期刊文献+
共找到289篇文章
< 1 2 15 >
每页显示 20 50 100
A Quality Evaluation System for Dissertation Based on Fuzzy Analytic Hierarchy Process
1
作者 Kang Xu Zhenhao Zhang +4 位作者 shuo wang Yunhui Lv Jiafei Li Xiaodan Cai Yongchun Cui 《Applied Mathematics》 2024年第7期441-454,共14页
A dissertation is a research report or scientific paper written by an author to obtain a certain degree. It reflects postgraduates’ research achievements and the educational quality of an institute, even a country. T... A dissertation is a research report or scientific paper written by an author to obtain a certain degree. It reflects postgraduates’ research achievements and the educational quality of an institute, even a country. To construct an optimized quality evaluation system for postgraduate dissertation (QESPD), we summarized the influencing factors and invited 10 experienced specialists to rate and prioritize them based on fuzzy analytic hierarchy process. Four primary indicators (innovation, integrity, scientificity and normativity) and 16 sub-indicators were selected to form the evaluation system. The order of primary indicators by weight, was innovation (0.4269), scientificity (0.2807), integrity (0.1728) and normativity (0.1196). The top five sub-dimensions were theoretical originality, scientific value, data reliability, design rationality and evidence credibility. To demonstrate the effectiveness of the proposed system, a case study was performed. In the case study, it was demonstrated that the established two-index-hierarchy QESPD in this study was a more scientific and reasonable evaluation system worthy of promotion and application. 展开更多
关键词 DISSERTATION Quality Evaluation Indicator System Fuzzy Analytic Hierarchy Process Case Study
下载PDF
CuPc/FeNC双组分催化剂协同催化硝酸盐转化为氨
2
作者 王毅 王硕 +6 位作者 付云凡 桑佳琪 臧一鹏 魏鹏飞 李合肥 汪国雄 包信和 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第1期104-113,共10页
氨(NH_(3))作为重要的化学品和能源储存介质,需求量与日俱增.本文旨在通过电化学硝酸根还原反应(NO_(3)^(−)RR),将NO_(3)^(−)转化为NH3,不仅解决了NO_(3)^(−)引起的环境污染问题,又可以满足对NH_(3)的迫切需求.然而,NO_(3)^(−)RR涉及多... 氨(NH_(3))作为重要的化学品和能源储存介质,需求量与日俱增.本文旨在通过电化学硝酸根还原反应(NO_(3)^(−)RR),将NO_(3)^(−)转化为NH3,不仅解决了NO_(3)^(−)引起的环境污染问题,又可以满足对NH_(3)的迫切需求.然而,NO_(3)^(−)RR涉及多个电子和质子转移过程,其中,NO_(2)^(−)是NO_(3)^(−)活化转化和深度还原合成NH_(3)的重要中间体.酞菁铜(CuPc)能够高效地活化转化NO_(3)^(−)为NO_(2)^(−),但在低过电位时无法有效地将NO2−还原为NH3,难以获得较高的氨法拉第效率(FENH3)和分电流密度.而氮配位的铁单原子催化剂(FeNC)则有较好的NO_(2)^(−)吸附活化特性.因此,利用双组分催化剂之间的协同作用以实现高效NO_(3)^(−)RR的活性和选择性是本文的主要研究思路.本文设计了CuPc/FeNC串联催化剂,利用CuPc和FeNC对NO_(3)^(−)和NO_(2)^(−)的吸附活化能力的差异,实现了高效的协同催化转化.X射线衍射、高角环形暗场扫描透射电镜、X射线光电子能谱及X射线吸收谱结果表明,FeNC催化剂中Fe原子均匀分布于ZIF-8热解后的基底.通过将FeNC和CuPc负载于气体扩散电极,在流动电解池中完成NO_(3)^(−)RR.CuPc/FeNC催化剂在较低电势区间中能够实现接近100%的NH3法拉第效率,同时在−0.57 V vs.RHE时达到273 mA cm–2的NH3分电流密度,并且在整个电势范围内有效地抑制了NO_(2)^(–)聚集.与单组分催化剂CuPc和FeNC对比结果表明,在−0.53 V vs.RHE时,CuPc/FeNC催化剂表现出较高的FE(NH_(3))/FE(NO_(2)^(−))比值,是CuPc催化剂的50倍;同时CuPc/FeNC催化剂上NH3分电流密度是FeNC催化剂的1.5倍.进一步研究了NO_(3)^(–)RR中的串联反应机制,其中FeNC催化剂表现出较高的NO_(2)^(–)RR活性,并且有效抑制了析氢反应.此外,CuPc/FeNC催化剂和FeNC催化剂在NO_(2)^(−)RR中表现出类似的NH3分电流密度,这表明在NO_(3)^(−)RR中,CuPc/FeNC催化剂性能的提高来源于FeNC位点能够进一步还原CuPc位点产生的NO_(2)^(–).理论计算结果表明,FeNC比CuPc表现出更强的NO_(2)^(–)吸附活化能力,说明NO_(2)^(−)在FeNC上更容易进行加氢还原.NO_(3)^(−)RR反应全路径分析结果表明,对于^(*)NO_(3)还原到*NO2过程,CuPc相对于FeNC位点具有明显降低的反应自由能,说明CuPc有利于NO_(2)^(−)的生成;而FeNC位点在后续的^(*)NO_(2)还原合成^(*)NH_(3)过程中具有更低的反应自由能,这与实验结果一致.一系列非原位和原位表征证明了CuPc催化剂在高电位下存在少量金属颗粒析出,与CuPc催化剂在高电位下NH_(3)分电流密度快速增加结果一致.综上,本工作中CuPc和FeNC催化剂之间的协同作用弥补了各自的不足,通过串联反应机制,在低过电位下有效增加了NH_(3)的法拉第效率和电流密度,实现了高效的协同催化转化,为设计和合成高效催化剂提供了新思路. 展开更多
关键词 硝酸根电化学还原为氨 协同催化转化 串联催化 双组分催化剂 动态现场原位表征
下载PDF
Analysis of the Risk of Water Breakout in the Bottom Plate of High-Intensity Mining of Extra-Thick Coal Seams
3
作者 shuo wang Hongdong Kang Xinchen wang 《Journal of Geoscience and Environment Protection》 2024年第5期81-91,共11页
In order to clarify the danger of water breakout in the bottom plate of extra-thick coal seam mining, 2202 working face of a mine in the west is taken as the research object, and it is proposed to use the on-site moni... In order to clarify the danger of water breakout in the bottom plate of extra-thick coal seam mining, 2202 working face of a mine in the west is taken as the research object, and it is proposed to use the on-site monitoring means combining borehole peeping and microseismic monitoring, combined with the theoretical analysis to analyze the danger of water breakout in the bottom plate. The results show that: 1) the theoretically calculated maximum damage depth of the bottom plate is 27.5 m, and its layer is located above the Austrian ash aquifer, which has the danger of water breakout;2) the drill hole peeping at the bottom plate of the working face shows that the depth of the bottom plate fissure development reaches 26 m, and the integrity of the water barrier layer has been damaged, so there is the risk of water breakout;3) for the microseismic monitoring of the anomalous area, the bottom plate of the return air downstream channel occurs in the field with a one-week lag, which shows that microseismic monitoring events may reflect the water breakout of the underground. This shows that the microseismic monitoring events can reflect the changes of the underground flow field, which can provide a reference basis for the early warning of water breakout. The research results can provide reference for the prediction of sudden water hazard. 展开更多
