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Comparison of different preoperative objective nutritional indices for evaluating 30-d mortality and complications after liver transplantation

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 143-154页

作者： Chuan Li hong-xia chen Yan-Hua Lai Department of Transplantation People’s Hospital of Guangxi Zhuang Autonomous RegionNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Clinical Pharmacy People’s Hospital of Guangxi Zhuang Autonomous RegionNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND The nutritional status is closely related to the prognosis of liver transplant re-cipients,but few studies have reported the role of preoperative objective nutri-tional indices in predicting liver transplant *** To compare the predictive value of various preoperative objective nutritional indicators for determining 30-d mortality and complications following liver transplantation(LT).METHODS A retrospective analysis was conducted on 162 recipients who underwent LT at our institution from December 2019 to June *** This study identified several independent risk factors associated with 30-d mor-tality,including blood loss,the prognostic nutritional index(PNI),the nutritional risk index(NRI),and the control nutritional *** 30-d mortality rate was 8.6%.Blood loss,the NRI,and the PNI were found to be independent risk factors for the occurrence of severe postoperative *** NRI achieved the highest prediction values for 30-d mortality[area under the curve(AUC)=0.861,P<0.001]and severe complications(AUC=0.643,P=0.011).Compared to those in the high NRI group,the low patients in the NRI group had lower preoperative body mass index and prealbumin and albumin levels,as well as higher alanine aminotransferase and total bilirubin levels,Model for End-stage Liver Disease scores and prothrombin time(P<0.05).Furthermore,the group with a low NRI exhibited significantly greater incidences of intraabdominal bleeding,primary graft nonfunction,and *** The NRI has good predictive value for 30-d mortality and severe complications following *** NRI could be an effective tool for transplant surgeons to evaluate perioperative nutritional risk and develop relevant nutritional therapy.

关键词： Liver transplantation Nutritional indicator Complications Prognosis Nutrition assessment

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Pitch control strategy before the rated power for variable speed wind turbines at high altitudes

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Journal of Hydrodynamics 2019年第2期31卷 379-388页

作者： Ming-wei Ge Wei-ming Ke hong-xia chen School of Renewable Energy North China Electric Power UniversityBeijingl 02206China School of Energy Power and Mechanical Engineering North China Electric Power UniversityBeijing 102206China

The wind turbines in the world's highest wind farm with an altitude of over 4 000 m in Naqu county of China were put into operation in *** with the wind turbines at lower altitudes,the rated wind speed of these wind turbines are much larger,and the corresponding tip-speed ratio at the rated power reduces significantly due to the lower air ***,the power coefficient at the point of the rated power is decreased to a rather low *** improve the performance of the wind turbines at very high altitudes,this paper proposes a new pitch control strategy for variable speed wind turbines at the constant-speed phase,especially at the rated-speed phase before the rated power is *** is shown that the new pitch control strategy works very well for the wind farms at very high altitude and with low air density,with the catch of the wind energy enhaneed and the aerodynamic loads significantly reduced.

关键词： Wind turbine pitch control strategy high altitudes

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Highly Selective Diphoshinoamine/Cr(III) Catalysts for Ethylene Tetramerization

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Chinese Chemical Letters 2006年第3期17卷 358-360页

作者： Tao JIANG hong xia chen Ying Nan NING Wei chen School of Chemistry ＆ Chemical Daqing Petroleum Institute Daqing 163318 SINOPEC Beijing Research Institute of Chemical Industry Beijing 100013

Two novel diphoshinoamine ligands have been synthesized. Combination of Cr（Ⅲ） and methylaluminoxane（MAO） generated active catalytic system which can catalyze tetramerization of ethylene with high catalytic activi... 详细信息

关键词： Ethylene tetramerization 1-octene Cr(Ⅲ) diphoshinoamine MAO catalyst

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Study on the oscillating phenomena of electrical potential across a liquid membrane

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Chinese Chemical Letters 2007年第3期18卷 309-312页

作者： Jin Zhang Gao hong xia Dai Hua chen Jie Ren Wu Yang Chemistry ＆ Chemical Engineering College Northwest Normal University Lanzhou 730070 China

The electrical oscillations across a liquid membrane in water/oil/water system was studied with octanol as oil phase by introducing two opposite charged surfactants in oil and aqueous phase, respectively. The sustained and rhythmic oscillation was observed. To a certain extent, the features of the oscillation （e.g. induction time, frequency, life time and orientation of the pulse pikes） strongly depend on the property of surfactant, dissolved in octanol. The mechanism may be explained by the formation and destruction of dual-ion surfactant membrane accompanying with emulsification at the interface and considering the coupling effect of diffusion and associated reaction in the vicinity of the interface.

