photogenerated charge carriers

Strategies to advance thermoelectric performance of PbSe and PbS materials

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Rare Metals 2024年第9期43卷 4099-4114页

作者： zheng-Hao Hou xin Qian Qiu-Juan Cui shu-Fang Wang Li-Dong Zhao Shijiazhuang Key Laboratory of Low Carbon Energy Materials College of Chemical EngineeringShijiazhuang University Hebei Key Lab of Optic-Electronic Information and Materials College of Physics Science and Technology Hebei University School of Materials Science and Engineering Beihang University

Thermoelectric materials possess the unique capability to convert thermal energy into electric energy and vice versa, making them promising for waste heat recovery and efficient cooling systems. Currently, extensively investigated thermoelectric materials such as Bi2Te3,PbTe and GeTe exhibit superior thermoelectric properties at room temperature and medium temperature ***, the broad application of these thermoelectric materials has been impeded by the high cost and restricted accessibility of Te and Ge in the earth's crust. Over the past few years, researchers have shown increasing interest in PbSe-and PbS-based materials, primarily attributed to their abundant elemental supply and relatively low costs. The assessment of research progress and a comprehensive overview of optimization strategies in time can significantly contribute to further improving the thermoelectric performance. These strategies include optimizing carrier concentration(aliovalent doping, dynamic doping and defect state), enhancing density-of-state effective mass(band convergence, band flattening and energy filtering effect), optimizing carrier mobility(band sharpening and band alignment) and reducing lattice thermal conductivity(all-scale hierarchical defect structures designing). This systematic summary and analysis provide novel insights and perspectives for the development of thermoelectric materials.

关键词： Carrier concentration

Predictors of complications after prophylactic ileostomy reversal for rectal cancer:A retrospective study

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1354-1362页

作者： Quan Lv xin-Peng shu Dong Peng Si-Qi Li zheng Xiang Department of Gastrointestinal Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Chongqing Key Laboratory of Department of General Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China

BACKGROUND Previous studies have analyzed the risk factors for complications after ileostomy reversal for rectal cancer(RC),but there were significant differences in the reported risk factors for complications after stoma *** studies have analyzed the risk factors for stoma-related complications and overall postoperative com-plications *** To analyze the risk factors for overall complications and stoma-related complications after ileostomy reversal for patients with *** This was a retrospective study of 439 patients who underwent ileostomy reversal at a clinical center and were followed up between September 2012 and September *** variables are expressed as the mean±SD and were analyzed with independent-sample t tests,while frequency variables are expressed as n(%),and theχ2 test or Fisher’s exact test was *** and multivariate logistic regression analyses were used to identify predictors of overall complications and stoma-related *** The overall complication rate after ileostomy reversal was 11.4%.Patients with lower preoperative albumin concentration(P<0.01),greater blood loss(P=0.017),and longer operative times(P<0.01)were more likely to experience postoperative *** incidence of stoma-related complications was 6.4%.Analysis of the study showed that a higher body mass index(BMI)(P<0.01),preoperative comorbid hypertension(P=0.049),time from primary surgery to ileostomy reversal(P<0.01)and longer operation time(P=0.010)were more likely to result in stomarelated complications *** logistic regression analysis revealed that a lower preoperative albumin level(P<0.01,OR=0.888,95%CI:0.828-0.958)was an independent risk factor for overall ***,multivariate analysis revealed that BMI(P<0.01,OR=1.176,95%CI:1.041-1.330)and time from primary surgery to ileostomy reversal(P<0.01,OR=1.140,95%CI:1.038-1.252)were independent risk factors for stoma-related compl

关键词： Ileostomy Reversal Risk factors Complications Rectal cancer

Design and test of an RF acceleration system loaded with magnetic alloy for the proton synchrotron of the Xi'an Proton Application Facility

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Nuclear Science and Techniques 2018年第7期29卷 116-123页

作者： Guang-Rui Li shu-xin zheng Hong-Jin Zeng Zhi-Yu Wang Cai-Jun Yu Gang Fu Hong-Juan Yao Xia-Ling Guan Xue-Wu Wang Wen-Hui Huang Laboratory of Particle&Radiation Imaging Tsinghua UniversityMinistry of EducationBeijing 100084China Laboratory for Advanced Radiation Sources and Application Tsinghua UniversityBeijing 100084China Department of Engineering Physics Tsinghua UniversityBeijing 100084China Beijing Institute of Radio Measurement Beijing 100084China

The Xi'an Proton Application Facility(XiPAF)is a facility dedicated to the experimental simulation of the space radiation *** facility uses a compact synchrotron as its final-stage *** synchrotron can accelerate a proton beam from 7 to 230 *** design results show that the radio frequency(RF) acceleration system should work in the frequency range of 1—6 MHz and provide a maximum voltage of >800 *** dilute the strong space charge effect during the injection period,we also aim to achieve multiharmonic acceleration.A compact RF acceleration system loaded with magnetic alloy cores has been designed and developed to fulfill these *** preliminary test results show that the system can work normally with a gap voltage of 800 *** a further RF power upgrade,the voltage can be improved to >1:2 kV.

