Transfer hydrogenation(TH) with in situ generated hydrogen donor is of great importance in reduction reactions, and an alternative strategy to traditional hydrogenation processes involving pressurized molecular hydrog...Transfer hydrogenation(TH) with in situ generated hydrogen donor is of great importance in reduction reactions, and an alternative strategy to traditional hydrogenation processes involving pressurized molecular hydrogen. Ammonia borane(NH3BH3, AB) is a promising material of hydrogen storage, and it has attracted much attention in reductive organic transformations owing to its high activity, good atom economy, nontoxicity, sustainability, and ease of transport and storage. This review focuses on summarizing the recent progress of AB-mediated TH reactions of diverse substrates including nitro compounds, nitriles, imines, alkenes, alkynes, carbonyl compounds(ketones and aldehydes), carbon dioxide,and N-and O-heterocycles. Syntheses protocols(metal-containing and metal-free), the effect of reaction parameters, product distribution, and variation of reactivity are surveyed, and the mechanism of each reaction involving the action mode of AB as well as structure-activity relationships is discussed in detail. Finally, perspectives are presented to highlight the challenges and opportunities for AB-enabled TH reactions of unsaturated compounds.展开更多
In current small batch and customized production mode,the products change rapidly and the personal demand increases sharply.Human-robot cooperation combining the advantages of human and robot is an effective way to so...In current small batch and customized production mode,the products change rapidly and the personal demand increases sharply.Human-robot cooperation combining the advantages of human and robot is an effective way to solve the complex assembly.However,the poor reusability of historical assembly knowledge reduces the adaptability of assembly system to different tasks.For cross-domain strategy transfer,we propose a human-robot cooperative assembly(HRCA)framework which consists of three main modules:expression of HRCA strategy,transferring of HRCA strategy,and adaptive planning of motion path.Based on the analysis of subject capability and component properties,the HRCA strategy suitable for specific tasks is designed.Then the reinforcement learning is established to optimize the parameters of target encoder for feature extraction.After classification and segmentation,the actor-critic model is built to realize the adaptive path planning with progressive neural network.Finally,the proposed framework is verified to adapt to the multi-variety environment,for example,power lithium batteries.展开更多
Rolling bearings are key components of the drivetrain in wind turbines,and their health is critical to wind turbine operation.In practical diagnosis tasks,the vibration signal is usually interspersed with many disturb...Rolling bearings are key components of the drivetrain in wind turbines,and their health is critical to wind turbine operation.In practical diagnosis tasks,the vibration signal is usually interspersed with many disturbing components,and the variation of operating conditions leads to unbalanced data distribution among different conditions.Although intelligent diagnosis methods based on deep learning have been intensively studied,it is still challenging to diagnose rolling bearing faults with small amounts of samples.To address the above issue,we introduce the deep residual joint transfer strategy method for the cross-condition fault diagnosis of rolling bearings.One-dimensional vibration signals are pre-processed by overlapping feature extraction techniques to fully extract fault characteristics.The deep residual network is trained in training tasks with sufficient samples,for fault pattern classification.Subsequently,three transfer strategies are used to explore the generalizability and adaptability of the pre-trained models to the data distribution in target tasks.Among them,the feature transferability between different tasks is explored by model transfer,and it is validated that minimizing data differences of tasks through a dual-stream adaptation structure helps to enhance generalization of the models to the target tasks.In the experiments of rolling bearing faults with unbalanced data conditions,localized faults of motor bearings and planet bearings are successfully identified,and good fault classification results are achieved,which provide guidance for the cross-condition fault diagnosis of rolling bearings with small amounts of training data.展开更多
Objective Both sequential embryo transfer(SeET)and double-blastocyst transfer(DBT)can serve as embryo transfer strategies for women with recurrent implantation failure(RIF).This study aims to compare the effects of Se...Objective Both sequential embryo transfer(SeET)and double-blastocyst transfer(DBT)can serve as embryo transfer strategies for women with recurrent implantation failure(RIF).This study aims to compare the effects of SeET and DBT on pregnancy outcomes.Methods Totally,261 frozen-thawed embryo transfer cycles of 243 RIF women were included in this multicenter retrospective analysis.According to different embryo quality and transfer strategies,they were divided into four groups:group A,good-quality SeET(GQ-SeET,n=38 cycles);group B,poor-quality or mixed-quality SeET(PQ/MQ-SeET,n=31 cycles);group C,good-quality DBT(GQ-DBT,n=121 cycles);and group D,poor-quality or mixed-quality DBT(PQ/MQ-DBT,n=71 cycles).The main outcome,clinical pregnancy rate,was compared,and the generalized estimating equation(GEE)model was used to correct potential confounders that might impact pregnancy outcomes.Results GQ-DBT achieved a significantly higher clinical pregnancy rate(aOR 2.588,95%CI 1.267–5.284,P=0.009)and live birth rate(aOR 3.082,95%CI 1.482–6.412,P=0.003)than PQ/MQ-DBT.Similarly,the clinical pregnancy rate was significantly higher in GQ-SeET than in PQ/MQ-SeET(aOR 4.047,95%CI 1.218–13.450,P=0.023).The pregnancy outcomes of GQ-SeET were not significantly different from those of GQ-DBT,and the same results were found between PQ/MQ-SeET and PQ/MQ-DBT.Conclusion SeET relative to DBT did not seem to improve pregnancy outcomes for RIF patients if the embryo quality was comparable between the two groups.Better clinical pregnancy outcomes could be obtained by transferring good-quality embryos,no matter whether in SeET or DBT.Embryo quality plays a more important role in pregnancy outcomes for RIF patients.展开更多
