The Southern Great Xing’an Range(SGXR)which forms part of the eastern segment of the Central Asian Orogenic Belt(CAOB)is known as one of the most important Cu-Mo-Pb-Zn-Ag-Au metallogenic belts in China,hosting a numb...The Southern Great Xing’an Range(SGXR)which forms part of the eastern segment of the Central Asian Orogenic Belt(CAOB)is known as one of the most important Cu-Mo-Pb-Zn-Ag-Au metallogenic belts in China,hosting a number of porphyry Mo(Cu),skarn Fe(Sn),epithermal Au-Ag,and hydrothermal veintype Ag-Pb-Zn ore deposits.Here we investigate the Bianjiadayuan hydrothermal vein-type Ag-Pb-Zn ore deposit in the southern part of the SGXR.Porphyry Sn±Cu±Mo mineralization is also developed to the west of the Ag-Pb-Zn veins in the ore field.We identify a five-stage mineralization process based on field and petrologic studies including(i)the early porphyry mineralization stage,(ii)main porphyry mineralization stage,(iii)transition mineralization stage,(iv)vein-type mineralization stage and(v)late mineralization stage.Pyrite is the predominant sulfide mineral in all stages except in the late mineralization stage,and we identify corresponding four types of pyrites:Py1 is medium-grained subhedral to euhedral occurring in the early barren quartz vein;Py2 is medium-to fine-grained euhedral pyrite mainly coexisting with molybdenite,chalcopyrite,minor sphalerite and galena;Py3 is fine-grained,subhedral to irregular pyrite and displays cataclastic textures with micro-fractures;Py4 occurs as euhedral microcrystals and forms irregularly shaped aggregate with sphalerite and galena.LA-ICP-MS trace element analyses of pyrite show that Cu,Pb,Zn,Ag,Sn,Cd and Sb are partitioned into pyrite as structurally bound metals or mineral micro/nano-inclusions,whereas Co,Ni,As and Se enter the lattice via isomorphism in all types of pyrite.The Cu,Zn,Ag,Cd concentrations gradually increase from Py1 to Py4,which we correlate with cooling and mixing of ore-forming fluid with meteoric water.Py2 contains the highest contents of Co,Ni,Se,Te and Bi,suggesting high temperature conditions for the porphyry mineralization stage.Ratios of Co/Ni(0.03-10.79,average 2.13)and sulphur isotope composition of sulfide indicate typical hydrothermal origin for pyrites.Theδ^34SCDT values of Py1(0.42‰-1.61‰,average 1.16‰),Py2(-1.23‰to 0.82‰,average 0.35‰),Py3(-0.36‰to 2.47‰,average 0.97‰),Py4(2.51‰-3.72‰,average 3.06‰),and other sulfides are consistent with those of typical porphyry deposit(-5‰to 5‰),indicating that the Pb-Zn polymetallic mineralization in the Bianjiadayuan deposit is genetically linked to the Yanshanian(JurassiceCretaceous)magmatic-hydrothermal events.Variations of d34S values are ascribed to the changes in physical and chemical conditions during the evolution and migration of the ore-forming fluid.We propose that the high Sn content of pyrite in the Bianjiadayuan hydrothermal vein-type PbeZn polymetallic deposit can be used as a possible pathfinder to prospect for Sn mineralization in the surrounding area or deeper level of the ore field in this region.展开更多
对科学基金各学科的发展态势进行分析,可以为诊断学科发展现状、制定学科发展战略规划提供参考依据。本研究从科研产出视角出发,以2013—2022年的Web of Science(WoS)论文为数据源,应用科学计量学方法,从学科结构、产出成效、国际合作...对科学基金各学科的发展态势进行分析,可以为诊断学科发展现状、制定学科发展战略规划提供参考依据。本研究从科研产出视角出发,以2013—2022年的Web of Science(WoS)论文为数据源,应用科学计量学方法,从学科结构、产出成效、国际合作三个维度,对科学基金各学科的发展态势进行横向对比分析。研究发现,在学科结构方面,中国在物质科学及工程技术类优势学科规模指标表现突出,效率指标差距显著,需着重鼓励优势学科原创性、引领性研究产出,实现突破式创新发展。中国的学科结构均衡性不断加强,在学科均衡协同发展的基础上,需优先支持国家战略需求领域和科学前沿领域突破。在资助成效方面,国家自然科学基金项目的资助具有较高投入产出效率,且有效推动了重要成果的产出,需继续加强高产出效率领域及重要成果团队的后续资助力度,进一步提升投入产出效率。在国际合作方面,中国天文学、管理科学国际合作论文份额最高,化学、医学份额最低,各学科的国际合作论文份额自2020年起均呈显著下降趋势,其中中美合作大幅下滑,材料科学和力学领域下降最为明显。需聚焦全球关注的热点科研问题,构建更加多元化的国际科研合作网络。展开更多
This paper proposes a Reinforcement learning(RL)algorithm to find an optimal scheduling policy to minimize the delay for a given energy constraint in communication system where the environments such as traffic arrival...This paper proposes a Reinforcement learning(RL)algorithm to find an optimal scheduling policy to minimize the delay for a given energy constraint in communication system where the environments such as traffic arrival rates are not known in advance and can change over time.For this purpose,this problem is formulated as an infinite-horizon Constrained Markov Decision Process(CMDP).To handle the constrained optimization problem,we first adopt the Lagrangian relaxation technique to solve it.Then,we propose a variant of Q-learning,Q-greedyUCB that combinesε-greedy and Upper Confidence Bound(UCB)algorithms to solve this constrained MDP problem.We mathematically prove that the Q-greedyUCB algorithm converges to an optimal solution.Simulation results also show that Q-greedyUCB finds an optimal scheduling strategy,and is more efficient than Q-learning withε-greedy,R-learning and the Averagepayoff RL(ARL)algorithm in terms of the cumulative regret.We also show that our algorithm can learn and adapt to the changes of the environment,so as to obtain an optimal scheduling strategy under a given power constraint for the new environment.展开更多
