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Raman probing carbon&aqueous electrolytes interfaces and molecular dynamics simulations towards understanding electrochemical properties under polarization conditions in supercapacitors

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Journal of Energy Chemistry 2021年第9期30卷 279-292页

作者： Rafael Vicentini Leonardo M.Da Silva Débora V.Franco willian g.nunes Juliane Fiates gustavo Doubek Luís F.M.Franco Renato g.Freitas Cristiano Fantini Hudson Zanin Advanced Energy Storage Division Carbon Sci-Tech LabsUniversity of CampinasAv Albert Einstein 400CampinasSP 13083-852Brazil Department of Chemistry Federal University of Jequitinhonha and Mucuri’s ValleyRodovia MGT 367km 5835000Alto da Jacuba39.100-000 DiamantinaMGBrazil Advanced Energy Storage Division Center for Innovation on New EnergiesLaboratory of Advanced BatteriesSchool of Chemical EngineeringUniversity of Campinas(UNICAMP)CampinasSP 13083-852Brazil Department of Chemistry Federal University of Mato GrossoICET-UFMT78060-900 CuiabáMTBrazil Departamento de Física ICExUniversidade Federal de Minas GeraisBelo HorizonteMG 31270-901Brazil

Raman probing of carbon electrode and electrolyte under dynamic conditions is performed here using different aqueous electrolytes to elucidate the fundamental events occurring in electrochemical supercapacitor during charge–discharge processes.The areal capacitance ranges from 1.54 to 2.31μF cm^(-2)μm and it is determined using different techniques.These findings indicate that the Helmholtz capacitance governs the overall charge-storage process instead of the space charge(quantum)capacitance commonly verified for HOPg electrodes in the range of~3 to 7μF cm^(-2).Molecular dynamics simulations are employed to elucidate the origin of the reversible Raman spectral changes during the charge–discharge processes.A correlation is verified between the reversible Raman shift and the surface excesses of the different ionic species.A theoretical framework is presented to relate the effect of the applied potential on the Raman shift and its correlation with the surface ionic charge.It is proposed that the Raman shift is governed by the interaction of solvated cations with graphite promoted by polarization conditions.It is the first time that a comparative study on different aqueous electrolyte p H and cation ion size has been performed tracking the Raman spectra change under dynamic polarization conditions and contrasting with comprehensive electrochemistry and dynamic molecular simulations studies.This study shines lights onto the charge-storage mechanism with evidence of Kohn anomaly reduction in the carbon electrode during the reversible adsorption/desorption and insertion/extraction of ionic species.

关键词： Defect reorganization in graphite Surface excess of charge Operando Raman studies Electrical double-layer capacitors

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Engineering Improved Photosynthesis in the Era of Synthetic Biology

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Plant Communications 2020年第2期1卷 1-17页

作者： willian Batista-Silva Paula da Fonseca-Pereira Auxiliadora Oliveira Martins Agustin Zsogon Adriano nunes-Nesi Wagner L.Araujo Departamento de Biologia Vegetal Universidade Federal de Vic¸osaVic¸osaMinas Gerais 36570-900Brazil

Much attention has been given to the enhancement of photosynthesis as a strategy for the optimization of crop productivity.As traditional plant breeding is most likely reaching a plateau,there is a timely need to accelerate improvements in photosynthetic efficiency by means of novel tools and biotechnological solutions.The emerging field of synthetic biology offers the potential for building completely novel pathways in predictable directions and,thus,addresses the global requirements for higher yields expected to occur in the 21st century.Here,we discuss recent advances and current challenges of engineering improved photosynthesis in the era of synthetic biology toward optimized utilization of solar energy and carbon sources to optimize the production of food,fiber,and fuel.

