Enhanced high-temperature performance of Li-rich layered oxide via surface heterophase coating

Li-rich layered oxides have become one of the most concerned cathode materials for high-energy lithiumion batteries, but they still suffer from poor cycling stability and detrimental voltage decay, especially at elevated temperature. Herein, we proposed a surface heterophase coating engineering based on amorphous/crystalline Li3 PO4 to address these issues for Li-rich layered oxides via a facile wet chemical method. The heterophase coating layer combines the advantages of physical barrier effect achieved by amorphous Li3 PO4 with facilitated Li+diffusion stemmed from crystalline Li3 PO4. Consequently, the modified Li(1.2) Ni(0.2) Mn(0.6) O2 delivers higher initial coulombic efficiency of 92% with enhanced cycling stability at 55 °C(192.9 mAh/g after 100 cycles at 1 C). More importantly, the intrinsic voltage decay has been inhibited as well, i.e. the average potential drop per cycle decreases from 5.96 mV to 2.99 mV. This surface heterophase coating engineering provides an effective strategy to enhance the high-temperature electrochemical performances of Li-rich layered oxides and guides the direction of surface modification strategies for cathode materials in the future.

Optimization of technical measures for improving high-temperature performance of asphalt-rubber mixture

Asphalt-rubber pavements often become dam-aged in high-temperature regions and appear rutted or wavy, and experience slippage. To improve the high-temperature performance of the asphalt-rubber mixture, technical measurements, such as, the optimal adjustment of gradation, technique of composite modification, and control of compaction were investigated. An optimal adjustment of aggregate gradation based on stone matrix asphalt improves the high-temperature stability of the asphaltrubber mixture significantly. Through composite modifi- cation, the effect of asphalt-rubber modification was enhanced, and the dynamic stability and relative defor- mation indices of the asphalt-rubber mixture were improved significantly. Furthermore, compaction parame- ters had a significant influence on the high-temperature stability of the asphalt-rubber mixture. The rolling times for compacting the asphalt-rubber mixture should be controlled to within 18-20 round-trips at a molding temperature at 180℃; if the rolling time is a 12 round-trip, the compaction temperature of the asphalt-rubber mixture should be controlled between 180 and 190℃.

Enhancement of the Mechanical Performance of SiCf/Phenolic Composites after High-temperature Pyrolysis Using ZrC/B_(4)C Particles

The composites were prepared by modifying silicon carbide fiber with particles of zirconium carbide(ZrC)and boron carbide(B_(4)C)and incorporating them into a phenolic resin matrix.The influence of ZrC and B_(4)C on the mechanical performance of SiCf/phenolic composites after high-temperature pyrolysis was studied through flexural performance test.The results show that the composite material has good thermal stability and high-temperature mechanical properties.After static ablation at 1400℃ for 15 minutes,the flexural strength of the composite material reaches 286 MPa,which is still 7.3%higher than at room temperature,indicating that the composite material still has good mechanical properties even after heat treatment at 1400℃.

Intelligent prediction on performance of high-temperature heat pump systems using different refrigerants

Two new binary near-azeotropic mixtures named M1 and M2 were developed as the refrigerants of the high-temperature heat pump(HTHP).The experimental research was used to analyze and compare the performance of M1 and M2-based in the HTHP in different running conditions.The results demonstrated the feasibility and reliability of M1 and M2 as new high-temperature refrigerants.Additionally,the exploration and analyses of the support vector machine(SVM)and back propagation(BP)neural network models were made to find a practical way to predict the performance of HTHP system.The results showed that SVM-Linear,SVM-RBF and BP models shared the similar ability to predict the heat capacity and power input with high accuracy.SVM-RBF demonstrated better stability for coefficient of performance prediction.Finally,the proposed SVM model was used to assess the potential of the M1 and M2.The results indicated that the HTHP system using M1 could produce heat at the temperature of 130°C with good performance.