Taking Ludian County in Zhaotong City of Yunnan Province for example,according to the data on residents'income gap in Ludian County during the period 2002-2011,we analyze the residents'income gap in Ludian Cou...Taking Ludian County in Zhaotong City of Yunnan Province for example,according to the data on residents'income gap in Ludian County during the period 2002-2011,we analyze the residents'income gap in Ludian County,and offer the forecast value of residents'income gap in Ludian County during the period 2012-2015,using Compertz curve model and Eviews software for fitting.The forecast value shows that the residents'income gap will continue to widen in Ludian County.Finally we put forth the recommendations for bridging the residents'income gap in Ludian County,in order to provide a reference for settling the problems concerning residents'income gap in other state-level povertystricken counties of Yunnan Province.展开更多
Oral expression skills play an essential role in the development of EFL students’language abilities,and how to improve EFL students’oral expression skills is an essential and challenging task.This study adopts a qua...Oral expression skills play an essential role in the development of EFL students’language abilities,and how to improve EFL students’oral expression skills is an essential and challenging task.This study adopts a quasi-experimental research method to carry out the research and proposes an AI-based reflective dialogue model.Based on this,an analysis of the impact brought by this model on EFL students’oral expression performance and learning anxiety levels.The results show that students in the experimental group have significantly higher oral expression performance than those in the control group in the three dimensions of grammatical accuracy,expressive fluency,and word accuracy.In addition,the students in the experimental group produced facilitated anxiety after using the AI-based reflective dialogue model for oral expression learning,which prompted the students to learn more diligently.展开更多
Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the d...Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the demand for high-quality multiplexers and demultiplexers.However,the criteria for ideal-mode multiplexers/demultiplexers,such as performance,scalability,compatibility,and ultra-compactness,have only partially been achieved using conventional bulky devices(e.g.,waveguides,grat-ings,and free space optics)—an issue that will substantially restrict the application of MDM techniques.Here,we present a neuro-meta-router(NMR)optimized through deep learning that achieves spatial multi-mode division and supports multi-channel communication,potentially offering scalability,com-patibility,and ultra-compactness.An MDM communication system based on an NMR is theoretically designed and experimentally demonstrated to enable simultaneous and independent multi-dataset transmission,showcasing a capacity of up to 100 gigabits per second(Gbps)and a symbol error rate down to the order of 104,all achieved without any compensation technologies or correlation devices.Our work presents a paradigm that merges metasurfaces,fiber communications,and deep learning,with potential applications in intelligent metasurface-aided optical interconnection,as well as all-optical pat-tern recognition and classification.展开更多
Objective： Gastric cancer （GC） is one of the leading causes of death in China and other Asian countries. Recently, gastric endoscopy has become the main approach for GC screening, but the identification of high-ris...Objective： Gastric cancer （GC） is one of the leading causes of death in China and other Asian countries. Recently, gastric endoscopy has become the main approach for GC screening, but the identification of high-risk individuals remains a challenge in GC screening programs. Methods： There were 7,302 patients with chronic gastritis involved in this study. Endoscopic examinations were performed, and their demographic characteristics and lifestyle data were collected. Each possible associated factor of GC/premalignant and precursor lesions was evaluated by univariate and multivariate logistic regressions. Nomograms were used for visualization of those models, and receiver operating characteristic （ROC） curve analysis was used to present the predictive accuracy. Resu Its： We detected 8 （0.11% ） gastric adenocarcinomas, 17 （0.23 %） dysplasia cases, 14 （0.19%） hyperplasia cases, 52 （0.71%） intestinal metaplasia cases, 217 （2.97%） inflammatory lesions, 141 （1.93%） gastric ulcers, 10 （0.14%） atrophic gastritis cases, 1,365 （18.69%） erosive gastritis cases, and 5,957 （81.58%） superficial gastritis cases in 7,302 patients. The age （P〈0.001）, gender （P=0.086）, labor intensity （P=0.018） and leek food intake （P=0.143） were identified as independent predictive factors of GC/premalignant lesions possibility. The corresponding nomogram exhibited an area under the curve （AUC） [95% confidence interval （95% CI）] of 0.82 （0.74-0.89） for the modeling group and 0.80 （0.75-0.85） for the validation group. The age （P=0.002）, gender （P=0.024）, smoldng （P=0.002） and leek food intake （P=0.039） were independent predictive factors of precursor lesions possibility. The corresponding nomogram exhibited an AUC （95% CI） of 0.62 （0.60-0.65） for the modeling group and 0.61 （0.59-0.63） for the validation group. Conclusions： We identified several potential associated factors and provided a preclinical nomogram with the potential to predict the possibility of GC/premalignant and precursor lesions.展开更多