关键词： Liquid membrane Chemical oscillation Electrical potential Surfactant

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Atomistic study of inverse size effect induced by interfacial plasticity in pearlitic multi-principal element alloy

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Rare Metals 2024年第7期43卷 3341-3355页

作者： chen Yang Qiao-Sheng xia Cun-hong Yin Dong-Peng Hua College of Mechanical Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Advanced Manufacturing Technology Ministry of EducationGuizhou UniversityGuiyang 550025China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China

Owing to the fine nano-laminated structure,the pearlitic multi-principal element alloy(PMPEA) exhibits excellent mechanical and tribological ***,the incomplete understanding of the size effect of its lamella thickness and the unclear understanding of the plasticity-interface interaction mechanism limit further optimization of *** this study,the FeCoNi/Ni_3Ti interface-mediated plastic deformation behavior in PMPEA and the variation of mechanical and tribological properties with lamella thickness within the nanoscale range using molecular dynamics(MD) simulation were *** results indicate that the mechanical and tribological properties of the PMPEA with lamella thicknesses below 10 nm have a significant inverse size effect,i.e.,the smaller the lamella thickness,the weaker the *** is because the plastic carrier-interface interaction mechanism changes from a strengthening mechanism that hinders dislocations to a weakening mechanism that promotes dislocations with the decreases in the lamella thickness,and the weakening effect becomes more pronounced as the lamella thickness decreases and the number of interfaces *** particular,the deformation behavior of Ni_3Ti lamellae changes from crystal-like to amorphous-like with decreasing ***,in the sample with larger lamella thickness,the occurrence of hierarchical slips in the body-centered cubic(BCC) phase due to the multiprincipal elements effect can better alleviate the stress concentration caused by the dislocation accumulation at the interface,so that the phase interface exhibits outstanding load-bearing *** the dislocation pattern in BCC phase shows a firm high-density cell,which makes the substrate exhibit a stable tribological response.

关键词： Multi-principal element alloy Nano-laminated structure Molecular dynamics simulation Nanoindentation and nanoscratch

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A New Construction Method for the Dual Tree Complex Wavelet Based on Direction Sensitivity

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自动化学报 2006年第1期32卷 47-53页

作者： WANG hong-xia chen Bo chenG Li-Zhi Department of Mathematics ＆ System Science National University of Defense Technology Changsha 410073

The conception of 'main direction' of multi-dimensional wavelet is established in this paper, and the capabilities of several classical complex wavelets for representing directional singularities are investigated based on their main directions. It is proved to be impossible to represent directional singularities optimally by a multi-resolution analysis (MRA) of L2(R2). Based on the above results, a new algorithm to construct Q-shift dual tree complex wavelet is proposed. By optimizing the main direction of parameterized wavelet filters, the difficulty in choosing stop-band frequency is overcome and the performances of the designed wavelet are improved too. Furthermore, results of image enhancement by various multi-scale methods are given, which show that the new designed Q-shift complex wavelet do offer significant improvement over the conventionally used wavelets. Direction sensitivity is an important index to the performance of 2D wavelets.

关键词：复合微波对偶树图象增加灵敏性

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Influence of transverse mode on retinal spot size and retinal injury effect:A theoreticalan alysis on 532-nm laser

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Journal of Innovative Optical Health Sciences 2014年第3期7卷 31-39页

作者： Jia-Rui Wang Guang-Yuan Yu Zai-Fu Yang Lu-Guang Jiao hong-xia chen xian-Biao Zou Department of Laser and Electromagnetic BiologyBeijing Institute of Radiation Medicine Beijing 100850P.R.China Department of Dermatology First Affliated Hospitalof PLA General HospitalBeijing 100048P.R.China

The fundamental transverse mode(TEM00)is preferable for experimental and theoretical study on the laser-induced retinal injury effect,for it can produce the minimal retinal image andestablish the most strict laser safety *** actually lasers with higher order mode werefrequently used in both earlier and recent *** higher order mode leads to largerretinal spot size and so higher damage threshold,but there are few quantitative analyses on *** this paper,a four-surface schematic eye model is established for human and *** propagation of 532-nm laser in schematic eye is analyzed by the ABCD law of *** is shown that retinal spot size increases with laser transverse mode *** relativelower mode order,the retinal spot diameter will not exceed the minimum laser-induced retinallesion(25~30μm in diameter),and so has little effect on retinal damage *** forhigher order mode,the larger'retinal spot requires more energy to induce injury and so the damage threshold *** beam divergence is lowered,the retinal spot size decreasescorrespondingly,so the efect of mode order can be *** retinal spot size of macaqueis slightly smaller than that of human and the ratio bet ween them is independent of mode *** conclude that the laser mode order has significant influence on retinal spot size but limitedinfluence on the retinal injury ffect.

关键词： Laser transverse mode four-surface schematic eye retinal spot size retinal injuryeffect.

