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Oxidation behavior of FeV_(2)O_(4)and FeCr_(2)O_(4)particles in the air:Nonisothermal kinetic and reaction mechanism

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1839-1848页

作者： Junyi xiang xi Lu Luwei Bai Hongru Rao Sheng liu Qingyun Huang Shengqin Zhang Guishang pei Xuewei Lü School of Metallurgy and Materials Engineering Chongqing University of Science and TechnologyChongqing 401331China Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Rep.of Korea College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

High-temperature oxidation behavior of ferrovanadium(FeV_(2)O_(4))and ferrochrome(FeCr_(2)O_(4))spinels is crucial for the application of spinel as an energy material,as well as for the clean usage of high-chromium vanadium ***,the nonisothermal oxidation behavior of FeV_(2)O_(4)and FeCr_(2)O_(4)prepared by high-temperature solid-state reaction was examined by thermogravimetry and X-ray diffraction(XRD)at heating rates of 5,10,and 15 K/*** apparent activation energy was determined by the Kissinger-Akahira-Sunose(KAS)method,whereas the mechanism function was elucidated by the Malek ***,in-situ XRD was conducted to deduce the phase transformation of the oxidation mechanism for FeV_(2)O_(4)and FeCr_(2)O_(4).The results reveal a gradual increase in the overall apparent activation energies for FeV_(2)O_(4)and FeCr_(2)O_(4)during *** stages of the oxidation process are observed based on the oxidation conversion rate of each *** oxidation mechanisms of FeV_(2)O_(4)and FeCr_(2)O_(4)are complex and have distinct *** particular,the chemical reaction controls the entire oxidation process for FeV_(2)O_(4),whereas that for FeCr_(2)O_(4)transitions from a three-dimensional diffusion model to a chemical reaction *** to the in-situ XRD results,numerous intermediate products are observed during the oxidation process of both compounds,eventually resulting in the final products FeVO_(4)and V2O_(5)for FeV_(2)O_(4)and Fe_(2)O_(3)and Cr_(2)O_(3)for FeCr_(2)O_(4),respectively.

关键词： FeV_(2)O_(4) FeCr_(2)O_(4) oxidation nonisothermal kinetics mechanism

Single pair of charge-2 Dirac and charge-2Weyl phonons in GeO_(2)

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Chinese Physics B 2024年第10期33卷 141-145页

作者： Dong-Chang He Jia-xi liu pei-Tao liu Jiang-Xu Li xing-Qiu Chen Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The presence of a pair of Weyl and Dirac points(WP-DP)in topological semimetal states is intriguing and sought after due to the effects associated with chiral topological ***,identifying these states in real materials poses a significant *** this study,by means of first-principles calculations we predict the coexistence of charge-2 Dirac and charge-2 Weyl phonons at high-symmetry points within a noncentrosymmetric P4_(1)2_(1)2 space ***,we propose GeO_(2)as an ideal candidate for realizing these ***,we observe two distinct surface arcs that connect the Dirac and Weyl points across the entire Brillouin zone,which could facilitate their detection in future experimental *** study not only presents a tangible material for experimentalists to explore the topological properties of WP-DP states but also opens up new avenues in the quest for ideal platforms to study chiral particles.

关键词： ological phonon Weyl points Dirac points

Artificial intelligence empowers the second-observer strategy for colonoscopy:a randomized clinical trial

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Gastroenterology Report 2023年第1期11卷 216-223页

作者： Pu Wang xiao-Gang liu Min Kang Xue Peng Mei-Ling Shu Guan-Yu Zhou pei-xi liu Fei xiong Ming-Ming Deng Hong-Fen xia Jian-Jun Li xiao-Qi Long Yan Song Liang-Ping Li Department of Gastroenterology Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChengduSichuanP.R.China Department of Gastroenterology The Affiliated Hospital of Southwest Medical UniversityLuzhouSichuanP.R.China Department of Gastroenterology Xinqiao HospitalThird Military Medical UniversityChongqingP.R.China Department of Gastroenterology Suining Central HospitalSuiningSichuanP.R.China

Background:In colonoscopy screening for colorectal cancer,human vision limitationsmay lead to highermiss rate of lesions;artificial intelligence(AI)assistance has been demonstrated to improve polyp ***,there still lacks direct evidence to demonstrate whether AI is superior to trainees or experienced nurses as a second observer to increase adenoma detection during *** this study,we aimed to compare the effectiveness of assistance fromAI and human observer during ***:A prospective multicenter randomized study was conducted from 2 September 2019 to 29 May 2020 at four endoscopy centers in *** patients were randomized to either computer-aided detection(CADe)-assisted group or observer-assisted *** primary outcome was adenoma per colonoscopy(APC).Secondary outcomes included polyp per colonoscopy(PPC),adenoma detection rate(ADR),and polyp detection rate(PDR).We compared continuous variables and categorical variables by using R studio(version 3.4.4).Results:A total of 1,261(636 in the CADe-assisted group and 625 in the observer-assisted group)eligible patients were ***(0.42 vs 0.35,P=0.034),PPC(1.13 vs 0.81,P<0.001),PDR(47.5%vs 37.4%,P<0.001),ADR(25.8%vs 24.0%,P=0.464),the number of detected sessile polyps(683 vs 464,P<0.001),and sessile adenomas(244 vs 182,P=0.005)were significantly higher in the CADe-assisted group than in the observer-assisted *** detections of the CADe system were lower than those of the human observer(122 vs 191,P<0.001).Conclusions:Compared with the human observer,the CADe system may improve the clinical outcome of colonoscopy and reduce disturbance to routine practice(*** No.:ChiCTR1900025235).