关键词 Extra-Thick Coal Seam High-Intensity Mining Microseismic Monitoring Water-Surge Hazard Borehole Peeping
下载PDF
Application of Horizontal Well Seismic Geo-Steering Technology in XX Block Development
4
作者 Xuecheng Jia Xiaoyi Cheng +4 位作者 Hui Ma Shilei Lu Xin Yang shuo wang Xiang Li 《Open Journal of Yangtze Oil and Gas》 2024年第3期65-74,共10页
During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such ... During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such as deep burial depth (>2000 m), thin coal sweet spot (3 m), and significant short-distance structural fluctuations. The challenges caused a high risk of missing targets and running out of the target layers, as well as difficulties in cementing and completion due to uneven well trajectories. To address these challenges, this paper focuses on solving the issues through detailed precise geological modeling, optimized trajectory design, and accurate seismic geology Steerable Drilling. 1) Based on reasonable velocity field construction and Time-Depth transformation, a precise directional model is constructed using the layer-by-layer approximation principle with reference to marker layers, improving the accuracy of the target spot and avoiding premature or delayed entry into the target;2) Based on a precise geological model, the dip angle of the strata ahead and the development of sweet spots are clearly defined, enabling optimized trajectory design for horizontal wells;3) Using “1 + N” dynamic modeling to update the geological model in real-time during the drilling process, and actively guide the drill bit through the horizontal segment smoothly by using multi-information judgment of the drill bit position. The actual drilling of 80 completed horizontal wells in this area show: That this approach effectively ensures the smooth trajectory and high-quality drilling rate of the horizontal well in the coal seam, providing a basis for subsequent hydraulic fracturing and increasing single-well production. At the same time, it has certain potential value and significance for similar coalbed methane developments under similar geological conditions. 展开更多
关键词 Seismic Geo-Steerable Horizontal Wells Coalbed Methane Marker Layers
下载PDF
从信号到知识——基于人工智能的医学影像裸数据诊断价值初探 被引量:1
5
作者 Bingxi He Yu Guo +28 位作者 Yongbei Zhu Lixia Tong Boyu Kong Kun wang Caixia Sun Hailin Li Feng Huang Liwei Wu Meng wang Fanyang Meng Le Dou Kai Sun Tong Tong Zhenyu Liu Ziqi Wei Wei Mu shuo wang Zhenchao Tang Shuaitong Zhang Jingwei Wei Lizhi Shao Mengjie Fang Juntao Li Shouping Zhu Lili Zhou shuo wang Di Dong Huimao Zhang Jie Tian 《Engineering》 SCIE EI CAS CSCD 2024年第3期60-69,共10页
Encouraging and astonishing developments have recently been achieved in image-based diagnostic technology.Modern medical care and imaging technology are becoming increasingly inseparable.However,the current diagnosis ... Encouraging and astonishing developments have recently been achieved in image-based diagnostic technology.Modern medical care and imaging technology are becoming increasingly inseparable.However,the current diagnosis pattern of signal to image to knowledge inevitably leads to information distortion and noise introduction in the procedure of image reconstruction(from signal to image).Artificial intelligence(AI)technologies that can mine knowledge from vast amounts of data offer opportunities to disrupt established workflows.In this prospective study,for the first time,we develop an AI-based signal-toknowledge diagnostic scheme for lung nodule classification directly from the computed tomography(CT)raw data(the signal).We find that the raw data achieves almost comparable performance with CT,indicating that it is possible to diagnose diseases without reconstructing images.Moreover,the incorporation of raw data through three common convolutional network structures greatly improves the performance of the CT models in all cohorts(with a gain ranging from 0.01 to 0.12),demonstrating that raw data contains diagnostic information that CT does not possess.Our results break new ground and demonstrate the potential for direct signal-to-knowledge domain analysis. 展开更多
关键词 Computed tomography DIAGNOSIS Deep learning Lung cancer Raw data
下载PDF
Ultra-wide band gap and wave attenuation mechanism of a novel star-shaped chiral metamaterial 被引量:1
6
作者 shuo wang Anshuai wang +7 位作者 Yansen WU Xiaofeng LI Yongtao SUN Zhaozhan ZHANG Qian DING G.D.AYALEW Yunxiang MA Qingyu LIN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第7期1261-1278,共18页
