期刊文献+
共找到6,039篇文章
< 1 2 250 >
每页显示 20 50 100
基于CNN-GRU-LightGBM模型的单井产量预测方法
1
作者 杨莉 周子希 +1 位作者 王婷婷 王艳铠 《科学技术与工程》 北大核心 2024年第18期7606-7614,共9页
单井日产量趋势预测研究在油田生产中具有重要意义。由于油井生产工况复杂,难以准确预测日产量,建立了基于多变量时序数据的产量模型。基于卷积门控循环单元(convolutional neural network-gate recurrent unit,CNN-GRU)提取深层特征进... 单井日产量趋势预测研究在油田生产中具有重要意义。由于油井生产工况复杂,难以准确预测日产量,建立了基于多变量时序数据的产量模型。基于卷积门控循环单元(convolutional neural network-gate recurrent unit,CNN-GRU)提取深层特征进行时序预测,基于梯度提升框架的集成模型(light gradient boosting machine,LightGBM)从回归预测角度进行预测,两者结果相互融合,进一步提高产量预测精度。同时,提出了一种可以实现多变量时序预测或回归预测模型在未知输入特征情况下准确预测产量的方法—超前参数递归预测策略。采用该方法对影响产量的重要特征进行超前预测,并将预测到的重要特征应用于预测产量的仿真测试中。仿真结果表明:本文模型与超前参数递归策略配合最好,在测试集上的预测准确度最高。相比单变量时序预测和回归预测模型,可显著提高预测精度。 展开更多
关键词 单井产量预测 超前参数预测 CNN-GRU LightGBM
下载PDF
异质双碳源对LiMn_(0.8)Fe_(0.2)PO_(4)复合材料电化学性能的影响
2
作者 李元超 黄卫峰 +5 位作者 梁鹏超 赵子芳 邢保艳 闫东亮 杨理 王松林 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第4期751-760,共10页
采用水基流变相辅助的固相法,以异质碳蔗糖和石墨为碳源,合成了LiMn_(0.8)Fe_(0.2)PO_(4)/C复合材料,研究了不同石墨加入方式对所制复合材料电化学性能的影响,并对所制备的LiMn_(0.8)Fe_(0.2)PO_(4)/C复合材料进行了X射线衍射(XRD)、N_... 采用水基流变相辅助的固相法,以异质碳蔗糖和石墨为碳源,合成了LiMn_(0.8)Fe_(0.2)PO_(4)/C复合材料,研究了不同石墨加入方式对所制复合材料电化学性能的影响,并对所制备的LiMn_(0.8)Fe_(0.2)PO_(4)/C复合材料进行了X射线衍射(XRD)、N_(2)吸附-脱附测试、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等表征。结果表明,不同石墨包覆工艺对材料结构和电化学性能具有显著影响。前驱体煅烧后再加入石墨获得的样品纯度高,形貌呈均一的椭圆形,在0.1C下的放电比容量为149 mAh·g^(-1),达到其理论比容量的87%;在5C下最大的放电比容量为133 mAh·g^(-1);在2C倍率下经过300次循环后比容量维持在127 mAh·g^(-1),衰减率仅为1.9%,表现出了优良的循环稳定性。 展开更多
关键词 LiMn_(0.8)Fe_(0.2)PO_(4)/C 双碳源包覆 水基流变相 正极材料 锂离子电池
下载PDF
Influence of water coupling coefficient on the blasting effect of red sandstone specimens 被引量:2
3
作者 yang li Renshu yang +1 位作者 Yanbing Wang Dairui Fu 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第1期148-166,共19页
This study investigates the impact of different water coupling coefficients on the blasting effect of red sandstone.The analysis is based on the theories of detonation wave and elastic wave,focusing on the variation i... This study investigates the impact of different water coupling coefficients on the blasting effect of red sandstone.The analysis is based on the theories of detonation wave and elastic wave,focusing on the variation in wall pressure of the blasting holes.Using DDNP explosive as the explosive load,blasting tests were conducted on red sandstone specimens with four different water coupling coefficients:1.20,1.33,1.50,and 2.00.The study examines the morphologies of the rock specimens after blasting under these different water coupling coefficients.Additionally,the fractal dimensions of the surface cracks resulting from the blasting were calculated to provide a quantitative evaluation of the extent of rock damage.CT scanning and 3D reconstruction were performed on the post-blasting specimens to visually depict the extent of damage and fractures within the rock.Additionally,the volume fractal dimension and damage degree of the post-blasting specimens are calculated.The findings are then combined with numerical simulation to facilitate auxiliary analysis.The results demonstrate that an increase in the water coupling coefficient leads to a reduction in the peak pressure on the hole wall and the crushing zone,enabling more of the explosion energy to be utilized for crack propagation following the explosion.The specimens exhibited distinct failure patterns,resulting in corresponding changes in fractal dimensions.The simulated pore wall pressure–time curve validated the derived theoretical results,whereas the stress cloud map and explosion energy-time curve demonstrated the buffering effect of the water medium.As the water coupling coefficient increases,the buffering effect of the water medium becomes increasingly prominent. 展开更多
关键词 Water coupling coefficient Radial uncoupled charge Numerical simulation Fractal dimension
下载PDF
Characteristics of laser-induced breakdown spectroscopy of liquid slag
4
作者 董长言 于洪霞 +4 位作者 孙兰香 李洋 刘修业 周平 黄少文 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第2期86-93,共8页
