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Oxygen vacancy engineering for tuning the catalytic activity of LaCoO_(3) perovskite

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Journal of Rare Earths 2024年第3期42卷 506-514,I0003页

作者： Jeong Hyun Cho Minjae Kim Inchan Yang Kyung Tae Park Chang Houn Rhee Hai Woong Park Ji Chul Jung Department of Chemical Engineering Myongji UniversityYongin 17058Republic of Korea Institute of Advanced Composite Materials Korea Institute of Science and TechnologyWanju-gunJeollabuk-do 55324Republic of Korea Iron&Steel Process Engineering research Group POSCOPohang 37859Republic of Korea Hydrogen research center Research Institute of Industrial Science&Technology(RIST)Pohang 37673Republic of Korea

Herein, we attempted to engineer oxygen vacancies on the surface of LaCoO_(3) perovskite through simple post-treatments(acid or reductive thermal treatments). Acid treatment induces oxygen vacancies through the selective etching of the La cations, whereas thermal treatment in a reducing atmosphere generates oxygen vacancies by directly removing lattice oxygen. The characterization results confirm that the number of surface oxygen vacancies, which are crucial in various catalytic oxidation reactions,considerably increases in the LaCoO_(3) catalysts treated with acid or reducing gas. Acid treatment enriches the oxygen vacancies while maintaining the structure of the LaCoO_(3) catalysts, which can not be achieved through reductive thermal treatment. Therefore, the acid treatment is considered a promising technique for oxygen vacancy engineering of perovskite catalysts for tuning their catalytic activities. Furthermore,the catalytic activities of the posttreated LaCoO_(3) catalysts for CO oxidation were evaluated and are noted to be considerably better than those of the pristine LaCoO_(3) catalyst due to their abundant oxygen vacancies. Consequently, we conclude that the oxygen vacancies of perovskite catalysts can be effectively engineered via two simple methods and play a significant role in CO oxidation.

关键词： LaCoO_(3)perovskite Acid treatment Reductive thermal treatment Oxygen vacancy CO oxidation Rare earths

Combining permissioned blockchain and Bayesian best-worst method for transparent supplier selection in supply chain management

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Science China(Technological Sciences) 2024年第8期67卷 2579-2593页

作者： LIU JiaJun ZHANG Jie LENG JieWu Shanghai Engineering research center of industrial Big Data and Intelligent System Institute of Artificial IntelligenceDonghua UniversityShanghai 201620China State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China

Supplier selection is an important business activity in order to realize the purchasing function in supply chain *** supplier selection process includes four stages,i.e.,bidding inviting,bidding,group decision-making,and results disclosure,involving the participation of manufacturing service demanders(MSDs),manufacturing service suppliers(MSSs),and ***,all the participants have raised concerns about the increased transparency in supplier ***,this study proposes a transparent supplier selection method by considering the engagement of *** this method,the Bayesian best-worst method(Bayesian BWM)is used to aggregate decision-makers'preferences into the overall optimal weights of the alternative MSSs,and the MSS with the largest weight is considered the suitable MSS for ***,blockchain is introduced to record the decision-making process information about supplier selection through a customized smart contract,where MSSs act as supervisors to supervise the decision-making process through the distributed consensus mechanism rather than directly participate in the decision-making ***,a case study of supplier selection in purchasing vibration acceleration sensors is *** result shows that the proposed method can support MSDs in selecting suitable MSS from alternative MSSs by aggregating decision-makers'preferences,and blockchain can provide credible information about the supplier selection process for MSSs,MSDs,and *** this way,the transparency of supplier selection is enhanced.

关键词： blockchain supplier selection supply chain transparency Bayesian BWM group decision-making

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Regulating metal-acid double site balance on mesoporous SiO2-Al2O3 composite oxide for supercritical n-decane cracking

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Petroleum Science 2024年第4期21卷 2881-2891页

作者： Liu-Ling Chen Jun Zhang Chun-Guang Li Li-Qun Fei Bo Wang Chen-Qi Zhang Yi Jiao Jian-Li Wang Institute of New Energy and Low-Carbon Technology Sichuan University Engineering research center of Combustion and Cooling for Aerospace Power Ministry of Education School of Chemical Engineering Sichuan University State Key Laboratory of industrial Vent Gas Reuse Southwest Institute of Chemical Co. Ltd Science and Technology on Scramjet Laboratory Beijing Power Machinery Research Institute

