In the realm of psychology and language acquisition,the exploration of“individual differences”-encompassing attributes such as personality traits,motivation,and language aptitude-has long been a focal point of schol...In the realm of psychology and language acquisition,the exploration of“individual differences”-encompassing attributes such as personality traits,motivation,and language aptitude-has long been a focal point of scholarly investigation.Within this sphere,the book“Researching Creativity in Second Language Acquisition”by Ashleigh Pipes offers a fresh perspective on the role of creativity as a significant individual difference in Second Language Acquisition(SLA).Positioned against the backdrop of extensive empirical research on individual differences,this book stands out by focusing on the often overlooked aspect of creativity,which Pipes argues,holds paramount importance in SLA.展开更多
In today’s society,the need for talent training is of utmost importance due to rapid development.To achieve high-quality talent training,we need to focus on building a collaborative education mechanism.Practical teac...In today’s society,the need for talent training is of utmost importance due to rapid development.To achieve high-quality talent training,we need to focus on building a collaborative education mechanism.Practical teaching and the second classroom,which serve as important carriers of educational talents,must align their educational goals and complement each other.This article explores the collaborative education mechanism of the second classroom and practical teaching for the ideological and political courses in colleges and universities.It proposes reasonable construction measures to provide some guidelines for teaching work.展开更多
The teaching of English speeches in universities aims to enhance oral communication ability,improve English communication skills,and expand English knowledge,occupying a core position in English teaching in universiti...The teaching of English speeches in universities aims to enhance oral communication ability,improve English communication skills,and expand English knowledge,occupying a core position in English teaching in universities.This article takes the theory of second language acquisition as the background,analyzes the important role and value of this theory in English speech teaching in universities,and explores how to apply the theory of second language acquisition in English speech teaching in universities.It aims to strengthen the cultivation of English skilled talents and provide a brief reference for improving English speech teaching in universities.展开更多
Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is d...Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is diagnosed by the electric field induced second harmonic(E-FISH)method,and the time-resolved electric field under different conditions is investigated.When positive pulse voltage is applied,the electric field has a peak of about 25 kV cm-1at the rising edge of the voltage pulse.A dark channel is left behind the plasma bullet and the electric field in the dark channel is about 5 kV cm-1.On the other hand,when negative pulse voltage is applied,the electric field has a peak of-16 kV cm-1when the negative voltage is increased to-8 kV.A relatively bright channel is left behind the plasma head and the electric field in this relatively bright channel is about-6 kV cm-1.When the pulse rising time increases from 60 to 200 ns,the peak electric field at both the rising edge and the falling edge of the voltage decreases significantly.When 0.5%of oxygen is added to the main working gas helium,the peak electric field at the rising edge is only about 15 kV cm-1.On the other hand,when 0.5%nitrogen is added,the peak electric field increases especially at the falling edge of the voltage pulse,where it increases reversely from-12 to-16 kV cm-1(the minus sign only represents the direction of electric field).展开更多
Rechargeable magnesium batteries(RMBs),as one of the most promising candidates for efficient energy storage devices with high energy,power density and high safety,have attracted increasing attention.However,searching ...Rechargeable magnesium batteries(RMBs),as one of the most promising candidates for efficient energy storage devices with high energy,power density and high safety,have attracted increasing attention.However,searching for suitable cathode materials with fast diffusion kinetics and exploring their magnesium storage mechanisms remains a great challenge.Cu S submicron spheres,made by a facile low-temperature synthesis strategy,were applied as the high-performance cathode for RMBs in this work,which can deliver a high specific capacity of 396mAh g^(-1)at 20 mA g^(-1) and a remarkable rate capacity of 250 m Ah g^(-1)at 1000 mA g^(-1).The excellent rate performance can be assigned to the nano needle-like particles on the surface of Cu S submicron spheres,which can facilitate the diffusion kinetics of Mg^(2+).Further storage mechanism investigations illustrate that the Cu S cathodes experience a two-step conversion reaction controlled by diffusion during the electrochemical reaction process.This work could make a contribution to the study of the enhancement of diffusion kinetics of Mg2+and the reaction mechanism of RMBs.展开更多
Based on the Hirota bilinear method,the second extended(3+1)-dimensional Jimbo–Miwa equation is established.By Maple symbolic calculation,lump and lump-kink soliton solutions are obtained.The interaction solutions be...Based on the Hirota bilinear method,the second extended(3+1)-dimensional Jimbo–Miwa equation is established.By Maple symbolic calculation,lump and lump-kink soliton solutions are obtained.The interaction solutions between the lump and multi-kink soliton,and the interaction between the lump and triangular periodic soliton are derived by combining a multi-exponential function or trigonometric sine and cosine functions with quadratic functions.Furthermore,periodiclump wave solution is derived via the ansatz including hyperbolic and trigonometric functions.Finally,3D plots,2D curves,density plots,and contour plots with particular choices of the suitable parameters are depicted to illustrate the dynamical features of these solutions.展开更多
