Crohn’s disease(CD)is a chronic,non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease(IBD).CD is prone to relapse,and its incidenc...Crohn’s disease(CD)is a chronic,non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease(IBD).CD is prone to relapse,and its incidence displays a persistent increase in developing countries.However,the pathogenesis of CD is poorly understood,with some studies emphasizing the link between CD and the intestinal microbiota.Specifically,studies point to the brain-gut-enteric microbiota axis as a key player in the occurrence and development of CD.Furthermore,investigations have shown whitematter lesions and neurologic deficits in patients with IBD.Based on these findings,brain activity changes in CD patients have been detected by blood oxygenation level dependent functional magnetic resonance imaging(BOLD-f MRI).BOLD-f MRI functions by detecting a local increase in relative blood oxygenation that results from neurotransmitter activity and thus reflects local neuronal firing rates.Therefore,biochemical concentrations of neurotransmitters or metabolites may change in corresponding brain regions of CD patients.To further study this phenomenon,brain changes of CD patients can be detected non-invasively,effectively and accurately by BOLD-f MRI combined with magnetic resonance spectroscopy(MRS).This approach can further shed light on the mechanisms of the occurrence and development of neurological CD.Overall,this paper reviews the current status and prospects on fMRI and MRS for evaluation of patients with CD based on the brain-gut-enteric microbiota axis.展开更多
Oesophageal adenocarcinoma is rapidly increasing in Western countries. This tumour frequently presents late in its course with metastatic disease and has a very poor prognosis. Barrett's oesophagus is an acquired ...Oesophageal adenocarcinoma is rapidly increasing in Western countries. This tumour frequently presents late in its course with metastatic disease and has a very poor prognosis. Barrett's oesophagus is an acquired condition whereby the native squamous mucosa of the lower oesophagus is replaced by columnar epithelium following prolonged gastro-oesophageal reflux and is the recognised precursor lesion for oesophageal adenocarcinoma. There are multiple national and society guidelines regarding screening,surveillance and management of Barrett's oesophagus,however all are limited regarding a clear evidence base for a well-demonstrated benefit and cost-effectiveness of surveillance,and robust risk stratification for patients to best use resources. Currently the accepted risk factors upon which surveillance intervals and interventions are based are Barrett's segment length and histological interpretation of the systematic biopsies. Further patient risk factors including other demographic features,smoking,gender,obesity,ethnicity,patient age,biomarkers and endoscopic adjuncts remain under consideration and are discussed in full. Recent evidence has been published to support earlier endoscopic intervention by means of ablation of the metaplastic Barrett's segment when the earliest signs of dysplasia are detected. Further work should concentrate on establishing better risk stratification and primary and secondary preventative strategies to reduce the risk of adenocarcinoma of the oesophagus.展开更多
Pre-modern Chinese crafts,such as iron smelting,cookery,medicine,and the production of vehicles,bows,and arrows indicate the traditional Chinese view of technology as being organic,holistic,and comprehensive.This view...Pre-modern Chinese crafts,such as iron smelting,cookery,medicine,and the production of vehicles,bows,and arrows indicate the traditional Chinese view of technology as being organic,holistic,and comprehensive.This view of technology is guided by the concept of he(和)and employs the means and methods of he,thus achieving the purport of he.In Chinese,the character he(和)possesses positive connotations.It originated from the meaning of"to season;to add flavoring to"(调和)and that of flavors being"perfectly harmonious"(和美).From this sensory experience,he gradually extended to the abstract levels of materiality,humanity,sociality,"order"(wei位),and "power,situation,force"(shi势).Finally,he was elevated to the supreme level of"qi of great harmony"(taihe zhi qi太和之气),which is comparable to the concept of dao(道).The philosophy of he has exerted wide impact on such areas as technology,art,national character,cultural psychology,and behavior patterns,and has become an integral part of China's inherent culture.The paradoxes and deviations of he hold their own profound philosophical implications that merit further exploration.As humanity confronts significant challenges,such as how we can coexist with others,with technology,and with nature,the ancient Eastern wisdom embodied in he continues to possess practical characteristics and value.展开更多