Hydrogen can be sustainably produced through photoelectrochemical(PEC)water splitting.The process of PEC water splitting is composed of two vital half-reactions:water oxidation to O2 on photoanode,and proton reduction...Hydrogen can be sustainably produced through photoelectrochemical(PEC)water splitting.The process of PEC water splitting is composed of two vital half-reactions:water oxidation to O2 on photoanode,and proton reduction to H2 on photocathode.Both in thermodynamics and kinetics,the oxidation of water on photoanode is much more challenging,because the formation of O2 involves the four-holes reaction process that is more difficult than the two-protons reduction.Accordingly,the oxidation of water into O2 is the rate-determining reaction for PEC water splitting,which is closely affected by the light harvesting,charge separation and transfer,as well as surface activity of photoanode.In principle,water oxidation is initiated by the photo-excited charge of photoanode.In this review,we took hematite photoanode as a typical example to illustrate the progress in modifying the charge separation and migration property of metal-oxide photoanodes for water oxidation.The typical strategies adopted to facilitate the charge transfer and separation of hematite photoanode were specifically summarized.In addition,the views designing and developing hematite photoanode with high-performance for water oxidation were presented.This review provides comprehensive information about the state-of-the-art progress of hematite-based photoanodes and forecast the developing directions of photoanode materials for solar water splitting.展开更多
Novel aggregation-induced charge transfer(CT) emission systems with long luminescence lifetime directed by supramolecular strategy have been successfully developed in water. The dimethylacridine-based electron donor(B...Novel aggregation-induced charge transfer(CT) emission systems with long luminescence lifetime directed by supramolecular strategy have been successfully developed in water. The dimethylacridine-based electron donor(Br Ac) with excellent aggregation ability can co-aggregate with a triazine-based electron acceptor(TRZ) to form nanorods in water, which exhibit CT emission with long lifetime(τ = 0.92 μs).As for a similar electron donor(Qa Ac) with poor aggregation ability, water-soluble pillar[5]arene(WP5)can be introduced to promote the aggregation process, leading to the obvious CT emission with long lifetime(τ = 0.61 μs). In addition, structural modification of the acceptor with substituent groups possessing stronger electron-accepting capabilities will cause red-shift(about 50 nm) of the emission, which allows conveniently constructing long lifetime organic luminescent materials with different emission colors.展开更多
In semiconductor photocatalysts,the easy recombination of photogenerated carriers seriously affects the application of photocatalytic materials in water treatment.To solve the serious problem of electron−hole pair rec...In semiconductor photocatalysts,the easy recombination of photogenerated carriers seriously affects the application of photocatalytic materials in water treatment.To solve the serious problem of electron−hole pair recombination in perylene diimide(PDI)organic semiconductors,we loaded ferric hydroxyl oxide(FeOOH)on PDI materials,successfully prepared novel FeOOH@PDI photocatalytic materials,and constructed a photo-Fenton system.The system was able to achieve highly efficient degradation of BPA under visible light,with a degradation rate of 0.112 min^(−1)that was 20 times higher than the PDI system,and it also showed universal degradation performances for a variety of emerging organic pollutants and anti-interference ability.The mechanism research revealed that the FeOOH has the electron trapping property,which can capture the photogenerated electrons on the surface of PDI,effectively reducing the compounding rate of photogenerated carriers of PDI and accelerating the iron cycling and H2O2 activation on the surface of FeOOH at the same time.This work provides new insights and methods for solving the problem of easy recombination of carriers in semiconductor photocatalysts and degrading emerging organic pollutants.展开更多
With the rapid development of virtual reality technology,it has been widely used in the field of education.It can promote the development of learning transfer,which is an effective method for learners to learn effecti...With the rapid development of virtual reality technology,it has been widely used in the field of education.It can promote the development of learning transfer,which is an effective method for learners to learn effectively.Therefore,this paper describes how to use virtual reality technology to achieve learning transfer in order to achieve teaching goals and improve learning efficiency.展开更多
Negative language transfer is a common phenomenon in Chinese college students 'English writing. Influenced by our native language, Chinese college students tend to apply Chinese language rules to English writing. ...Negative language transfer is a common phenomenon in Chinese college students 'English writing. Influenced by our native language, Chinese college students tend to apply Chinese language rules to English writing. This paper primarily focuses on the negative language transfer in College English writing. It tries to illustrate and analyze the negative language transfer in college students'English writing in terms of lexicon, syntax, discourse, and pragmatics. Based on the above analysis, it proceeds to put forward some suggestions on how to teach English writing effectively and efficiently.展开更多