A novel hollow star-shaped chiral metamaterial(SCM)is proposed by incorporating chiral structural properties into the standard hollow star-shaped metamaterial,exhibiting a wide band gap over 1500 Hz.To broaden the ban... A novel hollow star-shaped chiral metamaterial(SCM)is proposed by incorporating chiral structural properties into the standard hollow star-shaped metamaterial,exhibiting a wide band gap over 1500 Hz.To broaden the band gap,solid single-phase and two-phase SCMs are designed and simulated,which produce two ultra-wide band gaps(approximately 5116 Hz and 6027 Hz,respectively).The main reason for the formation of the ultra-wide band gap is that the rotational vibration of the concave star of two novel SCMs drains the energy of an elastic wave.The impacts of the concave angle of a single-phase SCM and the resonator radius of a two-phase SCM on the band gaps are studied.Decreasing the concave angle leads to an increase in the width of the widest band gap,and the width of the widest band gap increases as the resonator radius of the two-phase SCM increases.Additionally,the study on elastic wave propagation characteristics involves analyzing frequency dispersion surfaces,wave propagation directions,group velocities,and phase velocities.Ultimately,the analysis focuses on the transmission properties of finite periodic structures.The solid single-phase SCM achieves a maximum vibration attenuation over 800,while the width of the band gap is smaller than that of the two-phase SCM.Both metamaterials exhibit high vibration attenuation capabilities,which can be used in wideband vibration reduction to satisfy the requirement of ultra-wide frequencies. 展开更多
关键词 METAMATERIAL ultra-wide band gap wave propagation vibration suppression
下载PDF
D-Psicose intake exacerbates dextran sulfate sodium-induced colitis in mice through alteration in the gut microbiota and dysfunction of mucosal barrier 被引量:1
7
作者 Xuejiao Zhang Ang Li +5 位作者 Yuanyifei wang Jin wang Bowei Zhang Yan Zhang Jingmin Liu shuo wang 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期173-182,共10页
D-Psicose,as a low-calorie rare sugar,has attracted a lot of attention in recent years for alternating to sucrose.The anti-obesity effect of D-psicose has been extensively confirmed in previous studies,however,the imp... D-Psicose,as a low-calorie rare sugar,has attracted a lot of attention in recent years for alternating to sucrose.The anti-obesity effect of D-psicose has been extensively confirmed in previous studies,however,the impact of D-psicose on colitis remains vague.Here,we firstly evaluated the effect of the D-psicose prophylactic intervention on dextran sulfate sodium-induced colitis in C57BL/6 mice.The pathological symptoms,inflammatory cytokines levels,gut microbiota composition,short chain fatty acids(SCFAs)production and colonic barrier integrity were comprehensively evaluated.The results confirmed that D-psicose intervention aggravated colitis,characterized by the exacerbation of colon shortening,increase of colonic inflammatory infiltration,and marked exaltation of disease activity indices and IL-6,IL-1βand TNF-αlevels.Further,the dysfunction of gut microbiota was identified in the psicose group.The abundance of pro-inflammatory bacteria Lachnospiraceae_NK4A136_group was significantly up-regulated while the abundance of probiotics Akkermansia and Lactobacillus were significantly down-regulated in the psicose group compared to the model group.Moreover,the production of SCFAs was suppressed in the psicose group,accompanied by a decrease in the level of mucin 2(Muc-2).Collectively,the underlying mechanism of the exacerbation of colitis by D-psicose intervention might be attributed to microbiota dysfunction accompanied by the reduction of SCFAs,which leads to the damage of the mucosal barrier and the intensifi cation of inflammatory invasion. 展开更多
关键词 D-Psicose COLITIS Gut microbiota Short chain fatty acids Mucin 2
下载PDF
Effect of icosahedral phase formation on the stress corrosion cracking(SCC)behaviors of the as-cast Mg-8%Li(in wt.%)based alloys 被引量:1
8
作者 shuo wang Daokui Xu +2 位作者 Dongliang wang Zhiqiang Zhang Baojie wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期225-236,共12页
Through exploring the stress corrosion cracking(SCC)behaviors of the as-cast Mg-8%Li and Mg-8%Li-6%Zn-1.2%Y alloys in a 0.1 M NaCl solution,it revealed that the SCC susceptibility index(I_(SCC))of the Mg-8%Li alloy wa... Through exploring the stress corrosion cracking(SCC)behaviors of the as-cast Mg-8%Li and Mg-8%Li-6%Zn-1.2%Y alloys in a 0.1 M NaCl solution,it revealed that the SCC susceptibility index(I_(SCC))of the Mg-8%Li alloy was 47%,whilst the I_(SCC)of the Mg-8%Li-6%Zn-1.2%Y alloy was 68%.Surface,cross-sectional and fractography observations indicated that for the Mg-8%Li alloy,theα-Mg/β-Li interfaces acted as the preferential crack initiation sites and propagation paths during the SCC process.With regard to the Mg-8%Li-6%Zn-1.2%Y alloy,the crack initiation sites included the I-phase and the interfaces of I-phase/β-Li andα-Mg/β-Li,and the preferential propagation paths were the I-phase/β-Li andα-Mg/β-Li interfaces.Moreover,the SCC of the two alloys was concerned with hydrogen embrittlement(HE)mechanism. 展开更多
