检索结果-南通市图书馆

Promotion effect of niobium on ceria catalyst for selective catalytic reduction of NO with NH3

Journal of Rare Earths 2022年第10期40卷 1535-1545页

作者： Bolin Zhang Lifeng Deng Michael Liebau Yingjie Ren Chunyun Luo Bo Liu Shengen Zhang roger Glaser Institute for Advanced Materials and Technology University of Science and Technology BeijingBejing 100083China Shunde Graduate School University of Science and Technology BeijingFoshan 528399China Jiangsu Longkingcotech Co. Ltd.Yancheng224000China Institute of Chemical Technology Universit at LeipzigLeipzig04103Germany

The CeO_(2),Ce-Nb-O_(x) and Nb_(2)O_(5) catalysts were synthesized by citric acid method and the promotion effect of Nb on ceria for selective catalytic reduction(SCR)of NO with NH_(3) was *** catalytic activity measurements indicate that the mixed oxide Ce-Nb-O_(x) presents a higher SCR activity than the single oxide CeO_(2) or Nb_(2)O_(5) *** addition,the Ce-Nb-O_(x) catalyst shows high resistance towards H_(2)O and SO_(2) at 280℃.The Raman,X-ray photoelectron spectra and temperature programmed reduction with H_(2) results indicate that the incorporation of Nb provides abundant oxygen vacancies for capturing more surface adsorbed oxygen,which provides a superior redox capability and accelerates the renewal of active ***,the Fourier transform infrared spectra and temperature programmed desorption of NH_(3) results suggest that niobium pentoxide shows high surface acidity,which is partly retained in the Ce-Nb-O_(x) catalyst possessing a high content of Lewis and Br?nsted acid ***,the incorporation of Nb improves both the redox and acidic capacities of Ce-Nb-O_(x) catalyst for the SCR ***,the redox behavior is primarily taken on Ce and the acidity is well improved by Nb,so the synergistic effect should exist between Ce and *** terms of the reaction mechanism,in situ DRIFT experiments suggest that both NH_(3) on Lewis acid sites and NH_(4)^(+) on Bronsted acid sites can react with NO species,and adsorbed NO and NO_(2) species can both be reduced by NH_(3).In the SCR process,O_(2) primarily acts as the accelerant to improve the redox and acid cycles and plays an important *** work proves that the combination of redox and acidic properties of different constituents can be feasible for catalyst design to obtain a superior SCR performance.

关键词： Cerium-niobium Selective catalytic reduction Redox behavior Acid cycle Synergistic effect Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Decision support for the development,simulation and optimization of dynamic process models

引用

Frontiers of Chemical Science and Engineering 2022年第2期16卷 210-220页

作者： Norbert Asprion roger Böttcher Jan Schwientek Johannes Höller Patrick Schwartz Charlie Vanaret Michael Bortz BASF SE 67063 LudwigshafenGermany Fraunhofer ITWM 67663 KaiserslauternGermany

Simulation is besides experimentation the major method for designing,analyzing and optimizing chemical *** ability of simulations to reflect real process behavior strongly depends on model *** and adaption of process models are usually based on available plant *** such a model in various simulation and optimization studies can support the process designer in his *** steady state models there is also a growing demand for dynamic models either to adapt faster to changing conditions or to reflect batch *** this contribution challenges of extending an existing decision support framework for steady state models to dynamic models will be discussed and the resulting opportunities will be demonstrated for distillation and reactor examples.

关键词： decision support multicriteria optimization model validation dynamic model sensitivity analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Low Birth Weight in Cameroon: Research and Analysis of Factors Associated with Their Occurrence in Douala Maternity Wards

引用

Open Journal of Obstetrics and Gynecology 2024年第5期14卷 758-778页

作者： Henri Essome Merlin Boten Bounyom Astrid Ndolo Kondo Ingrid Doriane Ofakem Ilick Charlotte Epossè Ekoube Rita Bono Betoko Hassanatou Iyawa Fulbert Mangala Nkwele Théophile Nana Njamen Robert Tchounzou Alphonse Ngalame Nyong Charlotte Irène Cyrielle Edjoa Mboe Moustapha Bilkissou Junie Ngaha Yaneu Marga Vanina Ngono Akam Gervais Mounchikpou Ngouhouo Grâce Tocki Toutou Michel roger Ekono Nelly Noubi Pascal Foumane Training Teaching and Research Unit in Gynecology Obstetrics and Reproduction Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Laquintinie Hospital Douala Cameroon Faculty of Health Sciences University of Bamenda Bamenda Cameroon Faculty of Health Sciences University of Buea Buea Cameroon Faculty of Medicine and Biomedical Sciences University of Yaound&#233 1 Yaound&#233 Cameroon Faculty of Medicine and Pharmaceutical Sciences University of Ebolowa Ebolowa Cameroon