Rapid online analysis of liquid slag is essential for optimizing the quality and energy efficiency of steel production. To investigate the key factors that affect the online measurement of refined slag using laser-ind... Rapid online analysis of liquid slag is essential for optimizing the quality and energy efficiency of steel production. To investigate the key factors that affect the online measurement of refined slag using laser-induced breakdown spectroscopy(LIBS), this study examined the effects of slag composition and temperature on the intensity and stability of the LIBS spectra. The experimental temperature was controlled at three levels: 1350℃, 1400℃, and 1450℃. The results showed that slag composition and temperature significantly affected the intensity and stability of the LIBS spectra. Increasing the Fe content and temperature in the slag reduces its viscosity, resulting in an enhanced intensity and stability of the LIBS spectra. Additionally, 42 refined slag samples were quantitatively analyzed for Fe, Si, Ca, Mg, Al, and Mn at 1350℃, 1400℃, and 1450℃.The normalized full spectrum combined with partial least squares(PLS) quantification modeling was used, using the Ca Ⅱ 317.91 nm spectral line as an internal standard. The results show that using the internal standard normalization method can significantly reduce the influence of spectral fluctuations. Meanwhile, a temperature of 1450℃ has been found to yield superior results compared to both 1350℃ and 1400℃, and it is advantageous to conduct a quantitative analysis of the slag when it is in a “water-like” state with low viscosity. 展开更多
关键词 laser-induced breakdown spectroscopy(LIBS) SLAG temperature COMPOSITION VISCOSITY internal standard normalization partial least squares(PLS)
下载PDF
Effects of altering the ratio of C16:0 and cis-9 C18:1 in rumen bypass fat on growth performance, lipid metabolism, intestinal barrier, cecal microbiota, and inflammation in fattening bulls
5
作者 Haixin Bai Haosheng Zhang +3 位作者 Congwen Wang Modinat Tolani Lambo yang li Yonggen Zhang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第5期2156-2174,共19页
Background C16:0 and cis-9 C18:1 may have different effects on animal growth and health due to unique metabolism in vivo.This study was investigated to explore the different effects of altering the ratio of C16:0 and ... Background C16:0 and cis-9 C18:1 may have different effects on animal growth and health due to unique metabolism in vivo.This study was investigated to explore the different effects of altering the ratio of C16:0 and cis-9 C18:1 in fat supplements on growth performance,lipid metabolism,intestinal barrier,cecal microbiota,and inflammation in fattening bulls.Thirty finishing Angus bulls(626±69 kg,21±0.5 months)were divided into 3 treatments according to the randomized block design:(1)control diet without additional fat(CON),(2)CON+2.5%palmitic acid calcium salt(PA,90%C16:0),and(3)CON+2.5%mixed fatty acid calcium salt(MA,60%C16:0+30%cis-9 C18:1).The experiment lasted for 104 d,after which all the bulls were slaughtered and sampled for analysis.Results MA tended to reduce 0–52 d dry matter intake compared to PA(DMI,P=0.052).Compared with CON and MA,PA significantly increased 0–52 d average daily gain(ADG,P=0.027).PA tended to improve the 0–52 d feed conversion rate compared with CON(FCR,P=0.088).Both PA and MA had no significant effect on 52–104 days of DMI,ADG and FCR(P>0.05).PA tended to improve plasma triglycerides compared with MA(P=0.077),significantly increased plasma cholesterol(P=0.002)and tended to improve subcutaneous adipose weight(P=0.066)when compared with CON and MA.Both PA and MA increased visceral adipose weight compared with CON(P=0.021).Only PA increased the colonization of Rikenellaceae,Ruminococcus and Proteobacteria in the cecum,and MA increased Akkermansia abundance(P<0.05).Compared with CON,both PA and MA down-regulated the m RNA expression of Claudin-1 in the jejunum(P<0.001),increased plasma diamine oxidase(DAO,P<0.001)and lipopolysaccharide(LPS,P=0.045).Compared with CON and MA,PA down-regulated the ZO-1 in the jejunum(P<0.001)and increased plasma LPS-binding protein(LBP,P<0.001).Compared with CON,only PA down-regulated the Occludin in the jejunum(P=0.013).Compared with CON,PA and MA significantly up-regulated the expression of TLR-4 and NF-κB in the visceral adipose(P<0.001)and increased plasma IL-6(P<0.001).Compared