Introduction: Measles is a viral disease that is a major public health problem in both developed and developing countries. It is a contagious disease resulting from infection with the measles virus and is still respon...Introduction: Measles is a viral disease that is a major public health problem in both developed and developing countries. It is a contagious disease resulting from infection with the measles virus and is still responsible for more than 100,000 deaths per year. Although vaccination is one of the most successful and cost-effective public health interventions to reduce mortality and morbidity, approximately 1.4 million children worldwide die from vaccine-preventable diseases each year. In Zambia, MCV2 was 66% below WHO recommended target of 95%. This study therefore assessed the acceptability of second dose measles vaccination services among caretakers/mothers with children less than two years of age in Livingstone, Zambia. Methods: The study used analytical cross-sectional study design. A logistic regression analysis was performed to identify factors associated with acceptability of the second dose of measles vaccine. A semi structured questionnaire was administered to collect data on socio demographic characteristics and factors related to acceptability of the second dose of measles vaccine. SPSS version 26.0 was used for descriptive and inferential analysis at 5% level of significance. Results: There was no statistically significant difference in acceptability of the second dose of measles vaccine by gender, marital status, type of employment, income level, socio-cultural and traditional beliefs, and education level. However, there was a statistically significant difference in acceptability of the second dose of measles vaccine by knowledge level of second dose of measles vaccine. A Chi square test result indicated that second dose acceptability was higher with less children than that of respondents with many children (χ2(5) = 15.3, p and knowledge levels (χ2(2) = 14.8, p Changes in knowledge level from medium to high reduced the odds of second dose measles vaccine acceptability. Furthermore, this study showed that acceptance of the second measles vaccination increased from mothers/caretakers with low knowledge (3.6%) to medium knowledge (13.3%) and finally high knowledge (83.1%). Conclusion: Tailored messaging to increase knowledge among mothers and caregivers on the importance of the second dose of measles vaccine is critical in improving acceptability. Therefore, the researchers recommend that the health providers should continue to raise awareness associated with the low acceptability of the second dose of measles vaccine and improve on child preventable diseases such as measles.展开更多
Background: Anemia is one of the most prevalent complications during pregnancy. It is commonly considered a risk factor for poor pregnancy outcomes and can result in complications that threaten the life of both mother...Background: Anemia is one of the most prevalent complications during pregnancy. It is commonly considered a risk factor for poor pregnancy outcomes and can result in complications that threaten the life of both mother and fetus, such as preterm birth, and low birth weight. There is clear evidence to support prompt treatment in all patients with iron deficiency anemia because it is known that treatment improves quality of life and physical condition as well as alleviates fatigue and cognitive deficits. Objective: The aim of the study was to evaluate the value of addition of vitamin B6 to iron in treatment of iron deficiency anemia in pregnant women during the second trimester. Patients and Methods: The study was done by giving anemia pregnant women iron therapy and vitamin B6 which represent group A and iron therapy alone which represents group B. For each pregnant woman, age, parity and gestational history were taken before treatment. All pregnant women took their allocated treatment regularly for three weeks after diagnosis of iron deficiency anemia with complete blood picture and followed up after three weeks. Results: Results of the study revealed that there was no statistically significant difference between the two groups of therapy according to the hemoglobin level before treatment (p-value = 0.734), statistically significant higher mean value in after treatment than before treatment (p-value = 0.048), there was a significant difference in the rate of change of hemoglobin (p-value = 0.011) and body mass index (p-value 0.001). Conclusion: Iron and vitamin B6 seems to increase hemoglobin level more than iron only. Thus, in pregnant women with iron deficiency anemia iron plus vitamin B6 may be considered as a more effective alternative treatment than iron only.展开更多
Middle-mesial canals in mandibular molars are present in the population depending on age, sex and ethnicity. However, limited literature alludes to its prevalence. Troughing procedures may enhance identification, clea...Middle-mesial canals in mandibular molars are present in the population depending on age, sex and ethnicity. However, limited literature alludes to its prevalence. Troughing procedures may enhance identification, cleaning and shaping. This case report expresses the recognition and management of middle-mesial canal in a mandibular second molar of 24 years old Hispanic-Latino male.展开更多
This work presents the “Second-Order Comprehensive Adjoint Sensitivity Analysis Methodology (2<sup>nd</sup>-CASAM)” for the efficient and exact computation of 1<sup>st</sup>- and 2<sup>...This work presents the “Second-Order Comprehensive Adjoint Sensitivity Analysis Methodology (2<sup>nd</sup>-CASAM)” for the efficient and exact computation of 1<sup>st</sup>- and 2<sup>nd</sup>-order response sensitivities to uncertain parameters and domain boundaries of linear systems. The model’s response (<em>i.e.</em>, model result of interest) is a generic nonlinear function of the model’s forward and adjoint state functions, and also depends on the imprecisely known boundaries and model parameters. In the practically important particular case when the response is a scalar-valued functional of the forward and adjoint state functions characterizing a model comprising N parameters, the 2<sup>nd</sup>-CASAM requires a single large-scale computation using the First-Level Adjoint Sensitivity System (1<sup>st</sup>-LASS) for obtaining all of the first-order response sensitivities, and at most N large-scale computations using the Second-Level Adjoint Sensitivity System (2<sup>nd</sup>-LASS) for obtaining exactly all of the second-order response sensitivities. In contradistinction, forward other methods would require (<em>N</em>2/2 + 3 <em>N</em>/2) large-scale computations for obtaining all of the first- and second-order sensitivities. This work also shows that constructing and solving the 2<sup>nd</sup>-LASS requires very little additional effort beyond the construction of the 1<sup>st</sup>-LASS needed for computing the first-order sensitivities. Solving the equations underlying the 1<sup>st</sup>-LASS and 2<sup>nd</sup>-LASS requires the same computational solvers as needed for solving (<em>i.e.</em>, “inverting”) either the forward or the adjoint linear operators underlying the initial model. Therefore, the same computer software and “solvers” used for solving the original system of equations can also be used for solving the 1<sup>st</sup>-LASS and the 2<sup>nd</sup>-LASS. Since neither the 1<sup>st</sup>-LASS nor the 2<sup>nd</sup>-LASS involves any differentials of the operators underlying the original system, the 1<sup>st</sup>-LASS is designated as a “<u>first-level</u>” (as opposed to a “first-order”) adjoint sensitivity system, while the 2<sup>nd</sup>-LASS is designated as a “<u>second-level</u>” (rather than a “second-order”) adjoint sensitivity system. Mixed second-order response sensitivities involving boundary parameters may arise from all source terms of the 2<sup>nd</sup>-LASS that involve the imprecisely known boundary parameters. Notably, the 2<sup>nd</sup>-LASS encompasses an automatic, inherent, and independent “solution verification” mechanism of the correctness and accuracy of the 2nd-level adjoint functions needed for the efficient and exact computation of the second-order sensitivities.展开更多
