检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2018年第5期26卷 1192-1199页

作者： Min Xia Chunsong Ye Kewu Pi Defu Liu Andrea R. Gerson School of Power and Mechanical Engineering Wuhan University Wuhan 430072 Hubei China School of Resource and Environmental Engineering Hubei University of Technology Wuhan 430068 Hubei China Blue Minerals Consultancy Wattle Grove Tasmania 7109 Australia

Hydrous magnesium oxide coated fly ash(MFA) has environmental remediation potential by providing a substrate for the adsorption of aqueous cr(Ⅲ). Aqueous cr(Ⅲ) adsorption onto MFA was examined as a function of MFA dosage, p H and initial cr(Ⅲ) concentration with the Box–Behnken approach used for experimental design and optimization using response surface methodology(RSM). p H and dosage(dosage and concentration) have significant interactive effects on cr(Ⅲ) adsorption efficiency. Analysis of variance shows that the response surface quadratic model is highly significant and can effectively predict the experimental outcomes. cr(Ⅲ) removal efficiency of 98% was obtained using optimized conditions of MFA dosage, p H and initial cr(Ⅲ) concentration of 1.57 g·L^(-1), 4.11 and 126 mg·L^(-1), respectively. cr(Ⅲ) adsorption onto MFA is mainly attributed to the interaction between cr(Ⅲ) and the functional group \\OH of the hydrous magnesium oxide, in all probability caused by chemisorptions. The results of this study can conduce to reveal the interactions between cr(Ⅲ) pollutant and MFA characteristics, posing important implications for the cost-effective alternative adsorption technology in the treatment of heavy metal containing wastewater.

关键词：优化使用氧化物方法论 cr 含水反应表面苍蝇

Interaction of Mechanical and Electrochemical Factors duringCorrosion Fatigue of Fe-26cr-1Mo Stainless Steel in 1M H_2SO_4 Solution

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1995年第3期11卷 181-186页

作者： Jianqiu WANG Jin LI Ziyong ZHU and Wei KE (Corrosion Science Laboratory, Institute of Corrosion and Protection of Metals Chinese Academy of Sciences, Shenyang, 110015, China)Qishan ZANG and Zhongguang WANG (State Key Laboratory for Fatigue and Fracture Inst of Corrosion and Protection of Metals Chinese Acad of Sciences Shenyang China

The cyclic plastic straining electrode technique has been used to investigate the transient electrochemical behaviour of Fe-26cr1Mo stainless steel in 1M H2SO4 solution at a passive potential.The influence of plastic strain amplitude and plastic strain rate on the dissolution current response was analysed. The experimental results showed that the transient current was dependent on the competitive process of the surface film rupture and repassivation of the new surface. The high plastic strain amplitude and the high plastic strain rate caused a change of electrochemical activity of specimen surface. In the condition of low strain amplitude and strain rate, the characteristics of current response was mainly relative tp the process of new surface repassivation.The competition kinetics has been analysed through the comparison of plastic strain rate and repassivating rate

关键词： Mo cr Interaction of Mechanical and Electrochemical Factors duringCorrosion Fatigue of Fe-26cr-1Mo Stainless Steel in 1M H2SO4 Solution Fe SO

One-order-higher cr4+ conversion efficiency in cr4+:YAG transparent ceramics for a high-frequency passively Q-switched laser

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2019年第8期7卷 933-938页

作者： YINGSHUANG SHAN LE ZHANG TIANYUAN ZHOU CEN SHAO LEI ZHANG YUELONG MA QING YAO ZHIGANG JIANG FARIDA ASELIM HAO CHEN Jiangsu Key Laboratory of Advanced Laser Materials and Devices School of Physics and Electronic EngineeringJiangsu Normal UniversityXuzhou221116China Department of Physics and Astronomy Bowling Green State UniversityBowling GreenKentucky43403USA School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGeorgia30332USA SUSTech Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen518055China School of Mechanical Engineering Jiangsu UniversityZhenjiang212013China