Evaluation on High-temperature Adhesion Performance of Hot-applied Sealant for Asphalt Pavement

In order to investigate the high-temperature performances of the asphalt pavement hot-applied sealant, as well as to reduce failures of the sealant pullout, the softening point test and the flow test（two existing methods for evaluating high-temperature performances） were conducted. It was found that both tests could not accurately reflect the adhesion performances of the sealant at high temperatures. For this purpose, the adhesion test for PSAT（pressure sensitive adhesive tape） has been taken as a reference to develop a device that is suitable for evaluating the adhesion performances, by modifying relevant test parameters according to the road conditions at high temperatures. Thirteen common sealants were tested in the modified adhesion test, softening point test and f low test. The experimental results show that no significant correlation（p〉0.05） exists between the adhesion value, softening point, adhesion value and flow value; while a significant correlation（p〈0.05） exists between the softening point and flow value. The modified adhesion test is efficient in distinguishing the hightemperature adhesion performances of different sealants, and can be used as a standard method for evaluating such performances.

Thermo-Economic Performance of Geothermal Driven High-Temperature Flash Tank Vapor Injection Heat Pump System:A Comparison Study

Process heating constitutes a significant share of final energy consumption in the industrial sector around the world.In this paper,a high-temperature heat pump(HTHP)using flash tank vapor injection technology(FTVI)is proposed to develop low-temperature geothermal source for industrial process heating with temperature above 100°C.With heat sink output temperatures between 120°C and 150°C,the thermo-economic performance of the FTVI HTHP system using R1234ze(Z)as refrigerant is analyzed and also compared to the single-stage vapor compression(SSVC)system by employing the developed mathematical model.The coefficient of performance(COP),exergy efficiency(ηexe),net present value(NPV)and payback period(PBP)are used as performance indicators.The results show that under the typical working conditions,the COP andηexe of FTVI HTHP system are 3.00 and 59.66%,respectively,and the corresponding NPV and PBP reach 8.13×106 CNY and 4.13 years,respectively.Under the high-temperature heating conditions,the thermo-economic performance of the FTVI HTHP system is significantly better than that of the SSVC system,and the larger the temperature lift,the greater the thermo-economic advantage of the FTVI HTHP system.Additionally,the FTVI HTHP system is more capable than the SSVC system in absorbing the financial risks associated with changes of electricity price and natural gas price.

High-Temperature Performance Analysis of AlGaN/GaN Polarization Doped Field Effect Transistors Based on the Quasi-Multi-Channel Model

We report on the temperature-dependent dc performance of A1GaN/GaN polarization doped field effect transistors （PolFETs）. The rough decrements of drain current and transeonductance with the operation temperature are observed. Compared with the conventional HFETs, the drain current drop of the PolFET is smaller. The transeonductance drop of PolFETs at different gate biases shows different temperature dependences. From the aspect of the unique carrier behaviors of graded AlGaN/GaN heterostructure, we propose a quasi-multi-channel model to investigate the physics behind the temperature-dependent performance of AlGaN/GaN PolFETs.

Research on the construction of precise and healtli poverty -leviation performanceindex based on Analytic Hierarchy Process.

＂在文献研究法、 专家咨询法的基础上, 遵循科学性、 可操作性、 定性与定量相结合的原则, 采用层次分析法构建精准健康扶贫绩效评价指标体系,最终建立1个一级指标、3个二级指标、18个三级指标，为今后评价健康扶贫工作效果提供参考.

Different effects of economic and structural performance indexes on model construction of structural topology optimization

The objective and constraint functions related to structural optimization designs are classified into economic and performance indexes in this paper.The influences of their different roles in model construction of structural topology optimization are also discussed.Furthermore,two structural topology optimization models,optimizing a performance index under the limitation of an economic index,represented by the minimum compliance with a volume constraint（MCVC）model,and optimizing an economic index under the limitation of a performance index,represented by the minimum weight with a displacement constraint（MWDC）model,are presented.Based on a comparison of numerical example results,the conclusions can be summarized as follows：（1）under the same external loading and displacement performance conditions,the results of the MWDC model are almost equal to those of the MCVC model;（2）the MWDC model overcomes the difficulties and shortcomings of the MCVC model;this makes the MWDC model more feasible in model construction;（3）constructing a model of minimizing an economic index under the limitations of performance indexes is better at meeting the needs of practical engineering problems and completely satisfies safety and economic requirements in mechanical engineering,which have remained unchanged since the early days of mechanical engineering.