Diabetic foot ulcers(DFUs)represents a significant public health issue,with a rising global prevalence and severe potential complications including amputation.Traditional treatments often fall short due to various lim...Diabetic foot ulcers(DFUs)represents a significant public health issue,with a rising global prevalence and severe potential complications including amputation.Traditional treatments often fall short due to various limitations such as high recurrence rates and extensive resource utilization.This editorial explores the innovative use of acellular fish skin grafts as a transformative approach in DFU management.Recent studies and a detailed case report highlight the efficacy of acellular fish skin grafts in accelerating wound closure,reducing dressing changes,and enhancing patient outcomes with a lower socio-economic burden.Despite their promise,challenges such as limited availability,patient acceptance,and the need for further research persist.Addressing these through more extensive randomized controlled trials and fostering a multidisciplinary treatment approach may optimize DFU care and reduce the global health burden associated with these complex wounds.展开更多
基金financially supported by National Key Research and Development Program of China(2016YFC0600504)Fundamental Research Funds for the Central Universities(2652017218)
文摘The Southern Great Xing’an Range(SGXR)which forms part of the eastern segment of the Central Asian Orogenic Belt(CAOB)is known as one of the most important Cu-Mo-Pb-Zn-Ag-Au metallogenic belts in China,hosting a number of porphyry Mo(Cu),skarn Fe(Sn),epithermal Au-Ag,and hydrothermal veintype Ag-Pb-Zn ore deposits.Here we investigate the Bianjiadayuan hydrothermal vein-type Ag-Pb-Zn ore deposit in the southern part of the SGXR.Porphyry Sn±Cu±Mo mineralization is also developed to the west of the Ag-Pb-Zn veins in the ore field.We identify a five-stage mineralization process based on field and petrologic studies including(i)the early porphyry mineralization stage,(ii)main porphyry mineralization stage,(iii)transition mineralization stage,(iv)vein-type mineralization stage and(v)late mineralization stage.Pyrite is the predominant sulfide mineral in all stages except in the late mineralization stage,and we identify corresponding four types of pyrites:Py1 is medium-grained subhedral to euhedral occurring in the early barren quartz vein;Py2 is medium-to fine-grained euhedral pyrite mainly coexisting with molybdenite,chalcopyrite,minor sphalerite and galena;Py3 is fine-grained,subhedral to irregular pyrite and displays cataclastic textures with micro-fractures;Py4 occurs as euhedral microcrystals and forms irregularly shaped aggregate with sphalerite and galena.LA-ICP-MS trace element analyses of pyrite show that Cu,Pb,Zn,Ag,Sn,Cd and Sb are partitioned into pyrite as structurally bound metals or mineral micro/nano-inclusions,whereas Co,Ni,As and Se enter the lattice via isomorphism in all types of pyrite.The Cu,Zn,Ag,Cd concentrations gradually increase from Py1 to Py4,which we correlate with cooling and mixing of ore-forming fluid with meteoric water.Py2 contains the highest contents of Co,Ni,Se,Te and Bi,suggesting high temperature conditions for the porphyry mineralization stage.Ratios of Co/Ni(0.03-10.79,average 2.13)and sulphur isotope composition of sulfide indicate typical hydrothermal origin for pyrites.Theδ^34SCDT values of Py1(0.42‰-1.61‰,average 1.16‰),Py2(-1.23‰to 0.82‰,average 0.35‰),Py3(-0.36‰to 2.47‰,average 0.97‰),Py4(2.51‰-3.72‰,average 3.06‰),and other sulfides are consistent with those of typical porphyry deposit(-5‰to 5‰),indicating that the Pb-Zn polymetallic mineralization in the Bianjiadayuan deposit is genetically linked to the Yanshanian(JurassiceCretaceous)magmatic-hydrothermal events.Variations of d34S values are ascribed to the changes in physical and chemical conditions during the evolution and migration of the ore-forming fluid.We propose that the high Sn content of pyrite in the Bianjiadayuan hydrothermal vein-type PbeZn polymetallic deposit can be used as a possible pathfinder to prospect for Sn mineralization in the surrounding area or deeper level of the ore field in this region.