Past studies reveal the prevalence of anxiety,coupled with low motivation and disengagement among students in English-medium instruction(EMI)programs.Given the detrimental impact these negative emotions can have on le...Past studies reveal the prevalence of anxiety,coupled with low motivation and disengagement among students in English-medium instruction(EMI)programs.Given the detrimental impact these negative emotions can have on learning outcomes,it is imperative that teachers establish positive emotional rapport with their students.This study explores how experienced and highly rated EMI lecturers at a Chinese university’s overseas campus use communication strategies to build rapport with their students during interactive academic activities.It identifies the strategies used by these lecturers and examines how the strategies facilitate the teaching-learning process.The data,consisting of 10 hours of tutorials and 10 hours of supervisor-student supervision meetings,is analyzed using an adapted Conversation Analysis(CA)approach.The analysis reveals three types of communication strategies(CSs)frequently used by lecturers:back-channeling,codeswitching,and co-creation of messages.By employing these strategies,the lecturers established a strong rapport with the students,which created an encouraging and supportive learning environment.Consequently,this positive atmosphere facilitated students’learning of content knowledge through English.The findings of this study have implications for the training of lecturers who encounter difficulties in establishing rapport with multilingual students in the EMI setting.展开更多
We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein...We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein,we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions.Notably,the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions.Parameters,including temperature,organic co-solvents,pH,ionic strength,catalyst loading,substrate concentration,and reaction time,affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated,with the e.e.of the final(S)-l-Phenylethanol product and the conversion being 97%and 28.5%,respectively,after process optimization.The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions.MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.展开更多
This essay accesses to the approach of corpus applied to translation teaching, in order to improve the teaching methods, lay the foundation for the translation teaching reform, cultivate students research ability, and...This essay accesses to the approach of corpus applied to translation teaching, in order to improve the teaching methods, lay the foundation for the translation teaching reform, cultivate students research ability, and finally to establish a new type of translation teaching design-- "ability-development-oriented design". Also, this paper takes the word "good" for example, looking for the general rules to translate it and its common collocation, in order to design a translation class. Corpus-based learning and teaching provides us a new feasible way of translation class.展开更多
J. C. Catford is a world-renowned British linguist and translation theorist, and also an outstanding representative of the linguistic school of translation. His famous work A linguistic theory of translation was first...J. C. Catford is a world-renowned British linguist and translation theorist, and also an outstanding representative of the linguistic school of translation. His famous work A linguistic theory of translation was first published by Oxford University Press in 1965, and republished in 1967. It was among the list of the series of language and linguistic studies of Oxford University. This essay attempts to interpret this great book in five aspects, namely, definition of translation, types of translation, translation equivalence, transference, and limits of translatability, and tries to probe into the positive impact of its theories on the development of translation theory and its limitations.展开更多
Modified potential ecological risk index (MRI) was proposed based on the potential ecological risk index (RI) and risk assessment code (RAC) by modifying an index. The modified index was relevant to the chemical...Modified potential ecological risk index (MRI) was proposed based on the potential ecological risk index (RI) and risk assessment code (RAC) by modifying an index. The modified index was relevant to the chemical speciation of heavy metals. Xiawan Port, a typical region contaminated by industrial production, was selected as a case study area. The total concentrations and chemical speciation of heavy metals in sediments of Xiawan Port were analyzed. The experimental data indicate that Xiawan Port is seriously polluted by heavy metals, especially by Cd. The risks of heavy metals are evaluated by RI, RAC and MRI, respectively. The resluts of MRI show that the risks of heavy metals are in the decreasing order of Cd〉Pb〉Cu〉Zn. Comparison of results by different methods reveals that MRI integrates the characters of RI and RAC. MRI is recognized to be useful for risk managemnt of heavy metals in sediments.展开更多