关键词： photosynthesis synthetic biology genetic engineering yield improvement targeted manipulation

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Characterization of porous cobalt hexacyanoferrate and activated carbon electrodes under dynamic polarization conditions in a sodium-ion pseudocapacitor

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Journal of Energy Chemistry 2021年第3期30卷 53-62页

作者： Bruno Morandi Pires willian goncalves nunes Bruno guilherme Freitas Francisca Elenice Rodrigues Oliveira Vera Katic Cristiane Barbieri Rodella Leonardo Morais Da Silva Hudson Zanin Advanced Energy Storage Division Manufacturing CroupCarbon Sci-Tech LabsCenter for Innovation on New EnergiesUniversity of CampinasCampinas 13083-852SPBrazil Brazilian Synchrotron Light Laboratory(LNLS/Brazilian Center of Energy and Materiab(CNPEM)) Campinas 13083-970SPBrazil Department of Chemistry Laboratory of Fundamental and Applied ElectrochemistryFederal University of Jequitinhonha and Mucuri's VatleyAlto dajacuba 39100-000Diamantina-MGBrazil

We report here the activated carbon and cobalt hexacyanoferrate composite,which is applied as the electrode materials in symmetric supercapacitors containing a 1.0 M Na_(2)SO_(4) aqueous electrolyte.This novel material combines high specific surface area and electrochemical stability of activated carbon with the redox properties of cobalt hexacyanoferrate,resulting in maximum specific capacitance of 329 F g^(-1) with large voltage working window of 2.0 V.Electrochemical studies indicated that cobalt hexacyanoferrate introduces important pseudocapacitive properties accounting for the overall charge-storage process,especially when Ig^(-1).At lower gravimetric currents(e.g.,0.05 A g^(-1))and up to 1.0 V,the presence of cobalt hexacyanoferrate improves the specific energy for more than 300%.In addition,to better understanding the energy storage process we also provided a careful investigation of the electrode materials under dynamic polarization conditions using the in situ Raman spectroscopy and synchrotron light Xray diffraction techniques.Interesting complementary findings were obtained in these studies.We believe that this novel electrode material is promising for applications regarding the energy-storage process in pseudocapacitors with long lifespan properties.

关键词： Operando studies Raman XRD synchrotron light Cobalt hexacyanoferrate Activated carbon High specific capacitance

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Fractai Estimation of Joint Roughness Coefficients

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Science China Chemistry 1994年第12期37卷 1516-1524页

作者：谢和平 willian g.Pariseau China University of Mining and Technology Xuzhou 221008PRC Department of Mining Engineering University of UtahSalt Lake CityUtah 84112USA

Based on the triadic Koch curve,a generalized fractal model of joint profiles is establishedto simulate joint roughness.The fractal dimension of a joint profile can be directly obtained from the two pa-rameters,L~* and h~*, the average base length and average height of asperities of the joint,respectively,i,e D=log4/log[2(1+cos tan^1(2h’/L’))]This fractal dimension is strongly correlated with the value of the joint roughness coefficient (JRC). An empirical relationship is found in the form,JRC=85.2671·(D-1)~0.5679 Thus, the fractal analysis proposed provides a new method of estimating JRC

关键词： rock joint fractal dimension JRC Values fractal estimation

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Hospital Admissions and Mortality in Patients with Rheumatic Heart Disease in Brazil: An Analysis from 2008 to 2018

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Advances in Infectious Diseases 2020年第3期10卷 176-180页

作者： Mariana Silva nunes gustavo Tedde-Filho João Carlos geber-Júnior willian Darwin Júnior Viviane Uliane Peterle Ana Paula Monteiro gomides Academic of Centro Universitário de Brasília Brasília Brazil Medical Clinic Department of Universidade de Sã o Paulo S&#227 o Paulo Brazil Universidade de Sã o Paulo S&#227 o Paulo Brazil Centro Universitário de Brasília Brasília Brazil

Introduction: The Rheumatic Fever (RF) is a systemic inflammatory disease, caused by group A beta-hemolytic Streptococcus, predominating in children and adolescents. The clinical manifestations are varied and included... 详细信息