The balance between metal and acid sites directly affects the preparation of high-performance cracking catalysts with high heat sink and low ***,how to control acid-metal sites balance and its relationship with cracking performance are reported *** this work,a series of Pt/Al2O3-SiO2dual sites catalysts with different metal to acid active sites ratio(CM/CSA) were constructed by ethanolassisted impregnation method and the impact on n-decane cracking under supercritical conditions was systematically and deeply *** results showed that the conversion and carbon deposition increased gradually with varied CM/CSAand reached the balance at CM/CSAof *** proper ratio CM/CSA（0.13） can balance the deep dehydrogenation coking over metal active sites and high heat sink of cracking over acid active sites,the chemical heat sink reaches amazing 1.75 MJ/kg and carbon deposition is only22.03 mg/cm2at 750℃.Meanwhile,the few metal sites at low CM/CSAand the few strong acid sites at high CM/CSAare the main factors limiting the cracking *** CM/CSAlimit the activation of C-H bond and deep dehydrogenation of coking precursor,resulting in relative low cracking activity and carbon deposition,while high CM/CSAlimit the activation of C-C bond and increase the deep *** this contribution,design and construction of metal-acid dual sites can not only provide the technical solution for the preparation of high heat sink and low coking cracking catalyst,but also deepen the understanding of the cracking path of hydrocarbon fuel.

关键词： Metal-acid dual sites balance Catalytic cracking Hydrocarbon fuels Chemical heat sink Carbon deposition

Design and Verification of Parallel Hip Exoskeleton Considering Output Torque Anisotropy

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Journal of Bionic Engineering 2024年第3期21卷 1305-1320页

作者： Jilong Xu Yunzhan Niu Fucai Liu Engineering research center of the Ministry of Education for Intelligent Control System and Intelligent Equipment Yanshan UniversityQinhuangdao066004China Key Laboratory of industrial Computer Control Engineering of Heibei Province Yanshan UniversityQinhuangdao066004China College of Mechanical Engineering Yanshan UniversityQinhuangdao066004China

In rehabilitation training,it is crucial to consider the compatibility between exoskeletons and human legs in ***,most exoskeletons today adopt an anthropomorphic serial structure,which results in rotational centers that are not precisely aligned with the center of the hip *** address this issue,we introduce a novel exoskeleton called the Parallel Hip Exoskeleton(PH-Exo)in this ***-Exo is meticulously designed based on the anisotropic law of output *** the friction of the drive components,a dynamic model of the human-machine complex is *** analysis demonstrates that PH-Exo not only exhibits outstanding torque performance but also achieves high controllability in both flexion/extension and adduction/abduction ***,a robust controller is designed to address model uncertainty,friction,and external *** experiments indicate that under the control of the robust controller,each motor achieves excellent tracking performance.

关键词： Hip exoskeleton Parallel mechanism Misalignment Anisotropy Output torque

Deep decalcification of factory-provided freezing acidolysis solution to achieveα-high-strength gypsum

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Chinese Journal of Chemical Engineering 2024年第5期69卷 143-151页

作者： Wencai Ye Yulu Li Yonggang Dong Lin Yang Yun Yi Jianxin Cao School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025China Engineering research center of Efficient Utilization for industrial Waste Guizhou UniversityGuiyang 550025China Key Laboratory of Guizhou Province for Green Chemical Industry and Clean Energy Technology Guizhou UniversityGuiyang 550025China

The freezing acidolysis solution of the nitric acid-phosphate fertilizer process has a high calcium content,which makes it difficult to produce fine phosphate and high water-soluble phosphate fertilizer ***,based on the potential crystallization principle of calcium sulfate in NH_(4)NO_(3)-H_(3)PO_(4)-H_(2)O,the deep decalcification(*** removal)technology to achieveα-high-strength gypsum originated from freezing acidolysis-solutions has been firstly proposed and ***,calcium can be removed from the factory-provided freezing acidolysis-solution by neutralizing it with ammonia,followed by the addition of ammonium sulfate *** a result,the formation of calcium sulfate in the reaction system undergoes the nucleation and growth of CaSO_(4)·2H_(2)O(DH),as well as its dissolution and crystallization into short columnarα-CaSO_(4)·0.5H_(2)O(α-HH).Remarkably,with the molar ratio of SO_(4)^(2-)/Ca^(2+)at 1.8,the degree of neutralization(NH_(3)/HNO_(3) molar ratio)at 1.7,the reaction temperature of 94℃,and the reaction time of 300 min,the decalcification rate can reach 86.89%,of which the high-strengthα-CaSO_(4)·0.5H_(2)O(α-HH)will be ***,the deep decalcification product meets the standards for the production of fine phosphates and highly water-soluble phosphate ***,the 2 h flexural strength ofα-HH is 5.3 MPa and the dry compressive strength is 36.8 MPa,which is up to the standard of commercialα-HH.