The effects of O2 and the supported Pt nano-particles on the mechanisms and kinetics of the carbon support corrosion are investigated by monitoring the CO2 production using differential electrochemical mass spectromet...The effects of O2 and the supported Pt nano-particles on the mechanisms and kinetics of the carbon support corrosion are investigated by monitoring the CO2 production using differential electrochemical mass spectrometry in a dual-thin layer flow cell. Carbon can be oxidized in different distinct potential regimes; O2 accelerates carbon oxidation, the rates of CO2 production from carbon oxidation in O2 saturated solution are two times of that in N2 saturated solution at the same potential; Pt can catalyze the carbon oxidation, with supported Pt nanoparticles, the overpotential for carbon oxidation is much smaller than that without loading in the carbon electrode. The mechanism for the enhanced carbon oxidation by Pt and O2 are discussed.展开更多
The paper is a literature review,aiming to examine the relationship between teachers' classroom assessment feedback and student motivation. Previous studies have been mainly focused on how each of the two has infl...The paper is a literature review,aiming to examine the relationship between teachers' classroom assessment feedback and student motivation. Previous studies have been mainly focused on how each of the two has influenced students' performances and achievement. However, according to the theoretical framework proposed by Brookhart (1997), it has been suggested that teachers' feedback may influence student motivation first, which, in turn, may have an impact on students' performances and achievement. Therefore, this paper first examines the nature and different types of feedback, and then gives a summary and critique of research studies on the relationship between teachers' feedback and student motivation. Areas that deserve further study are also indicated.展开更多
To increase the efficiency of the multidisciplinary optimization of aircraft, an aerodynamic approximation model is improved. Based on the study of aerodynamic approximation model constructed by the scaling correction...To increase the efficiency of the multidisciplinary optimization of aircraft, an aerodynamic approximation model is improved. Based on the study of aerodynamic approximation model constructed by the scaling correction model, case-based reasoning technique is introduced to improve the approximation model for optimization. The aircraft case model is constructed by utilizing the plane parameters related to aerodynamic characteristics as attributes of cases, and the formula of case retrieving is improved. Finally, the aerodynamic approximation model for optimization is improved by reusing the correction factors of the most similar aircraft to the current one. The multidisciplinary optimization of a civil aircraft concept is carried out with the improved aerodynamic approximation model. The results demonstrate that the precision and the efficiency of the optimization can be improved by utilizing the improved aerodynamic approximation model with ease-based reasoning technique.展开更多
A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functio...A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functions of the main components are explained.Then after a comprehensive analysis of data transmission and a job life cycle model,a novel proactive file transmission and job management mechanism is devised to enhance the software architecture,and the command line programs are wrapped into web services in such a way that they can efficiently transmit files,supply instant status feedback and automatically manage the jobs.Experiments show that the proposed approach achieves higher performance with less memory usage compared to the related work, and the usability is also improved.This work has already been put into use in a production system of scientific computing and the data processing efficiency of the system is greatly improved.展开更多
In a case study investigating Chinese EFL university majors' perceptions of a portfolio-based writing assessment (PBWA) project, English majors were sampled to find out whether the portfolio method made them more i...In a case study investigating Chinese EFL university majors' perceptions of a portfolio-based writing assessment (PBWA) project, English majors were sampled to find out whether the portfolio method made them more interested in writing and/or improved their writing process and writing strategies. Four sophomores were chosen from among an experimental group at a local university in China. Analysis of data from student journals, interviews and reflective essays showed that taking part in portfolio writing empowered them to take charge of their own learning and motivated them to write better. The students welcomed PBWA as a fairer assessment tool than timed, one-shot essay tests. They held more interest in English writing, improved their writing strategies and shifted their attention from products of writing to process of writing and, thus, preferred scores from PBWA as a more satisfactory indicator of their writing ability.展开更多
Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with...Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with ozone. The calculated results demonstrate that the single water molecule can reduce the activated barrier of the naked OH+Oa reaction with the value of about 4.18 kJ/mol. In addition, the transition state theory is carried out to determine whether the single water molecule could enhance the rate constant of the OH+O3 reaction. The computed kinetic data indicate that the rate of the ozone reaction with the formed complexes between OH and water is much slower than that of the OH+O3 reaction, whereas the rate constant of OH reaction with the formed H20---Oa complex is 2 times greater than that of the naked OH radical with ozone reaction. However, these processes in the atmosphere are not important because the reactions can not compete well with the naked reaction of OH with ozone under atmospheric condition.展开更多
In light of the traditional teaching method used in English classes in China and many other places, this article states the importance of linking instruction and assessment in the English teaching process and presents...In light of the traditional teaching method used in English classes in China and many other places, this article states the importance of linking instruction and assessment in the English teaching process and presents different approaches to linking instruction and assessment in classroom teaching which are proven effective in solidifying students' knowledge of English and improving students' comprehensive English competence. Then, based on the results from the assessments, a Fuzzy Comprehensive Grading Approach is adopted in calculating students' final grade. The Approach is based on the fuzzy set theory of fuzzy mathematics, and it considers diverse factors and assigns proper weight to different factors in grading, using fuzzy matrix operation in calculating students' grades; therefore, it is comprehensive and reliable, and can avoid the influence of odd scores and give a truer and more balanced measurement of students' English ability.展开更多
AIM To explore the association between Helicobacter pylori(H. pylori) infection and obesity/weight gain in a Chinese population.METHODS Our primary outcome was the change in body mass index(BMI). The generalized linea...AIM To explore the association between Helicobacter pylori(H. pylori) infection and obesity/weight gain in a Chinese population.METHODS Our primary outcome was the change in body mass index(BMI). The generalized linear models were used to explore the association between H. pylori infection and the change of BMI, and the logistic regression models were used to explore the association between H. pylori infection and obesity.RESULTS A total of 3039 subjects were recruited and analyzed, of which 12.8% were obese. The prevalence of H. pylori infection was 53.9%(1639/3039) overall and 54.6%(212/388) in the obese subjects. The change of BMI in the H. pylori(+) group was not significantly higher than that in the H. pylori(-) group after adjustment for potential confounding factors [RR = 0.988, 95%CI:0.924-1.057, P = 0.729]. The prevalence of obesity decreased 1.1% in the H. pylori(+) group and 0.5% in the H. pylori(-) group. The RR of H. pylori infection for obesity was 0.831(95%CI: 0.577-1.197, P = 0.321) after the adjustment.CONCLUSION H. pylori infection was not associated with overweight/obesity observed from the retrospective study in this Chinese population.展开更多
The coastal area of southern China is frequently affected by marine meteorological disasters,and is also one of the key areas that influence the short-term climate change of China.Due to a lack of observational facili...The coastal area of southern China is frequently affected by marine meteorological disasters,and is also one of the key areas that influence the short-term climate change of China.Due to a lack of observational facilities and techniques,little has been done in this area in terms of operational weather monitoring and scientific research on atmospheric and marine environment.With the support of China Meteorological Administration (CMA) and Guangdong Meteorological Bureau (GMB),the Marine Meteorological Science Experiment Base (MMSEB) at Bohe,Maoming has been jointly established by Guangzhou Institute of Tropical and Marine Meteorology (GITMM) and Maoming Meteorological Bureau (MMB) of Guangdong Province after three years of hard work.It has become an integrated coastal observation base that is equipped with a complete set of sophisticated instruments.Equipment maintenance and data quality control procedures have been implemented to ensure the long-term,steady operation of the instruments and the availability of high quality data.Preliminary observations show that the data obtained by the MMSEB reveal many interesting features in the boundary layer structure and air-sea interaction in such disastrous weather as typhoons and sea fog.The MMSEB is expected to play an important role in the scientific research of disastrous weather related to marine meteorology.展开更多