g>Introduction:g> The Rheumatic Fever (RF) is a systemic inflammatory disease, caused by group A beta-hemolytic Streptococcus, predominating in children and adolescents. The clinical manifestations are varied and included in Jones Criteria for diagnosis. The cardiac manifestations are the most relevant, causing severe sequelae such as valvulitis. The RF is still a major public health problem in developing countries despite its primary prophylaxis being simple and effective if well applied. The overall objective of this study was to evaluate the number of hospital admissions and deaths in Brazil from 2008 to 2018. g>Methodology:g> Cross-sectional, descriptive, quantitative, documentary study with database provided by the Health Informatics Department of the Brazilian Ministry of Health (DATASUS).g> Results:g> In the studied period, a higher prevalence was observed among females (48,232 hospitalizations) and in the adult age group (59,270 hospitalizations and 3972 deaths). The total number of hospitalizations was 83,209 and the total number of deaths was 6572. The total mortality rate was 7.84. The region with the highest number of hospitalizations was the Southeast (22,863 hospitalizations). The total amount spent in hospitalizations was R$879,676,458.63, with an average value per hospitalization of R$ 10,496.21. The average length of stay was 12.7 days. g>Conclusion: g>Rheumatic heart disease is an important cause of hospitalizations in Brazil. Measures of early diagnosis and adequate treatment should be strongly stimulated.

关键词： Rheumatic Heart Disease Hospitalizations Number of Deaths

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Optimization of the Electrospinning Conditions by Box-Behnken Design to Prepare Poly(Vinyl Alcohol)/Chitosan Crosslinked Nanofibers

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Journal of Materials Science and Chemical Engineering 2020年第4期8卷 13-31页

作者： Vinícius R. Viana willian H. Ferreira Edwin g. Azero Marcos L. Dias Cristina T. Andrade Instituto de Macromoléculas Professora Eloisa Mano Universidade Federal do Rio de Janeiro Centro de Tecnologia Bloco J Rio de Janeiro Brazil Departmento de Ciências Naturais Universidade Federal do Estado do Rio de Janeiro Avenida Pasteur Rio de Janeiro Brazil

Electrospun poly(vinyl alcohol)/chitosan nanofibers had their solution and process parameters optimized using a Box-Behnken design and desirability function. Four factors (applied voltage, flow rate, distance tip-to-plate and amount of chitosan) were varied to produce electrospun mats with a low fiber diameter. An empirical model was developed for each response using response surface methodology (RSM), which revealed that flow rate had no significant influence on the assessed responses. With desirability function, the optimal conditions to produce the nanofibers were applied voltage of 13.1 kV, 30% chitosan concentration and distance tip-to-plate of 10 cm. The fiber diameter and standard deviation were 196.5 ± 28.3 nm, compared to the predicted values of 185.9 ± 26.8 nm. The desirability function allied with Box-Benhken design proved themselves important tools to predict process parameters for the development of nanofibers. The mats were crosslinked with glutaraldehyde for 24 h and 48 h and presented good water stability and enhanced mechanical properties.

关键词： Electrospinning Poly(Vinyl Alcohol) Chitosan Box-Behnken Design

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在佩斯梅克运载系统发射的宇宙飞行器上进行的碳-酚醛飞行试验

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导弹与航天运载技术 1980年第2期 66-82页

作者： Thomas E.Walton Jr willian g. Witte 徐雪英

由50％碳纤维和50％酚醛树脂组成的碳-酚醛材料,在由佩斯梅克（PacemaKer）运载系统发射的可回收的宇宙飞行器上进行了飞行试验。制作的宇宙飞行器防热层,其烧蚀材料中的碳纤维在飞行器的各部位具有不同的排列方向。宇宙飞行器的试验环... 详细信息

由50％碳纤维和50％酚醛树脂组成的碳-酚醛材料,在由佩斯梅克（PacemaKer）运载系统发射的可回收的宇宙飞行器上进行了飞行试验。制作的宇宙飞行器防热层,其烧蚀材料中的碳纤维在飞行器的各部位具有不同的排列方向。宇宙飞行器的试验环境所产生的热流在半球鼻锥处达13.6兆瓦/米;（1200英热单位/英尺;-秒）,驻点压力达1.27兆牛顿/米;（12.5大气压）。实验结果表明:由于高热流、剥裂的可能及炭的机械剥蚀,在鼻锥区可产生最大质量损失。在宇宙飞行器的锥部可观察到基本均匀的表面后退和炭层厚度。测量的热流率与计算的紊流和层流热流率的比较,以及用声传感器对边界层声压脉动的测量,可显示出边界层产生了转捩。声传感器为自由飞行研究中对边界层转捩的一般性研究提供了新的有趣的数据形式。