BACKGROUND The increasing kidney retransplantation rate has created a parallel field of research,including the risk factors and outcomes of this advanced form of renal replacement therapy.The presentation of experienc...BACKGROUND The increasing kidney retransplantation rate has created a parallel field of research,including the risk factors and outcomes of this advanced form of renal replacement therapy.The presentation of experiences from different kidney transplantation centers may help enrich the literature on kidney retransplantation,as a specific topic in the field of kidney transplantation.AIM To identify the risk factors affecting primary graft function and graft survival rates after second kidney transplantation(SKT).METHODS The records of SKT cases performed between January 1977 and December 2014 at a European tertiary-level kidney transplantation center were retrospectively reviewed and analyzed.Beside the descriptive characteristics,the survivals of patients and both the first and second grafts were described using Kaplan-Meier curves.In addition,Kaplan-Meier analyses were also used to estimate the survival probabilities at 1,3,5,and 10 post-operative years,as well as at the longest followup duration available.Moreover,bivariate associations between various predictors and the categorical outcomes were assessed,using the suitable biostatistical tests,according to the predictor type.RESULTS Out of 1861 cases of kidney transplantation,only 48 cases with SKT were eligible for studying,including 33 men and 15 women with a mean age of 42.1±13 years.The primary non-function(PNF)graft occurred in five patients(10.4%).In bivariate analyses,a high body mass index(P=0.009)and first graft loss due to acute rejection(P=0.025)were the only significant predictors of PNF graft.The second graft survival was reduced by delayed graft function in the first(P=0.008)and second(P<0.001)grafts.However,the effect of acute rejection within the first year after the first transplant did not reach the threshold of significance(P=0.053).The mean follow-up period was 59.8±48.6 mo.Censored graft/patient survival rates at 1,3,5 and 10 years were 90.5%/97.9%,79.9%/95.6%,73.7%/91.9%,and 51.6%/83.0%,respectively.CONCLUSION Non-immediate recovery modes of the first and second graft functions were significantly associated with unfavorable second graft survival rates.Patient and graft survival rates of SKT were similar to those of the first kidney transplantation.展开更多
Language teaching is not a one-way process.It interacts with language learning in an extremely intricate way.To improve language teaching,we need to take the process of language learning into account.This paper tries ...Language teaching is not a one-way process.It interacts with language learning in an extremely intricate way.To improve language teaching,we need to take the process of language learning into account.This paper tries to explore and understand what strategies the second language learners consciously or subconsciously adopt during their language learning process through the analyses of the linguistic errors they commit,so as to provide some insights into language teaching practice.展开更多
In recent years,traditional Chinese culture has been continuously revived,integrated into the times and entered people’s daily lives.Chinese-style songs,as a combination of traditional cultural connotations and emerg...In recent years,traditional Chinese culture has been continuously revived,integrated into the times and entered people’s daily lives.Chinese-style songs,as a combination of traditional cultural connotations and emerging song forms,have gradually emerged on the music stage in China and even around the world.In the field of teaching Chinese as a second language,the research on teaching Chinese songs has received increasing attention.This article combines the theory of the association between music and language to summarize the research results of Chinese-style songs and their application in the field of teaching Chinese as a second language in the past 30 years.The current research problems are discussed,and suggestions are proposed in order to provide some reference value for teaching Chinese as a second language.展开更多
Motivation is a key factor that influences the outcome of second language(L2)learning.Chinese as a second language(CSL)learners,however,may experience demotivation in their Chinese learning process which will,more oft...Motivation is a key factor that influences the outcome of second language(L2)learning.Chinese as a second language(CSL)learners,however,may experience demotivation in their Chinese learning process which will,more often than not,reduce their learning interest and eventually affect their learning effect,therefore,it is necessary to enhance the learners’motivation level.This article first reviews the research literature in motivation in general,then discusses the CSL learners’demotivation in their Chinses learning process studying in China.Finally,it introduces motivational strategies to activate CSL learners’motivation in learning Chinese.展开更多
In cognitive linguistics,debates on the status and functions of categorization have been a heated issue.In semantics and second language acquisition,scholars have discussed and achieved vocabulary acquisition from dif...In cognitive linguistics,debates on the status and functions of categorization have been a heated issue.In semantics and second language acquisition,scholars have discussed and achieved vocabulary acquisition from different perspectives and academic levels.Vocabulary learning exerts a fundamental role in second language vocabulary acquisition(SLVA),and it is closely related to learners’cognitive competence.However,studies on second language vocabulary acquisition under the categorization theory in cognitive linguistics have received less attention from linguists when compared with other studies.This paper employs two representative dimensions,the basic-level effect and the prototype effect,under the categorization theory to further delve into the implications on second language vocabulary acquisition.This article first provides a comprehensive introduction to the nature and the approaches of the categorization theory,and then analyzes the relations and implications for second language vocabulary acquisition under the categorization theory from the perspective of the basic-level and the prototype effects.The research results showed that the basic-level effect on SLVA is mainly on the classification of word categories distinguished from the superordinate and subordinate categories,while the prototype effect is more on understanding the complexity and use of word meaning.展开更多
In this paper, we define some new sets of non-elementary functions in a group of solutions x(t) that are sine and cosine to the upper limit of integration in a non-elementary integral that can be arbitrary. We are usi...In this paper, we define some new sets of non-elementary functions in a group of solutions x(t) that are sine and cosine to the upper limit of integration in a non-elementary integral that can be arbitrary. We are using Abel’s methods, described by Armitage and Eberlein. The key is to start with a non-elementary integral function, differentiating and inverting, and then define a set of three functions that belong together. Differentiating these functions twice gives second-order nonlinear ODEs that have the defined set of functions as solutions. We will study some of the second-order nonlinear ODEs, especially those that exhibit limit cycles. Using the methods described in this paper, it is possible to define many other sets of non-elementary functions that are giving solutions to some second-order nonlinear autonomous ODEs.展开更多