The development of efficient green energy technology is imperative in the face of energy crises and environmental concerns.Photocatalysis,which utilizes solar energy for processes such as carbon dioxide(CO_(2)) reduct...The development of efficient green energy technology is imperative in the face of energy crises and environmental concerns.Photocatalysis,which utilizes solar energy for processes such as carbon dioxide(CO_(2)) reduction,organic pollutants degradation,and hydrogen(H_(2)) production through water splitting,is a promising approach.The key to high-efficiency photocatalysis lies in the design of superior photocatalysts.Graphene quantum dots(GQDs) have sparked significant interest in photocatalysis due to their exceptional up conversion photoluminescence(UCPL),strong light-capturing capability,and unique photoinduced charge transfer properties.However,their standalone use is limited by stability and activity.By integrating GQDs into composite photocatalysts,the separation of photogenerated electron-hole pairs is enhanced,boosting photocatalytic performance.This review provides the first overview and summary of the preparation methods of GQDs in photocatalysts,encompassing top-down and bottom-up strategy.Subsequently,a pioneering detailed summary was made on the applications of GQDs-semiconductor composites(metal organic frameworks,CdS,and bismuth-based oxides,etc.) in photocatalytic reactions such as CO_(2) reduction,organic pollutant degradation,and H_(2) generation.Furthermore,the corresponding representative examples and mechanisms are also elaborated and discussed respectively.Finally,the challenges and prospects for GQDs-based photocatalysts in the field of photocatalysis are proposed.This review provides inspiration and guidance for the development of efficient GQDs-based photocatalysts.展开更多
Electrochemical water splitting(EWS),a sustainable pathway for green hydrogen production,faces critical industrial chal-lenges:insuffi cient activity and stability at high current densities,reliance on scarce noble me...Electrochemical water splitting(EWS),a sustainable pathway for green hydrogen production,faces critical industrial chal-lenges:insuffi cient activity and stability at high current densities,reliance on scarce noble metals,and unresolved kinetic bottlenecks in proton-coupled electron transfer(PCET)dynamics.Natural metalloenzymes drive water splitting at excep-tionally low overpotentials via precisely coordinated proton-coupled electron transfer(PCET)pathways within their active sites,achieving effi ciencies approaching the theoretical thermodynamic potential of the reaction(1.23 V vs.RHE),thereby off ering transformative design principles for synthetic catalysts.This review begins by analyzing the structural motifs and catalytic mechanisms of natural metalloenzymes involved in the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),with a particular focus on their PCET-driven reaction dynamics.Subsequently,we summarize the inspir-ing strategies derived from the design of the natural enzyme active sites and their ligand environments,highlighting their relevance to HER and OER catalyst development.In conclusion,we advocate for a multiscale,nature-inspired catalyst design paradigm that integrates deep learning,high-throughput computation,and cutting-edge in situ characterization to systematically understand and optimize intrinsic activity(overpotential),stability,and reaction pathway(selectivity),thereby achieving synergistic design from atomic-scale active sites to macroscopic system architectures.These nature-inspired strategies could bridge the gap between enzymatic precision and industrial scalability,unlocking EWS technologies with enzyme-like effi ciency and durability.展开更多
The ammunition loading system manipulator is susceptible to gear failure due to high-frequency,heavyload reciprocating motions and the absence of protective gear components.After a fault occurs,the distribution of fau...The ammunition loading system manipulator is susceptible to gear failure due to high-frequency,heavyload reciprocating motions and the absence of protective gear components.After a fault occurs,the distribution of fault characteristics under different loads is markedly inconsistent,and data is hard to label,which makes it difficult for the traditional diagnosis method based on single-condition training to generalize to different conditions.To address these issues,the paper proposes a novel transfer discriminant neural network(TDNN)for gear fault diagnosis.Specifically,an optimized joint distribution adaptive mechanism(OJDA)is designed to solve the distribution alignment problem between two domains.To improve the classification effect within the domain and the feature recognition capability for a few labeled data,metric learning is introduced to distinguish features from different fault categories.In addition,TDNN adopts a new pseudo-label training strategy to achieve label replacement by comparing the maximum probability of the pseudo-label with the test result.The proposed TDNN is verified in the experimental data set of the artillery manipulator device,and the diagnosis can achieve 99.5%,significantly outperforming other traditional adaptation methods.展开更多
Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various ele...Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various electrolysis technologies,the emerging anion exchange membrane water electrolyser(AEMWE)exhibits the most potential for green hydrogen production,offering a potentially costeffective and sustainable approach that combines the advantages of high current density and fast start from proton exchange membrane water electrolyser(PEMWE)and low-cost catalyst from traditional alkaline water electrolyser(AWE)systems.Due to its relatively recent emergence over the past decade,a series of efforts are dedicated to improving the electrochemical reaction performance to accelerate the development and commercialization of AEMWE technology.A catalytic electrode comprising a gas diffusion layer(GDL)and a catalyst layer(CL)is usually called a gas diffusion electrode(GDE)that serves as a fundamental component within AEMWE,and also plays a core role in enhancing mass transfer during the electrolysis process.Inside the GDEs,bubbles nucleate and grow within the CL and then are transported through the GDL before eventually detaching to enter the electrolyte in the flow field.The transfer processes of water,gas bubbles,charges,and ions are intricately influenced by bubbles.This phenomenon is referred to as bubble-associated mass transfer.Like water management in fuel cells,effective bubble management is crucial in electrolysers,as its failure can result in various overpotential losses,such as activation losses,ohmic losses,and mass transfer losses,ultimately degrading the AEMWE performance.Despite significant advancements in the development of new materials and techniques in AEMWE,there is an urgent need for a comprehensive discussion focused on GDEs,with a particular emphasis on bubbleassociated mass transfer phenomena.This review aims to highlight recent findings regarding mass transfer in GDEs,particularly the impacts of bubble accumulation;and presents the latest advancements in designing CLs and GDLs to mitigate bubble-related issues.It is worth noting that a series of innovative bubble-free-GDE designs for water electrolysis are also emphasized in this review.This review is expected to be a valuable reference for gaining a deeper understanding of bubble-related mass transfer,especially the complex bubble behavior associated with GDEs,and for developing innovative practical strategies to advance AEMWE for green hydrogen production.展开更多
