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A novel weld-pool-length monitoring method based on pixel analysis in plasma arc additive manufacturing

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Advances in Manufacturing 2024年第2期12卷 335-348页

作者： Bao-Ri Zhang yong-hua Shi Bionic Robot Research Department Ji Hua LaboratoryFoshan528200GuangdongPeople’s Republic of China Guangdong Provincial Engineering Research Center for Special Welding Technology and Equipment School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou510640People’s Republic of China

The real-time monitoring of the weld pool during deposition is important for automatic control in plasma arc additive *** obtain a high deposition accuracy,it is essential to maintain a stable weld pool *** this study,a novel passive visual method is proposed to measure the weld pool *** the proposed method,the image quality was improved by designing a special visual system that employed an endoscope and a *** also includes pixel brightness-based and gradient-based algorithms that can adaptively detect feature points at the boundary when the weld pool geometry *** algorithm can also be applied to materials with different solidification *** was performed to measure the real weld pool length in world coordinates,and outlier rejection was performed to increase the accuracy of the ***,tests were carried out on the intersection component,and the results showed that the proposed method performed well in tracking the changing weld pool length and was applicable to the real-time monitoring of different types of materials.

关键词： Plasma arc additive manufacturing(PAAM) Weld pool geometry Gradient analysis Real-time detection

The Role of Consumer Privacy Concerns in Shaping Platform Strategy for Online Markets

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Journal of the Operations Research Society of China 2024年第2期12卷 363-386页

作者： Jin-Kun Yang yong-Rui Duan Jia-Zhen huo School Economics and Management Tongji UniversityShanghai 200092China

We investigate the effects of consumer privacy concerns on the pricing and personal data collection strategy of an online *** online platform derives revenues from disclosing consumer information to *** compete for the information in order to enable them to price discriminate and thus derive revenues from consumer purchases.A novel aspect of our research is that we allow the online platform to sell only a subset of consumer *** develop analytical models where consumers can/cannot protect their *** analysis yields three main ***,in the monopoly case,we find that when the consumer privacy disclosure aversion cost is relatively low,it is optimal for the platform to sell all consumer information to the ***,in the duopoly case,we illustrate that when the consumer privacy disclosure aversion cost is relatively low,the platform will sell all consumer information to only one firm;when the cost is moderate,the platform will choose to sell the information of only some consumers and to only one firm;when the cost is relatively high,the platform will select only some of the consumers and sell their information to both ***,it will be better for the platform to provide the information protection service for free when the privacy cost is low.

关键词： Price discrimination User privacy Consumer information Two-sided market Privacy disclosure aversion cost

Recent advances and practical challenges of high-energy-density flexible lithium-ion batteries

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 79-98页

作者： Guangxiang Zhang Xin Chen Yulin Ma hua huo Pengjian Zuo Geping Yin Yunzhi Gao Chuankai Fu State Key Laboratory of Space Power-Sources Harbin Institute of TechnologyHarbin 150001China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China

With the rapid iteration and update of wearable flexible devices,high-energy-density flexible lithium-ion batteries are rapidly ***,energy density,and safety are all important indicators for flexible lithium-ion batteries,which can be determined jointly by material selection and structural ***,recent progress on high-energy-density electrode materials and flexible structure designs are *** electrode materials and the next-generation high-energy-density electrode materials are analyzed in *** electrolytes with high safety and excellent flexibility are classified and *** strategies to increase the mass loading of active materials on the electrodes by designing the current collector and electrode structure are discussed with keys of representative *** the novel configuration structures to enhance the flexibility of batteries are *** the end,it is pointed out that it is necessary to quantify the comprehensive performance of flexible lithium-ion batteries and simultaneously enhance the energy density,flexibility,and safety of batteries for the development of the next-generation high-energy-density flexible lithium-ion batteries.

关键词： lithium-ion batteries flexibility high energy density safety

Construction of Naphthalenediimide Lanthanide(Ⅲ)-MOFs and Composites Incorporated Electron-Rich Pyrene Derivative as Multifunctional Fluorescence Sensing for Nitro Aromatic Compounds and Aldehydes

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Chinese Journal of Chemistry 2024年第3期42卷 283-293页

作者： Rong huo Ting Zhang Guang Zeng Chen Wang yong Heng Xing Feng Ying Bai College of Chemistry and Chemical Engineering Liaoning Normal UniversityDalianLiaoning116029 China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning116023 China