Introduction: Low birth weight (LBW) is defined by the World Health Organization (WHO) as a birth weight strictly below 2500 g, whatever the term of pregnancy. It constitutes a major public health problem, both in developed and developing countries, due to its magnitude and its strong association with infant morbidity and mortality. Main objective was to study the factors associated with the occurrence of small-for-gestational-age newborns in Douala. Methodology: We carried out a cross-sectional analytical study with prospective data collection using a technical pretested sheet in the maternity wards of the Douala General Hospital, the Laquintinie Hospital, and the District hospitals of Deido, Nylon and Bonassama over a period of 4 months (January to April 2020). We were interested in any newborn, born alive, vaginally or by cesarean section, of low weight, seen in the first 24 hours from a full-term single-fetal pregnancy whose mother had given her consent. Our sampling was consecutive and non-exhaustive. We excluded newborns whose term was unclear and those with congenital malformations or signs of embryo-foetopathy. Data collection was done using survey sheets. Statistical analyzes were carried out with CS Pro 7.3 and SPSS version 25.0 software. The Student, Chi-square and Fischer tests were used to compare the means of the variables, the percentages with a significance threshold P value Results: During the study period, 305 full-term newborns were included, divided into 172 boys and 133 girls. The percentage of small-for-gestational-age newborns was 9.8%;after multivariate analysis by logistic regression to eliminate confounding factors, we found maternal factors associated with small for gestational age newborns;maternal age less than 20 years, primiparity, gestational age (37 - 38), a delay in prenatal visits greater than 14 weeks, anemia in pregnancy, positive toxoplasmosis serology in pregnancy, a body mass index of Conclusion: Our study revealed the potenti

关键词： Newborn Low Birth Weight Gestational Age Douala

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Draft of an Anthropometric Reference System for Full-Term Cameroonian Newborns: Prospective Study with Analytical Aim in the Maternity Wards of Douala

引用

Open Journal of Obstetrics and Gynecology 2024年第3期14卷 435-450页

作者： Henri Essome Charlotte Epossè Ekoube Fulbert Mangala Nkwele Rita Carole Mbono Betoko Irène Cyrielle Edjoa Mboe Michel roger Ekono Alphonse Ngalame Nyong Robert Tchounzou Ingrid Doriane Ofakem Ilick Hassanatou Iyawa Moustapha Bilkissou Astrid Ndolo Kondo Junie Ngaha Yaneu Marga Vanina Ngono Akam Gervais Mounchikpou Ngouhouo Grâce Tocki Toutou Nelly Noubi Valère Mve Koh Théophile Nana Njamen Training Teaching and Research Unit in Gynecology Obstetrics and Reproduction Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Department of Obstetrics and Gynecology Laquintinie Hospital Douala Cameroon Department of Pediatrics Laquintinie Hospital Douala Cameroon Faculty of Health Sciences of Buea University of Buea Buea Cameroon Pluridisciplinary Department Laquintinie Hospital Douala Cameroon Faculty of Medicine and Biomedical Sciences University of Yaounde 1 Yaounde Cameroon

Introduction: Anthropometry applied to newborns is a reliable indicator of the quality of fetal growth. The latter is influenced by genetic, racial and nutritional factors varying from one population to another, explaining why a standard cannot be applied to all populations. Research question: should the Caucasian frame of reference be dogmatically applied in our African context? Multicenter studies are therefore necessary;hence the interest of this work, the main objective of which was to describe the anthropometric profile of full-term newborns in the city of Douala. Methodology: We carried out a cross-sectional study with an analytical aim and prospective data collection in the maternity wards of the Douala General Hospital, Laquintinie Hospital, District hospitals of Deido, Nylon and Bonassama over a period of 4 months (January to April 2020). We were interested in any newborn, born alive, vaginally or by cesarean section, seen in the first 24 hours from a full-term single-fetal pregnancy whose mother had given consent. We excluded newborns whose term was unclear and those with congenital malformations or signs of embryo-foetopathy. Data collection was done using structured and pre-tested survey sheets. The study variables were obstetric and anthropometric. Statistical analyzes were carried out with CS Pro 7.3 and SPSS version 25.0 software. The Student, Chi-square and Fischer tests were used to compare the means of the variables, the percentages with a significance threshold P value Results: During the study period, 305 full-term newborns were included, divided into 172 boys and 133 girls. The average anthropometric parameters of the full-term newborn in the city of Douala were: average weight: 3305 grams, average height: 49.8 centimeters, average head circumference: 34.6 centimeters, average upper arm circumference: 11.3 centimeters, circumference average thoracic: 32.8 centimeters. The percentile distribution showed a 10th percentile at 2656 grams and a 90th