Effects of Dietary Crude Fiber Levels on Growth Performance and Serum Biochemical Index of Dingan Geese Aged from 35 to 70 Days

[Objective] The study was carried out to investigate the effects of dietary crude fiber on growth performance and serum biochemical in-dex of Dingan geese aged from 35 to 70 days.[Method] A total of 120 Dingan geese on day 28 with the same genetic background and similar initial weight(1 384.83.73±0.76 g) were randomly assigned into 3 groups, with 4 replicates per group and 10 geese per replicate. Geese were fed the diets containing 4.29%, 5.29% and 6.29 % crude fiber, respectively. The experiment lasted 35 d.[Result] Final weight and daily gain of 5.29 %CF group were significantly higher than those of 6.29 % CF group(P<0.05);Feed intake was markedly higher than those of 4.29% and 6.29 % CF groups(P<0.05);Feed gain ratio was significantly lower than that of 6.29 % CF group(P<0.05). Compared with 4.29% and 6.29 % CF groups, serum albumin concentrations of 5.29 % CF group increased significantly(P<0.05), while serum total protein and globin contents were higher(P>0.05), but serum uric acid level was lower(P>0.05).[Conclusion] 5.29 % crude fiber could lead to higher growth performance of Dingan geese.

Natural Lignin:A Sustainable and Cost-Effective Electrode Material for High-Temperature Na-Ion Battery

Rechargeable sodium-ion batteries usually suffer from accelerated electrode destruction at high temperatures and high synthesis costs of electrode materials.Therefore,it is highly desirable to explore novel organic electrodes considering their cost-effectiveness and large adaptability to volume changes.Herein,natural biomass,pristine lignin,is employed as the sodium-ion battery anodes,and their sodium storage performance is investigated at room temperature and 60℃.The lignin anodes exhibit excellent high-temperature sodium-ion battery performance.This mainly results from the generation of abundant reactive sites(C=O)due to the high temperature-induced homogeneous cleavage of the C_(β)-O bond in the lignin macromolecule.This work can inspire researchers to explore other natural organic materials for large-scale applications and high-value utilization in advanced energy storage devices.

Research on Evaluating Index of Lightning Protection Safety Performance of High Voltage Overhead Transmission Line

In order to improve the lightning protection performance of transmission lines, lightning protection management has been divided into every tower that lightning protection performance has been evaluated respectively. According to factors such as landform, span, tower type, grounding resistance, isolator type, and so on, relative ratio of tripping operation of every tower in the line has been calculated to evaluate its lightning protection safety performance, it is beneficial to operation maintenance and lightning reconstruction of transmission lines.

Effects of Crude Fiber Levels on Production Performance, Organ Index and Serum Biochemical Parameters of Dingan Geese Aged from 1 to 28 Days

[Objective]The paper was to investigate the effects of dietary crude fiber level on production performance,organ index and serum biochemical parameters of Dingan geese aged from 1 to 28 days.[Method]A total of 144 1-day-old Dingan geese with the same genetic background and similar initial weight(88.75±0.21g)were randomly assigned into 3 groups with 4 replicates per group and 12 geese per replicate,and fed with the diets containing 2.56%,3.52% and 4.48% crude fiber,respectively.The trial lasted 28 d.[Result]1)The final weight and daily gain of 3.52% CF group were significantly higher than those of 2.56% CF group(P<0.05);the feed/gain ratio was markedly lower than that of 2.56% CF group(P<0.05).2)The slaughter rate,semi-eviscerated rate and leg muscle rate of 3.52% CF group were higher than those of 2.56% and 4.48% CF groups(P>0.05).3)As the dietary crude fiber levels rose,the abdominal fat rate showed a downward trend(P>0.05).4)The liver index of 3.52% CF group was significantly higher than that of 2.56% CF group(P<0.05).4)Compared with 2.5%and 4.48% CF groups,the serum albumin concentrations of 3.52% CF group markedly increased(P<0.05),the serum total protein and globin contents were higher(P>0.05),but the serum uric acid level was lower(P>0.05).[Conclusion]When the crude fiber level was 3.52%,the production performances of Dingan geese aged from 1 to 28 days were better,and the liver index and serum albumin level could be obviously improved.

