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International Journal of Minerals,Metallurgy and Materials 2015年第7期22卷 755-761页

作者： Rui Yang wan-qi jie Hang Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical University

Using tellurium as a solvent, we grew ZnTe ingots of 30 mm in diameter and 70 mm in length by a temperature gradient solution growth method. Hall tests conducted at 300 K indicated that the as-grown ZnTe exhibits p-type conductivity, with a carrier concentration of approximately 10^14cm^-3, a mobility of approximately 300 cm^2·V·s^-1, and a resistivity of approximately 10^2 Ω·cm. A simple and effective method was proposed for chemical surface texturization of ZnTe using an HF：H2O2：H2O etchant. Textures with the sizes of approximately 1μm were produced on {100}, {110}, and { 111}zn surfaces after etching. The etchant is also very promising in crystal characterization because of its strong anisotropic character and Te-phase selectivity.

关键词： semiconductor materials crystal growth electrical properties surfaces etching microstructure

Preparation and characterization of γ-La_2S_3 nanoparticles from thermal decomposition

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 748-752页

作者： Pei-sen Li Huan-yong Li wan-qi jie School of Materials Science and Engineering Northwestern Polytechnical University Xi＇an 710072 China

To synthesize pure γ-La2S3 at lower temperature,lanthanide complex La（Et2S2CN）3·phen,containing La？S bond,was chosen as the precursors to *** obtained samples were characterized by X-ray power diffraction （XRD）,field-emission scanning electron microscopy （FE-SEM） with an energy dispersive spectrometer and UV-Vis diffuse reflectance *** decomposition mechanism of the lanthanide complex was studied by thermogravimetric analyses （TGA）.The results show that the obtained samples are cubic phase particles with sizes among 20-50 nm and the band gap is 2.97 eV,which is bigger than that of its bulk ***/DTG results indicate that La（Et2S2CN）3·phen decomposed to γ-La2S3 via La4（Et2S2CN）3 as an intermediate product.

关键词： chalcogenides nanoparticles thermogravimetric analysis decomposition optical properties

Effect of Gd content on hot-tearing susceptibility of Mg-6Zn-xGd casting alloys

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China Foundry 2022年第2期19卷 131-139页

作者： He qin Guang-yu Yang Xun-wei Zheng Shi-feng Luo Tong Bai wan-qi jie State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China Dongfeng Nissan Aeolus Xiangyang Automobile Co. Ltd.Xiangyang 441100HubeiChina

The hot-tearing susceptibility(HTS)of Mg-6Zn-xGd(x=0.5,1,2,3,4,6)alloys was evaluated using a constrained rod casting(CRC)*** results show that the HTS curve follows a typical"Λ"shape with the increase of Gd *** Mg-6Zn-2Gd alloy has the highest while Mg-6Zn-6Gd alloy has the lowest HTS *** hot-tearing behavior characteristics of Mg-6Zn-xGd alloys were further studied through a multifunctional hot-tearing test *** to the dendrite contact point inferred from the stress curve,the Clyne-Davies criterion was modified and found to be accurate in predicting the HTS of Mg-6Zn-xGd *** observation reveals that the grain size and the volume of eutectic liquid are the two key factors affecting HTS of Mg-6Zn-xGd *** large grain with columnar structure can easily promote initiation and propagation of hot-tearing due to the poor feeding and coordinating deformation capability,which have a harmful effect on HTS.A higher volume fraction of eutectic phase can refill the cracking and provide continuous feeding channels by dendrite bridge and thicker liquid film,thus increase the hot-tearing resistance.

关键词： Mg-Zn-Gd alloy hot-tearing susceptibility modified Clyne-Davies model microstructure

Numerical simulation for macrosegregation in direct-chill casting of 2024 aluminum alloy with an extended continuum mixture model

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Transactions of Nonferrous Metals Society of China 2018年第5期28卷 1007-1015页

作者： Hai-jun LUO wan-qi jie Zhi-ming GAO Yong-jian ZHENG State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072 China Chair of Simulation and Modeling of Metallurgical Processes Montan Universitaet Leoben 8700 Leoben Austria

An extended continuum mixture model for macrosegregation is applied to predicting Cu and Mg segregation in large-size ingot of 2024 aluminum alloy during direct chill casting（DC）. A microsegregation model using the approximate phase diagram data was coupled with macroscopic transport equations for macrosegregation profiles. Then, the impacts of transport mechanisms on the formation of macrosegregation were discussed. It is found that copper and magnesium have a similar segregation configuration from the billet center to surface. Negative segregation is observed in the centerline and subsurface, whereas positive segregation is obtained in the surface and somewhat underestimated positive segregation in the middle radius. Further, the discrepancy between the predicted and experimental results was discussed in detail. The results show that the magnesium to some extent alleviates the copper segregation in ternary alloy, compared with that in binary alloy. The predicted results show good agreement with measured experimental data obtained from literatures.