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Two-stage Planning Method for Energy Router Considering Its Optimal Operation in Distribution Networks

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 605-616页

作者： Meifu chen Mingchao xia Qifang chen School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China

An energy router can effectively optimize the network loss and power quality of distribution networks. The optimal configuration of the energy router is relatively complex because issues dynamically influence each other, such as the location of the energy router, optimal number and capacity of its ports, and building new distribution lines for the ports. Presently, there has been very few research studies on the practical problems for the energy router. In this paper, a planning model of an energy router combined with the distribution network is established, which fully exploits the active and reactive power control abilities of the energy router to optimize the operation of the grid. The configuration problem is decoupled into two stages. The upper layer determines the location of the energy router and the parameters of the candidate new distribution lines for the ports. The lower layer calculates the optimal configuration of the energy router by minimizing the total annual cost. Because of the same rated bus voltage in the distribution network, the existing structure of the energy router is changed to be more applicable for the distribution network, and then the power flow model of the energy router is also modified. Due to the nonlinearity of the model, the planning model is converted into a mixed-integer second-order cone model to solve efficiently. In addition, some core factors influencing the optimal scheme of the energy router are also analyzed in this paper. Simulation results show that the optimal scheme of the energy router can significantly improve the economic deployment of the energy router, and optimize the network loss and power quality of the distribution network.

关键词： Capacity allocation distribution network energy router optimal operation

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Minimum mass-entransy dissipation profile for one-way isothermal diffusive mass-transfer process with mass-resistance and massleakage

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Science China(Technological Sciences) 2024年第8期67卷 2427-2435页

作者： chen LinGen xia ShaoJun Institute of Thermal Science and Power Engineering Wuhan Institute of TechnologyWuhan 430205China School of Mechanical Electrical EngineeringWuhan Institute of TechnologyWuhan 430205China School of Power Engineering Naval University of EngineeringWuhan 430033China

As a new concept,mass-entransy is one of the twins in the core of entransy *** can describe mass-transfer ability for masstransfer processes(MTPes),just as thermal-entransy for describing heat-transfer ***,mass-entransy dissipation can be utilized to evaluate the loss of mass-transfer *** mass-entransy dissipation(MMED) is utilized to optimize one-way isothermal diffusive MTPes with mass-leakage and mass-transfer law(g ∝ Δ(c),where c means concentration).For a given net amount of mass-transferred key components at the low-concentration side,optimality-condition for the MMED of isothermal diffusive MTPes is obtained by using the *** of the amount of mass-transferred and mass-leakage on optimal results are analyzed,and the obtained optimization profiles are compared with those for MTP profiles of constant-concentration-difference(c_1-c_2=const) and constant-concentration-ratio(c_1/c_2=const).The product of square of key-component-concentration(KCC) difference between high-and low-concentration sides and inert component concentration at high-concentration side for the MMED of the MTP with no mass-leakage is a constant,and the optimal relationship of the KCCs between high-and low-concentration sides with mass-leakage is significantly different from the *** mass-leakage is relatively small,the MTP with c_1-c_2=const strategy is superior to that with c_1/c_2=const strategy,and the latter is superior to the former with an increase in mass-leakage.A combination of mass-entransy concept,finite-time thermodynamics,and averaged-optimization-method is a meaningful tool for optimizing MTPes.

关键词： diffusive mass-transfer-law mass-leakage one-way isothermal mass-transfer minimum mass-entransy dissipation finite-time thermodynamics averaged-optimization-method

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Planning Model for Energy Routers Considering Peer-to-Peer Energy Transactions Among Multiple Distribution Networks

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1026-1043页

作者： Meifu chen Mingchao xia Qifang chen School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China IEEE

A high proportion of renewable energy affects the power quality of distribution networks,and surplus energy will be sold to the upstream grid at a low *** this paper,considering peer-to-peer energy transactions,the energy router-based multiple distribution networks are analyzed to solve the above problems and realize collaborative consumption of renewable ***,the investing cost of an energy router is high,and research on the economic operation of energy routers in distribution networks is ***,this paper establishes a planning model for energy routers considering peer-to-peer energy transactions among distribution networks,and explores the benefits of peer-to-peer energy transactions through energy router based multiple distribution networks.A structure of an energy router suitable for peer-to-peer energy transactions is selected,and a power flow calculation model based on a multilayer structure is *** energy router’s scheduling model is established,and unique functions of the energy router and revenue of each distribution network are considered.A power flow calculation model based on peer-to-peer interconnection of multiple distribution networks through energy routers is also ***,simulation results verify the effectiveness of the proposed planning *** show that peer-topeer energy transaction among distribution networks through energy routers can effectively reduce the comprehensive cost of distribution networks,significantly improve the power quality of the distribution networks,and reduce the impact of power fluctuation on the upstream grid incurred by the distribution network.

关键词： Capacity allocation energy router multiple distribution networks peer-to-peer energy transaction power flow optimization

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