基金the National Natural Science Foundation of China,No.81473506the Natural Science Foundation of Zhejiang Province,No.LY17H290009the Ministry of Construction,Zhejiang Province,No.WKJ-ZJ-1531
文摘Crohn’s disease(CD)is a chronic,non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease(IBD).CD is prone to relapse,and its incidence displays a persistent increase in developing countries.However,the pathogenesis of CD is poorly understood,with some studies emphasizing the link between CD and the intestinal microbiota.Specifically,studies point to the brain-gut-enteric microbiota axis as a key player in the occurrence and development of CD.Furthermore,investigations have shown whitematter lesions and neurologic deficits in patients with IBD.Based on these findings,brain activity changes in CD patients have been detected by blood oxygenation level dependent functional magnetic resonance imaging(BOLD-f MRI).BOLD-f MRI functions by detecting a local increase in relative blood oxygenation that results from neurotransmitter activity and thus reflects local neuronal firing rates.Therefore,biochemical concentrations of neurotransmitters or metabolites may change in corresponding brain regions of CD patients.To further study this phenomenon,brain changes of CD patients can be detected non-invasively,effectively and accurately by BOLD-f MRI combined with magnetic resonance spectroscopy(MRS).This approach can further shed light on the mechanisms of the occurrence and development of neurological CD.Overall,this paper reviews the current status and prospects on fMRI and MRS for evaluation of patients with CD based on the brain-gut-enteric microbiota axis.
文摘Oesophageal adenocarcinoma is rapidly increasing in Western countries. This tumour frequently presents late in its course with metastatic disease and has a very poor prognosis. Barrett's oesophagus is an acquired condition whereby the native squamous mucosa of the lower oesophagus is replaced by columnar epithelium following prolonged gastro-oesophageal reflux and is the recognised precursor lesion for oesophageal adenocarcinoma. There are multiple national and society guidelines regarding screening,surveillance and management of Barrett's oesophagus,however all are limited regarding a clear evidence base for a well-demonstrated benefit and cost-effectiveness of surveillance,and robust risk stratification for patients to best use resources. Currently the accepted risk factors upon which surveillance intervals and interventions are based are Barrett's segment length and histological interpretation of the systematic biopsies. Further patient risk factors including other demographic features,smoking,gender,obesity,ethnicity,patient age,biomarkers and endoscopic adjuncts remain under consideration and are discussed in full. Recent evidence has been published to support earlier endoscopic intervention by means of ablation of the metaplastic Barrett's segment when the earliest signs of dysplasia are detected. Further work should concentrate on establishing better risk stratification and primary and secondary preventative strategies to reduce the risk of adenocarcinoma of the oesophagus.
基金the support of the Center for Cultural Studies on Science and Technology in China at Technische Universitat Berlin。
文摘Pre-modern Chinese crafts,such as iron smelting,cookery,medicine,and the production of vehicles,bows,and arrows indicate the traditional Chinese view of technology as being organic,holistic,and comprehensive.This view of technology is guided by the concept of he(和)and employs the means and methods of he,thus achieving the purport of he.In Chinese,the character he(和)possesses positive connotations.It originated from the meaning of"to season;to add flavoring to"(调和)and that of flavors being"perfectly harmonious"(和美).From this sensory experience,he gradually extended to the abstract levels of materiality,humanity,sociality,"order"(wei位),and "power,situation,force"(shi势).Finally,he was elevated to the supreme level of"qi of great harmony"(taihe zhi qi太和之气),which is comparable to the concept of dao(道).The philosophy of he has exerted wide impact on such areas as technology,art,national character,cultural psychology,and behavior patterns,and has become an integral part of China's inherent culture.The paradoxes and deviations of he hold their own profound philosophical implications that merit further exploration.As humanity confronts significant challenges,such as how we can coexist with others,with technology,and with nature,the ancient Eastern wisdom embodied in he continues to possess practical characteristics and value.