关键词 Magnesium-lithium alloy Stress corrosion cracking I-phase Fracture analysis
下载PDF
The research progress of an E//B neutral particle analyzer 被引量:1
9
作者 马龙 屈玉凡 +12 位作者 罗圆 谢德豪 汪彦熹 王硕 曲国峰 任培培 罗小兵 刘星泉 韩纪锋 Roy WADA 林炜平 臧临阁 朱敬军 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期10-16,共7页
An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of ... An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of fast ions in the HL-2A/3 tokamak.The E//B NPA contains three main units,i.e.the stripping unit,the analyzing unit and the detection unit.A gas stripping chamber was adopted as the stripping unit.The results of the simulations and beam tests for the stripping chamber are presented.Parallel electric and magnetic fields provided by a NdFeB permanent magnet and two parallel electric plates were designed and constructed for the analyzing unit.The calibration of the magnetic and electric fields was performed using a 50 kV electron cyclotron resonance ion source(ECRIS)platform.The detection unit consists of 32lutetium-yttrium oxyorthosilicate(LYSO)detector modules arranged in two rows.The response functions ofα,hydrogen ions(H^(+),H_(2)^(+)and H_(3)^(+))andγfor a detector module were measured with^(241)Am,^(137)Cs and^(152)Eu sources together with the 50 kV ECRIS platform.The overall results indicate that the designed E//B NPA device is capable of measuring the intensity of neutral hydrogen and deuteron atoms with energy higher than 20 keV. 展开更多
关键词 E//B neutral particle analyzer gas stripping lutetium-yttrium oxyorthosilicate electron cyclotron resonance ion source platform
下载PDF
m^(1)A inhibition fuels oncolytic virus-elicited antitumor immunity via downregulating MYC/PD-L1 signaling 被引量:1
10
作者 Shujin Li Tian Feng +7 位作者 Yuantong Liu Qichao Yang An Song shuo wang Jun Xie Junjie Zhang Bifeng Yuan Zhijun Sun 《International Journal of Oral Science》 SCIE CAS CSCD 2024年第3期486-498,共13页
N^(1)-methyladenosine(m^(1)A)RNA methylation is critical for regulating mRNA translation;however,its role in the development,progression,and immunotherapy response of head and neck squamous cell carcinoma(HNSCC)remain... N^(1)-methyladenosine(m^(1)A)RNA methylation is critical for regulating mRNA translation;however,its role in the development,progression,and immunotherapy response of head and neck squamous cell carcinoma(HNSCC)remains largely unknown.Using Tgfbr1 and Pten conditional knockout(2cKO)mice,we found the neoplastic transformation of oral mucosa was accompanied by increased m^(1)A modification levels.Analysis of m^(1)A-associated genes identified TRMT61A as a key m^(1)A writer linked to cancer progression and poor prognosis.Mechanistically,TRMT61A-mediated tRNA-m^(1)A modification promotes MYC protein synthesis,upregulating programmed death-ligand 1(PD-L1)expression.Moreover,m^(1)A modification levels were also elevated in tumors treated with oncolytic herpes simplex virus(oHSV),contributing to reactive PD-L1 upregulation.Therapeutic m^(1)A inhibition sustained oHSV-induced antitumor immunity and reduced tumor growth,representing a promising strategy to alleviate resistance.These findings indicate that m^(1)A inhibition can prevent immune escape after oHSV therapy by reducing PD-L1 expression,providing a mutually reinforcing combination immunotherapy approach. 展开更多
关键词 IMMUNITY SUSTAINED representing
下载PDF
The microbial community,nutrient supply and crop yields differ along a potassium fertilizer gradient under wheat-maize double-cropping systems
11
作者 Zeli Li Fuli Fang +10 位作者 Liang Wu Feng Gao Mingyang Li Benhang Li Kaidi Wu Xiaomin Hu shuo wang Zhanbo Wei Qi Chen Min Zhang Zhiguang Liu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第10期3592-3609,共18页
Soil microorganisms play critical roles in ecosystem function.However,the relative impact of the potassium(K)fertilizer gradient on the microbial community in wheat-maize double-cropping systems remains unclear.In thi... Soil microorganisms play critical roles in ecosystem function.However,the relative impact of the potassium(K)fertilizer gradient on the microbial community in wheat-maize double-cropping systems remains unclear.In this long-term field experiment(2008-2019),we researched bacterial and fungal diversity,composition,and community assemblage in the soil along a K fertilizer gradient in the wheat season(K0,no K fertilizer;K1,45 kg ha^(-1) K_(2)O;K_(2),90 kg ha^(-1)K_(2)O;K3,135 kg ha^(-1)K_(2)O)and in the maize season(K0,no K fertilizer;K_(1),150 kg ha^(-1) K_(2)O;K_(2),300 kg ha^(-1)K_(2)O;K_(3),450 kg ha^(-1)K_(2)O)using bacterial 16S rRNA and fungal internally transcribed spacer(ITS)data.We observed that environmental variables,such as mean annual