This work presents a comprehensive second-order predictive modeling (PM) methodology based on the maximum entropy (MaxEnt) principle for obtaining best-estimate mean values and correlations for model responses and par...This work presents a comprehensive second-order predictive modeling (PM) methodology based on the maximum entropy (MaxEnt) principle for obtaining best-estimate mean values and correlations for model responses and parameters. This methodology is designated by the acronym 2<sup>nd</sup>-BERRU-PMP, where the attribute “2<sup>nd</sup>” indicates that this methodology incorporates second- order uncertainties (means and covariances) and second (and higher) order sensitivities of computed model responses to model parameters. The acronym BERRU stands for “Best-Estimate Results with Reduced Uncertainties” and the last letter (“P”) in the acronym indicates “probabilistic,” referring to the MaxEnt probabilistic inclusion of the computational model responses. This is in contradistinction to the 2<sup>nd</sup>-BERRU-PMD methodology, which deterministically combines the computed model responses with the experimental information, as presented in the accompanying work (Part I). Although both the 2<sup>nd</sup>-BERRU-PMP and the 2<sup>nd</sup>-BERRU-PMD methodologies yield expressions that include second (and higher) order sensitivities of responses to model parameters, the respective expressions for the predicted responses, for the calibrated predicted parameters and for their predicted uncertainties (covariances), are not identical to each other. Nevertheless, the results predicted by both the 2<sup>nd</sup>-BERRU-PMP and the 2<sup>nd</sup>-BERRU-PMD methodologies encompass, as particular cases, the results produced by the extant data assimilation and data adjustment procedures, which rely on the minimization, in a least-square sense, of a user-defined functional meant to represent the discrepancies between measured and computed model responses.展开更多
This work presents a comprehensive second-order predictive modeling (PM) methodology designated by the acronym 2<sup>nd</sup>-BERRU-PMD. The attribute “2<sup>nd</sup>” indicates that this met...This work presents a comprehensive second-order predictive modeling (PM) methodology designated by the acronym 2<sup>nd</sup>-BERRU-PMD. The attribute “2<sup>nd</sup>” indicates that this methodology incorporates second-order uncertainties (means and covariances) and second-order sensitivities of computed model responses to model parameters. The acronym BERRU stands for “Best- Estimate Results with Reduced Uncertainties” and the last letter (“D”) in the acronym indicates “deterministic,” referring to the deterministic inclusion of the computational model responses. The 2<sup>nd</sup>-BERRU-PMD methodology is fundamentally based on the maximum entropy (MaxEnt) principle. This principle is in contradistinction to the fundamental principle that underlies the extant data assimilation and/or adjustment procedures which minimize in a least-square sense a subjective user-defined functional which is meant to represent the discrepancies between measured and computed model responses. It is shown that the 2<sup>nd</sup>-BERRU-PMD methodology generalizes and extends current data assimilation and/or data adjustment procedures while overcoming the fundamental limitations of these procedures. In the accompanying work (Part II), the alternative framework for developing the “second- order MaxEnt predictive modelling methodology” is presented by incorporating probabilistically (as opposed to “deterministically”) the computed model responses.展开更多
This work illustrates the innovative results obtained by applying the recently developed the 2<sup>nd</sup>-order predictive modeling methodology called “2<sup>nd</sup>- BERRU-PM”, where the ...This work illustrates the innovative results obtained by applying the recently developed the 2<sup>nd</sup>-order predictive modeling methodology called “2<sup>nd</sup>- BERRU-PM”, where the acronym BERRU denotes “best-estimate results with reduced uncertainties” and “PM” denotes “predictive modeling.” The physical system selected for this illustrative application is a polyethylene-reflected plutonium (acronym: PERP) OECD/NEA reactor physics benchmark. This benchmark is modeled using the neutron transport Boltzmann equation (involving 21,976 uncertain parameters), the solution of which is representative of “large-scale computations.” The results obtained in this work confirm the fact that the 2<sup>nd</sup>-BERRU-PM methodology predicts best-estimate results that fall in between the corresponding computed and measured values, while reducing the predicted standard deviations of the predicted results to values smaller than either the experimentally measured or the computed values of the respective standard deviations. The obtained results also indicate that 2<sup>nd</sup>-order response sensitivities must always be included to quantify the need for including (or not) the 3<sup>rd</sup>- and/or 4<sup>th</sup>-order sensitivities. When the parameters are known with high precision, the contributions of the higher-order sensitivities diminish with increasing order, so that the inclusion of the 1<sup>st</sup>- and 2<sup>nd</sup>-order sensitivities may suffice for obtaining accurate predicted best- estimate response values and best-estimate standard deviations. On the other hand, when the parameters’ standard deviations are sufficiently large to approach (or be outside of) the radius of convergence of the multivariate Taylor-series which represents the response in the phase-space of model parameters, the contributions stemming from the 3<sup>rd</sup>- and even 4<sup>th</sup>-order sensitivities are necessary to ensure consistency between the computed and measured response. In such cases, the use of only the 1<sup>st</sup>-order sensitivities erroneously indicates that the computed results are inconsistent with the respective measured response. Ongoing research aims at extending the 2<sup>nd</sup>-BERRU-PM methodology to fourth-order, thus enabling the computation of third-order response correlations (skewness) and fourth-order response correlations (kurtosis).展开更多
文摘In the realm of psychology and language acquisition,the exploration of“individual differences”-encompassing attributes such as personality traits,motivation,and language aptitude-has long been a focal point of scholarly investigation.Within this sphere,the book“Researching Creativity in Second Language Acquisition”by Ashleigh Pipes offers a fresh perspective on the role of creativity as a significant individual difference in Second Language Acquisition(SLA).Positioned against the backdrop of extensive empirical research on individual differences,this book stands out by focusing on the often overlooked aspect of creativity,which Pipes argues,holds paramount importance in SLA.