The cr4+-doped yttrium aluminum garnet(cr4+:YAG) saturable absorber, a new generation of passively Q-switched solid-state laser material, faces a significant obstacle of low conversion rate of chromium from trivalent to tetravalent, degrading efficiency in a passively Q-switched laser. In this paper, highly transparent cr4+:YAG ceramics were fabricated and committed to compare the laser performance with cr4+:YAG crystals on a 1 μm passively Q-switched laser. Thanks to the grain boundary effect, the cr4+conversion efficiency of 0.05 at.% cr4+:YAG transparent ceramics coated with high transparency(HT) films(T = 86.46% at 1064 nm)was nine times higher than that of 0.1 at.% cr4+:YAG single crystals coated with HT films(T = 84.00% at1064 nm). Differing from the counterpart cr4+:YAG crystals, no absorption saturation tendency was observed for the 0.05 at.% cr:YAG ceramics when the pump power exceeded ~1900 mW. Furthermore, the repetition frequency reached 217 kHz for 0.05 at.% cr:YAG ceramics, which was a three-fold factor increase from that of the corresponding single crystal. The advantages of transparent ceramics over single crystals were proved through laser performance for the first time, to the best of our knowledge. This study also provided compelling evidence for replacing single crystals with ceramics for ultrafast dynamics.

关键词： One-order-higher cr4+conversion conversion efficiency in cr high-frequency passively Q-switched laser

Effect of cr Doping on the Surface Characteristics of Ni Metal Studied with First-Principles Calculation

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2019年第4期32卷 461-470页

作者： Xian-Feng Sun Hai-Tao Wang En-Hou Han CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China

The influence of cr doping on the surface characteristics of Ni metal, including the surface energy, work function,adsorption and dissociation, has been investigated by means of first-principles calculation based on density functional theory. The results reveal that with the increase in cr doping amount, the surface energies for all(111),(110) and(100)surfaces increase, whereas the work functions of(111) and(100) surfaces decrease followed by an increase and that of(110) surface has been decreasing. On the typical Ni(111) and Ni-cr(111) surfaces, the adsorption energies follow the sequence O > OH > H > H_2O, and the doping of cr increases the chemical activity of surfaces leading to the improvement of adsorption energies. The H_2O dissociating to OH and H is easier than the subsequent OH dissociating to O and H. The addition of cr into Ni surface decreases the energy barriers and significantly increases the reaction rate constants.

关键词： Density functional theory Surface characteristics Nickel cr addition Atomistic simulation

cr2+:ZnS Saturable Absorber Passively Q-Switched Ho:LuVO4 Laser

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2015年第10期32卷 59-62页

作者：崔铮姚宝权段小明白爽李江袁晋鹤戴通宇李超宇潘裕柏 National Key Laboratory of Tunable Laser Technology Harbin Institute of Technology Harbin 150001 Key Laboratory of Transparent and Opto-functional Advanced Inorganic Materials Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050

We report a cw Tm：YAP laser resonantly pumped Ho：LuV04 laser in passively Q-switched （PQS） mode with cr2＋：ZnS as a saturable absorber （SA）. The influence of different transmittances of the output coupler on laser output performance is analyzed. With T = 50%, the max/mum PQS average output power of 2.3 W is ob- tained, corresponding to the slope efficiency and the optical-optical conversion efficiency are 35.1% and 19.8%, respectively. Also, the minimum pulse width of 100ns is achieved at the maximum pulse repetition frequency of 34.2kHz. When the maximum cw output power is 2.7W, the beam quality factor of the horizontal direc- tion Mx2 = 1.04 and the vertical direction M2 = 1.10 are obtained. In addition, the central wavelength of the laser output remains to be 2057.5nm with the output coupler transmittances of 50% and 60% in both cw and PQS operations. The results show that the cr2＋：ZnS can be used as an SA in a Ho：LuVO4 laser around 2-μm wavelength.

