检索结果-南通市图书馆

Synthesis of vanadium powder by magnesiothermic reduction of V_(2)O_(3)in a reactive molten salt

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第4期30卷 650-659页

作者： Da-peng Zhong gui-shang pei Jia-long Kang Jun-yi Xiang Cheng Pan Wu-an Gu Xue-wei Lv Lan-jie Li Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China Pangang Group Research Institute Co. Ltd.Panzhihua 617000SichuanChina College of Chemical Engineering Sichuan UniversityChengdu 610065SichuanChina The State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China Chengde Iron and Steel Group Co. Ltd.HBIS Group Co.Ltd.Chengde 067102HebeiChina

As an important strategic metal,vanadium is generally used to prepare special steels,titanium alloys,and hydrogen storage materials.A new method of producing vanadium(metal)powder from V_(2)O_(3)using block Mg is presented *** an auxiliary molten salt,V_(2)O_(3)was successfully transformed into V by Mg *** by-product,MgO,was transformed into MgCl_(2)by adding ZrCl_(4),which prevented the generation of MgV_(2)O_(4)and allowed the reaction to proceed *** rod-like alloy phases,Zr_(0.03)V_(1.97),which formed in the presence of excess Mg,may hinder the diffusion of oxygen from the *** recovery rate of vanadium after separation and purification was approximately 45%–50%,where the main loss occurred during ball *** the optimal conditions(Mg content of 48.3%,reduction time of 1.5 h,and temperature of 850℃),the purity of vanadium exceeded 99 wt.%,and the O content decreased to 0.34 wt.%.

关键词： Deoxidation Vanadium powder Magnesiothermic reduction Molten salt

Effect of TiO2 on reduction behavior of Cr2O3 in CaO-SiO2-Al2O3-MgO-TiO2-Cr2O3 by carbon from Fe-C melt

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2020年第10期27卷 1145-1152页

作者： Jun-yi Xiang gui-shang pei Wei Lv Bao-hua Li gui-bao Qiu Xue-wei Lv College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and Advanced Materials Chongqing UniversityChongqing 400044China

The chromium-bearing titanomagnetite ore will turn to be the important raw material for blast furnace process in Panxi area,*** reduction behavior of Cr2O3 between CaO-SiO2-Al2O3-TiO2-Cr2O3 and Fe-C systems was *** effect of TiO2 content in the slag system on the reduction of Cr2O3,TiO2,and SiO2 and the con sumption of C in hot metal was investigated by both theoretical calculation and physical *** theoretical calculation results reveal that higher reduction temperature promotes the reduction of Cr and Ti,while high basicity and TiO2 content have little influence on the reduction of chromium but significantly influence the reduction of *** smelting reduction experiment results show that the content of Cr in hot metal significantly in creases with extendi ng the reduction time and decreases with the increase in TiO2 ***,the content of Ti in hot metal significantly increases as the TiO2 increases,reaching 0.073,0.085,0.107,and 0.121 wt.%for 5,10,15,and 20 wt.%of TiO2 input,*** studies proved that the reduction of Cr2O3 was a first-order *** addition of TiO2 inhibited the reduction of Cr2O3 and resulted in the decrease in reaction rate constant.

关键词： Smelting reduction Titanomagnetite Blast furnace slag Chromium oxide Titanium oxide

Solid-state reaction of a CaO−V_(2)O_(5)mixture:A fundamental study for the vanadium extraction process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第9期28卷 1462-1468页

作者： Jun-yi Xiang Xin Wang gui-shang pei Qing-yun Huang Xue-wei Lv College of Materials Science and Engineering Chongqing UniversityChongqing 400044China School of Metallurgy and Materials Engineering Chongqing University of Science and TechnologyChongqing 401331China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and Advanced Materials Chongqing UniversityChongqing 400044China

The aim of this study was to investigate the phase transformation and kinetics of the solid-state reaction of CaO−V_(2)O_(5),which is the predominant binary mixture involved in the vanadium recovery *** analysis,X-ray diffraction spectroscopy,scanning electron microscopy,and energy dispersive spectrometry were used to characterize the solid-state reaction of the *** extent of the solid reac-tion was derived using the preliminary quantitative phase analysis of the X-ray *** results indicate that the solid reaction of the CaO−V_(2)O_(5)mixture is strongly influenced by the reaction temperature and CaO/V_(2)O_(5)mole *** transformation of calcium vanadate in-volves a step-by-step reaction of CaO−V_(2)O_(5),CaO−CaV_(2)O_(6),and CaO−Ca_(2)V_(2)O7 depending on the CaO/V_(2)O_(5)mole *** kinetic data of the solid reaction of the CaO−V_(2)O_(5)(1:1)mixture followed a second-order reaction *** activation energy(Ea)and preexponential factor(A)were determined to be 145.38 kJ/mol,and 3.67×10^(8)min^(−1),respectively.