There is a positive transfer from native language vocabulary learning strategy to that of the second language. The comparison between them shows that the traditional Chinese character learning strategies have profound...There is a positive transfer from native language vocabulary learning strategy to that of the second language. The comparison between them shows that the traditional Chinese character learning strategies have profound effect on English vocabulary learning on the basis of morphology, lexicon as well as discourse categories. If the mutual effect can be applied in English vocabulary learning effectively, positive transfer emerges.展开更多
This paper reconsiders the role of L 1 pragmatic transfer on English learning after a brief historical review of the pragmatic transfer research. As pragmatic transfer is a communicative strategy which the language le...This paper reconsiders the role of L 1 pragmatic transfer on English learning after a brief historical review of the pragmatic transfer research. As pragmatic transfer is a communicative strategy which the language learners tend to use to deal with the immediate problems and difficulties in communication and to develop their pragmatic competence of the target language, the paper comes to the conclusion that foreign language teachers should consciously introduce the pragmatic transfer as a communicative strategy into the classroom teaching, and try to find effective means to cultivate their students＇ abilities of pragmatic transfer in order to develop pragmatic competence.展开更多
The transfer of mother tongue has always been influencing students in second language acquisition.This paper attempts to analyze the negative transfer in vocabulary of non-English majors in vocational colleges and bri...The transfer of mother tongue has always been influencing students in second language acquisition.This paper attempts to analyze the negative transfer in vocabulary of non-English majors in vocational colleges and briefly proposes some strategies to reduce the negative transfer of mother tongue.展开更多
Bilingual subtitling is often employed as an economical and effective method in media language transfer. It could be regarded as a branch of translation and often employs translation theories and strategies when carry...Bilingual subtitling is often employed as an economical and effective method in media language transfer. It could be regarded as a branch of translation and often employs translation theories and strategies when carrying out the blingual task. However, there are several other factors that from media industry and administration need to be combined with translation during the process of subtitling. This paper uses the Italian movie"The Scientific Card Player"as an example to give an analysis of several factors which are involved in movie subtitling, including the poly-semiotic nature of audiovisual material, movie censorship, subtitling and translating techniques and strategies.展开更多
Recently, the definition of sepsis was concluded to be a life-threatening organ dysfunction caused by a dysregulated host response to infection. Severe patients always present with uncorrectable hypotension or hyperla...Recently, the definition of sepsis was concluded to be a life-threatening organ dysfunction caused by a dysregulated host response to infection. Severe patients always present with uncorrectable hypotension or hyperlactacidemia, which is defined as septic shock. The new definition emphasizes dysregulation of the host response and multiple organ dysfunction, which is partially attributed to metabolic disorders induced by energy crisis and oxidative stress. Mitochondria are a cellular organelle that are well known as the center of energy production, and mitochondrial damage or dysfunction is commonly induced in septic settings and is a predominant factor leading to a worse prognosis. In the present review, we determine the major mitochondrial disorders from morphology to functions in sepsis. In the following, several clinical or pre-clinical assays for monitoring mitochondrial function are demonstrated according to accumulated evidence, which is the first step of specific therapy targeting to modulate mitochondrial function. Accordingly, various reagents used for regulating mitochondrial enzyme activities and promoting biogenesis have been documented, among which mitochondriatargeted cation, TPP-conjugated antioxidants are the most valuable for future trials and clinical treatment to improve mitochondrial function as they may take advantage of the prognosis associated with septic complications.展开更多
This paper proposes an autonomous maneuver decision method using transfer learning pigeon-inspired optimization(TLPIO)for unmanned combat aerial vehicles(UCAVs)in dogfight engagements.Firstly,a nonlinear F-16 aircraft...This paper proposes an autonomous maneuver decision method using transfer learning pigeon-inspired optimization(TLPIO)for unmanned combat aerial vehicles(UCAVs)in dogfight engagements.Firstly,a nonlinear F-16 aircraft model and automatic control system are constructed by a MATLAB/Simulink platform.Secondly,a 3-degrees-of-freedom(3-DOF)aircraft model is used as a maneuvering command generator,and the expanded elemental maneuver library is designed,so that the aircraft state reachable set can be obtained.Then,the game matrix is composed with the air combat situation evaluation function calculated according to the angle and range threats.Finally,a key point is that the objective function to be optimized is designed using the game mixed strategy,and the optimal mixed strategy is obtained by TLPIO.Significantly,the proposed TLPIO does not initialize the population randomly,but adopts the transfer learning method based on Kullback-Leibler(KL)divergence to initialize the population,which improves the search accuracy of the optimization algorithm.Besides,the convergence and time complexity of TLPIO are discussed.Comparison analysis with other classical optimization algorithms highlights the advantage of TLPIO.In the simulation of air combat,three initial scenarios are set,namely,opposite,offensive and defensive conditions.The effectiveness performance of the proposed autonomous maneuver decision method is verified by simulation results.展开更多