关键词： direct-chill casting macrosegregation numerical simulation continuum model 2024 aluminum alloy

Temporal pulsed x-ray response of CdZnTe:In detector

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Chinese Physics B 2018年第12期27卷 450-454页

作者： Rong-Rong Guo Ya-Dong Xu Gang-qiang Zha Tao wang wan-qi jie School of Optoelectronic and Communication Engineering Xiamen University of Technology State Key Laboratory of Solidification Processing Northwestern Polytechnical University (NWPU)

The temporal response of cadmium-zinc-telluride(CZT) crystals is evaluated at room temperature by using an ultrafast-pulsed x-ray source. The dynamics of carrier relaxation in a CZT single crystal is modeled at a microscopic level based on a multi-trapping effect. The effects of the irradiation flux and bias voltage on the amplitude and full width at half maximum(FWHM) of the transient currents are investigated. It is demonstrated that the temporal response process is affected by defect level occupation fraction. A fast photon current can be achieved under intense pulsed x-ray irradiation to be up to 2.78×10~9 photons mm-2·s-1. Meanwhile, it is found that high bias voltage could enhance carrier detrapping by suppressing the capture of structure defects and thus improve the temporal response of CZT detectors.

关键词： CdZnTe ultrafast-pulsed x-rays transient current charge carrier

Influence of filling parameters on fatigue properties of A357 alloy produced by counter pressure plaster mold casting

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Transactions of Nonferrous Metals Society of China 2013年第5期23卷 1281-1285页

作者：李强郝启堂介万奇 Maijer DAAN 西北工业大学凝固技术国家重点实验室西安710072 Department of Materials Engineering University of British Columbia

The influence of filling parameters including pouring temperature, filling speed, boost pressure and synchronous pressure on the fatigue of A357 alloy produced by counter pressure plaster casting was studied. The Taguchi method was used to investigate the relationship between the fatigue performance and filling parameters. The results show that filling speed is the most significant factor among the four parameters. Synchronous pressures is less influential on the fatigue life when the value of synchronous pressure is from 400 kPa to 600 kPa.

关键词： counter pressure casting A357 alloy filing parameters fatigue properties

Rotary bending fatigue behavior of A356 –T6 aluminum alloys by vacuum pressurizing casting

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China Foundry 2015年第5期12卷 326-332页

作者： Yong-qin Liu wan-qi jie Zhi-ming Gao Yong-jian Zheng Hai-jun Luo Wen-tao Song State Key Laboratory of Solidification Processing Northwestern Polytechnical University School of Aerospace Mechanical and Manufacturing Engineering RMIT University Simulation and Modeling of Metallurgical Processes Montanuniversitaet Leoben

Vacuum pressurizing casting technique, providing better mould filling and inter-dendritic feeding, can reduce the porosity greatly in cast aluminum alloys, and improve the fatigue properties. The rotary bending fatigue properties of A356-T6 alloys prepared by vacuum pressurizing casting were investigated. The S-N curve and limit strength 90 MPa under fatigue life of 107 cycles were obtained. The analyses on the fatigue fractography and microstructure of specimens showed that the fatigue fracture mainly occurs at the positions with casting defects in the subsurface, especially at porosities regions, which attributed to the crack propagation during the fatigue fracture process. Using the empirical crack propagation law of Pairs-Erdogon, the quantitative relationship among the initial crack size, fatigue life and applied stress was established. The fatigue life decreases with an increase in initial crack size. Two constants in the Pairs-Erdogon equation of aluminum alloy A356-T6 were calculated using the experimental data.