The development of host-guest MOF luminescent composites has attracted considerable attention. However,it is still a challenge to reasonably design large scale conjugated polycarboxylic acids metal-organic framework (MOF) and modulate donor-acceptor interaction. Herein,a series of isostructural 3D porous lanthanide MOF [Ln_(2)(BINDI)0.5(NO_(3))(DMA)(H_(2)O)]∙DMA∙2.5H_(2)O (Ln = La (1),Ce (2),Pr (3) and Nd (4);H_(4)BINDI (N,N’-bis(5-isophthalic acid)-1,4,5,8-naphthalenediimide) were synthesized. Considering the electron-deficient performances of Ln-BINDI MOFs,D-A type composites Ln-MOFs (1—4@H_(4)TBAPy) were prepared via the incorporation of electron-rich H_(4)TBAPy (1,3,6,8-tetrakis(p-benzoic acid) pyrene),which more improved the luminescence performance of complexes 1—4 and can be used as fluorescence sensors for the detection of nitro compounds and aldehydes. High sensitivity of 1@H_(4)TBAPy towards pNBA,pNA PNP,DNP,and TNP could be achieved through hydrogen bond interactions between MOF and analytes,as well as the π-π interaction between H_(4)TBAPy and the naphthalene ring of BINDI,thus the fluorescence quenching efficiency of 1@H_(4)TBAPy was better than that of the complex 1. In addition,it is found that 1@H_(4)TBAPy has high selectivity and sensitivity to aromatic aldehyde SA,5-Mesal and HMBA. Such strategy to enhance the emission of NDI based Ln-BINDI MOFs,will open up an avenue to obtain more fluorescent MOFs for sensing.

关键词： Ln-MOF Pyrene molecule NACs Aldehydes Fluorescence sensing Carboxylate ligands Charge transfer Donor-acceptor systems

Microstructure evolution of Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14)amorphous alloy after semi-solid isothermal treatment

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China Foundry 2024年第3期21卷 287-294页

作者： Xin-hua huang Jing-wen Pu yong-xin Luo Yue-jun Ouyang School of Material Electricity and Intelligent ManufacturingHuaihua UniversityHuaihua 330031HunanChina Hunan Renewable Aluminum Innovation Research Center Huaihua UniversityHuaihua 330031HunanChina

The as-cast amorphous Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14)composites,comprising in situ formedβ-Ti ductile crystalline precipitates,were prepared by water cooled copper mold suction ***,the semi-solid composites were obtained after the as-cast composites were treated by semi-solid isothermal *** microstructure evolution and kinetics of the composites were *** show that the microstructures of both the as-cast and semi-solid composites comprise ofβ-Ti crystal phases and amorphous matrix *** and after treatment,the crystals evolve from fine granular or fine dendritic crystals to coarse *** the treatment temperature increasing or the time prolonging,the average crystal size gradually increases and the surface morphology of the crystals gradually becomes *** studying the microstructural evolution and dynamics during the isothermal treatment process,it is found that the final morphology ofβ-Ti crystals is influenced by the isothermal treatment temperature and time(t),and theβ-Ti evolution rate increases with an increase in treatment *** addition,a linear relationship was observed between the size of cubicβ-Ti crystals(D^(3))and t;the growth kinetics factor K is 3.8μm^(3)·s^(-1).As the K value closes to 4μm^(3)·s^(-1),it is inferred the morphology evolution ofβ-Ti crystals is a coarsening behavior controlled by the diffusion of solute elements.

关键词： Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14) amorphous matrix composites semi-solid as-cast microstructure

Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

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Journal of Environmental Sciences 2024年第2期136卷 237-247页

作者： hua Tang Ying Wang Shengling Si Hongli Li David Da yong Chen National Institute of Metrology 18 BeisanhuandongluChaoyang DistrictBeijing 100029China School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China Si Chuan Zhong Ce Biao Wu Technology Co.Ltd. Sichuan 610052China Department of Chemistry University of British ColumbiaVancouver V6T 1Z1BCCanada

A method of quantification of perfluorinated compounds(PFCs)from atmospheric particulate matter(APM)is described.A single step pretreatment method,selective pressurized liquid extraction(SPLE),was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment *** effective sorbent was selected to purify the PFCs during SPLE,followed by liquid chromatography-tandem mass spectrometry(LC–MS/MS),for quantification of *** affecting the SPLE efficiency,including temperature,static extraction time,and number of extraction cycles used,were *** optimum conditions were found to be 120℃,10 min,and 3 cycles,***-MS/MS method was developed to obtain the optimal sensitivity specific to *** method detection limits(MDLs)were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/*** ensure accurate values were obtained,each step of the experiment was evaluated and controlled to prevent *** optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target ***,the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to *** is observed that some PFCs follow the trend of total PFC changes,and can be attributed to the environment influencing events and policy enforcement,while others don't seem to change as much with time of the year or from year to year.