基金financially supported by the National Natural Science Foundation of China (21908033,21576059,21666008)Fok Ying-Tong Education Foundation (161030)+1 种基金the Program of Introducing Talents of Discipline to Universities of China (111 Program,D20023)Guizhou Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules ([2020]004)。
文摘Transfer hydrogenation(TH) with in situ generated hydrogen donor is of great importance in reduction reactions, and an alternative strategy to traditional hydrogenation processes involving pressurized molecular hydrogen. Ammonia borane(NH3BH3, AB) is a promising material of hydrogen storage, and it has attracted much attention in reductive organic transformations owing to its high activity, good atom economy, nontoxicity, sustainability, and ease of transport and storage. This review focuses on summarizing the recent progress of AB-mediated TH reactions of diverse substrates including nitro compounds, nitriles, imines, alkenes, alkynes, carbonyl compounds(ketones and aldehydes), carbon dioxide,and N-and O-heterocycles. Syntheses protocols(metal-containing and metal-free), the effect of reaction parameters, product distribution, and variation of reactivity are surveyed, and the mechanism of each reaction involving the action mode of AB as well as structure-activity relationships is discussed in detail. Finally, perspectives are presented to highlight the challenges and opportunities for AB-enabled TH reactions of unsaturated compounds.
基金the National Key Research and Development Program of China(No.2019YFB1706300)the National Natural Science Foundation of China(No.52075094)。
文摘In current small batch and customized production mode,the products change rapidly and the personal demand increases sharply.Human-robot cooperation combining the advantages of human and robot is an effective way to solve the complex assembly.However,the poor reusability of historical assembly knowledge reduces the adaptability of assembly system to different tasks.For cross-domain strategy transfer,we propose a human-robot cooperative assembly(HRCA)framework which consists of three main modules:expression of HRCA strategy,transferring of HRCA strategy,and adaptive planning of motion path.Based on the analysis of subject capability and component properties,the HRCA strategy suitable for specific tasks is designed.Then the reinforcement learning is established to optimize the parameters of target encoder for feature extraction.After classification and segmentation,the actor-critic model is built to realize the adaptive path planning with progressive neural network.Finally,the proposed framework is verified to adapt to the multi-variety environment,for example,power lithium batteries.
基金This work was supported by National Natural Science Foundation of China(52275080).The authors are grateful to the reviewers for their valuable comments and to Bei Wang for her help in polishing the English of this paper.
文摘Rolling bearings are key components of the drivetrain in wind turbines,and their health is critical to wind turbine operation.In practical diagnosis tasks,the vibration signal is usually interspersed with many disturbing components,and the variation of operating conditions leads to unbalanced data distribution among different conditions.Although intelligent diagnosis methods based on deep learning have been intensively studied,it is still challenging to diagnose rolling bearing faults with small amounts of samples.To address the above issue,we introduce the deep residual joint transfer strategy method for the cross-condition fault diagnosis of rolling bearings.One-dimensional vibration signals are pre-processed by overlapping feature extraction techniques to fully extract fault characteristics.The deep residual network is trained in training tasks with sufficient samples,for fault pattern classification.Subsequently,three transfer strategies are used to explore the generalizability and adaptability of the pre-trained models to the data distribution in target tasks.Among them,the feature transferability between different tasks is explored by model transfer,and it is validated that minimizing data differences of tasks through a dual-stream adaptation structure helps to enhance generalization of the models to the target tasks.In the experiments of rolling bearing faults with unbalanced data conditions,localized faults of motor bearings and planet bearings are successfully identified,and good fault classification results are achieved,which provide guidance for the cross-condition fault diagnosis of rolling bearings with small amounts of training data.
文摘Objective Both sequential embryo transfer(SeET)and double-blastocyst transfer(DBT)can serve as embryo transfer strategies for women with recurrent implantation failure(RIF).This study aims to compare the effects of SeET and DBT on pregnancy outcomes.Methods Totally,261 frozen-thawed embryo transfer cycles of 243 RIF women were included in this multicenter retrospective analysis.According to different embryo quality and transfer strategies,they were divided into four groups:group A,good-quality SeET(GQ-SeET,n=38 cycles);group B,poor-quality or mixed-quality SeET(PQ/MQ-SeET,n=31 cycles);group C,good-quality DBT(GQ-DBT,n=121 cycles);and group D,poor-quality or mixed-quality DBT(PQ/MQ-DBT,n=71 cycles).The main outcome,clinical pregnancy rate,was compared,and the generalized estimating equation(GEE)model was used to correct potential confounders that might impact pregnancy outcomes.Results GQ-DBT achieved a significantly higher clinical pregnancy rate(aOR 2.588,95%CI 1.267–5.284,P=0.009)and live birth rate(aOR 3.082,95%CI 1.482–6.412,P=0.003)than PQ/MQ-DBT.Similarly,the clinical pregnancy rate was significantly higher in GQ-SeET than in PQ/MQ-SeET(aOR 4.047,95%CI 1.218–13.450,P=0.023).The pregnancy outcomes of GQ-SeET were not significantly different from those of GQ-DBT,and the same results were found between PQ/MQ-SeET and PQ/MQ-DBT.Conclusion SeET relative to DBT did not seem to improve pregnancy outcomes for RIF patients if the embryo quality was comparable between the two groups.Better clinical pregnancy outcomes could be obtained by transferring good-quality embryos,no matter whether in SeET or DBT.Embryo quality plays a more important role in pregnancy outcomes for RIF patients.