soil temperature(MAT)and precipitation,available K,ammonium,nitrate,and organic matter,impacted the soil bacterial and fungal communities,and their impacts varied with fertilizer treatments and crop species.Furthermore,the relative abundance of bacteria involved in soil nutrient transformation(phylum Actinobacteria and class Alphaproteobacteria)in the wheat season was significantly increased compared to the maize season,and the optimal K fertilizer dosage(K2 treatment)boosted the relative bacterial abundance of soil nutrient transformation(genus Lactobacillus)and soil denitrification(phylum Proteobacteria)bacteria in the wheat season.The abundance of the soil bacterial community promoting root growth and nutrient absorption(genus Herbaspirillum)in the maize season was improved compared to the wheat season,and the K2 treatment enhanced the bacterial abundance of soil nutrient transformation(genus MND1)and soil nitrogen cycling(genus Nitrospira)genera in the maize season.The results indicated that the bacterial and fungal communities in the double-cropping system exhibited variable sensitivities and assembly mechanisms along a K fertilizer gradient,and microhabitats explained the largest amount of the variation in crop yields,and improved wheat?maize yields by 11.2-22.6 and 9.2-23.8%with K addition,respectively.These modes are shaped contemporaneously by the different meteorological factors and soil nutrient changes in the K fertilizer gradients. 展开更多
关键词 potassium fertilizer gradient microbial community wheat-maize double cropping climate change yield
下载PDF
Highly selective photocatalytic reduction of CO_(2) to CH_(4) on electron-rich Fe species cocatalyst under visible light irradiation
12
作者 Qianying Lin Jiwu Zhao +8 位作者 Pu Zhang shuo wang Ying wang Zizhong Zhang Na Wen Zhengxin Ding Rusheng Yuan Xuxu wang Jinlin Long 《Carbon Energy》 SCIE EI CAS CSCD 2024年第1期255-266,共12页
Efficient photocatalytic reduction of CO_(2) to high-calorific-value CH4,an ideal target product,is a blueprint for C_(1)industry relevance and carbon neutrality,but it also faces great challenges.Herein,we demonstrat... Efficient photocatalytic reduction of CO_(2) to high-calorific-value CH4,an ideal target product,is a blueprint for C_(1)industry relevance and carbon neutrality,but it also faces great challenges.Herein,we demonstrate unprecedented hybrid SiC photocatalysts modified by Fe-based cocatalyst,which are prepared via a facile impregnation-reduction method,featuring an optimized local electronic structure.It exhibits a superior photocatalytic carbon-based products yield of 30.0μmol g^(−1) h^(−1) and achieves a record CH_(4) selectivity of up to 94.3%,which highlights the effectiveness of electron-rich Fe cocatalyst for boosting photocatalytic performance and selectivity.Specifically,the synergistic effects of directional migration of photogenerated electrons and strongπ-back bonding on low-valence Fe effectively strengthen the adsorption and activation of reactants and intermediates in the CO_(2)→CH_(4) pathway.This study inspires an effective strategy for enhancing the multielectron reduction capacity of semiconductor photocatalysts with low-cost Fe instead of noble metals as cocatalysts. 展开更多
关键词 artificial synthesis of CH_(4) electronic structure optimization Fe species cocatalyst photocatalytic CO_(2) reduction SiC
下载PDF
Repeated inoculation with rumen fluid accelerates the rumen bacterial transition with no benefit on production performance in postpartum Holstein dairy cows
13
作者 Fanlin Kong Feiran wang +3 位作者 Yijia Zhang shuo wang Wei wang Shengli Li 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第2期795-811,共17页
Background The dairy cow’s postpartum period is characterized by dramatic physiological changes,therefore imposing severe challenges on the animal for maintaining health and milk output.The dynamics of the ruminal mi... Background The dairy cow’s postpartum period is characterized by dramatic physiological changes,therefore imposing severe challenges on the animal for maintaining health and milk output.The dynamics of the ruminal microbiota are also tremendous and may play a crucial role in lactation launch.We aim to investigate the potential benefits of early microbial intervention by fresh rumen microbiota transplantation(RMT)and sterile RMT in postpartum dairy cows.Twelve fistulated peak-lactation dairy cows were selected to be the donors for rumen fluid collection.Thirty postpartum cows were divided into 3 groups as the transplantation receptors respectively receiving 10 L fresh rumen fluid(FR),10 L sterile rumen fluid(SR),or 10 L saline(CON)during 3 d after calving.Results Production performance,plasma indices,plasma lipidome,ruminal microbiome,and liver transcriptome were recorded.After fresh and sterile RMT,we found that the molar proportion of propionic acid was increased on d 7 in the FR and SR groups and the bacterial composition was also