文摘In today’s society,the need for talent training is of utmost importance due to rapid development.To achieve high-quality talent training,we need to focus on building a collaborative education mechanism.Practical teaching and the second classroom,which serve as important carriers of educational talents,must align their educational goals and complement each other.This article explores the collaborative education mechanism of the second classroom and practical teaching for the ideological and political courses in colleges and universities.It proposes reasonable construction measures to provide some guidelines for teaching work.
文摘The teaching of English speeches in universities aims to enhance oral communication ability,improve English communication skills,and expand English knowledge,occupying a core position in English teaching in universities.This article takes the theory of second language acquisition as the background,analyzes the important role and value of this theory in English speech teaching in universities,and explores how to apply the theory of second language acquisition in English speech teaching in universities.It aims to strengthen the cultivation of English skilled talents and provide a brief reference for improving English speech teaching in universities.
基金National Key Research and Development Program of China(No.2021YFE0114700)National Natural Science Foundation of China(Nos.52130701 and 51977096)。
文摘Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is diagnosed by the electric field induced second harmonic(E-FISH)method,and the time-resolved electric field under different conditions is investigated.When positive pulse voltage is applied,the electric field has a peak of about 25 kV cm-1at the rising edge of the voltage pulse.A dark channel is left behind the plasma bullet and the electric field in the dark channel is about 5 kV cm-1.On the other hand,when negative pulse voltage is applied,the electric field has a peak of-16 kV cm-1when the negative voltage is increased to-8 kV.A relatively bright channel is left behind the plasma head and the electric field in this relatively bright channel is about-6 kV cm-1.When the pulse rising time increases from 60 to 200 ns,the peak electric field at both the rising edge and the falling edge of the voltage decreases significantly.When 0.5%of oxygen is added to the main working gas helium,the peak electric field at the rising edge is only about 15 kV cm-1.On the other hand,when 0.5%nitrogen is added,the peak electric field increases especially at the falling edge of the voltage pulse,where it increases reversely from-12 to-16 kV cm-1(the minus sign only represents the direction of electric field).
基金the support from the Fundamental Research Funds for the Central Universities of Chongqing University(No.2020CDCGCL005)。
文摘Rechargeable magnesium batteries(RMBs),as one of the most promising candidates for efficient energy storage devices with high energy,power density and high safety,have attracted increasing attention.However,searching for suitable cathode materials with fast diffusion kinetics and exploring their magnesium storage mechanisms remains a great challenge.Cu S submicron spheres,made by a facile low-temperature synthesis strategy,were applied as the high-performance cathode for RMBs in this work,which can deliver a high specific capacity of 396mAh g^(-1)at 20 mA g^(-1) and a remarkable rate capacity of 250 m Ah g^(-1)at 1000 mA g^(-1).The excellent rate performance can be assigned to the nano needle-like particles on the surface of Cu S submicron spheres,which can facilitate the diffusion kinetics of Mg^(2+).Further storage mechanism investigations illustrate that the Cu S cathodes experience a two-step conversion reaction controlled by diffusion during the electrochemical reaction process.This work could make a contribution to the study of the enhancement of diffusion kinetics of Mg2+and the reaction mechanism of RMBs.
文摘Based on the Hirota bilinear method,the second extended(3+1)-dimensional Jimbo–Miwa equation is established.By Maple symbolic calculation,lump and lump-kink soliton solutions are obtained.The interaction solutions between the lump and multi-kink soliton,and the interaction between the lump and triangular periodic soliton are derived by combining a multi-exponential function or trigonometric sine and cosine functions with quadratic functions.Furthermore,periodiclump wave solution is derived via the ansatz including hyperbolic and trigonometric functions.Finally,3D plots,2D curves,density plots,and contour plots with particular choices of the suitable parameters are depicted to illustrate the dynamical features of these solutions.