关键词： calcium vanadate vanadium extraction solid-state reaction kinetics

Role of temperature in tribolayers in fretting wear ofγ-TiAl alloy

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第5期12卷 939-953页

作者： Yulei YANG Hongfei shang Huiping pei Jimin XU Yi LIANG Minghui PAN School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing100084China Institute of Tribology Hefei University of TechnologyHefei230009China

The formation of tribolayers may play significant influences on fretting *** elevated temperature,the adhesion among wear debris and the increased diffusion rate facilitate the formation of ***,the intensification of oxidation at elevated temperature and the low diffusion rate in oxides may play an adverse *** present study aims to investigate the role of temperature in tribolayers in fretting wear using aγ-TiAl *** electron microscope,energy dispersive spectrometer,Raman spectrometer,transmission electron microscope and nanoindentation were utilized to investigate the wear debris,tribolayers,and wear *** fretting tests showed that,compared with that at room temperature(RT)and 350℃,significant reduction in wear rate and decrease in the fluctuation of friction coefficient occurred at 550 and 750℃.It was further revealed that when temperature raised from room temperature(RT)to 750℃,the oxidation of the wear debris increased slightly and the diffusion coefficients increased prominently,which facilities the formation of well tribo-sintered *** well tribo-sintered tribolayers presented homogenous structure,nanocrystalline grains with excellent mechanical properties,and resulted in the improvement in the fretting wear resistance of theγ-TiAl alloy at 550 and 750℃.

关键词： tribolayer temperature fretting wear γ-TiAl alloy

Recovery of vanadium from vanadium slag by composite roasting with CaO/MgO and leaching

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2020年第11期30卷 3114-3123页

作者： Jun-yi XIANG Xin WANG gui-shang pei Qing-yun HUANG Xue-wei LÜ College of Materials Science and Engineering Chongqing UniversityChongqing 400044China College of Metallurgy and Materials Engineering Chongqing University of Science and TechnologyChongqing 401331China Chongqing Key Laboratory of Vanadium−Titanium Metallurgy and Advanced Materials Chongqing UniversityChongqing 400044China

A novel process of composite roasting with CaO/MgO and subsequent acid leaching was proposed to improve the recovery rate of vanadium from Linz–Donawiz(LD)converter vanadium *** effects of the MgO/(CaO+MgO)molar ratio and the roasting and leaching parameters on the recovery of vanadium were *** results showed that the leaching efficiency of vanadium decreased from 88%to 81%when CaO was replaced completely by MgO;however,it could be improved by roasting with the composite of CaO/*** maximum vanadium leaching efficiency of 94%was achieved under the optimum MgO/(CaO+MgO)mole ratio of 0.5:*** results from X-ray diffractometry(XRD)and scanning electron microscopy with energy-dispersive X-ray spectroscopy(SEM−EDS)confirm that the formation rate of acid-soluble vanadates can be enhanced during roasting with the composite of CaO/MgO and that the leaching kinetics can be accelerated owing to the suppression of calcium sulfate precipitation.