significantly changed when compared with the CON group.A similarity analysis showed that the similarities between the CON group and FR or SR group on d 7 were 48.40%or 47.85%,whereas the similarities between microbiota on d 7 and 21 in the FR and SR groups were 68.34%or 66.85%.Dry matter intake and feed efficiency were not affected by treatments.Plasmaβ-hydroxybutyrate concentration in the FR group was decreased and significantly different lipids mainly included phosphatidylcholine and lysophosphatidylcholine containing polyunsaturated fatty acids.Hepatic transcriptomics analysis indicated acutephase response pathways were upregulated in the SR group.Conclusions Our study suggests that RMT can shorten the transition process of the ruminal microbiota of postpartum dairy cows with no benefit on dry matter intake or feed efficiency.Inoculation with rumen fluid may not be a useful approach to promote the recovery of postpartum dairy cows. 展开更多
关键词 Dairy cow LIPIDOMICS Liver Rumen microbiota transplantation Transition period
下载PDF
Advantageous properties of halide perovskite quantum dots towards energy-efficient sustainable applications
14
作者 Qian Zhao shuo wang +9 位作者 Young-Hoon Kim Shekhar Mondal Qingqing Miao Simiao Li Danya Liu Miao wang Yaxin Zhai Jianbo Gao Abhijit Hazarika Guo-Ran Li 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第6期949-965,共17页
As lead halide perovskite(LHP)semiconductors have shown tremendous promise in many application fields,and particularly made strong impact in the solar photovoltaic area,low dimensional quantum dot forms of these perov... As lead halide perovskite(LHP)semiconductors have shown tremendous promise in many application fields,and particularly made strong impact in the solar photovoltaic area,low dimensional quantum dot forms of these perovskites are showing the potential to make distinct marks in the fields of electronics,optoelectronics and photonics.The so-called perovskite quantum dots(PQDs)not only possess the most important features of LHP materials,i.e.,the unusual high defect tolerance,but also demonstrate clear quantum size effects,along with exhibiting desirable optoelectronic properties such as near perfect photoluminescent quantum yield,multiple exciton generation and slow hot-carrier cooling.Here,we review the advantageous properties of these nanoscale perovskites and survey the prospects for diverse applications which include lightemitting devices,solar cells,photocatalysts,lasers,detectors and memristors,emphasizing the distinct superiorities as well as the challenges. 展开更多
关键词 Perovskite quantum dot LIGHT-EMITTING Detector Laser Solar cell
下载PDF
Experimental study on the gas-stripping chamber of an E//B neutral particle analyzer
15
作者 Long Ma De-Hao Xie +14 位作者 Yan-Xi wang shuo wang Ji-Feng Han Wei-Ping Lin Jian-Li Liu Xing-Quan Liu Yu-Guo Liu Xiao-Bing Luo Yuan Luo Guo-Feng Qu Yu-Fan Qu Pei-Pei Ren Roy Wada Lin-Ge Zang Jing-Jun Zhu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第11期98-107,共10页
Stripping units take a key role in the neutral particle analyzer(NPA).A renovated gas-stripping unit was constructed for the newly designed E//B NPA.Using H_(2)as the working gas,we measured the gas inlet pressure(P_(... Stripping units take a key role in the neutral particle analyzer(NPA).A renovated gas-stripping unit was constructed for the newly designed E//B NPA.Using H_(2)as the working gas,we measured the gas inlet pressure(P_(0))and vacuum chamber pressure(P_(3)).The pressure distribution inside the gas-stripping room was calculated with Ansys Fluent,using the measured P_(0)and P_(3)as boundary conditions.The stripping efficiency of the stripping unit was then simulated utilizing the Geant4 Monte Carlo code for the H and D particles.The pressure P_(0)=40 Pa,which is one-sixth of what found in the previous design and corresponds to a thickness of 1.27×10^(17)atoms∕cm^(2),was obtained as the optimum working pressure for the upgraded stripping unit.An 50 kV electron cyclotron resonance(ECR)ion source platform was designed and constructed for E//B NPA calibration,and its performance has been measured.Using the ECR ion source platform,we measured the efficiency of the stripping unit through an inverse experiment with proton beams.We compared the current ratios of measurements with and without H_(2)gas to Geant4 simulation results.We found adequate agreement between the overall trends of the experiment and the simulation.The significant deviation for incident energies below 20 keV may result from the scattering effects of low-energy protons,leading to reduced accuracy in single-scattering physics in Geant4 simulations.Applying the scattering corrections observed in the reverse experiments obtains more accurate stripping efficiencies for H and D atoms in the energy range of 20–200 keV and the global efficiency with the maximum values of 95.0%for H atoms and 78.9%for D atoms at 200 keV. 展开更多