文摘Introduction: Measles is a viral disease that is a major public health problem in both developed and developing countries. It is a contagious disease resulting from infection with the measles virus and is still responsible for more than 100,000 deaths per year. Although vaccination is one of the most successful and cost-effective public health interventions to reduce mortality and morbidity, approximately 1.4 million children worldwide die from vaccine-preventable diseases each year. In Zambia, MCV2 was 66% below WHO recommended target of 95%. This study therefore assessed the acceptability of second dose measles vaccination services among caretakers/mothers with children less than two years of age in Livingstone, Zambia. Methods: The study used analytical cross-sectional study design. A logistic regression analysis was performed to identify factors associated with acceptability of the second dose of measles vaccine. A semi structured questionnaire was administered to collect data on socio demographic characteristics and factors related to acceptability of the second dose of measles vaccine. SPSS version 26.0 was used for descriptive and inferential analysis at 5% level of significance. Results: There was no statistically significant difference in acceptability of the second dose of measles vaccine by gender, marital status, type of employment, income level, socio-cultural and traditional beliefs, and education level. However, there was a statistically significant difference in acceptability of the second dose of measles vaccine by knowledge level of second dose of measles vaccine. A Chi square test result indicated that second dose acceptability was higher with less children than that of respondents with many children (χ2(5) = 15.3, p and knowledge levels (χ2(2) = 14.8, p Changes in knowledge level from medium to high reduced the odds of second dose measles vaccine acceptability. Furthermore, this study showed that acceptance of the second measles vaccination increased from mothers/caretakers with low knowledge (3.6%) to medium knowledge (13.3%) and finally high knowledge (83.1%). Conclusion: Tailored messaging to increase knowledge among mothers and caregivers on the importance of the second dose of measles vaccine is critical in improving acceptability. Therefore, the researchers recommend that the health providers should continue to raise awareness associated with the low acceptability of the second dose of measles vaccine and improve on child preventable diseases such as measles.
文摘Background: Anemia is one of the most prevalent complications during pregnancy. It is commonly considered a risk factor for poor pregnancy outcomes and can result in complications that threaten the life of both mother and fetus, such as preterm birth, and low birth weight. There is clear evidence to support prompt treatment in all patients with iron deficiency anemia because it is known that treatment improves quality of life and physical condition as well as alleviates fatigue and cognitive deficits. Objective: The aim of the study was to evaluate the value of addition of vitamin B6 to iron in treatment of iron deficiency anemia in pregnant women during the second trimester. Patients and Methods: The study was done by giving anemia pregnant women iron therapy and vitamin B6 which represent group A and iron therapy alone which represents group B. For each pregnant woman, age, parity and gestational history were taken before treatment. All pregnant women took their allocated treatment regularly for three weeks after diagnosis of iron deficiency anemia with complete blood picture and followed up after three weeks. Results: Results of the study revealed that there was no statistically significant difference between the two groups of therapy according to the hemoglobin level before treatment (p-value = 0.734), statistically significant higher mean value in after treatment than before treatment (p-value = 0.048), there was a significant difference in the rate of change of hemoglobin (p-value = 0.011) and body mass index (p-value 0.001). Conclusion: Iron and vitamin B6 seems to increase hemoglobin level more than iron only. Thus, in pregnant women with iron deficiency anemia iron plus vitamin B6 may be considered as a more effective alternative treatment than iron only.
文摘Middle-mesial canals in mandibular molars are present in the population depending on age, sex and ethnicity. However, limited literature alludes to its prevalence. Troughing procedures may enhance identification, cleaning and shaping. This case report expresses the recognition and management of middle-mesial canal in a mandibular second molar of 24 years old Hispanic-Latino male.
文摘This work presents the “Second-Order Comprehensive Adjoint Sensitivity Analysis Methodology (2<sup>nd</sup>-CASAM)” for the efficient and exact computation of 1<sup>st</sup>- and 2<sup>nd</sup>-order response sensitivities to uncertain parameters and domain boundaries of linear systems. The model’s response (<em>i.e.</em>, model result of interest) is a generic nonlinear function of the model’s forward and adjoint state functions, and also depends on the imprecisely known boundaries and model parameters. In the practically important particular case when the response is a scalar-valued functional of the forward and adjoint state functions characterizing a model comprising N parameters, the 2<sup>nd</sup>-CASAM requires a single large-scale computation using the First-Level Adjoint Sensitivity System (1<sup>st</sup>-LASS) for obtaining all of the first-order response sensitivities, and at most N large-scale computations using the Second-Level Adjoint Sensitivity System (2<sup>nd</sup>-LASS) for obtaining exactly all of the second-order response sensitivities. In contradistinction, forward other methods would require (<em>N</em>2/2 + 3 <em>N</em>/2) large-scale computations for obtaining all of the first- and second-order sensitivities. This work also shows that constructing and solving the 2<sup>nd</sup>-LASS requires very little additional effort beyond the construction of the 1<sup>st</sup>-LASS needed for computing the first-order sensitivities. Solving the equations underlying the 1<sup>st</sup>-LASS and 2<sup>nd</sup>-LASS requires the same computational solvers as needed for solving (<em>i.e.</em>, “inverting”) either the forward or the adjoint linear operators underlying the initial model. Therefore, the same computer software and “solvers” used for solving the original system of equations can also be used for solving the 1<sup>st</sup>-LASS and the 2<sup>nd</sup>-LASS. Since neither the 1<sup>st</sup>-LASS nor the 2<sup>nd</sup>-LASS involves any differentials of the operators underlying the original system, the 1<sup>st</sup>-LASS is designated as a “<u>first-level</u>” (as opposed to a “first-order”) adjoint sensitivity system, while the 2<sup>nd</sup>-LASS is designated as a “<u>second-level</u>” (rather than a “second-order”) adjoint sensitivity system. Mixed second-order response sensitivities involving boundary parameters may arise from all source terms of the 2<sup>nd</sup>-LASS that involve the imprecisely known boundary parameters. Notably, the 2<sup>nd</sup>-LASS encompasses an automatic, inherent, and independent “solution verification” mechanism of the correctness and accuracy of the 2nd-level adjoint functions needed for the efficient and exact computation of the second-order sensitivities.