关键词： Ho ZnS Saturable Absorber Passively Q-Switched Ho:LuVO4 Laser cr

Enhanced wetting and properties of carbon/carbon-Cu composites with cr_3C_2 coatings by cr-solution immersion method

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2018年第3期34卷 458-465页

作者： Bo Kong Jinming Ru Hongdi Zhang Tongxiang Fan State Key Laboratory for Metal Matrix Composite Shanghai Jiaotong University Institute of Advanced Manufacturing and Modern Equipment Technology Jiangsu University

A facile ammonium-dichromate solution immersion method was introduced to synthesize the copperwettable cr3C2 coating on and inside the carbon-carbon （C/C） preform. The formation mechanism and the microstructures of the cr3C2 coatings were studied. The contact angle between molten copper and the C/C decreased from 140°to 60°, demonstrating the significant improvement in the wettability. The cr3C2- coated C/C-Cu composite with only 4.2% porosity and 3.69 gcm^-3 density was manufactured through copper infiltration. As a result, the thermal and electrical conductivity of the modified C/C-Cu increased significantly due to the infiltrated copper. Also the mechanical properties of the composites including both the flexural and compressive strengths were enhanced by over 100%. The modified C/C-Cu composite exhibited lower friction coefficients and wear rates for different load levels than those of the commercial C/Cu composite. These results demonstrate the potential of the modified C/C-Cu material for use in electrical contacts.

关键词： Enhanced wetting and properties of carbon/carbon-Cu composites with cr3C2 coatings by cr-solution immersion method cr Cu

Effect of cr content and cooling rate on the primary phase of Al-2.5Mn alloy

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1551-1558页

作者： Hang-qi Feng Zhi-bo Yang Ye-tong Bai Li Zhang Yu-lin Liu School of Materials Science and Engineering Shenyang Aerospace University

The effect of cr content and cooling rate on the microstructure of Al-Mn alloy was studied using well resistance furnace melting,and the alloy was analyzed using scanning electron microscopy(SEM)and X-ray diffraction(XRD).The experimental results showed that adding cr could significantly improve the morphology of the primary phase in the Al-2.5Mn alloy.Without cr,the primary phase in the alloy was thick,needle-like,and strip-like structure.After adding 0.2wt%-0.5wt%cr,the primary phase in the upper part of the alloy was gradually fined and reached the best effect at 0.35wt%cr.When the content of cr was 0.5wt%,the microstructure of the primary phase in the upper part began to coarsen.The bottom of the alloy was a large bulk phase,but still much finer than that without adding cr.XRD and SEM analysis showed that the precipitation phase at the bottom was mainly Al85Mn7cr8,while the fine microstructure at the top was Al6Mn and Al3Mn.The results of the cooling rate experiments showed that the primary phase of Al-2.5Mn-0.35cr was further refined,and the eutectic microstructure was partly achieved,under air-cooling condition.And when the cooling method was iron die-cooling,the microstructure of the Al-2.5Mn-0.35cr alloy was changed into a eutectic microstructure.

关键词： Al-2.5Mn alloy cr content primary phase cooling rate

Fluorescent probe gold nanodots to quick detect cr(VI) via oxidoreduction quenching process

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2019年第1期62卷 133-141页

作者： Yueqi Zhao Yuanqing Sun Yingnan Jiang Shanliang Song Tianxin Zhao Yue Zhao Xinyu Wang Baoquan Li Bai Yang Quan Lin State Key Laboratory of Supramolecular Structure and Material College of Chemistry Jilin University State Key Laboratory of Heavy Oil Processing College of Science China University of PetroleumBeijing Jilin Ginseng Academy Changchun University of Chinese Medicine Department of Oral Pathology School and Hospital of Stomatology Jilin University

A method is described here for the quickly(<30 s) accurate determination of cr(VI)(cr_2O_7^(2-)), based on fluorescent probes gold nanodots(AuNDs, excitation/emission peaks at 395/604 nm) coated with glutathione(GSH).... 详细信息

