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Aging Behavior of As-Extruded Ti Particles Reinforced VW94 Composites

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 401-406页

作者： Dongmei pu Xianhua Chen Jingfeng Wang Jun Tan Jianbo li Hong Yang bo Feng Kaihong Zheng Fusheng Pan College of Materials Science and Engineering Chongqing UniversityChongqing 400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400045China Institute of New Materials Guangdong Academy of SciencesGuangzhou 510650China

The ageing behavior of as-extruded Ti_(P)/VW94 composites was investigated.The peak hardness of the composites increases compared to the matrix alloy and the 5%Ti_(P)/VW94 composite presents the highest peak hardness of 148.7 HV after aging for about 50 h.However,the hardness increments first decrease and then slightly increase with increasing Ti particle content due to the introduction of high-density dislocations by Ti particles.

关键词： Magnesium matrix composites Ti particles Ageing behavior Hardness

A novel structural variant of RET causes familial Hirschsprung's disease via nonsense-mediated mRNA decay

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Genes & Diseases 2024年第1期11卷 7-10页

作者： Qi Wang Siyu pu bo Xiang Jing Chen Department of Pediatric Surgery and Laboratory of Pediatric Surgery Rare Diseases CenterInstitute of Immunology and InflammationFrontiers Science Center for Disease-Related Molecular NetworkWest China HospitalSichuan UniversityChengduSichuan 610041China

Hirschsprung's disease(HsCR)is the most common type of developmental gastrointestinal malformation causing intestinal obstruction in children,with an incidence of 1/5000 in live births.1 it is characterized by the absence of intrinsic ganglion cells in the myenteric and submucosal plexuses of the distal gastrointestinal tract,leading to the dysregulation of smooth muscle contraction/relaxation and resulting in intestinal obstruction.Depending on the length of the aganglionic intestine,HSCR can be categorized into short-segmental HSCR(S-HSCR),which affects up to the sigmoid colon from the anus,and long-segmental HSCR(LHSCR),which affects beyond the sigmoid colon.1 In some rare conditions,aganglionic lesions can affect the full length of the colon or even the whole intestine.

关键词： intestine colon relaxation

Real-time Energy Management Method for Electric-hydrogen Hybrid Energy Storage Microgrids Based on DP-MPC

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 324-336页

作者： Qi li Xueli Zou Yuchen pu Weirong Chen School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China

With the increasing presence of intermittent energy resources in microgrids,it is difficult to precisely predict the output of renewable resources and their load demand.In order to realize the economical operations of the system,an energy management method based on a model predictive control(MPC)and dynamic programming(DP)algorithm is proposed.This method can reasonably distribute the energy of the battery,fuel cell,electrolyzer and external grid,and maximize the output of the distributed power supply while ensuring the power balance and cost optimization of the system.Based on an ultra-shortterm forecast,the output power of the photovoltaic array and the demand power of the system load are predicted.The offline global optimization of traditional dynamic programming is replaced by the repeated rolling optimization in a limited period of time to obtain power values of each unit in the energy storage system.Compared with the traditional DP,MILP-MPC and the logic based real-time management method,the proposed energy management method is proved to be feasible and effective.

关键词： Electric-hydrogen hybrid energy economic energy management improved dynamic programming microgrid model predictive control

Access to High-Molecular-Weight Polyethylenes through High Temperature Ethylene Polymerization Catalysed by Ethylene-Bridged ansa-(3-R-Cyclopentadienyl)(Fluorenyl) Zirconocene Complexes

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Chinese Journal of Polymer Science 2024年第1期42卷 42-51,I0007页

作者： bo li Haiyan Ma Jiling Huang Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

A series of C1-symmetric ethylene-bridged ansa-(3-R-cyclopentadienyl)(fluorenyl) metallocene complexes(Zr: 1-5;Hf: 6) have been synthesized, characterized and investigated as catalyst precursors for the high temperature ethylene polymerization. Using methylaluminoxane(MAO) as the cocatalyst, zirconium complexes 1-5 bearing a bulky substituent on the 3-position of the cyclopendienyl ring showed high catalytic activities up to 1.48×10^(7) g PE·mol_(Zr)^(-1)·h^(-1) toward the polymerization of ethylene and afforded polyethylenes with high molecular weights(1.49×10^(5)-6.31×10^(5) g/mol), meanwhile exhibting great thermal stability at high temperatures up to 120 ℃ together with a long catalytic life time up to 2 h. By adopting low Al/Zr ratios, such as 125, polyethylenes with ultra high molecular weights up to 2.86×106 g/mol were obtained. It is worthy of noting that zirconium complexes 1-4 bearing a substituent with an aryl pendant showed temperature-dependent activities, which increased rapidly with the increase of polymerization temperature, thus weak interaction of the pendent aryl group with the cationic active center is proposed to account for the very low activities displayed at low temperatures. In contrast to zirconocene complexes 1-5, hafnocene complex 6 only displayed very low catalytic activities toward the polymerization of ethylene and afforded polyethylenes with molecular weights ten times smaller than those obtained by zirconocene complexes 1-5. Zirconocene complexes 1-5 were also able to catalyse the polymerization of propylene at high temperatures, but only afforded waxes with low molecular weights.