Usefulness of myocardial performance index for assessing right ventricular function after percutaneous closure of atrial septal defect

Objective Assessment of right ventricular function in patients with atrial septal defect(ASD)is difficult.The Doppler myocardial performance index(MPI)may provide a method of assessing function in these patients.The purposes of this study were to evaluate the right ventricular function and its changes in patients with ASD after transcatheter closure of ASD.Methods MPI,defined as the sum of isovolumic relaxation time and isovolumic contraction time derived by ejection time,was measured from tricuspid inflow and right ventricular outflow;Doppler velocity profiles recorded during routine echocardiography.Twenty nine patients(13 men,16 women;mean age 25.28±12.69,range 6 to 57 years)were diagnosed to secundum ASD[the stretched diameters of ASD were from 9 To 36(24.91±7.98)mm],and had a successfully placed Amplatzer septal occluder(ASO)(the sizes of ASO were from 11 to 40 mm);there were 81 sex-matched,age-matched healthy people(control group 41men,40 women;mean age 29.02±14.22,range 4 to 45 years).MPI was measured again on 3 days and 1 month after closure of ASD.Change in the study group was assessed and compared to the control subjects with structurally normal hearts.A complete 2-dimensional and Doppler echocardiographic examination was performed in all study groups.Results 1)The isovolumic relaxation and isovolumic contraction times[respectively(77.59±14.39)ms vs(60.93±12.94)ms,P<0.0001;(28.28±10.88)ms vs(23.64±9.01)ms,P=0.027]were prolonged,and ejection time[(260.65±21.86)ms vs(271.85±21.92)ms,P=0.033]was shortened in patients with ASD compared with that in control subjects,resulting in a marked increase in the MPI(0.40±0.07 vs 0.31±0.05,P<0.0001)from normal values;2)by Pearson's correlations,the MPI had no correlation with heart rate and blood pressure in control subjects and patients with ASD,but it correlated positively with age in patients with ASD;3)by Pearson's correlations,the MPI correlated positively with the diameter of ASD and pulmonary artery pressure;4)after transcatheter closure of ASD,the MPI decreased markedly.Conclusions 1)MPI is a conceptually new,simple,and reproducible Doppler index in patients with ASD;2)MPI is free from the effect of age,heart rate and blood pressure;(3)MPI appears to be relatively dependent on changes in the diameter of ASD and pulmonary artery pressure;4)the right ventricular function was improved after transcatheter closure of ASD.

Research Advances in Detection Techniques of High Performance Liquid Chromatography-Refractive Index Detector

As a highly sensitive and stable detector,refractive index detector is usually used for quantitative detection of substances such as polymer,sugar and organic acid. The research reviewed the application of HPLC-RID in the fields of quantitative determination of medicine and food,in order to lay a foundation for wider use of RID.

Performance index limits of high reinforced concrete shear wall components

The deformation performance index limits of high reinforced concrete （RC） shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in the previous work were first used to verify the correctness of the nonlinear finite element method. Then, the nonlinear finite element method was applied to study the deformability of a set of high RC shear wall components designed according to current Chinese codes and with shear span ratio λ≥2.0. Parametric studies were made on the influence of shear span ratio, axial compression ratio, ratio of flexural capacity to shear capacity and main flexural reinforcement ratio of confined botmdary members. Finally, the deformation performance index and its limits of high RC shear wall components under severe earthquakes were proposed by the finite element model results, which offers a reference in determining the performance status of RC shear wall components designed based on Chinese codes.