关键词： vanadium vanadium slag roasting acid leaching recovery

Alternative splicing of the PECTINESTERASE gene encoding a cell wall-degrading enzyme affects postharvest softening in grape

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第3期23卷 863-875页

作者： Hainan Liu Maosong pei Charles Ampomah-Dwamena Yaxin shang Yihe Yu Tonglu Wei Qiaofang Shi Dalong Guo College of Horticulture and Plant Protection Henan University of Science and TechnologyLuoyang 471000China Henan Engineering Technology Research Center of Quality Regulation and Control of Horticultural Plants Luoyang 471000China The New Zealand Institute for Plant&Food Research Limited(PFR) Auckland 1010New Zealand

The firmness of table grape berries is a crucial quality parameter. Despite extensive research on postharvest fruit softening, its precise molecular mechanisms remain elusive. To enhance our comprehension of the underlying molecular factors, we initially identified differentially expressed genes(DEGs) by comparing the transcriptomes of folic acid(FA)-treated and water-treated(CK) berries at different time points. We then analyzed the sequences to detect alternatively spliced(AS) genes associated with postharvest softening. A total of 2,559 DEGs were identified and categorized into four subclusters based on their expression patterns, with subcluster-4 genes exhibiting higher expression in the CK group compared with the FA treatment group. There were 1,045 AS-associated genes specific to FA-treated berries and 1,042 in the CK-treated berries, respectively. Gene Ontology(GO) annotation indicated that the AS-associated genes in CK-treated berries were predominantly enriched in cell wall metabolic processes,particularly cell wall degradation processes. Through a comparison between treatment-associated AS genes and subcluster-4 DEGs, we identified eight genes, including Pectinesterase 2(VvPE2, Vitvi15g00704), which encodes a cell wall-degrading enzyme and was predicted to undergo an A3SS event. The reverse transcription polymerase chain reaction further confirmed the presence of a truncated transcript variant of VvPE2 in the FA-treated *** study provides a comprehensive analysis of AS events in postharvest grape berries using transcriptome sequencing and underscores the pivotal role of VvPE2 during the postharvest storage of grape berries.

关键词： grape postharvest softening folic acid alternative splicing Pectinesterase 2 alternative 3'splice site(A3SS)

A novel traditional Chinese medicine combination for radiation

在线全文

学校读者我要写书评

暂无评论

Radiation Medicine and Protection 2024年第1期5卷 37-42页

作者： Ming shang Yicheng Ke Jiangyun Liu Zhifei Cao Liying Zhang Wenyang Zhang Weiwei pei Guangming Zhou Yongqi Liu Provincial-Level Key Laboratory for Molecular Medicine of Major Diseases and the Prevention and Treatment with Traditional Chinese Medicine Research in Gansu Colleges and Universities Gansu University of Chinese MedicineLanzhou 730000China School of Radiation Medicine and Protection Medical College of Soochow UniversitySuzhou 215123China Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions Suzhou 215123China College of Pharmaceutical Sciences Soochow UniversitySuzhou 215123China Department of Pathology The Second Affiliated HospitalMedical College of Soochow UniversitySuzhou 215123China

Objective:To formulate an efficacious radioprotective combination of Chinese medicines with minimal ***:Aqueous and alcoholic extracts from 38 traditional Chinese herbs were *** produce drugcontaining sera,rats received six doses of each extract via oral gavage at 12-h ***,human lung epithelial BEAS-2B cells were cultured in these drug-containing *** cell viability was assessed after different doses of irradiation to identify the radioprotective effects of Chinese herbal *** efficacy of a selected Chinese herbal extract combination was further confirmed through cell viability analysis via in vitro colony formation and survival rate assessments in C57BL/6 mice ***:Extracts from Angelicae Sinensis Radix(ASR;two extracts),Citri Reticulatae Pericarpium(CRP),Platycladi Cacumen(PC),Schisandrae chinensis Fructus(SF),Scutellariae Radix(SR),and Glycyrrhizae Radix et Rhizome(GRR)demonstrated radioprotective *** combination of the seven Chinese herbal extracts notably increased the survival and viability of the BEAS-2B cells exposed to varying doses of ***,the group of mice receiving Chinese medicine combination and irradiation exhibited prolonged survival after exposure to 6.5 Gy Xrays with a median survival of(14=2)d compared to(11=2)d in the irradiated group without the herbal ***,the Chinese medicine combination group displayed a significantly higher 28 d survival rate(30%)compared to the irradiation-only group(16.6%,P<0.05).Conclusion:The novel combination of Chinese herbal extracts from ASR,CRP,PC,SF,SR,and GRR has the potential for radiation protection applications.