关键词： ansa-Metallocene Ethylene Propylene Polymerization High temperature

Protein crystallization with DNA templates

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Particuology 2024年第3期86卷 262-268页

作者： bo Zhang Jia Yu Zhe pu Wenhui Guo Ruoqi Yang Yu Wen Zhijiang Rong Hui Wang Xiaoli Wu bo Wang Hongyan Sun School of Environment and Resources Taiyuan University of Science and TechnologyTaiyuan030024China School of Chemical Engineering and Technology Taiyuan University of Science and TechnologyTaiyuan030024China

Protein crystallization plays a significant role in three-dimensional structural analysis and protein pu-rification.It is important to increase the crystallization efficiency,which is possible by adding hetero-geneous templates in crystallization systems.DNA is biologically compatible and artificially designable polymer,which is easy to extract.In this study,single-and double-stranded DNA of precise sequences were designed and used as templates to promote protein crystallization of lysozyme and catalase.In-fluence of DNA,single-stranded DNA with 10,20,40 bases and double-stranded DNA with 10,20,40 base pairs,were investigated.The success rate of obtaining crystals of lysozyme and catalase in equal period was significantly improved with the addition of DNA comparing without templates added.Double-stranded DNA led to higher nucleation rate than that with single-stranded DNA.The promotion of nucleation was more obvious at low concentration of protein solution and with longer chain DNA templates.Crystal number and crystallization rate was enhanced with addition of long double-stranded DNA templates.All the results confirm that DNA is an effective polymer additive to enhance protein crystallization,especially for the application of the scarce protein crystallization.

关键词： DNA Polymer Additive Protein Crystallization

The effect of bladder function on the efficacy of transurethral prostatectomy in patients with benign prostatic hyperplasia:a retrospective,single-center study

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Asian Journal of Andrology 2024年第1期26卷 112-118页

作者： Jin li Xian-Yan-ling Yi Ze-Yu Chen bo Chen Yin Huang Da-Zhou liao pu-Ze Wang De-Hong Cao Jian-Zhong Ai liang-Ren liu West China School of Medicine Sichuan UniversityChengdu 610041China Department of Urology Institute of UrologyWest China HospitalSichuan UniversityChengdu 610041China

We investigated the impact and predictive value of bladder function in patients with benign prostatic hyperplasia(BPH)on the efficacy of transurethral prostatectomy.Symptomatic,imaging,and urodynamic data of patients who underwent transurethral prostatectomy at West China Hospital of Sichuan University(Chengdu,China)from July 2019 to December 2021 were collected.Follow-up data included the quality of life(QoL),International Prostate Symptom Score(IPSS),and IPSS storage and voiding(IPSS-s and IPSS-v).Moreover,urinary creatinine(Cr),nerve growth factor(NGF),brain-derived neurotrophic factor(BDNF),and prostaglandin estradiol(PGE2)were measured in 30 patients with BPH and 30 healthy participants.Perioperative indicators were determined by subgroup analyses and receiver operating characteristic(ROC)curve analysis.Among the 313 patients with BPH included,patients with severe micturition problems had more improvements but higher micturition grades postoperatively than those with moderate symptoms.Similarly,good bladder sensation,compliance,and detrusor contractility(Dc)were predictors of low postoperative IPSS and QoL.The urinary concentrations of BDNF/Cr,NGF/Cr,and PGE2/Cr in patients were significantly higher than those in healthy participants(all Pboth urinary indicators and postoperative recovery of patients.Patients with good DC,as predicted by urinary indicators,had lower IPSS and IPSS-v than those with reduced DC at the 1st month postoperatively(both Plid predictors of preoperative bladderfunction and postoperative recovery.