关键词： Nitrophosphate Ammonia neutralization Deep decalcification High-strengthα-hemihydrate gypsum Controlled crystallization at atmospheric pressure

Influence of Formulation and Hot-Pressing Conditions on the Performance of Bio-Based Molasses Adhesive for Plywood

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Journal of Renewable Materials 2024年第8期12卷 1383-1397页

作者： Jajang Sutiawan Alifah Syahfitri Sukma Surya Kusumah Dede Hermawan Rita Kartika Sari Luthfi Hakim Efri Mardawati Muhammad Adly Rahandi Lubis research center for Biomass and Bioproducts National Research and Innovation AgencyCibinong16911Indonesia Forest Product Department Faculty of Forestry and EnvironmentIPB UniversityBogor16680Indonesia Department of Forest Products Faculty of ForestryUniversitas Sumatera UtaraMedan20155Indonesia research Collaboration center for Biomass and Biorefinery BRIN and Universitas PadjadjaranBandung40600Indonesia Department of Agro-industrial Technology Universitas PadjadjaranBandung40600Indonesia

Molasses can serve as a natural adhesive for plywood and ***,several disadvantages remain,including lower dimensional stability and low bonding strength compared to other ***,modifications are needed to use molasses as an adhesive for *** research aims to improve bio-based molasses(MO)adhesive for plywood using citric acid(CA)*** addition,this research aims to analyze the effect of adding citric acid and to investigate the optimum hot-pressing temperature to produce the best quality *** the first stage,the molasses and citric acid were combined in a ratio of 100:0,75:25,50:50,25:75,0:100 w/w%.Then,the second stage focuses on analyzing the influences of pressing temperature based on an optimum first *** research demonstrated that the addition of CA altered the gelation time,solid content,viscosity,and pH of the molasses *** addition,the thermal properties of molasses adhesives were changed after mixing with citric *** phenomena indicate changes in characteristics,such as the curing of ***,the characteristics of plywood showed a steady improvement as the CA ratio increased but revealed a significant decline for the 25:75 MO-CA *** raising the pressing temperature from 180°C to 200°C,the quality of plywood was effectively *** plywood that was bonded using adhesives with a 50:50 MO-CA ratio exhibited superior mechanical properties and improved dimensional stability compared to the plywood bonded solely with ***,the optimal mechanical and physical properties resulted in plywood bonded with a 50:50 MO-CA ratio when subjected to a pressing temperature of 200°*** Thermal and FTIR measurements revealed that CA established ester bonds with both the MO and wood *** conclusion,the mechanical characteristics of plywood were improved,while maintaining its excellent dimensional stability.

关键词： Citric acid composite molasses pressing temperature plywood

Prevalence and intensity of urinary schistosomiasis and soil-transmitted helminths among women of reproductive age in Mwaluphamba,Kwale

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Asian Pacific Journal of Tropical Medicine 2024年第2期17卷 71-83页

作者： Samuel M.Ngui Joseph M.Mwangangi Joachim Richter Josephine W.Ngunjiri Department of Biological Sciences University of EmbuKenya Medical Entomology Kenya Medical Research Institute(KEMRI)Center for Geographic Medicine Research Coast KilifiKenya Institute of International Health Global Health CenterCharitéUniversity MedicineBerlinCorporate Member of Free University and Humboldt University and Berlin Institute of HealthBerlinGermany Swiss Tropical and Public Health Institute BaselSwitzerland Tropical and Infectious Diseases Department of Biological sciencesUniversity of EmbuKenya

Objective:To assess the epidemiology of urinary schistosomiasis and soil-transmitted helminthiasis among women of reproductive age in Mwaluphamba,Kwale County,***:A community-based cross-sectional study design was employed to randomly sample 422 women of reproductive age(15-<50 years)from four villages in Mwaluphamba *** specimens were collected and examined using the Kato-Katz method,while filtration technique was used to analyze urine ***’sociodemographic details were obtained using a standardized ***:Urinary schistosomiasis prevalence was at 4.7%(20/422,95%CI 2.8%-6.9%)while the prevalence of soil-transmitted helminthiasis infection was 4.5%(19/422,95%CI 2.6%-6.7%).The infection intensities of urinary schistosomiasis among the study participants ranged from 1 to 120 eggs/10 mL of urine with median egg count of 18.45 eggs/10 *** patients were diagnosed with light infection,of 56.16 egg/gram and 48.48 egg/gram for Trichuris trichiura and hookworms,*** without latrines had 15.7 times higher risk of having urinary schistosomiasis compared to those with a ***,use of surface water(aOR=1.0,95%CI 0.2-1.4,P=0.010)and crossing the river to go to a place(aOR=1.1,95%CI 0.3-1.6,P=0.009)were statistically significant risk factors for getting urinary *** bivariable regression analysis,defecating around the water source(OR=4.3,95%CI 1.5-12.9)had a statistically significant association with the prevalence of soil-transmitted helminthiasis(P=0.008).Conclusions:This study has given an insight on the prevalence and intensity of urinary schistosomiasis and soil-transmitted helminthiasis in Mwaluphamba location that form a basis for strengthening the control and elimination programmes for these neglected tropical diseases.