with CON,only PA up-regulated the TNF-αin the visceral adipose(P=0.01).Compared with CON and MA,PA up-regulated IL-6 in the visceral adipose(P<0.001),increased plasma TNF-α(P<0.001),and reduced the Ig G content in plasma(P=0.035).Compared with CON,PA and MA increased C16:0 in subcutaneous fat and longissimus dorsi muscle(P<0.05),while more C16:0 was also deposited by extension and desaturation into C18:0 and cis-9 C18:1.However,neither PA nor MA affected the content of cis-9 C18:1 in longissimus dorsi muscle compared with CON(P>0.05).Conclusions MA containing 30%cis-9 C18:1 reduced the risk of high C16:0 dietary fat induced subcutaneous fat obesity,adipose tissue and systemic low-grade inflammation by accelerating fatty acid oxidative utilization,improving colonization of Akkermansia,reducing intestinal barrier damage,and down-regulating NF-κB activation. 展开更多
关键词 C16:0 cis-9 C18:1 Finishing bulls Intestinal homeostasis Lipid metabolism Low-grade inflammation
下载PDF
Cinobufotalin prevents bone loss induced by ovariectomy in mice through the BMPs/SMAD and Wnt/β-catenin signaling pathways
6
作者 Da-zhuang Lu li-jun Zeng +8 位作者 yang li Ran-li Gu Meng-long Hu Ping Zhang Peng Yu Xiao Zhang Zheng-wei Xie Hao liu Yong-sheng Zhou 《Animal Models and Experimental Medicine》 CAS CSCD 2024年第3期208-221,共14页
Background:Osteoporosis is a chronic bone disease characterized by bone loss and decreased bone strength.However,current anti-resorptive drugs carry a risk of various complications.The deep learning-based efficacy pre... Background:Osteoporosis is a chronic bone disease characterized by bone loss and decreased bone strength.However,current anti-resorptive drugs carry a risk of various complications.The deep learning-based efficacy prediction system(DLEPS)is a forecasting tool that can effectively compete in drug screening and prediction based on gene expression changes.This study aimed to explore the protective effect and potential mechanisms of cinobufotalin(CB),a traditional Chinese medicine(TCM),on bone loss.Methods:DLEPS was employed for screening anti-osteoporotic agents according to gene profile changes in primary osteoporosis.Micro-CT,histological and morphological analysis were applied for the bone protective detection of CB,and the osteogenic differentiation/function in human bone marrow mesenchymal stem cells(hBMMSCs)were also investigated.The underlying mechanism was verified using qRT-PCR,Western blot(WB),immunofluorescence(IF),etc.Results:A safe concentration(0.25mg/kg in vivo,0.05μM in vitro)of CB could effectively preserve bone mass in estrogen deficiency-induced bone loss and promote osteogenic differentiation/function of hBMMSCs.Both BMPs/SMAD and Wnt/β-catenin signaling pathways participated in CB-induced osteogenic differentiation,further regulating the expression of osteogenesis-associated factors,and ultimately promoting osteogenesis.Conclusion:Our study demonstrated that CB could significantly reverse estrogen deficiency-induced bone loss,further promoting osteogenic differentiation/function of hBMMSCs,with BMPs/SMAD and Wnt/β-catenin signaling pathways involved. 展开更多
关键词 BMPs/SMAD bone loss cinobufotalin hBMMSCs OSTEOGENESIS OSTEOPOROSIS Wnt/β-catenin signaling pathways
下载PDF
Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle
7
作者 Wei-li Wu Chang-gui Cheng +2 位作者 yang li Shi-fa Wei De-li Chen 《China Foundry》 SCIE EI CAS CSCD 2024年第2期185-196,共12页
In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab quality.In ord... In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab quality.In order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT software.Results show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either side.As the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes uneven.Although increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction. 展开更多
关键词 continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate
下载PDF
NIR-triggered on-site NO/ROS/RNS nanoreactor:Cascade-amplified photodynamic/photothermal therapy with local and systemic immune responses activation
8
作者 Ziqing Xu Yakun Kang +9 位作者 Jie Zhang Jiajia Tang Hanyao Sun yang li Doudou He Xuan Sha Yuxia Tang Ziyi Fu Feiyun Wu Shouju Wang 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第6期58-73,共16页