关键词： BPH function of bladder IPSS:urodynamics

Rapid Simultaneous Determination of Four Ganoderic Acids in Ganoderma(Chinese Name:lingzhi)by Direct Infusion-Multiple Reaction Monitoring Cubed

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Journal of Analysis and Testing 2024年第1期8卷 52-62页

作者： Nian Wu bo Peng Ting li Pengfei Tu Shengpeng Wang bo li Wenjing liu Yuelin Song Modern Research Center for Traditional Chinese Medicine Beijing Research Institute of Chinese MedicineBeijing University of Chinese MedicineBeijing 100029China Amway(China)botanical Research Center Wuxi 214011China State Key Laboratory of Quality Research in Chinese Medicine Institute of Chinese Medical SciencesUniversity of MacaoTaipa 999078China Amway(Shanghai)Innovation&Science Co. LtdShanghai 201508China School of Pharmacy Henan University of Chinese MedicineZhengzhou 450046China

Attributing to the rapid demand expansion for the edible medicinal materials in the market,the limited throughput of highperformance liquid chromatography-multiple reaction monitoring(HPLC-MRM)cannot fully address the measurement workload for a huge number of testing samples.Hence,it is urgent to pursue more efficient approaches for the quality evaluation.Because of the greater selectivity of MRM cubed(MRM^(3))over MRM,there might be a chance to omit the time-intensive LC separation.In current study,we attempted to develop a direct infusion(DI)-MRM^(3) program,and the applicability was thereafter assessed through simultaneous determination of four ganoderic acids(GAs)in one of the most famous tonic herbal medicines namely Ganoderma(Chinese name:lingzhi).Primary parameters such as Q1>Q3>QliT ion transitions,collision energy(CE),and excitation energy were optimized by programming online energy-resolved mass spectrometry with authentic compounds.A single DI-MRM measurement merely costed four minutes,and in spite of the wide occurrences of isomers,satisfactory selectivity was achieved.Method validation assays demonstrated the method to be sensitive,precise,accurate,and reproducible.The quantitative results from DI-MRM^(3) were also justified by conducting LC-MRM measurements in parallel.Significant differences occurred for the content patterns between the two original sources namely Ganoderma lucidum and G.sinense,and,moreover,either cultivar or harvest time showed dramatical influence on the quantitative features of the four targeted GAs.More importantly,DI-MRM3 is a meaningful analytical option for rapid quantitative analysis of herbal medicines,because of the comparable reliability,nonetheless,less consumptions of both measurement time and solvent,compared with LC-MRM.

关键词： Direct infusion Multiple reaction monitoring cubed High-throughput quantitative analysis Ganoderic acids Ganoderma

Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids

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Petroleum Science 2024年第1期21卷 551-566页

作者： li-li Yang Ze-Yu liu Shi-bo Wang Xian-bo He Guan-Cheng Jiang Jie Zhang MOE Key Laboratory of Petroleum Engineering State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum(Beijing)Changping DistrictBeijing102249China MOE Key CNPC Drilling Research Institute Changping DistrictBeijing102206China

With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to reservoir damage and wellbore instability.In this paper,micronized barite(MB)was modified(mMB)by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite partly.The suspension stability of water-based drilling fluids(WBDFs)weighted with API barite:mMB=2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs,exhibiting the static sag factor within 0.54 and the whole stability index of 2.The viscosity and yield point reached the minimum,with a reduction of more than 40%compared with API barite only at the same density.Through multi-stage filling and dense accumulation of weighting materials and clays,filtration loss was decreased,mud cake quality was improved,and simultaneously it had great reservoir protection performance,and the permeability recovery rate reached 87%.In addition,it also effectively improved the lubricity of WBDFs.The sticking coefficient of mud cake was reduced by 53.4%,and the friction coefficient was 0.2603.Therefore,mMB can serve as a versatile additive to control the density,rheology,filtration,and stability of WBDFs weighted with API barite,thus regulating comprehensive performance and achieving reservoir protection capacity.This work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs.

关键词： Drilling fluids Weighting materials Filtration control Reservoir protection Stability property

Propagation form of internal cracks induced by continuous casting soft reduction and control strategy for internal quality

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Journal of Iron and Steel Research(International) 2024年第3期31卷 622-633页

作者： pu Wang liang Chen Qun-wei Tang Wei-tao li Shao-xiang li Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Weifang Special Steel Group Co..Ltd. Weifang 262400ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

The propagation form of internal cracks induced by continuous casting soft reduction and the control strategy for enhancing the internal quality of 45 steel through industrial trials and a three-dimensional flow-heat transfer-solidification coupling model were investigated.The results showed that the internal cracks induced by soft reduction exhibited a characteristic of being"coarse in the middle and fine at both ends",and displayed an elliptical arc distribution on the loose side of the strand cross section.The cracks originated within the brittle temperature range and propagated inward to the liquid impenetrable temperature and outward to the zero ductility temperature or below.The control strategy for enhancing the internal quality of the 45 steel strand through soft reduction is to adjust the casting speed or the reduction zone appropriately,ensuring that the central solid fraction of the reduction zone falls within the range of 0.33-0.99.At this point,a reasonable reduction amount is allocated to eliminate the center shrinkage cavities and center segregation,even if it results in minor reduction-induced cracks.

关键词： Continuous casting Soft reduction Crack propagation Internal quality Control strategy