文摘Past studies reveal the prevalence of anxiety,coupled with low motivation and disengagement among students in English-medium instruction(EMI)programs.Given the detrimental impact these negative emotions can have on learning outcomes,it is imperative that teachers establish positive emotional rapport with their students.This study explores how experienced and highly rated EMI lecturers at a Chinese university’s overseas campus use communication strategies to build rapport with their students during interactive academic activities.It identifies the strategies used by these lecturers and examines how the strategies facilitate the teaching-learning process.The data,consisting of 10 hours of tutorials and 10 hours of supervisor-student supervision meetings,is analyzed using an adapted Conversation Analysis(CA)approach.The analysis reveals three types of communication strategies(CSs)frequently used by lecturers:back-channeling,codeswitching,and co-creation of messages.By employing these strategies,the lecturers established a strong rapport with the students,which created an encouraging and supportive learning environment.Consequently,this positive atmosphere facilitated students’learning of content knowledge through English.The findings of this study have implications for the training of lecturers who encounter difficulties in establishing rapport with multilingual students in the EMI setting.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA11030404),the Key Project from Chinese Academy of Sciences(KGZD-EW-606)the National Natural Science Foundation of China(21302199)Guangzhou Science and Technology Plan Projects(201510010012)
文摘We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein,we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions.Notably,the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions.Parameters,including temperature,organic co-solvents,pH,ionic strength,catalyst loading,substrate concentration,and reaction time,affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated,with the e.e.of the final(S)-l-Phenylethanol product and the conversion being 97%and 28.5%,respectively,after process optimization.The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions.MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.
文摘This essay accesses to the approach of corpus applied to translation teaching, in order to improve the teaching methods, lay the foundation for the translation teaching reform, cultivate students research ability, and finally to establish a new type of translation teaching design-- "ability-development-oriented design". Also, this paper takes the word "good" for example, looking for the general rules to translate it and its common collocation, in order to design a translation class. Corpus-based learning and teaching provides us a new feasible way of translation class.
文摘J. C. Catford is a world-renowned British linguist and translation theorist, and also an outstanding representative of the linguistic school of translation. His famous work A linguistic theory of translation was first published by Oxford University Press in 1965, and republished in 1967. It was among the list of the series of language and linguistic studies of Oxford University. This essay attempts to interpret this great book in five aspects, namely, definition of translation, types of translation, translation equivalence, transference, and limits of translatability, and tries to probe into the positive impact of its theories on the development of translation theory and its limitations.
基金Projects (51039001, 50978087, 51009063, 50808071) supported by the National Natural Science Foundation of ChinaProject (SX2010-026) supported by State Council Three Gorges Project Construction Committee Executive Office,China+2 种基金Project (2009ZX07212-001) supported by Ministry of Environmental Protection of ChinaProject (BYHGLC-2010-02) supported by Guangzhou Water Authority,ChinaProject (CX2010B157) supported by Hunan Provincial Innovation Foundation for Postgraduate,China
文摘Modified potential ecological risk index (MRI) was proposed based on the potential ecological risk index (RI) and risk assessment code (RAC) by modifying an index. The modified index was relevant to the chemical speciation of heavy metals. Xiawan Port, a typical region contaminated by industrial production, was selected as a case study area. The total concentrations and chemical speciation of heavy metals in sediments of Xiawan Port were analyzed. The experimental data indicate that Xiawan Port is seriously polluted by heavy metals, especially by Cd. The risks of heavy metals are evaluated by RI, RAC and MRI, respectively. The resluts of MRI show that the risks of heavy metals are in the decreasing order of Cd〉Pb〉Cu〉Zn. Comparison of results by different methods reveals that MRI integrates the characters of RI and RAC. MRI is recognized to be useful for risk managemnt of heavy metals in sediments.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.20773116), the one hundred Talents' Program Sciences, and the National China (No.2010CB923302) of the Chinese Academy of Basic Research Program of
文摘The effects of O2 and the supported Pt nano-particles on the mechanisms and kinetics of the carbon support corrosion are investigated by monitoring the CO2 production using differential electrochemical mass spectrometry in a dual-thin layer flow cell. Carbon can be oxidized in different distinct potential regimes; O2 accelerates carbon oxidation, the rates of CO2 production from carbon oxidation in O2 saturated solution are two times of that in N2 saturated solution at the same potential; Pt can catalyze the carbon oxidation, with supported Pt nanoparticles, the overpotential for carbon oxidation is much smaller than that without loading in the carbon electrode. The mechanism for the enhanced carbon oxidation by Pt and O2 are discussed.