关键词： Anthropometry Full-Term Newborn Douala

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Minimal conceptual models for tropical cyclone intensification

引用

Tropical Cyclone Research and Review 2022年第2期11卷 61-75页

作者： Michael T.Montgomery roger K.Smith Department of Meteorology Naval Postgraduate SchoolMontereyCAUSA Meteorological Institute Ludwig-Maximilians UniversityMunichGermany

We examine a hierarchy of minimal conceptual models for tropical cyclone *** models are framed mostly in terms of axisymmetric balance *** the first set of models,the heating rate is prescribed in such a way to mimic a deep overturning circulation with convergence in the lower troposphere and divergence in the upper troposphere,characteristic of a region of deep moist *** the second set,the heating rate is related explicitly to the latent heat release of ascending air *** release of latent heat markedly reduces the local static stability of ascending air,raising two possibilities in the balance *** first possibility is that the effective static stability and the related discriminant in the Eliassen equation for the overturning circulation in saturated air,although small,remains positive so the Eliassen equation is globally *** second possibility,the more likely one during vortex intensification,is that the effective static stability in saturated air is negative and the Eliassen equation becomes locally *** models help to understand the differences between the early Ooyama models of 1968 and 1969,the Emanuel,1989 model,and the later Emanuel models of 1995,1997 and *** provide insight also into the popular explanation of the WISHE feedback mechanism for tropical cyclone *** implications for recent work are discussed.

关键词： Tropical cyclone intensification Conventional spin-up mechanism Minimal models Nonlinear boundary layer spin-up mechanism WISHE feedback Mechanism

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Synergistic effect of cobalt and niobium in Co_(3)-Nb-O_(x)on performance of selective catalytic reduction of NO with NH_(3)

引用

Rare Metals 2022年第1期41卷 166-178页

作者： Bo-Lin Zhang Li-Feng Deng Bo Liu Chun-Yun Luo Michael Liebau Shen-Gen Zhang roger Glaser Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China Shunde Graduate School University of Science and Technology BeijingFoshan 528399China Jiangsu Longkingcotech Co. Ltd.Yancheng 224000China Institute of Chemical Technology Universita¨t LeipzigLeipzig 04103Germany e-mail:roger.glaeser

Combining the redox properties of Co and the acid properties of Nb in a Co_(3)-Nb-O_(x)catalyst is shown to provide superior performance in the selective catalytic reduction of NO with NH_(3)(NH_(3)-SCR).Co_(3)O_(4)shows average activity,however,it exhibits a poor N_(2)***_(2)O_(5)is not active for NH_(3)-***,the mixed Co_(3)-Nb-O_(x) catalyst shows higher NO conversion and N_(2)selectivity than the single Co_(3)O_(4)and Nb_(2)O_(5)catalysts at 100–300℃.The results of temperature programmed reduction by H_(2)and X-ray photoelectron(XP)spectra indicate that the addition of Nb changes the chemical states of Co and decreases the concentration of Co^(3+) and Oa,adjusting the activity for catalytic oxidation to a moderate *** suppresses the formation of undesired N_(2)O from the over-oxidation of NH_(3).Incorporation of Co and Nb into one solid synergistically couples their redox behavior and surface acidity,ensuring the high catalytic activity and N2 selectivity in NH3-SCR.

关键词： Co-Nb Selective catalytic reduction Lowtemperature Acid property Redox behavior

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Which psychosocial factors are associated with return to sport following concussion? A systematic review

引用

Journal of Sport and Health Science 2022年第4期11卷 438-449页

作者： Jacqueline van Ierssel Kaleigh Ferdinand Pennock Margaret Sampson roger Zemek Jeffrey G.Caron Children’s Hospital of Eastern Ontario Research Institute OttawaON K1H 8L1Canada Faculty of Kinesiology and Physical Education University of TorontoTorontoON M5S 2W6Canada Department of Pediatrics Faculty of MedicineUniversity of OttawaOttawaON K1H 8M5Canada Faculty of Medicine University of MontrealMontrealQC H3T 1J4Canada Center for Interdisciplinary Research in Rehabilitation MontrealQC H3S 1M9Canada