关键词：宇宙飞行器半球酚醛材料热层热流率声传感器运载系统量热计卡计飞行试验试飞梅克佩斯

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节理粗糙度系数的分形估算

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地质科学译丛 1992年第1期9卷 85-90页

作者：谢和平 willian g.Pariseau 王建锋王仁铎中国矿业大学 University of Utah. 315 WBB SaltLake City Utah 84112

节量剖面粗糙度可以被认为是具有有限生长的分形结构。为了模拟节理粗糙度，基于传统的科契曲线，本文建立了节理剖面的广义分形模型。根据节理凸起体的平均基底长度L^*和平均高度h^*两参数，可直接得到节理剖面的分维数，即：D=log4/lo... 详细信息

节量剖面粗糙度可以被认为是具有有限生长的分形结构。为了模拟节理粗糙度，基于传统的科契曲线，本文建立了节理剖面的广义分形模型。根据节理凸起体的平均基底长度L^*和平均高度h^*两参数，可直接得到节理剖面的分维数，即：D=log4/log[2(1+cos tan^-1(2h/L)]，此分维数D与节理粗糙度系数具有密切关系。其经验关系是：JRC＝85．2671（D－1）^0.5679。因此，可以说本文所提出的分形分析技术为估算JRC值提供了一种新的方法。

关键词：节理粗糙度系数分形结构岩石力学抗剪强度

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Prevalence of giardia duodenalis among dogs seized by the Center for Control of Zoonoses (CCZ) of the city of Lages, Santa Catarina, Brazil

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Health 2013年第1期5卷 119-124页

作者： Rosileia Marinho Quadros Paulo Henrique Exterckotter Weiss geison willian Ezequiel Renato Batista Tamanho geanice Lepo Marcio Rodrigues da Silva Carlos Roberto Joao da Silva Junior Flavio Antonio Pacheco de Araujo Luiz Claudio Miletti Universidade do Estado de Santa Catarina LagesBrazil

The knowledge of the epidemiology of parasitic infections in stray and domestic animals, especially of its incidence and prevalence, is fundamental to adopting effective prophylactic measures. Stray dogs play an important role in environmental contamination favoring the transmission cycle of zoonotic agents. Among the parasitic infections that affect humans, giardia duodenalis is the most common intestinal protozoa and was designated as a re-emerging infectious disease. This study aimed to determine the prevalence of g. duodenalis in dogs siezed by the Center for Control of Zoonoses (CCZ) of the city of Lages, Santa Catarina, Brazil using two diagnostic techniques. In 357 stool samples analysed, the prevalence of g. duodenalis cysts was 5.3% (19/357) and 4.8% (17/357) detected by floatation and sedimentation techniques, respecttively. No correspondence between gender and age was found among the methods used for analyzing the infected dogs in this study. Our data suggested that two diagnostic techniques should be used in a complementary way to ensure that false negatives are not neglected.

关键词： giardia Duodenalis Dogs Zoonoses Brazil

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willian Beardmore有限公司的真空除气法

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重型机械 1964年第24期 25-26页

作者： A.g.姆克米兰雨云

Beardmore的钢液除气试验是在1955年开始的,1957年建造了一个真空处理车间。真空室直径为3.0 5米,高为4.57米,适合于放一个能浇铸直径为1323毫米、重量为22吨的钢锭的模子,但试验时,大多数都是直径为813毫米、重量为10吨的钢锭。盛钢桶... 详细信息

Beardmore的钢液除气试验是在1955年开始的,1957年建造了一个真空处理车间。真空室直径为3.0 5米,高为4.57米,适合于放一个能浇铸直径为1323毫米、重量为22吨的钢锭的模子,但试验时,大多数都是直径为813毫米、重量为10吨的钢锭。盛钢桶放在真空室的顶部,铝密封装置与限制飞溅的漏斗安在真空室的盖子上。

关键词：真空除气真空室真空处理低压室毫米汞柱 willian Beardmore 铜桶

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