基金this study were approved by the Ethical Committee(Institutional Review Board,IRB)of the Faculty of Medicine,Assiut University,Egypt and Martin-Luther University,Germany(IRB approval number:17200548/2015).
文摘BACKGROUND The increasing kidney retransplantation rate has created a parallel field of research,including the risk factors and outcomes of this advanced form of renal replacement therapy.The presentation of experiences from different kidney transplantation centers may help enrich the literature on kidney retransplantation,as a specific topic in the field of kidney transplantation.AIM To identify the risk factors affecting primary graft function and graft survival rates after second kidney transplantation(SKT).METHODS The records of SKT cases performed between January 1977 and December 2014 at a European tertiary-level kidney transplantation center were retrospectively reviewed and analyzed.Beside the descriptive characteristics,the survivals of patients and both the first and second grafts were described using Kaplan-Meier curves.In addition,Kaplan-Meier analyses were also used to estimate the survival probabilities at 1,3,5,and 10 post-operative years,as well as at the longest followup duration available.Moreover,bivariate associations between various predictors and the categorical outcomes were assessed,using the suitable biostatistical tests,according to the predictor type.RESULTS Out of 1861 cases of kidney transplantation,only 48 cases with SKT were eligible for studying,including 33 men and 15 women with a mean age of 42.1±13 years.The primary non-function(PNF)graft occurred in five patients(10.4%).In bivariate analyses,a high body mass index(P=0.009)and first graft loss due to acute rejection(P=0.025)were the only significant predictors of PNF graft.The second graft survival was reduced by delayed graft function in the first(P=0.008)and second(P<0.001)grafts.However,the effect of acute rejection within the first year after the first transplant did not reach the threshold of significance(P=0.053).The mean follow-up period was 59.8±48.6 mo.Censored graft/patient survival rates at 1,3,5 and 10 years were 90.5%/97.9%,79.9%/95.6%,73.7%/91.9%,and 51.6%/83.0%,respectively.CONCLUSION Non-immediate recovery modes of the first and second graft functions were significantly associated with unfavorable second graft survival rates.Patient and graft survival rates of SKT were similar to those of the first kidney transplantation.
文摘Language teaching is not a one-way process.It interacts with language learning in an extremely intricate way.To improve language teaching,we need to take the process of language learning into account.This paper tries to explore and understand what strategies the second language learners consciously or subconsciously adopt during their language learning process through the analyses of the linguistic errors they commit,so as to provide some insights into language teaching practice.
文摘In recent years,traditional Chinese culture has been continuously revived,integrated into the times and entered people’s daily lives.Chinese-style songs,as a combination of traditional cultural connotations and emerging song forms,have gradually emerged on the music stage in China and even around the world.In the field of teaching Chinese as a second language,the research on teaching Chinese songs has received increasing attention.This article combines the theory of the association between music and language to summarize the research results of Chinese-style songs and their application in the field of teaching Chinese as a second language in the past 30 years.The current research problems are discussed,and suggestions are proposed in order to provide some reference value for teaching Chinese as a second language.
基金This article is supported by the following projects:A Study on Individual Differences in Chinese Learning Needs and the Effect of Chinese Learning of International Students in Anhui Province(Grant No.SK2020A0034)A Study on the Effective Input and Output of Multimodal Synergy in College English Audio-video Classroom(Grant No.acjyyb2022078).
文摘Motivation is a key factor that influences the outcome of second language(L2)learning.Chinese as a second language(CSL)learners,however,may experience demotivation in their Chinese learning process which will,more often than not,reduce their learning interest and eventually affect their learning effect,therefore,it is necessary to enhance the learners’motivation level.This article first reviews the research literature in motivation in general,then discusses the CSL learners’demotivation in their Chinses learning process studying in China.Finally,it introduces motivational strategies to activate CSL learners’motivation in learning Chinese.
基金“Research on the Development Path of Ideological Leadership of Ideological and Political Education in Colleges and Universities in the New Era”of the Counselor Special Research Projects of Furlong College,Hunan University of Science and Arts in 2023(Project number:FRfdy2307)。
文摘In cognitive linguistics,debates on the status and functions of categorization have been a heated issue.In semantics and second language acquisition,scholars have discussed and achieved vocabulary acquisition from different perspectives and academic levels.Vocabulary learning exerts a fundamental role in second language vocabulary acquisition(SLVA),and it is closely related to learners’cognitive competence.However,studies on second language vocabulary acquisition under the categorization theory in cognitive linguistics have received less attention from linguists when compared with other studies.This paper employs two representative dimensions,the basic-level effect and the prototype effect,under the categorization theory to further delve into the implications on second language vocabulary acquisition.This article first provides a comprehensive introduction to the nature and the approaches of the categorization theory,and then analyzes the relations and implications for second language vocabulary acquisition under the categorization theory from the perspective of the basic-level and the prototype effects.The research results showed that the basic-level effect on SLVA is mainly on the classification of word categories distinguished from the superordinate and subordinate categories,while the prototype effect is more on understanding the complexity and use of word meaning.