A method is described here for the quickly(cr(VI)(cr_2O_7^(2-)), based on fluorescent probes gold nanodots(AuNDs, excitation/emission peaks at 395/604 nm) coated with glutathione(GSH). The fluorescence of the AuNDs responses linearly to cr(VI) concentrations, ranging widely from 1 nM to 10 m M with detection limit as low as 0.35 nM. At the same time, the AuNDs is demonstrated highly selective for cr(VI) detection over other acid group ions and metal ions without any masking reagent. These make probability for practical use. The quenching mechanism is investigated deeply via fluorescent lifetime, XPS and TEM analysis. Different from most reported quenching explanation of aggregation derived from charge attraction, these results verify the redox reaction between cr_2O_7^(2-)and sulfhydryl(–S) of GSH. The Au(I)–S bonds of AuNDs broke, accompanies with the oxidation of –S to form S–S bonds. As a result, AuNDs cross linked to each other. In the end, the fluorescence quenched. Attractively, the present study provides a new strategy for pollutant detection, such as from harmful cr(VI) of cr_2O_7^(2-)to nontoxic cr(III).

关键词： fluorescent probe of cr (Ⅵ) Au nanodots quick and quantitative detection fluorescence quenching mechanism pollutant detection

Effects of cr content on corrosion behaviour and corrosion products of spring steels

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2019年第9期26卷 1000-1010页

作者： Mao-fang Zuo Yin-li Chen Zhen-li Mi Yi-de Wang Hai-tao Jiang Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China

Neutral salt spray corrosion experiments of spring steels with different cr contents were carried out for different corrosion periods. The optical microscope was used to observe the macroscopic corrosion morphology of the steel surface. The corrosion pit morphology of steel surface was observed by laser scanning confocal microscopy and scanning electron microscopy, and three-dimensional simulation was carried out. At the same time, the corrosion products (rust layer) were qualitatively and quantitatively analysed by X-ray diffraction. As the results show, cr is beneficial to improving corrosion resistance of the experimental steel matrix, and the higher the content of cr, the stronger the corrosion resistance will be. With increase in cr content in steel, the development of corrosion process will be more effectively suppressed. With the increase in cr content, the denser the corrosion products, the stronger the bond with the metal matrix is. The corrosion products have obvious stratification;the outer layer is mainly composed of c-FeOOH, which is relatively loose and not firmly integrated with the matrix, while the inner layer contains a-FeOOH and Fe3O4, which are relatively dense and closely integrated with the matrix. The types of corrosion are constantly changing during different phases of corrosion.

关键词： Spring steel cr content Corrosion behaviour Corrosion product Rust layer

Characteristics of the stabilized/solidified municipal solid wastes incineration fly ash and the leaching behavior of cr and Pb

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2016年第1期10卷 192-200页

作者： Yan SHAO Haobo HOU Guangxing WANG Sha WAN Min ZHOU School of Resource and Environment Science Wuhan University Wuhan 430072 China GNSS Research Center Wuhan University Wuhan 430072 China

Fly ash is a hazardous byproduct of municipal solid wastes incineration （MSWI）. An alkali activated blast fumace slag-based cementifious material was used to stabilize/solidify the fly ash at experimental level. The characteristics of the stabilized/solidified fly ash, including metal leachability, mineralogical characteristics and the distributions of metals in matrices, were tested by toxic characteristic leaching procedure （TCLP）, X-ray diffrac- tion （XRD） and scanning electron microscopy-energy dispersive spectrometer （SEM-EDS） respectively. Contin- uous acid extraction was utilized to extract metal ions and characterize their leaching behavior. The stabilization/ solidification procedure for MSWI fly ash demonstrates a strong fixing capacity for the metals by the formation of C- S-H phase, hydrated calcium aluminosilicate and ettringite. The stabilized/solidified fly ash shows a dense and homogeneous microstructure. cr is mainly solidified in hydrated calcium aluminosilicate, C-S-H and ettringite phase through physical encapsulation, precipitation, adsorption or substitution mechanisms, and Pb is mainly solidified in C-S-H phase and absorbed in the Si-O structure.

关键词： municipal solid waste incineration （MSWI）fly ash blast furnace slag leaching behavior cr Pb