Photothermal and photodynamic therapies(PTT/PDT)hold promise for localized tumor treatment,yet their full potential is hampered by limitations such as the hypoxic tumor microenvironment and inadequate systemic immune ... Photothermal and photodynamic therapies(PTT/PDT)hold promise for localized tumor treatment,yet their full potential is hampered by limitations such as the hypoxic tumor microenvironment and inadequate systemic immune activation.Addressing these challenges,we present a novel near-infrared(NIR)-triggered RNS nanoreactor(PBNO-Ce6)to amplify the photodynamic and photothermal therapy efficacy against triple-negative breast cancer(TNBC).The designed PBNOCe6 combines sodium nitroprusside-doped Prussian Blue nanoparticles with Chlorin e6 to enable on-site RNS production through NIR-induced concurrent NO release and ROS generation.This not only enhances tumor cell eradication but also potentiates local and systemic antitumor immune responses,protecting mice from tumor rechallenge.Our in vivo evaluations revealed that treatment with PBNO-Ce6 leads to a remarkable 2.7-fold increase in cytotoxic T lymphocytes and a 62%decrease in regulatory T cells in comparison to the control PB-Ce6(Prussian Blue nanoparticles loaded with Chlorin e6),marking a substantial improvement over traditional PTT/PDT.As such,the PBNO-Ce6 nanoreactor represents a transformative approach for improving outcomes in TNBC and potentially other malignancies affected by similar barriers. 展开更多
关键词 photothermal therapy photodynamic therapy nitric oxide reactive nitrogen species triple-negative breast cancer immune response NANOREACTOR
下载PDF
Deactivation mechanism for water splitting:Recent advances
9
作者 Yansong Jia yang li +8 位作者 Qiong Zhang Sohail Yasin Xinyu Zheng Kai Ma Zhengli Hua Jianfeng Shi Chaohua Gu Yuhai Dou Shixue Dou 《Carbon Energy》 SCIE EI CAS CSCD 2024年第7期53-82,共30页
Hydrogen(H_(2)) has been regarded as a promising alternative to fossil-fuel energy.Green H_(2) produced via water electrolysis(WE)powered by renewable energy could achieve a zero-carbon footprint.Considerable attentio... Hydrogen(H_(2)) has been regarded as a promising alternative to fossil-fuel energy.Green H_(2) produced via water electrolysis(WE)powered by renewable energy could achieve a zero-carbon footprint.Considerable attention has been focused on developing highly active catalysts to facilitate the reaction kinetics and improve the energy efficiency of WE.However,the stability of the electrocatalysts hampers the commercial viability of WE.Few studies have elucidated the origin of catalyst degradation.In this review,we first discuss the WE mechanism,including anodic oxygen evolution reaction(OER)and cathodic hydrogen evolution reaction(HER).Then,we provide strategies used to enhance the stability of electrocatalysts.After that,the deactivation mechanisms of the typical commercialized HER and OER catalysts,including Pt,Ni,RuO_(2),and IrO_(2),are summarized.Finally,the influence of fluctuating energy on catalyst degradation is highlighted and in situ characterization methodologies for understanding the dynamic deactivation processes are described. 展开更多
关键词 deactivation mechanism hydrogen evolution in situ characterization oxygen evolution water splitting
下载PDF
Unraveling the atomic interdiffusion mechanism of NiFe_(2_)O_(4) oxygen carriers during chemical looping CO_(2) conversion
10
作者 Da Song Yan lin +8 位作者 Shiwen Fang yang li Kun Zhao Xinfei Chen Zhen Huang Fang He Zengli Zhao Hongyu Huang Fanxing li 《Carbon Energy》 SCIE EI CAS CSCD 2024年第8期105-121,共17页