关键词： artificial intelligence colon cancer screening adenoma early detection computer-aided detection

Phosphotungstic acid immobilized on amino-functionalized TS-1 zeolite as a solid acid catalyst for the synthesis of tributyl citrate

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Chinese Journal of Chemical Engineering 2024年第6期70卷 199-210页

作者： pei Li Bianfang Shi Junyao Shen Ran Cui Wenze Guo Ling Zhao Zhenhao xi State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

The amino-functionalization of TS-1 zeolite followed by immobilization of phosphotungstic acid(HPW)was presented to prepare a strong solid acid catalyst for the synthesis of bio-based tributyl citrate from the esterification of citric acid and n-butanol.γ-Aminopropyltriethoxysilane(APTES)was first grafted on the TS-1 zeolite via the condensation reactions with surface hydroxyl groups,and subsequently the HPW was immobilized via the reaction between the amino groups and the protons from HPW-forming strong ionic *** Keggin structure of HPW and MFI topology of TS-1 zeolite were well maintained after the *** amino-functionalization generated abundant uniformly distributed active sites on TS-1 for HPW immobilization,which promoted the dispersity,abundance,as well as the stability of the acid *** tetrahedrally coordinated framework titanium and non-framework titania behaved as weak Lewis acid sites,and the protons from the immobilized HPW acted as the moderate or strong Brønsted acid *** optimized TBC yield of 96.2%(mol)with a conversion of-COOH of 98.1%(mol)was achieved at 150℃for 6 h over the HPW immobilized on amino-functionalized *** catalyst exhibited good stability after four consecutive reaction runs,where the activity leveled off at still a relatively high level after somewhat deactivation possibly caused by the leaching of a small portion of weakly anchored APTES or HPW.

关键词： Amino-functionalization Phosphotungstic acid TS-1 zeolite Esterification Tributyl citrate

Isogeometric Analysis for the Arbitrary AFG Microbeam with Two-Phase Nonlocal Stress-Driven Model

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Acta Mechanica Solida Sinica 2024年第2期37卷 341-360页

作者： pei-Liang Bian Zhaowei liu Hai Qing Tiantang Yu Department of Engineering Mechanics Hohai UniversityNanjing211100China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

Scale effects play critical roles in the mechanical responses of *** isogeometric analysis was developed here to investigate the mechanical responses of an axially functionally graded *** Euler–Bernoulli beam model was utilized,and size effects in the structure were modeled with a stress-driven two-phase local/nonlocal integral *** governing equation of microstructures was given in an equivalent differential form with two additional constitutive boundary *** framework was verified and utilized to analyze the microbeam’s static and dynamic mechanical *** present work showed great potential for modeling various types of functionally graded microstructures.

关键词： Isogeometric analysis Size effect Functionally graded material Nonlocal theory Euler-Bernoulli beam

Improvements in energy saving and thermal comfort for electric vehicles in summer through coupled electrochromic and radiative cooling smart windows

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Building Simulation 2024年第8期17卷 1231-1251页

作者： Zhoujie Duan Shuangdui Wu Hongli Sun Borong Lin pei Ding Tao Cui Jeremy To xi Zhang College of Architectureand Environment Sichuan UniversityChengdu610065China Department of Building Science Tsinghua UniversityBejing 100084China KeyLaboratoryofEco Planning&Green Building MinistryofEducationTsinghua UniversityBeijing100084China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China School of EmergencyManagement Xihua UniversityChengdu 610039China Department of PSVD Mercedes-benz Group China Ltd.Beijing 100102China

In hot climates,the large amount of cooling load in electric vehicle(EV)results in a lot of battery energy consumption,leading the decrease of driving *** the widespread application of windows in EV,the electrochromic glass(EC)shows great prospect in lowering the cooling ***,researches on the application of EC in EV lack the consideration of both passive cooling measures and passenger comfort,which limits the further application of *** this paper,we proposed an idea combining the novel techniques of both electrochromism and radiative *** fluid dynamics(CFD)is modeled to simulate the application of electrochromic and radiative cooling coupled smart windows in hot parking conditions,exploring the improvement effect of the window on the thermal environment,comfort and energy saving of the *** results indicate that,under the intense sunlight with an outdoor temperature of 33℃,activating the air conditioning to maintain an average interior temperature of 26℃,the coupled windows reduced the cooling capacity of the air conditioning by 762 W compared to regular windows,which can further increase the range of ***,compared to simple electrochromic fully colored glass,the integration of radiative cooling technology can lower the window surface temperature by up to 10.7℃.Moreover,compared to regular windows,the coupled windows lowered the standard effective temperature(SET*)for passengers by approximately 7℃,significantly improving *** research findings are expected to provide guidance for optimizing window design and enhancing the performance of EV.