关键词： aluminum alloys vacuum pressurizing casting rotary bending fatigue porosity crack propagation

Electrochemical chemoselective thiocarbamylation of late-stage Tyr-containing drugs and peptides

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Science China Chemistry 2024年第10期67卷 3382-3388页

作者： wan-jie Wei Xin-Yu wang Hai-Tao Tang Fei-Hu Cui Yun-qi Wu Ying-Ming Pan State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China)Collaborative Innovation Center for Guangxi Ethnic MedicineSchool of Chemistry and Pharmaceutical SciencesGuangxi Normal University

The synthesis and modification of peptides occupy a unique position in the field of drug development, and the functionalization of amino acids is a valuable strategy as an alternative to peptide modification. Currently, the development of tyrosine(Tyr) as a target amino acid is a major challenge in the field of chemistry. Herein, we report an electrochemical radical coupling reaction of labeling tyrosine-containing active drugs and peptides with thiocarbamate derivatives for the first time. This tri-component, onepot reaction can be performed smoothly under simple, gentle, and clean electrochemical conditions and is suitable for the functionalization of various Tyr-containing drug molecular derivatives and peptides.

关键词： tyrosine electrochemical radical coupling chemical modification peptides

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Effect of cooling method on TiN precipitation behavior of high-titanium high-strength steel during solidification

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Journal of Iron and Steel Research International 2024年第7期31卷 1692-1703页

作者： Xue-jian Zhang Guang-wei Yang Yong wan Yong-hong Wen Chuan-sheng Tang Ming-qi Liu Li-jie Tian Key Laboratory of Metallurgical Emission Reduction and Resources Recycling Anhui University of TechnologyMa'anshan 243002AnhuiChina School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina Baosteel Central Research Institute Baoshan Iron and Steel Co.Ltd.Shanghai 201999China

Metallographic microscopy,scanning electron microscopy and TiN growth thermodynamic and kinetic equations were used to investigate the morphology,quantity,and size of TiN in the center of high-titanium high-strength steels under different solidification cooling *** results showed that TiN in the center of the experimental steels mainly existed in three forms:single,composite(Al2O3-TiN),and multi-particle *** began precipitating at around 1497℃(solidification fraction of 0.74).From the end of melting to solidification for 180 s,the cooling rates in the center of the experimental steels for furnace cooling,air cooling,refractory mold cooling,and cast iron mold cooling tended to stabilize at 0.17,0.93,1.65,and 2.15℃/s,*** size of TiN in the center of the experimental steel cooled using furnace cooling was mainly concentrated in the 5-15 pm *** contrast,the size of TiN in the center of the experimental steels cooled using air cooling,refractory mold cooling,and cast iron mold cooling were mainly concentrated in the 1-5 pm *** addition,their density of TiN in the center of the experimental steels is signif-icantly higher than that of the furnace-cooled experimental *** and kinetic precipitation models of TiN established predicted the growth size of TiN in a high-titanium high-strength steel when the solidification cooling rates are not below 0.93℃/s.

关键词： High-titanium steel Cooling method TiN Thermodynamics Kinetics

Multimodal Machine Learning Guides Low Carbon Aeration Strategies in Urban Wastewater Treatment

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Engineering 2024年第5期36卷 51-62页

作者： Hong-Cheng wang Yu-qi wang Xu wang wan-Xin Yin Ting-Chao Yu Chen-Hao Xue Ai-jie wang State Key Laboratory of Urban Water Resource and Environment School of Civil and Environmental EngineeringHarbin Institute of Technology(Shenzhen)Shenzhen 518055China Key Laboratory of Drinking Water Safety and Distribution Technology of Zhejiang Province College of Civil Engineering and ArchitectureZhejiang UniversityHangzhou 310058China

The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising ***,we introduce an ML technique based on multimodal strategies,focusing specifically on intelligent aeration control in wastewater treatment plants(WWTPs).The generalization of the multimodal strategy is demonstrated on eight ML *** results demonstrate that this multimodal strategy significantly enhances model indicators for ML in environmental science and the efficiency of aeration control,exhibiting exceptional performance and *** random forest with visual models achieves the highest accuracy in forecasting aeration quantity in multimodal models,with a mean absolute percentage error of 4.4%and a coefficient of determination of *** testing in a full-scale plant reveals that the multimodal model can reduce operation costs by 19.8%compared to traditional fuzzy control *** potential application of these strategies in critical water science domains is *** foster accessibility and promote widespread adoption,the multimodal ML models are freely available on GitHub,thereby eliminating technical barriers and encouraging the application of artificial intelligence in urban wastewater treatment.

关键词： Wastewater treatment Multimodal machine learning Deep learning Aeration control Interpretable machine learning