基金National Natural Science Foundation of China(41702037,41831285,and 21773114).
文摘Hydrogen can be sustainably produced through photoelectrochemical(PEC)water splitting.The process of PEC water splitting is composed of two vital half-reactions:water oxidation to O2 on photoanode,and proton reduction to H2 on photocathode.Both in thermodynamics and kinetics,the oxidation of water on photoanode is much more challenging,because the formation of O2 involves the four-holes reaction process that is more difficult than the two-protons reduction.Accordingly,the oxidation of water into O2 is the rate-determining reaction for PEC water splitting,which is closely affected by the light harvesting,charge separation and transfer,as well as surface activity of photoanode.In principle,water oxidation is initiated by the photo-excited charge of photoanode.In this review,we took hematite photoanode as a typical example to illustrate the progress in modifying the charge separation and migration property of metal-oxide photoanodes for water oxidation.The typical strategies adopted to facilitate the charge transfer and separation of hematite photoanode were specifically summarized.In addition,the views designing and developing hematite photoanode with high-performance for water oxidation were presented.This review provides comprehensive information about the state-of-the-art progress of hematite-based photoanodes and forecast the developing directions of photoanode materials for solar water splitting.
基金supported by the National Natural Science Foundation of China (No. 21871136)the Natural Science Foundation of Jiangsu Province (No. BK20211179)the Fundamental Research Funds for the Central Universities (No.NE2019002)。
文摘Novel aggregation-induced charge transfer(CT) emission systems with long luminescence lifetime directed by supramolecular strategy have been successfully developed in water. The dimethylacridine-based electron donor(Br Ac) with excellent aggregation ability can co-aggregate with a triazine-based electron acceptor(TRZ) to form nanorods in water, which exhibit CT emission with long lifetime(τ = 0.92 μs).As for a similar electron donor(Qa Ac) with poor aggregation ability, water-soluble pillar[5]arene(WP5)can be introduced to promote the aggregation process, leading to the obvious CT emission with long lifetime(τ = 0.61 μs). In addition, structural modification of the acceptor with substituent groups possessing stronger electron-accepting capabilities will cause red-shift(about 50 nm) of the emission, which allows conveniently constructing long lifetime organic luminescent materials with different emission colors.
基金supported by the National Natural Science Foundation of China(No.22306178 and 22176155)Outstanding Youth Talents of Sichuan Science and Technology Program(No.22JCQN0061)+1 种基金National Natural Science Foundation of China(No.22306012)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110578).
文摘In semiconductor photocatalysts,the easy recombination of photogenerated carriers seriously affects the application of photocatalytic materials in water treatment.To solve the serious problem of electron−hole pair recombination in perylene diimide(PDI)organic semiconductors,we loaded ferric hydroxyl oxide(FeOOH)on PDI materials,successfully prepared novel FeOOH@PDI photocatalytic materials,and constructed a photo-Fenton system.The system was able to achieve highly efficient degradation of BPA under visible light,with a degradation rate of 0.112 min^(−1)that was 20 times higher than the PDI system,and it also showed universal degradation performances for a variety of emerging organic pollutants and anti-interference ability.The mechanism research revealed that the FeOOH has the electron trapping property,which can capture the photogenerated electrons on the surface of PDI,effectively reducing the compounding rate of photogenerated carriers of PDI and accelerating the iron cycling and H2O2 activation on the surface of FeOOH at the same time.This work provides new insights and methods for solving the problem of easy recombination of carriers in semiconductor photocatalysts and degrading emerging organic pollutants.
文摘With the rapid development of virtual reality technology,it has been widely used in the field of education.It can promote the development of learning transfer,which is an effective method for learners to learn effectively.Therefore,this paper describes how to use virtual reality technology to achieve learning transfer in order to achieve teaching goals and improve learning efficiency.
文摘Negative language transfer is a common phenomenon in Chinese college students 'English writing. Influenced by our native language, Chinese college students tend to apply Chinese language rules to English writing. This paper primarily focuses on the negative language transfer in College English writing. It tries to illustrate and analyze the negative language transfer in college students'English writing in terms of lexicon, syntax, discourse, and pragmatics. Based on the above analysis, it proceeds to put forward some suggestions on how to teach English writing effectively and efficiently.