关键词 NPA Gas-stripping ECR ion source Stripping efficiency GEANT4
下载PDF
Deep learning approaches to recover the plasma current density profile from the safety factor based on Grad–Shafranov solutions across multiple tokamaks
16
作者 张瀚予 周利娜 +6 位作者 刘钺强 郝广周 王硕 杨旭 苗雨田 段萍 陈龙 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第5期17-28,共12页
Many magnetohydrodynamic stability analyses require generation of a set of equilibria with a fixed safety factor q-profile while varying other plasma parameters.A neural network(NN)-based approach is investigated that... Many magnetohydrodynamic stability analyses require generation of a set of equilibria with a fixed safety factor q-profile while varying other plasma parameters.A neural network(NN)-based approach is investigated that facilitates such a process.Both multilayer perceptron(MLP)-based NN and convolutional neural network(CNN)models are trained to map the q-profile to the plasma current density J-profile,and vice versa,while satisfying the Grad–Shafranov radial force balance constraint.When the initial target models are trained,using a database of semianalytically constructed numerical equilibria,an initial CNN with one convolutional layer is found to perform better than an initial MLP model.In particular,a trained initial CNN model can also predict the q-or J-profile for experimental tokamak equilibria.The performance of both initial target models is further improved by fine-tuning the training database,i.e.by adding realistic experimental equilibria with Gaussian noise.The fine-tuned target models,referred to as fine-tuned MLP and fine-tuned CNN,well reproduce the target q-or J-profile across multiple tokamak devices.As an important application,these NN-based equilibrium profile convertors can be utilized to provide a good initial guess for iterative equilibrium solvers,where the desired input quantity is the safety factor instead of the plasma current density. 展开更多
关键词 plasma equilibrium deep learning safety factor profile current density profile TOKAMAK
下载PDF
Superposition of dual electric fields in covalent organic frameworks for efficient photocatalytic hydrogen evolution
17
作者 Chao Li shuo wang +8 位作者 Yuan Liub Xihe Huang Yan Zhuang Shuhong Wu Ying wang Na Wen Kaifeng Wu Zhengxin Ding Jinlin Long 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第8期164-175,共12页
Covalent organic frameworks(COFs)are promising materials for converting solar energy into green hydrogen.However,limited charge separation and transport in COFs impede their application in the photocatalytic hydrogen ... Covalent organic frameworks(COFs)are promising materials for converting solar energy into green hydrogen.However,limited charge separation and transport in COFs impede their application in the photocatalytic hydrogen evolution reaction(HER).In this study,the intrinsically tunable internal bond electric field(IBEF)at the imine bonds of COFs was manipulated to cooperate with the internal molecular electric field(IMEF)induced by the donor-acceptor(D-A)structure for an efficient HER.The aligned orientation of IBEF and IMEF resulted in a remarkable H_(2) evolution rate of 57.3 mmol·g^(-1)·h^(-1)on TNCA,which was approximately 520 times higher than that of TCNA(0.11 mmol·g^(-1)·h^(-1))with the opposing electric field orientation.The superposition of the dual electric fields enables the IBEF to function as an accelerating field for electron transfer,kinetically facilitat-ing the migration of photogenerated electrons from D to A.Furthermore,theoretical calculations indicate that the inhomogeneous charge distribution at the C and N atoms in TNCA not only pro-vides a strong driving force for carrier transfer but also effectively hinders the return of free elec-trons to the valence band,improving the utilization of photoelectrons.This strategy of fabricating dual electric fields in COFs offers a novel approach to designing photocatalysts for clean energy synthesis. 展开更多
关键词 Covalent organic framework Internal molecular electric field Internal bond electric field PHOTOCATALYSIS Hydrogen evolution
下载PDF
Integrated analysis of plasma rotation effect on HL-3 hybrid scenario
18
作者 薛淼 郑国尧 +5 位作者 薛雷 李佳鲜 王硕 杜海龙 朱毅仁 周月 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期329-336,共8页