关键词： electrochromism radiative cooling smart windowel ectric vehicle cabin thermal comfort energy saving

On electro-acoustic characteristics of a marine broadband sparker for seismic exploration

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Journal of Oceanology and Limnology 2024年第3期42卷 760-771页

作者： Jing LI Kai liu Liancheng ZHANG Chenguang liu Yanliang pei Baohua liu Key Laboratory of Marine Geology and Metallogency First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory of Marine Geology Laoshan LaboratoryQingdao 266237China Key Laboratory of Fluid Transmission Technology of Zhejiang Province Zhejiang Sci-Tech UniversityHangzhou 310018China Key Laboratory of Submarine Acoustic Investigation and Application of Qingdao(Preparatory) Qingdao 266061China Key Laboratory of Deep Sea Mineral Resources Development Shandong(Preparatory)Qingdao 266061China

The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and *** highresolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure,and identify *** optimize the performance of sparker seismic source,we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode *** show that the sound source level increased with the increase of the charging voltage,whereas the main frequency decreased when the charging voltage *** addition,it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level *** the load energy decreased with increasing electrode number,the sound source level still increased but the main frequency ***,the primary to bubble(P/B)ratio increased with the increase of the electrode *** gain a deeper insight into the electro-acoustic characteristics,we investigate the relationship between sound source level and power peak,from which a good correlation was observed.A more practical statistical analysis on the rise rate of current was processed,and a perfect logarithmic function was ***,we found that the main frequency was most possibly subjected to the electrical energy,especially the charging energy per *** results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 *** last,the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 *** study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.

关键词： high-resolution marine seismic exploration sparker seismic source sound source level main frequency electro-acoustic characteristics

Impacts of multi-foulings on salinity gradient energy conversion process in negatively charged conical nanochannels

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Science China(Technological Sciences) 2024年第6期67卷 1714-1726页

作者： MAO RuiJie CHEN xi ZHOU RuHong LONG Rui liu ZhiChun liu Wei School of Energy and Power Engineering Huazhong University of Science and TechnologyWuhan430074China China-EU Institute for Clean and Renewable Energy Huazhong University of Science and TechnologyWuhan430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan430074China

Membrane fouling inevitably occurs during nanofluidic reverse ***,the impact of multi-fouling on the energy conversion performance of negatively charged conical nanochannels under asymmetrical configurations is systematically *** results reveal that in Configuration I,where a high-concentration solution is applied at the tip side,at small concentration ratios,multiple foulings reduce the electric *** Configuration II,where a low-concentration solution is applied at the tip side,multiple foulings near the base side contribute to the electric *** fouling that formed near the lowconcentration entrance diminished the electric power and energy conversion ***-fouling lowered the electrical power consumption by 69.27%and 99.94%in Configurations I and II,*** Configuration I,the electric power first increased with increasing fouling surface charge density,reached its maximum value,and thereafter *** Configuration II,the electric power first decreased with increasing fouling surface charge density,reached its minimum value,and thereafter *** negative or positive charge densities of fouling contribute to the electric power and energy conversion efficiency.

关键词： conical nanochannel fouling nanofluidic reverse electrodialysis salinity gradient energy

Influence of cutterhead opening ratio on soil arching effect and face stability during tunnelling through non-uniform soils

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Underground Space 2024年第4期17卷 45-59页

作者： Xue-Jian Chen pei-pei Fang Qiu-Nan Chen Jun Hu Kai Yao Yong liu State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China Hubei Technology Innovation Center for Smart Hydropower Wuhan 430000China College of Civil Engineering Anhui Jianzhu UniversityHefei 230601China School of Civil Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Civil and Architectural Engineering Hainan UniversityHaikou 570228China School of Qilu Transportation Shandong UniversityJinan 250002China

Tunnelling has increasingly become an essential tool in the exploration of underground space.A typical construction problem is the face instability during tunnelling,posing a great threat to associated *** face instability often occurs with the soil arching *** study investigates the combined effect of cutterhead opening ratio and soil non-uniformity on soil arching effect and face stability,via conducting random finite-element analysis coupled with Monte–Carlo *** results underscore that the face stability is strongly associated with the evolution of stress *** obtained stability factors in the uniform soils can serve as a reference for the design of support pressure in practical tunnelling *** addition,non-uniform soils exhibit a lower stability factor than uniform soils,which implies that the latter likely yields an underestimated probability of face *** tunnel face is found to have a probability of failure more than 50%if the spatial non-uniformity of soil is *** the end,a practical framework is established to determine factor of safety(FOS)corresponding to different levels of probability of face failure considering various opening ratios in non-uniform *** required FOS is 1.70 to limit the probability of face instability no more than 0.1%.Our findings can facilitate the prediction of probability of instability in the conventionally deterministic design of face pressure.

关键词： Tunnel Face stability Soil arching effect Cutterhead opening ratio Non-uniform soil Random field