文摘对科学基金各学科的发展态势进行分析,可以为诊断学科发展现状、制定学科发展战略规划提供参考依据。本研究从科研产出视角出发,以2013—2022年的Web of Science(WoS)论文为数据源,应用科学计量学方法,从学科结构、产出成效、国际合作三个维度,对科学基金各学科的发展态势进行横向对比分析。研究发现,在学科结构方面,中国在物质科学及工程技术类优势学科规模指标表现突出,效率指标差距显著,需着重鼓励优势学科原创性、引领性研究产出,实现突破式创新发展。中国的学科结构均衡性不断加强,在学科均衡协同发展的基础上,需优先支持国家战略需求领域和科学前沿领域突破。在资助成效方面,国家自然科学基金项目的资助具有较高投入产出效率,且有效推动了重要成果的产出,需继续加强高产出效率领域及重要成果团队的后续资助力度,进一步提升投入产出效率。在国际合作方面,中国天文学、管理科学国际合作论文份额最高,化学、医学份额最低,各学科的国际合作论文份额自2020年起均呈显著下降趋势,其中中美合作大幅下滑,材料科学和力学领域下降最为明显。需聚焦全球关注的热点科研问题,构建更加多元化的国际科研合作网络。
基金This work was supported by the research fund of Hanyang University(HY-2019-N)This work was supported by the National Key Research&Development Program 2018YFA0701601.
文摘This paper proposes a Reinforcement learning(RL)algorithm to find an optimal scheduling policy to minimize the delay for a given energy constraint in communication system where the environments such as traffic arrival rates are not known in advance and can change over time.For this purpose,this problem is formulated as an infinite-horizon Constrained Markov Decision Process(CMDP).To handle the constrained optimization problem,we first adopt the Lagrangian relaxation technique to solve it.Then,we propose a variant of Q-learning,Q-greedyUCB that combinesε-greedy and Upper Confidence Bound(UCB)algorithms to solve this constrained MDP problem.We mathematically prove that the Q-greedyUCB algorithm converges to an optimal solution.Simulation results also show that Q-greedyUCB finds an optimal scheduling strategy,and is more efficient than Q-learning withε-greedy,R-learning and the Averagepayoff RL(ARL)algorithm in terms of the cumulative regret.We also show that our algorithm can learn and adapt to the changes of the environment,so as to obtain an optimal scheduling strategy under a given power constraint for the new environment.
文摘Taking Ludian County in Zhaotong City of Yunnan Province for example,according to the data on residents'income gap in Ludian County during the period 2002-2011,we analyze the residents'income gap in Ludian County,and offer the forecast value of residents'income gap in Ludian County during the period 2012-2015,using Compertz curve model and Eviews software for fitting.The forecast value shows that the residents'income gap will continue to widen in Ludian County.Finally we put forth the recommendations for bridging the residents'income gap in Ludian County,in order to provide a reference for settling the problems concerning residents'income gap in other state-level povertystricken counties of Yunnan Province.
基金2024 Provincial Teaching Reform Program for Graduate Students in the Second Batch of the 14th Five-Year Plan of Zhejiang Provincial Office of Education:Innovation and Practice of“Six Synergistic”Graduate Teaching Guided by Educator’s Spirit(No.JGCG2024406)Key Project of Zhejiang Provincial Education Science Planning:Research on an interdisciplinary teaching model to promote students’computational thinking from multiple analytical perspectives[No.2025SB103].