Background:Psycho social factors predict recurrent inj ury and return to preinjury level of performance following orthopedic injury but are poorly understood following *** management protocols prioritize physical measures of ***,the objective of this study was to describe the psychosocial factors associated with return to sport(RTS) and how they are measured in athletes who sustained a ***:MEDLINE,Embase,APA PsycINFO,CINAHL,and SPORTDiscus were searched through February 2,*** studies included original peer-reviewed publications describing psychosocial factors associated with RTS following a diagnosed *** primary outcome was scales or measures employed and/or key thematic ***:Of the 3615 studies identified,10 quantitative cohort studies(Oxford Centre for Evidence-Based Medicine Level-3) representing 2032 athletes(85% male;high-school and collegiate collision/contact athletes) and 4 qualitative studies representing 66 athletes(74% male;70% American football;aged 9-28 years) were *** identified 3 overarching themes and 10 outcome measures related to psychosocial factors associated with RTS following concussion:(a) fear(e.g,of recurrent concussion,of RTS,of losing playing status);(b) emotional factors(e.g,depression,anxiety,perceived stress,mental health,disturbance mood);and(c) contextual factors(e.g,social support,pressure,sense of identity).Conclusion:Although current medical clearance decisions prioritize physical measures of recovery,evidence suggests diverse psychosocial factors influence RTS following *** remains unclear which psychosocial factors contribute to a successful RTS,including the influence of sex/gender and *** studies should evaluate the association of psychological readiness with physical measures of recovery at medical clearance,preinjury level of performance,and risk of recurrent concussion to support RTS clinical decision-making.

关键词： Concussion Recovery Rehabilitation Sport psychology Sporting injuries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

3D shear flows driven by Lévy noise at the boundary

引用

Probability, Uncertainty and Quantitative Risk 2023年第1期8卷 75-94页

作者： Wai-tong(Louis)Fan Ali Pakzad Krutika Tawri roger Temam Department of Mathematics Indiana University BloomingtonIN 47405USA Department of Mathematics California State University NorthridgeCA 91330USA Department of Mathematics University of California BerkeleyCA 94720USA

This paper is concerned with the stochastic incompressible Navier–Stokes equations in a layer of fluid between two flat no-slip *** fluid is driven by the noisy movement of the bottom boundary,where the noise is given by a Lévy *** establishing existence of a martingale solution,we use the background flow method to derive an upper bound on the turbulent energy dissipation *** estimate recovers one of the basic scaling ideas of turbulence theory,namely,that the dissipation rate is independent of the viscosity at high Reynolds number.

关键词： Existence Lévy noise Navier–Stokes equations 3D shear flows Upper bound

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Long-Time Turbulence Model Deduced from the Navier-Stokes Equations

引用

Chinese Annals of Mathematics,Series B 2015年第5期36卷 883-894页

作者： roger LEWANDOWSKI IRMAR and Fluminance Team University of Rennes 1 and INRIA Campus Beaulieu

The author shows the existence of long-time averages to turbulent solutions of the Navier-Stokes equations and determines the equations satisfied by them, involving a Reynolds stress that is shown to be dissipative.

关键词： Navier-Stokes方程湍流模型方程推导雷诺兹应力平均值耗散

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of illness perception on negative emotions and fatigue in chronic rheumatic diseases:Rumination as a possible mediator

引用

World Journal of Clinical Cases 2022年第34期10卷 12515-12531页

作者： Yanxia Lu Xia Jin Li-Wei Feng CSK Tang Michelle Neo roger C Ho Department of Medical Psychology and Ethics School of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinan 250012Shandong ProvinceChina The Third Hospital of Jinan Jinan 250132Shandong ProvinceChina College of Education for the Future Beijing Normal UniversityZhuhai 519087Guangdong ProvinceChina Department of Obstetrics and Gynecology National University of SingaporeThe Chinese University of Hong KongSingapore 117570Singapore Department of Psychological Medicine National University of SingaporeSingapore 119228Singapore

BACKGROUND Illness perception has long been hypothesized to be linked to psychological well-b eing in patients with rheumatic diseases,although substantial evidence is lacking,and the contribution of ruminative coping style to this relationship is *** To investigate the roles of illness perception and rumination in predicting fatigue and negative emotions in patients with chronic rheumatic *** Illness perception,rumination,fatigue and negative emotions(***,anxiety and stress)were assessed by the Illness Perception Questionnaire-Revised,Stress Reactive Rumination Scale,Multidimensional Assessment of Fatigue,and the Depression,Anxiety and Stress Scale *** regression analysis,the Sobel test,and the bootstrap were used to identify the mediating effect of *** All five subscales of illness perception,including perceived illness identity,chronicity,cyclical nature,consequences and coherence of illness,were significantly associated with fatigue and negative *** mediational analysis,rumination was found to mediate three components of illness perception(the identity,cyclical nature and consequences of illness)and negative emotions/*** Perceived identity,cyclical nature,and consequences of illness are significantly associated with fatigue and negative emotions in patients with chronic rheumatic diseases and these associations are mediated by *** findings suggest that psychological intervention should target rumination to improve physical and emotional well-being of patients with chronic rheumatic diseases.

关键词： Fatigue Illness perception Negative emotions Rheumatoid arthritis Rumination Systemic lupus erythematosus

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：