文摘The paper is a literature review,aiming to examine the relationship between teachers' classroom assessment feedback and student motivation. Previous studies have been mainly focused on how each of the two has influenced students' performances and achievement. However, according to the theoretical framework proposed by Brookhart (1997), it has been suggested that teachers' feedback may influence student motivation first, which, in turn, may have an impact on students' performances and achievement. Therefore, this paper first examines the nature and different types of feedback, and then gives a summary and critique of research studies on the relationship between teachers' feedback and student motivation. Areas that deserve further study are also indicated.
文摘To increase the efficiency of the multidisciplinary optimization of aircraft, an aerodynamic approximation model is improved. Based on the study of aerodynamic approximation model constructed by the scaling correction model, case-based reasoning technique is introduced to improve the approximation model for optimization. The aircraft case model is constructed by utilizing the plane parameters related to aerodynamic characteristics as attributes of cases, and the formula of case retrieving is improved. Finally, the aerodynamic approximation model for optimization is improved by reusing the correction factors of the most similar aircraft to the current one. The multidisciplinary optimization of a civil aircraft concept is carried out with the improved aerodynamic approximation model. The results demonstrate that the precision and the efficiency of the optimization can be improved by utilizing the improved aerodynamic approximation model with ease-based reasoning technique.
基金The National Natural Science Foundation of China(No.60573117)the National Basic Research Program of China(973 Program)(No.2007CB310805)
文摘A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functions of the main components are explained.Then after a comprehensive analysis of data transmission and a job life cycle model,a novel proactive file transmission and job management mechanism is devised to enhance the software architecture,and the command line programs are wrapped into web services in such a way that they can efficiently transmit files,supply instant status feedback and automatically manage the jobs.Experiments show that the proposed approach achieves higher performance with less memory usage compared to the related work, and the usability is also improved.This work has already been put into use in a production system of scientific computing and the data processing efficiency of the system is greatly improved.
基金part achievements of the project "Reform of Reading-to-writing courses of English Major" supported by Guangdong Province Higher Educational Reform Essential Project(2013)the education reform project of Southern Medical University
文摘In a case study investigating Chinese EFL university majors' perceptions of a portfolio-based writing assessment (PBWA) project, English majors were sampled to find out whether the portfolio method made them more interested in writing and/or improved their writing process and writing strategies. Four sophomores were chosen from among an experimental group at a local university in China. Analysis of data from student journals, interviews and reflective essays showed that taking part in portfolio writing empowered them to take charge of their own learning and motivated them to write better. The students welcomed PBWA as a fairer assessment tool than timed, one-shot essay tests. They held more interest in English writing, improved their writing strategies and shifted their attention from products of writing to process of writing and, thus, preferred scores from PBWA as a more satisfactory indicator of their writing ability.
基金This work was supported by the National Natural Science Foundation of China (No.10865003) and the Science and Technology Foundation of GuiZhou Province, China (No.[201112107). We thank the Key Laboratory of Guizhou High Performance Computational Chemistry for computer time.