基金financial support provided by National Natural Science Foundation of China(No.22262024)research start-up funding from Changzhou University(No.ZMF23020031)+1 种基金the technical support from the Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology,Jiangxi Province Academic and Technical Leader of Major Disciplines(No.20232BCJ22008)Key Project of Natural Science Foundation of Jiangxi Province(No.20232ACB204007)。
文摘The development of efficient green energy technology is imperative in the face of energy crises and environmental concerns.Photocatalysis,which utilizes solar energy for processes such as carbon dioxide(CO_(2)) reduction,organic pollutants degradation,and hydrogen(H_(2)) production through water splitting,is a promising approach.The key to high-efficiency photocatalysis lies in the design of superior photocatalysts.Graphene quantum dots(GQDs) have sparked significant interest in photocatalysis due to their exceptional up conversion photoluminescence(UCPL),strong light-capturing capability,and unique photoinduced charge transfer properties.However,their standalone use is limited by stability and activity.By integrating GQDs into composite photocatalysts,the separation of photogenerated electron-hole pairs is enhanced,boosting photocatalytic performance.This review provides the first overview and summary of the preparation methods of GQDs in photocatalysts,encompassing top-down and bottom-up strategy.Subsequently,a pioneering detailed summary was made on the applications of GQDs-semiconductor composites(metal organic frameworks,CdS,and bismuth-based oxides,etc.) in photocatalytic reactions such as CO_(2) reduction,organic pollutant degradation,and H_(2) generation.Furthermore,the corresponding representative examples and mechanisms are also elaborated and discussed respectively.Finally,the challenges and prospects for GQDs-based photocatalysts in the field of photocatalysis are proposed.This review provides inspiration and guidance for the development of efficient GQDs-based photocatalysts.
基金supported by the National Natural Science Foundation of China(No.51832003)the National Key Research and Development Program of China(No.2021YFA0715700).
文摘Electrochemical water splitting(EWS),a sustainable pathway for green hydrogen production,faces critical industrial chal-lenges:insuffi cient activity and stability at high current densities,reliance on scarce noble metals,and unresolved kinetic bottlenecks in proton-coupled electron transfer(PCET)dynamics.Natural metalloenzymes drive water splitting at excep-tionally low overpotentials via precisely coordinated proton-coupled electron transfer(PCET)pathways within their active sites,achieving effi ciencies approaching the theoretical thermodynamic potential of the reaction(1.23 V vs.RHE),thereby off ering transformative design principles for synthetic catalysts.This review begins by analyzing the structural motifs and catalytic mechanisms of natural metalloenzymes involved in the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),with a particular focus on their PCET-driven reaction dynamics.Subsequently,we summarize the inspir-ing strategies derived from the design of the natural enzyme active sites and their ligand environments,highlighting their relevance to HER and OER catalyst development.In conclusion,we advocate for a multiscale,nature-inspired catalyst design paradigm that integrates deep learning,high-throughput computation,and cutting-edge in situ characterization to systematically understand and optimize intrinsic activity(overpotential),stability,and reaction pathway(selectivity),thereby achieving synergistic design from atomic-scale active sites to macroscopic system architectures.These nature-inspired strategies could bridge the gap between enzymatic precision and industrial scalability,unlocking EWS technologies with enzyme-like effi ciency and durability.
文摘The ammunition loading system manipulator is susceptible to gear failure due to high-frequency,heavyload reciprocating motions and the absence of protective gear components.After a fault occurs,the distribution of fault characteristics under different loads is markedly inconsistent,and data is hard to label,which makes it difficult for the traditional diagnosis method based on single-condition training to generalize to different conditions.To address these issues,the paper proposes a novel transfer discriminant neural network(TDNN)for gear fault diagnosis.Specifically,an optimized joint distribution adaptive mechanism(OJDA)is designed to solve the distribution alignment problem between two domains.To improve the classification effect within the domain and the feature recognition capability for a few labeled data,metric learning is introduced to distinguish features from different fault categories.In addition,TDNN adopts a new pseudo-label training strategy to achieve label replacement by comparing the maximum probability of the pseudo-label with the test result.The proposed TDNN is verified in the experimental data set of the artillery manipulator device,and the diagnosis can achieve 99.5%,significantly outperforming other traditional adaptation methods.
基金support from the National Natural Science Foundation of China(Grant No.52006029)the Promotion Foundation for Young Science and Technology Talents in Jilin Province(Grant No.QT202113)+2 种基金the Special Foundation of Industrial Innovation in Jilin Province(Grant No.2019C056-2)the Special Foundation for Outstanding Young Talents Training in Jilin(Grant No.20200104107)the UK EPSRC(EP/W03784X/1)。
文摘Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various electrolysis technologies,the emerging anion exchange membrane water electrolyser(AEMWE)exhibits the most potential for green hydrogen production,offering a potentially costeffective and sustainable approach that combines the advantages of high current density and fast start from proton exchange membrane water electrolyser(PEMWE)and low-cost catalyst from traditional alkaline water electrolyser(AWE)systems.Due to its relatively recent emergence over the past decade,a series of efforts are dedicated to improving the electrochemical reaction performance to accelerate the development and commercialization of AEMWE technology.A catalytic electrode comprising a gas diffusion layer(GDL)and a catalyst layer(CL)is usually called a gas diffusion electrode(GDE)that serves as a fundamental component within AEMWE,and also plays a core role in enhancing mass transfer during the electrolysis process.Inside the GDEs,bubbles nucleate and grow within the CL and then are transported through the GDL before eventually detaching to enter the electrolyte in the flow field.The transfer processes of water,gas bubbles,charges,and ions are intricately influenced by bubbles.This phenomenon is referred to as bubble-associated mass transfer.Like water management in fuel cells,effective bubble management is crucial in electrolysers,as its failure can result in various overpotential losses,such as activation losses,ohmic losses,and mass transfer losses,ultimately degrading the AEMWE performance.Despite significant advancements in the development of new materials and techniques in AEMWE,there is an urgent need for a comprehensive discussion focused on GDEs,with a particular emphasis on bubbleassociated mass transfer phenomena.This review aims to highlight recent findings regarding mass transfer in GDEs,particularly the impacts of bubble accumulation;and presents the latest advancements in designing CLs and GDLs to mitigate bubble-related issues.It is worth noting that a series of innovative bubble-free-GDE designs for water electrolysis are also emphasized in this review.This review is expected to be a valuable reference for gaining a deeper understanding of bubble-related mass transfer,especially the complex bubble behavior associated with GDEs,and for developing innovative practical strategies to advance AEMWE for green hydrogen production.