文摘In this paper, we define some new sets of non-elementary functions in a group of solutions x(t) that are sine and cosine to the upper limit of integration in a non-elementary integral that can be arbitrary. We are using Abel’s methods, described by Armitage and Eberlein. The key is to start with a non-elementary integral function, differentiating and inverting, and then define a set of three functions that belong together. Differentiating these functions twice gives second-order nonlinear ODEs that have the defined set of functions as solutions. We will study some of the second-order nonlinear ODEs, especially those that exhibit limit cycles. Using the methods described in this paper, it is possible to define many other sets of non-elementary functions that are giving solutions to some second-order nonlinear autonomous ODEs.
文摘This work presents a comprehensive second-order predictive modeling (PM) methodology based on the maximum entropy (MaxEnt) principle for obtaining best-estimate mean values and correlations for model responses and parameters. This methodology is designated by the acronym 2<sup>nd</sup>-BERRU-PMP, where the attribute “2<sup>nd</sup>” indicates that this methodology incorporates second- order uncertainties (means and covariances) and second (and higher) order sensitivities of computed model responses to model parameters. The acronym BERRU stands for “Best-Estimate Results with Reduced Uncertainties” and the last letter (“P”) in the acronym indicates “probabilistic,” referring to the MaxEnt probabilistic inclusion of the computational model responses. This is in contradistinction to the 2<sup>nd</sup>-BERRU-PMD methodology, which deterministically combines the computed model responses with the experimental information, as presented in the accompanying work (Part I). Although both the 2<sup>nd</sup>-BERRU-PMP and the 2<sup>nd</sup>-BERRU-PMD methodologies yield expressions that include second (and higher) order sensitivities of responses to model parameters, the respective expressions for the predicted responses, for the calibrated predicted parameters and for their predicted uncertainties (covariances), are not identical to each other. Nevertheless, the results predicted by both the 2<sup>nd</sup>-BERRU-PMP and the 2<sup>nd</sup>-BERRU-PMD methodologies encompass, as particular cases, the results produced by the extant data assimilation and data adjustment procedures, which rely on the minimization, in a least-square sense, of a user-defined functional meant to represent the discrepancies between measured and computed model responses.
文摘This work presents a comprehensive second-order predictive modeling (PM) methodology designated by the acronym 2<sup>nd</sup>-BERRU-PMD. The attribute “2<sup>nd</sup>” indicates that this methodology incorporates second-order uncertainties (means and covariances) and second-order sensitivities of computed model responses to model parameters. The acronym BERRU stands for “Best- Estimate Results with Reduced Uncertainties” and the last letter (“D”) in the acronym indicates “deterministic,” referring to the deterministic inclusion of the computational model responses. The 2<sup>nd</sup>-BERRU-PMD methodology is fundamentally based on the maximum entropy (MaxEnt) principle. This principle is in contradistinction to the fundamental principle that underlies the extant data assimilation and/or adjustment procedures which minimize in a least-square sense a subjective user-defined functional which is meant to represent the discrepancies between measured and computed model responses. It is shown that the 2<sup>nd</sup>-BERRU-PMD methodology generalizes and extends current data assimilation and/or data adjustment procedures while overcoming the fundamental limitations of these procedures. In the accompanying work (Part II), the alternative framework for developing the “second- order MaxEnt predictive modelling methodology” is presented by incorporating probabilistically (as opposed to “deterministically”) the computed model responses.
文摘This work illustrates the innovative results obtained by applying the recently developed the 2<sup>nd</sup>-order predictive modeling methodology called “2<sup>nd</sup>- BERRU-PM”, where the acronym BERRU denotes “best-estimate results with reduced uncertainties” and “PM” denotes “predictive modeling.” The physical system selected for this illustrative application is a polyethylene-reflected plutonium (acronym: PERP) OECD/NEA reactor physics benchmark. This benchmark is modeled using the neutron transport Boltzmann equation (involving 21,976 uncertain parameters), the solution of which is representative of “large-scale computations.” The results obtained in this work confirm the fact that the 2<sup>nd</sup>-BERRU-PM methodology predicts best-estimate results that fall in between the corresponding computed and measured values, while reducing the predicted standard deviations of the predicted results to values smaller than either the experimentally measured or the computed values of the respective standard deviations. The obtained results also indicate that 2<sup>nd</sup>-order response sensitivities must always be included to quantify the need for including (or not) the 3<sup>rd</sup>- and/or 4<sup>th</sup>-order sensitivities. When the parameters are known with high precision, the contributions of the higher-order sensitivities diminish with increasing order, so that the inclusion of the 1<sup>st</sup>- and 2<sup>nd</sup>-order sensitivities may suffice for obtaining accurate predicted best- estimate response values and best-estimate standard deviations. On the other hand, when the parameters’ standard deviations are sufficiently large to approach (or be outside of) the radius of convergence of the multivariate Taylor-series which represents the response in the phase-space of model parameters, the contributions stemming from the 3<sup>rd</sup>- and even 4<sup>th</sup>-order sensitivities are necessary to ensure consistency between the computed and measured response. In such cases, the use of only the 1<sup>st</sup>-order sensitivities erroneously indicates that the computed results are inconsistent with the respective measured response. Ongoing research aims at extending the 2<sup>nd</sup>-BERRU-PM methodology to fourth-order, thus enabling the computation of third-order response correlations (skewness) and fourth-order response correlations (kurtosis).