文摘Oral expression skills play an essential role in the development of EFL students’language abilities,and how to improve EFL students’oral expression skills is an essential and challenging task.This study adopts a quasi-experimental research method to carry out the research and proposes an AI-based reflective dialogue model.Based on this,an analysis of the impact brought by this model on EFL students’oral expression performance and learning anxiety levels.The results show that students in the experimental group have significantly higher oral expression performance than those in the control group in the three dimensions of grammatical accuracy,expressive fluency,and word accuracy.In addition,the students in the experimental group produced facilitated anxiety after using the AI-based reflective dialogue model for oral expression learning,which prompted the students to learn more diligently.
基金supported by the National Key Research and Development Program of China(2023YFB2804704)the National Natural Science Foundation of China(12174292,12374278,and 62105250).
文摘Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the demand for high-quality multiplexers and demultiplexers.However,the criteria for ideal-mode multiplexers/demultiplexers,such as performance,scalability,compatibility,and ultra-compactness,have only partially been achieved using conventional bulky devices(e.g.,waveguides,grat-ings,and free space optics)—an issue that will substantially restrict the application of MDM techniques.Here,we present a neuro-meta-router(NMR)optimized through deep learning that achieves spatial multi-mode division and supports multi-channel communication,potentially offering scalability,com-patibility,and ultra-compactness.An MDM communication system based on an NMR is theoretically designed and experimentally demonstrated to enable simultaneous and independent multi-dataset transmission,showcasing a capacity of up to 100 gigabits per second(Gbps)and a symbol error rate down to the order of 104,all achieved without any compensation technologies or correlation devices.Our work presents a paradigm that merges metasurfaces,fiber communications,and deep learning,with potential applications in intelligent metasurface-aided optical interconnection,as well as all-optical pat-tern recognition and classification.
基金supported by the National Natural Science Foundation of China(Grant No.81302160 and 81272447)Beijing Natural Science Foundation ProgramScientific Research Key Program of Beijing Municipal Commission of Education(Grant No.KZ201410025024)
文摘Objective： Gastric cancer （GC） is one of the leading causes of death in China and other Asian countries. Recently, gastric endoscopy has become the main approach for GC screening, but the identification of high-risk individuals remains a challenge in GC screening programs. Methods： There were 7,302 patients with chronic gastritis involved in this study. Endoscopic examinations were performed, and their demographic characteristics and lifestyle data were collected. Each possible associated factor of GC/premalignant and precursor lesions was evaluated by univariate and multivariate logistic regressions. Nomograms were used for visualization of those models, and receiver operating characteristic （ROC） curve analysis was used to present the predictive accuracy. Resu Its： We detected 8 （0.11% ） gastric adenocarcinomas, 17 （0.23 %） dysplasia cases, 14 （0.19%） hyperplasia cases, 52 （0.71%） intestinal metaplasia cases, 217 （2.97%） inflammatory lesions, 141 （1.93%） gastric ulcers, 10 （0.14%） atrophic gastritis cases, 1,365 （18.69%） erosive gastritis cases, and 5,957 （81.58%） superficial gastritis cases in 7,302 patients. The age （P〈0.001）, gender （P=0.086）, labor intensity （P=0.018） and leek food intake （P=0.143） were identified as independent predictive factors of GC/premalignant lesions possibility. The corresponding nomogram exhibited an area under the curve （AUC） [95% confidence interval （95% CI）] of 0.82 （0.74-0.89） for the modeling group and 0.80 （0.75-0.85） for the validation group. The age （P=0.002）, gender （P=0.024）, smoldng （P=0.002） and leek food intake （P=0.039） were independent predictive factors of precursor lesions possibility. The corresponding nomogram exhibited an AUC （95% CI） of 0.62 （0.60-0.65） for the modeling group and 0.61 （0.59-0.63） for the validation group. Conclusions： We identified several potential associated factors and provided a preclinical nomogram with the potential to predict the possibility of GC/premalignant and precursor lesions.
基金Supported by the Zhejiang Medical Technology Project,No.2022RC009 and No.2024KY645.
文摘Diabetic foot ulcers(DFUs)represents a significant public health issue,with a rising global prevalence and severe potential complications including amputation.Traditional treatments often fall short due to various limitations such as high recurrence rates and extensive resource utilization.This editorial explores the innovative use of acellular fish skin grafts as a transformative approach in DFU management.Recent studies and a detailed case report highlight the efficacy of acellular fish skin grafts in accelerating wound closure,reducing dressing changes,and enhancing patient outcomes with a lower socio-economic burden.Despite their promise,challenges such as limited availability,patient acceptance,and the need for further research persist.Addressing these through more extensive randomized controlled trials and fostering a multidisciplinary treatment approach may optimize DFU care and reduce the global health burden associated with these complex wounds.