关键词： Urinary schistosomiasis Prevalence Soiltransmitted helminths Mwaluphamba

通过共晶策略整合双光响应分子:光显著效应、负光致变色和荧光增强

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Science China Materials 2024年第1期67卷 223-231页

作者：叶阳戚路广孙莹胡兴晨轩辕书天郝红勋谢闯 School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China National Engineering research center of industrial Crystallization Technology Tianjin 300072China

将多个响应分子整合到单晶体中是光机械晶体材料领域的一次全新尝试.本工作通过共晶制备了首个包含两种光响应分子的光机械晶体(9AC-NPE),每种分子都对应其独特的需要满足拓扑堆积条件的光二聚反应.紫外光照射下成功激发了晶体中的两种... 详细信息

将多个响应分子整合到单晶体中是光机械晶体材料领域的一次全新尝试.本工作通过共晶制备了首个包含两种光响应分子的光机械晶体(9AC-NPE),每种分子都对应其独特的需要满足拓扑堆积条件的光二聚反应.紫外光照射下成功激发了晶体中的两种光二聚反应,同时表现出光显著效应、负光致变色和多发射峰的荧光增强.本文还将该共晶作为一个研究平台,比较和发现了两种光二聚反应在光反应速率和响应波长上的差异,这为制备具有复杂光机械行为的晶体材料提供了潜在的解决方案.此外,还发展了该共晶在光学打印中的概念设计.本工作加深了对光机械晶体材料设计和应用的理解,可作为该领域未来研究的重要参考.

关键词：晶体材料光致变色荧光增强 NPE 紫外光照射光响应策略整合反应速率

Two-stage dynamic recrystallization and texture evolution in Al-7Mg alloy during hot torsion

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1900-1911页

作者： Kwang Tae Son Chang Hee Cho Myoung Gyun Kim Ji Woon Lee School of Mechanical Industrialand Manufacturing EngineeringOregon State UniversityCorvallis OR 97331USA Department of Materials Science Engineering Northwestern UniversityEvanston IL 60208USA research Institute of industrial Science and Technology(RIST) Pohang 37673Rep.of Korea Division of Advanced Materials Engineering Kongju National UniversityCheonan 31080Rep.of Korea center for Advanced Materials and Parts of Powders Kongju National UniversityCheonan 31080Rep.of Korea

Hot torsion tests were performed on the Al-7Mg alloy at the temperature ranging from 300 to 500℃ and strain rates between 0.05 and 5 s^(-1) to explore the progressive dynamic recrystallization(DRX)and texture *** DRX behavior of the alloy manifested two distinct stages:Stage 1 at strain of≤2 and Stage 2 at strains of≥*** Stage 1,there was a slight increase in the DRXed grain fraction(X_(DRX))with predominance of discontinuous DRX(DDRX),followed by a modest change in X_(DRX) until the transition to Stage *** 2 was marked by an accelerated rate of DRX,culminating in a substantial final X_(DRX) of~*** backscattered diffraction(EBSD)analysis on a sample in Stage 2 revealed that continuous DRX(CDRX)predominantly occurred within the(121)[001]grains,whereas the(111)[110]grains underwent a geometric DRX(GDRX)evolution without a noticeable sub-grain ***,a modified Avrami’s DRX kinetics model was utilized to predict the microstructural refinement in the Al-7Mg alloy during the DRX *** this kinetics model did not accurately capture the DDRX behavior in Stage 1,it effectively simulated the DRX rate in Stage *** texture index was employed to assess the evolution of the texture isotropy during hot-torsion test,demonstrating significant improvement(>75%)in texture randomness before the commencement of Stage *** initial texture evolution is attributed to the rotation of parent grains and the substructure evolution,rather than to an increase in X_(DRX).

关键词： Al-7Mg alloys hot deformation hot torsion tests dynamic recrystazlliation microstructure texture