文摘There is a positive transfer from native language vocabulary learning strategy to that of the second language. The comparison between them shows that the traditional Chinese character learning strategies have profound effect on English vocabulary learning on the basis of morphology, lexicon as well as discourse categories. If the mutual effect can be applied in English vocabulary learning effectively, positive transfer emerges.
文摘This paper reconsiders the role of L 1 pragmatic transfer on English learning after a brief historical review of the pragmatic transfer research. As pragmatic transfer is a communicative strategy which the language learners tend to use to deal with the immediate problems and difficulties in communication and to develop their pragmatic competence of the target language, the paper comes to the conclusion that foreign language teachers should consciously introduce the pragmatic transfer as a communicative strategy into the classroom teaching, and try to find effective means to cultivate their students＇ abilities of pragmatic transfer in order to develop pragmatic competence.
文摘The transfer of mother tongue has always been influencing students in second language acquisition.This paper attempts to analyze the negative transfer in vocabulary of non-English majors in vocational colleges and briefly proposes some strategies to reduce the negative transfer of mother tongue.
文摘Bilingual subtitling is often employed as an economical and effective method in media language transfer. It could be regarded as a branch of translation and often employs translation theories and strategies when carrying out the blingual task. However, there are several other factors that from media industry and administration need to be combined with translation during the process of subtitling. This paper uses the Italian movie"The Scientific Card Player"as an example to give an analysis of several factors which are involved in movie subtitling, including the poly-semiotic nature of audiovisual material, movie censorship, subtitling and translating techniques and strategies.
基金supported by grants from the National Natural Science Foundation of China(No.81730057,81501698)the National Key Research and Development Program of China(No.2017YFC11003302)the Shenzhen San-ming Project(No.SZSM20162011)
文摘Recently, the definition of sepsis was concluded to be a life-threatening organ dysfunction caused by a dysregulated host response to infection. Severe patients always present with uncorrectable hypotension or hyperlactacidemia, which is defined as septic shock. The new definition emphasizes dysregulation of the host response and multiple organ dysfunction, which is partially attributed to metabolic disorders induced by energy crisis and oxidative stress. Mitochondria are a cellular organelle that are well known as the center of energy production, and mitochondrial damage or dysfunction is commonly induced in septic settings and is a predominant factor leading to a worse prognosis. In the present review, we determine the major mitochondrial disorders from morphology to functions in sepsis. In the following, several clinical or pre-clinical assays for monitoring mitochondrial function are demonstrated according to accumulated evidence, which is the first step of specific therapy targeting to modulate mitochondrial function. Accordingly, various reagents used for regulating mitochondrial enzyme activities and promoting biogenesis have been documented, among which mitochondriatargeted cation, TPP-conjugated antioxidants are the most valuable for future trials and clinical treatment to improve mitochondrial function as they may take advantage of the prognosis associated with septic complications.
基金the Science and Technology Innovation 2030-Key Project of“New Generation Artificial Intelligence”(2018AAA0100803)the National Natural Science Foundation of China(U20B2071,91948204,T2121003,U1913602)。
文摘This paper proposes an autonomous maneuver decision method using transfer learning pigeon-inspired optimization(TLPIO)for unmanned combat aerial vehicles(UCAVs)in dogfight engagements.Firstly,a nonlinear F-16 aircraft model and automatic control system are constructed by a MATLAB/Simulink platform.Secondly,a 3-degrees-of-freedom(3-DOF)aircraft model is used as a maneuvering command generator,and the expanded elemental maneuver library is designed,so that the aircraft state reachable set can be obtained.Then,the game matrix is composed with the air combat situation evaluation function calculated according to the angle and range threats.Finally,a key point is that the objective function to be optimized is designed using the game mixed strategy,and the optimal mixed strategy is obtained by TLPIO.Significantly,the proposed TLPIO does not initialize the population randomly,but adopts the transfer learning method based on Kullback-Leibler(KL)divergence to initialize the population,which improves the search accuracy of the optimization algorithm.Besides,the convergence and time complexity of TLPIO are discussed.Comparison analysis with other classical optimization algorithms highlights the advantage of TLPIO.In the simulation of air combat,three initial scenarios are set,namely,opposite,offensive and defensive conditions.The effectiveness performance of the proposed autonomous maneuver decision method is verified by simulation results.