AN ARTERIAL PERFORMANCE INDEX

A quantitative index for evaluating the performance of artery was introduced according to the idea of energy exchange between arterial wall and blood.The index was studied by using the exponential and parabolic pressure-volume relations or human arteries. Methods for estimating the index in vivo based on aWindkessel model of the arterial system were proposed. Data from patients withcongestive heart failure and hypertension were used for illustration. It was shownthat the index has physiological meaning and is a useful parameter for evaluationthe performance of artery.

A“Three-index”Seismic Performance Evaluation Method Based on Sino-US Seismic Code

The Code for Seismic Design of Buildings(GB50011-2010)in 2016 and the method of seismic performance-based design for high-rise buildings in the Guide for Performance-based Design of High-Rise Buildings(TBI2017)are compared.In view of the characteristics and limitations of the seismic performance index set by the Sino-US seismic code,a“three-index”performance index system and evaluation process considering the displacement angle of the structural interlayer,the plastic damage degree of components and the plastic strain of material is put forward;combining the example of time-history analysis of a out-of-code high-rise building under the rare earthquakes is verified.The results show that the method of seismic performance evaluation by using deformation control index in Sino-US seismic code is relatively simple;however,both are lacking in the setting of specific components and the whole structure level respectively.The"three-index"system can comprehensively and quantitatively evaluate the seismic performance of out-of-code high-rise buildings.

Effects of NS Series Composite Lactobacillus Prepa-ration on Performance,Plasma Biochemical Indexes and Immunity of Sows

[Objective] The study was aimed to investigate the effects of NS series composite lactobacillus preparation on production performance and some immune indexes of sows. [Method] The sows were fed on the diets supplemented with the NS series composite lactobacillus prepara- tion, and the changes of production performance, plasma biochemical indexes, levels of IgG, IgA and IgM in serum and colostrum, and T lympho- cyte subpopulations were detected. [ Result] When the NS series composite lactobacillus preparation was supplemented to the sow diet at a propor- tion of 0.2%, the average weaning litter weight at 21 days old was significantly increased. The serum contents of total protein and glucose as well as the serum activities of aspartate aminotransferase （AST）, alkaline phosphatase （ALP） and superoxide dismutase （SOD） were significantly in- creased after 30 d post delivery. Moreover, the levels of IgG, IgA and IgM in serum and colostrum of sows were significantly increased at the time of delivery and after 30 d post delivery. The antibodies in colostrum could be maintained at high levels. The percentage of CD3 ＊ and CD4~ ｜ympho- cyte subpopulations was also increased after supplementation with the NS series composite lactobacillus preparation at a proportion of 0.2%. [ （Con- des＇ion] The NS series composite lactobacillus preparation can improve performance, promote growth and metabolism, and enhance humoral and cellular immunity in sows.

Performance Analysis of Listed Companies in the UAE-Using DEA Malmquist Index Approach

Data Envelopment Analysis (DEA) is becoming an increasingly popular tool for assessing the relative performance of industries and companies. By applying DEA theory to the non-financial sector, the relative efficiency of 27 listed corporations in the United Arab Emirates (UAE) has been analyzed in this paper. The focus of the study has been on the impact of the financial crisis and the recovery thereafter. Further, the productivity change was decomposed into technical efficiency change and technological change by using the non-parametric Malmquist Productivity Index (MPI) over the period from 2007 to 2014. Based on Malmquist analysis, we find that the most efficient industries during the post-crisis period were food and beverages, telecommunication and pharmaceuticals. In contrast, the sectors that were adversely affected by the crisis were services, real estate, construction and cements. The break-up of the TFP indicated that the efficiency indices in the top performing industries were driven by technological improvements or frontier effects. The top-performing companies in the UAE during the 2007-14 period demonstrated innovation-led growth, aided by the use of better technology, investments in capital equipment, and adoption of new production processes.