关键词： Selective pressurized liquid extraction Liquid chromatography-mass spectrometry Perfluorinated compounds Atmospheric particulate matter Pollution control

Optimal V_(2)O_(3) extraction by sustainable vanadate electrolysis in molten salts

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Tungsten 2024年第1期6卷 141-149页

作者： Bao-Yan Feng Zhong-hua Zhao yong-Zheng Jia Jia-Liang An Ming-yong Wang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Green Recovery and Extraction of Rare and Precious Metals University of Science and Technology BeijingBeijing 100083China

Recently,an environmentally friendly electrolysis process of soluble vanadates is proposed and successfully confirmed for V_(2)O_(3) *** this paper,the solubilities of various vanadates(***_(3),Na_(4)V_(2)O_(7) and Na_(3)VO_(4))in NaCl molten salt are *** dependences of V_(2)O_(3) extraction on vanadate form,anode material and molten salt system are studied.A long-term electrolysis is carried *** result indicates that the solubilities of all vanadates are high and meet electrolytic *** to Na_(4)V_(2)O_(7) and Na_(3)VO_(4),NaVO_(3) exhibits larger current efficiency and lower electricity *** using SnO_(2) anode instead of graphite anode,the current efficiency of NaVO_(3) electrolysis can be increased to 58.1%and carbon pollution is avoided at 700℃.The extraction rate of V_(2)O_(3) reaches 81.3%after long-term electrolysis of 51 *** work optimizes the electrochemical preparation process of V_(2)O_(3) from various vanadates and contributes to the improvement of current efficiency and extraction rate.

关键词： Molten salt electrolysis Vanadate Vanadium trioxide Current efficiency

Evaluation of suitability,adaptability,and reserve potential of construction land on the Qinghai-Tibet Plateau

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Journal of Geographical Sciences 2024年第1期34卷 41-61页

作者： YANG hua XU yong ZHOU Kan WANG Lijia XU Lin Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Construction land is the leading carrier of human activities such as production and *** the construction land suitability(CLS)on the Qinghai-Tibet Plateau(QTP)holds significant implications for harmonizing the relationship between ecological protection and human activity and promoting population and industry layout ***,no relevant studies provide a complete CLS assessment of the *** this study,we developed a model-based CLS evaluation framework coupling of pattern and process to calculate the global CLS on the QTP based on a previously developed CLS evaluation ***,using the land-use data of 1990,2000,2010,and 2020,we examined the adaptability of existing construction land(ECL)to the CLS assessment result through the adaptability index and vertical gradient index and further analyzed the limitations of maladaptive construction ***,we calculated the potential area of reserve suitable construction *** article includes four conclusions:(1)The highly suitable,suitable,moderately suitable,marginally suitable,and unsuitable CLS classes cover areas of 0.33×10^(4)km^(2),10.42×10^(4)km^(2),18.06×10^(4)km^(2),24.12×10^(4)km^(2),and 205.29×10^(4)km^(2),*** approximately 11%of the study area on the QTP is suitable for large-scale permanent construction land,and approximately 79.50%of the area is unsuitable under current economic and technological conditions.(2)The ECL adaptability index is 85.16%,85.93%,85.18%,and 78.01%during 1990–2020,respectively,with an average adaptability index exceeding 80%on the *** ECL distribution generally conforms to construction land suitable space characteristics but with a significant spatial difference.(3)From 1990 to 2020,the maladaptive ECL was dominated by rural settlement land,transport land,and special land,with a rapidly increasing proportion of urban and other construction *** maladaptive ECL is constrained by both elevation and slope in the southern Qinghai Pla

关键词： land resource construction land suitability existing construction land adaptability human activity Qinghai-Tibet Plateau

Tetraphenylethene-based hole transporting material for highly efficient and stable perovskite solar cells

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Science China Chemistry 2024年第6期67卷 2009-2015页

作者： Peng Wang Pei Yuan Chenghao Ge Rongjun Zhao Lin Xie yong hua School of Materials and Energy Yunnan UniversityKunming650091China

2,2,7,7-Tetrakis-(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene(Spiro-OMeTAD)has been identified as the most widely used and effective hole transporting material(HTM)in perovskite solar cells(PSCs).However,the complicated multistep synthesis and low intrinsic hole mobility of Spiro-OMe TAD limit its commercialized ***,developing highly efficient HTMs with less synthetic steps becomes increasingly ***,understanding hot carriers transfer dynamics at the interface of perovskite layer and hole transport layer is crucial for further enhancing PSCs performance towards Shockley-Queisser limit,which still lacks full investigation to ***,a new HTM based on tetraphenylethene(WP1)was successfully synthesized by a simple one-step reaction *** was found that WP1-based HTM exhibits more matched energy level,higher hole mobility and conductivity than those of the control Spiro-OMe *** femtosecond transient absorption results reveal that the transfer rate of hot holes in perovskite/WP1 sample is four times higher than that of perovskite/Spiro-OMeTAD,thereby helping enhance the device ***,the efficiency of PSCs is enhanced to 24.04%(WP1)from 22.85%(Spiro-OMeTAD).Moreover,the un-encapsulated device prepared with WP1 exhibits better long-term stability,retaining 87%of its initial PCE value after storing for 72 days under air environment,while the reference device shows76%of its initial *** work indicates that simple tetraphenylethene-based organic small molecule could be a very promising HTM candidate for highly efficient PSCs,and gives some significant insights for understanding intrinsic hot carriers transfer dynamics in device.

关键词： tetraphenylethene hole transporting material perovskite solar cells mobility hot carrier