关键词：质子同步加速器加速系统物理设计设备 RF 装载合金磁性

Mechanism Design for Ancillary Service Market Considering Social Welfare and Fairness

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1000-1010页

作者： Zhi Wu Yuanxi Wu Wei Gu zheng Xu shu zheng Jingtao Zhao School of Electrical Engineering Southeast UniversityNanjing 210096China NARI Technology Co. Ltd.Nanjing 211106China IEEE CSEE

Increasing penetration of distributed energy resources in the distribution network(DN)is threatening safe operation of the DN,which necessitates setup of the ancillary service market in the *** the ancillary service market,distribution system operator(DSO)is responsible for safety of the DN by procuring available capacities of *** existing studies,this paper proposes a novel market mechanism composed of two parts:choice rule and payment *** proposed choice rule simultaneously considers social welfare and fairness,encouraging risk-averse aggregators to participate in the ancillary service *** is then formulated as a linear programming problem,and a distributed solution using the multi-cut Benders decomposition is ***,successful implementation of the choice rule depends on each aggregator’s truthful adoption of private ***,a payment rule is also designed,which is proved to possess two properties:incentive compatibility and individual *** results demonstrate effectiveness of the proposed choice rule on improving fairness and verify properties of the payment rule.

关键词： Aggregator ancillary service market distributed mechanism fairness mechanism design

Impact response and energy absorption of metallic buffer with entangled wire mesh damper

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Defence Technology（防务技术） 2024年第5期35卷 137-150页

作者： Chao zheng Jun Wu Mangong Zhang xin Xue Institute of Metal Rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350116China Wuhan Second Ship Design and Research Institute Wuhan 430205China

An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering *** impact response and the energy dissipation mechanism of hat-shaped EWMD under different quasi-static compression deformations(2-7 mm)and impact heights(100-200 mm)are investigated using experimental and numerical *** results demonstrate distinct stages in the quasi-static mechanical characteristics of hat-shaped EWMD,including stiffness softening,negative stiffness,and stiffness *** loss factor gradually increases with increasing compression deformation before entering the stiffness hardening *** impact loads,the hat-shaped EWMD exhibits optimal impact energy absorption when it enters the negative stiffness stage(150 mm),resulting in the best impact isolation effect of metallic ***,the impact energy absorption significantly decreases when hat-shaped EWMD enters the stiffness hardening ***,quasi-static compression analysis after experiencing different impact loads reveals the disappearance of the negative stiffness ***,with increasing impact loads,the stiffness hardening point progressively shifts to an earlier stage.

关键词： Metallic buffer Hat-shaped EWMD Drop impact Energy absorption characteristics Mechanical behavior

Strong anisotropy of thermal transport in the monolayer of a new puckered phase of PdSe

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Frontiers of physics 2024年第3期19卷 143-151页

作者： zheng shu Huifang Xu Hejin Yan Yongqing Cai Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoTaipaMacao 999078China

We examine the electronic and transport properties of a new phase PdSe monolayer with a puckered structure calculated by first-principles and Boltzmann transport *** spin−orbit coupling is found to play a negligible effect on the electronic properties of PdSe *** lattice thermal conductivity of PdSe monolayer exhibits remarkable anisotropic characteristic due to anisotropic phonon group velocity along different directions and its intrinsic structure *** compromised electronic mobility despite a relatively low thermal conduction results in a moderate ZT value but significantly anisotropic thermoelectric performance in single-layer *** present work suggests that the remarkable thermal transport anisotropy of PdSe monolayer can be used for thermal management,and enhance the scope of possibilities for heat flow manipulation in PdSe based *** sizeable puckered cages and wiggling lattice implies it an ideal platform for ionic and molecular engineering for thermoelectronic applications.

关键词： 2D materials first-principles calculations phonon

Comparison of models to predict air infiltration rate of buildings with different surrounding environments

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Building Simulation 2024年第6期17卷 1007-1021页

作者： shu zheng Xiujiao Song Lin Duanmu Yu Xue Xudong Yang Department of Building Science Tsinghua UniversityBeijing100084China School of Civil Engineering Dalian University of TechnologyDalian116024China Shanxi Research Institute for Clean Energy Tsinghua UniversityTaiyuan030032China

The air infiltration rate of buildings strongly influences indoor environment and energy *** this study,several traditional methods for determining the air infiltration rate were compared,and their accuracy in different scenarios was ***,a method combining computational flow dynamics(CFD)with the Swami and Chandra(S-C)model was developed to predict the influence of the surrounding environment on the air infiltration *** buildings in Dalian,China,were selected:one with a simple surrounding environment and the other with a complex surrounding environment;their air infiltration rates were *** test results were used to validate the accuracy of the air infiltration rate solution models in different urban *** the building with a simple environment,the difference between the simulation and experimental results was 0.86%–22.52%.For the building with a complex environment,this difference ranged from 17.42%to 159.28%.We found that most traditional models provide accurate results for buildings with simple surrounding and that the simulation results widely vary for buildings with complex *** results of the method of combining CFD with the S-C model were more accurate,and the relative error between the simulation and test results was 10.61%.The results indicate that the environment around the building should be fully considered when calculating the air infiltration *** results of this study can guide the application of methods of determining air infiltration rate.

关键词： air infiltration rate models CFD simulation building surrounding air infiltration rate test