The hybrid scenario,which has good confinement and moderate MHD instabilities,is a proposed operation scenario for international thermonuclear experimental reactor(ITER).In this work,the effect of plasma rotation on t... The hybrid scenario,which has good confinement and moderate MHD instabilities,is a proposed operation scenario for international thermonuclear experimental reactor(ITER).In this work,the effect of plasma rotation on the HL-3 hybrid scenario is analyzed with the integrated modeling framework OMFIT.The results show that toroidal rotation has no obvious effect on confinement with a high line averaged density of n_(bar)~(7)×10^(19)m^(-3).In this case,the ion temperature only changes from 4.7 keV to 4.4 keV with the rotation decreasing from 10^(5) rad/s to 10^(3) rad/s,which means that the turbulent heat transport is not dominant.While in the scenarios characterized by lower densities,such as n_(bar)~4×10^(19)m^(-3),turbulent transport becomes dominant in determining heat transport.The ion temperature rises from 3.8 keV to 6.1 keV in the core as the rotation velocity increases from 10^(3) rad/s to 10^(5) rad/s.Despite the ion temperature rising,the rotation velocity does not obviously affect electron temperature or density.Additionally,it is noteworthy that the variation in rotation velocity does not significantly affect the global confinement of plasma in scenarios with low density or with high density. 展开更多
关键词 HL-3 hybrid scenario toroidal rotation integrated modeling
下载PDF
Critical behavior of quasi-two-dimensional ferromagnet Cr_(1.04)Te_(2)
19
作者 钮伟 宋沁心 +10 位作者 常世琦 王敏 袁奎 高嘉程 王硕 王振东 刘凯斐 刘萍 徐永兵 张晓倩 普勇 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期87-94,共8页
The self-intercalation of Cr into pristine two-dimensional(2D) van der Waals ferromagnetic CrTe_(2),which forms chromium tellurides(Cr_(x)Te_(2)),has garnered interest due to their remarkable magnetic characteristics ... The self-intercalation of Cr into pristine two-dimensional(2D) van der Waals ferromagnetic CrTe_(2),which forms chromium tellurides(Cr_(x)Te_(2)),has garnered interest due to their remarkable magnetic characteristics and the wide variety of chemical compositions available.Here,comprehensive basic characterization and magnetic studies are conducted on quasi-2D ferromagnetic Cr_(1.04)Te_(2) crystals.Measurements of the isothermal magnetization curves are conducted around the critical temperature to systematically investigate the critical behavior.Specifically,the critical exponents β=0.2399,γ=0.859,and δ=4.3498,as well as the Curie temperature T_(C)=249.56 K,are determined using various methods,including the modified Arrott plots,the Kouvel-Fisher method,the Widom scaling method,and the critical isotherm analysis.These results indicate that the tricritical mean-field model accurately represents the critical behavior of Cr_(1.04)Te_(2.A magnetic phase diagram with tricritical phenomenon is thus constructed.Further investigations confirm that the critical exponents obtained conform to the scalar equation near T_(C),indicating their self-consistency and reliability.Our work sheds light on the magnetic properties of quasi-2D Cr_(1.04)Te_(2),broadening the scope of the van der Waals crystals for developments of future spintronic devices operable at room temperature. 展开更多
关键词 critical behavior van der Waals magnets self-intercalation magnetic measurement
下载PDF
The impact of the novel starch-lipid complexes on the glucolipids metabolism, inflammation, and gut dysbiosis of type 2 diabetes mellitus rats
20
作者 Yingshuang Lu Renbing Qin +8 位作者 Jin wang Fengjuan Xiang Yan Zhang Bowei Zhang Dancai Fan Huan Lü Xuemeng Ji Shujun wang shuo wang 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第6期3210-3223,共14页
It has been widely accepted that resistant starch(RS)provides numerous health benefits for human.In this research,we aimed at evaluating the performance of novel starch-lipid complexes,RS5,in comparison with RS2 on ph... It has been widely accepted that resistant starch(RS)provides numerous health benefits for human.In this research,we aimed at evaluating the performance of novel starch-lipid complexes,RS5,in comparison with RS2 on physical features,glucolipids metabolism,inflammation,and gut microbiota profiles of type 2 diabetes mellitus(T2DM)rats.The T2DM model was established by streptozotocin injection to the high-fat-sugar fed rats.According to a serial of biochemical analyses,we found that RS5 diets were strongly correlated with enhanced homeostatic model assessment for insulin secretion(HOMA-IS),high-density lipoprotein cholesterol(HDL-C),adiponectin(ADP),insulin action index(IAI),glucagon-like peptide-1(GLP1),and short-chain fatty acids(SCFAs)in T2DM rats whilst negatively associated with the low-density lipoprotein(LDL-C)and inflammatory cytokines,showing the capabilities to ameliorate T2DM symptoms by regulation of glucolipid metabolism,gut metabolites,and inflammation.On the other hand,RS2-enriched supplementations were influential in the mediation of insulin secretion to improve glucose metabolism.The increasing evidence collected herein suggested that intestinal microbiota could mediate glucolipids metabolism and alleviate inflammation after certain microflora nourished by RS.In addition,RS intake made an impact on phosphoinositide 3-kinase/protein kinase B signaling pathway that might contribute to the improvement of glucose metabolism,insulin resistance,and inflammatory responses. 展开更多
关键词 Resistant starch Type 2 diabetes Glucolipid metabolism Gut microbiota INFLAMMATION
下载PDF
上一页 1 2 15 下一页 到第
使用帮助 返回顶部