关键词： Radiation protection Acute radiation syndrome Chinese medicine Drug-containing serum

Perinatal prevalence of birth defects in the Mainland of China,2000–2021:a systematic review and meta-analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2024年第7期20卷 669-681页

作者： Liang-Yu Kang Zi-Rui Guo Wei-Jing shang gui-Ying Cao Yi-Ping Zhang Qiao-Mei Wang Hai-Ping Shen Wan-Nian Liang Min Liu Department of Epidemiology and Biostatistics School of Public HealthPeking UniversityNo.38Xueyuan RoadHaidian DistrictBeijing100191China Vanke School of Public Health Tsinghua UniversityNo.1Tsinghua GardenHaidian DistrictBeijing100084China Department of Maternal and Child Health National Health Commission of the People’s Republic of ChinaNo.1Xizhimenwai South RoadXicheng DistrictBeijingChina Institute of Healthy China Tsinghua UniversityNo.1Tsinghua GardenHaidian DistrictBeijing100084China Key Laboratory of Epidemiology of Major Diseases(Peking University) Ministry of Education BeijingNo.38Xueyuan RoadHaidian DistrictBeijing100191China

Background Although birth defects are of great concern globally,the latest national prevalence has not yet been quantified in *** conducted a systematic review and meta-analysis to estimate the perinatal prevalence of birth defects in the Mainland of China between 2000 and *** We performed a systematic literature search of six databases for relevant articles published between January 1,2000,and March 1,*** included published studies that reported data on the perinatal prevalence of birth defects in the Mainland of *** DerSimonian and Laird random-effects models were used to estimate the pooled prevalence and its 95%confidence interval(CI).We also conducted subgroup analyses and univariable meta-regressions to explore differences in prevalence by time period,geographic region,and other *** We included 254 studies reporting the perinatal prevalence of birth defects and 86 studies reporting only the prevalence of specific types of birth *** on 254 studies covering 74,307,037 perinatal births and 985,115 cases with birth defects,the pooled perinatal prevalence of birth defects was 122.54(95%CI 116.20–128.89)per 10,000 perinatal births in the Mainland of China during 2000–***,the perinatal prevalence of birth defects increased from 95.60(86.51–104.69)per 10,000 in 2000–2004 to 208.94(175.67–242.22)per 10,000 in 2020–*** were also significant disparities among different geographical *** heart defects(33.35 per 10,000),clefts of the lip and/or palate(13.52 per 10,000),polydactyly(12.82 per 10,000),neural tube defects(12.82 per 10,000),and inborn errors of metabolism(11.41 per 10,000)were the five most common types of birth *** perinatal prevalence among males was significantly higher than that among females(β=2.44×10^(−3),P=0.003);a higher perinatal prevalence of birth defects was observed among perinatal births whose mothers were≥35 years(β=4.34×10^(−3),P<0.001).Conclusion Compreh

关键词： Birth defects China Perinatal Prevalence

The Active Compensation Technique for Large Reflector Antennas Based on Quadratic Curve Fitting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第7期24卷 229-237页

作者： Tian-Xiang Zheng Bin-Bin Xiang Han-Wei Cui Wei Wang pei-Yuan Lian shang-Ming Lin Yang Zhang Jian-Ping Zhou Kai Li School of Mechanical Engineering Xinjiang University School of Mechano-Electronic Engineering Xidian University Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Sciences

Active reflectors are often used to compensate the surface distortion caused by environmental factors that degrade the electromagnetic performance of large high-frequency reflector antennas. This is crucial for maintaining high gain operation in antennas. A distortion compensation method for the active reflector of a large dual-reflector antenna is proposed. A relationship is established between the surface deformation and the optical path difference for the primary reflector by geometric optics. Subsequently, employing finite element analysis, a polynomial fitting approach is used to describe the impact of adjusting points on the reflector surface based on the coordinates of each node. By standardizing the positions of various panels on the reflector, the fitting ns can be applied to the reflector panels of similar shapes. Then, based on the distribution characteristics of the primary reflector panels, the adjustment equation for the actuators is derived by the influence matrix method. It can be used to determine the adjustment amount of actuators to reduce the rms of the optical path difference. And, the least squares method is employed to resolve the matrix equation. The example of a 110 m aperture dual-reflector antenna is carried out by finite element analysis and the proposed method. The results show that the optical path difference is reduced significantly at various elevation cases, which indicates that the proposed method is effective.

关键词： Methods: analytical Methods: numerical Telescopes