文摘Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with ozone. The calculated results demonstrate that the single water molecule can reduce the activated barrier of the naked OH+Oa reaction with the value of about 4.18 kJ/mol. In addition, the transition state theory is carried out to determine whether the single water molecule could enhance the rate constant of the OH+O3 reaction. The computed kinetic data indicate that the rate of the ozone reaction with the formed complexes between OH and water is much slower than that of the OH+O3 reaction, whereas the rate constant of OH reaction with the formed H20---Oa complex is 2 times greater than that of the naked OH radical with ozone reaction. However, these processes in the atmosphere are not important because the reactions can not compete well with the naked reaction of OH with ozone under atmospheric condition.
文摘In light of the traditional teaching method used in English classes in China and many other places, this article states the importance of linking instruction and assessment in the English teaching process and presents different approaches to linking instruction and assessment in classroom teaching which are proven effective in solidifying students' knowledge of English and improving students' comprehensive English competence. Then, based on the results from the assessments, a Fuzzy Comprehensive Grading Approach is adopted in calculating students' final grade. The Approach is based on the fuzzy set theory of fuzzy mathematics, and it considers diverse factors and assigns proper weight to different factors in grading, using fuzzy matrix operation in calculating students' grades; therefore, it is comprehensive and reliable, and can avoid the influence of odd scores and give a truer and more balanced measurement of students' English ability.
基金Supported by the State Key Laboratory of Pathogen and Biosecurity(Academy of Military Medical Science)No.SKLPBS1442the Youth Talent Support Program of the School of Public Health,Peking University
文摘AIM To explore the association between Helicobacter pylori(H. pylori) infection and obesity/weight gain in a Chinese population.METHODS Our primary outcome was the change in body mass index(BMI). The generalized linear models were used to explore the association between H. pylori infection and the change of BMI, and the logistic regression models were used to explore the association between H. pylori infection and obesity.RESULTS A total of 3039 subjects were recruited and analyzed, of which 12.8% were obese. The prevalence of H. pylori infection was 53.9%(1639/3039) overall and 54.6%(212/388) in the obese subjects. The change of BMI in the H. pylori(+) group was not significantly higher than that in the H. pylori(-) group after adjustment for potential confounding factors [RR = 0.988, 95%CI:0.924-1.057, P = 0.729]. The prevalence of obesity decreased 1.1% in the H. pylori(+) group and 0.5% in the H. pylori(-) group. The RR of H. pylori infection for obesity was 0.831(95%CI: 0.577-1.197, P = 0.321) after the adjustment.CONCLUSION H. pylori infection was not associated with overweight/obesity observed from the retrospective study in this Chinese population.
基金National Public Benefit Research Foundation (Meteorology) (GYHY200906008)
文摘The coastal area of southern China is frequently affected by marine meteorological disasters,and is also one of the key areas that influence the short-term climate change of China.Due to a lack of observational facilities and techniques,little has been done in this area in terms of operational weather monitoring and scientific research on atmospheric and marine environment.With the support of China Meteorological Administration (CMA) and Guangdong Meteorological Bureau (GMB),the Marine Meteorological Science Experiment Base (MMSEB) at Bohe,Maoming has been jointly established by Guangzhou Institute of Tropical and Marine Meteorology (GITMM) and Maoming Meteorological Bureau (MMB) of Guangdong Province after three years of hard work.It has become an integrated coastal observation base that is equipped with a complete set of sophisticated instruments.Equipment maintenance and data quality control procedures have been implemented to ensure the long-term,steady operation of the instruments and the availability of high quality data.Preliminary observations show that the data obtained by the MMSEB reveal many interesting features in the boundary layer structure and air-sea interaction in such disastrous weather as typhoons and sea fog.The MMSEB is expected to play an important role in the scientific research of disastrous weather related to marine meteorology.