By employing metal oxides as oxygen carriers,chemical looping demonstrates its effectiveness in transferring oxygen between reduction and oxidation environments to partially oxidize fuels into syngas and convert CO_(2... By employing metal oxides as oxygen carriers,chemical looping demonstrates its effectiveness in transferring oxygen between reduction and oxidation environments to partially oxidize fuels into syngas and convert CO_(2) into CO.Generally,NiFe_(2_)O_(4) oxygen carriers have demonstrated remarkable efficiency in chemical looping CO_(2) conversion.Nevertheless,the intricate process of atomic migration and evolution within the internal structure of bimetallic oxygen carriers during continuous high‐temperature redox cycling remains unclear.Consequently,the lack of a fundamental understanding of the complex ionic migration and oxygen transfer associated with energy conversion processes hampers the design of high‐performance oxygen carriers.Thus,in this study,we employed in situ characterization techniques and theoretical calculations to investigate the ion migration behavior and structural evolution in the bulk of NiFe_(2_)O_(4) oxygen carriers during H_(2) reduction and CO_(2)/lab air oxidation cycles.We discovered that during the H_(2) reduction step,lattice oxygen rapidly migrates to vacancy layers to replenish consumed active oxygen species,while Ni leaches from the material and migrates to the surface.During the CO_(2) splitting step,Ni migrates toward the core of the bimetallic oxygen carrier,forming Fe–Ni alloys.During the air oxidation step,Fe–Ni migrates outward,creating a hollow structure owing to the Kirkendall effect triggered by the swift transfer of lattice oxygen.The metal atom migration paths depend on the oxygen transfer rates.These discoveries highlight the significance of regulating the release–recovery rate of lattice oxygen to uphold the structures and reactivity of oxygen carriers.This work offers a comprehensive understanding of the oxidation/reduction‐driven atomic interdiffusion behavior of bimetallic oxygen carriers. 展开更多
关键词 chemical looping CO_(2)splitting density functional theory in situ characterization ionic migration
下载PDF
Flame-retardant ammonium polyphosphate/MXene decorated carbon foam materials as polysulfide traps for fire-safe and stable lithium-sulfur batteries
11
作者 yang li Yong-Cheng Zhu +5 位作者 Sowjanya Vallem Man li Seunghyun Song Tao Chen Long-Cheng Tang Joonho Bae 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期313-323,I0008,共12页
Lithium-sulfur(Li-S)batteries are one of the most promising modern-day energy supply systems because of their high theoretical energy density and low cost.However,the development of high-energy density Li-S batteries ... Lithium-sulfur(Li-S)batteries are one of the most promising modern-day energy supply systems because of their high theoretical energy density and low cost.However,the development of high-energy density Li-S batteries with high loading of flammable sulfur faces the challenges of electrochemical performance degradation owing to the shuttle effect and safety issues related to fire or explosion accidents.In this work,we report a three-dimensional(3D)conductive nitrogen-doped carbon foam supported electrostatic self-assembled MXene-ammonium polyphosphate(NCF-MXene-APP)layer as a heat-resistant,thermally-insulated,flame-retardant,and freestanding host for Li-S batteries with a facile and costeffective synthesis method.Consequently,through the use of NCF-MXene-APP hosts that strongly anchor polysulfides,the Li-S batteries demonstrate outstanding electrochemical properties,including a high initial discharge capacity of 1191.6 mA h g^(-1),excellent rate capacity of 755.0 mA h g^(-1)at 1 C,and long-term cycling stability with an extremely low-capacity decay rate of 0.12%per cycle at 2 C.More importantly,these batteries can continue to operate reliably under high temperature or flame attack conditions.Thus,this study provides valuable insights into the design of safe high-performance Li-S batteries. 展开更多
关键词 FLAME-RETARDANT MXene Ammonium polyphosphate Safety Lithium-sulfur battery
下载PDF
Nondestructive technique for identifying nuclides using neutron resonance transmission analysis at CSNS Back-n
12
作者 Sheng-Da Tang Yong-Hao Chen +72 位作者 Jing-Yu Tang Rui-Rui Fan Qiang li Gong li Dong liu Zheng-Yao Jin Xing-Zhu Cui Tian-Xiang Chen Yi-Wei yang Rong liu Han Yi yang li Zhen yang Qi An Hao-Fan Bai Jiang-Bo Bai Jie Bao Ping Cao Qi-Ping Chen Zhen Chen Zeng-Qi Cui An-Chuan Fan Chang-Qing Feng Fan-Zhen Feng Ke-Qing Gao Min-Hao Gu Chang-Cai Han Zi-Jie Han Guo-Zhu He Yong-Cheng He yang Hong Yi-Wei Hu Han-Xiong Huang Wei-Hua Jia Hao-yu Jiang Wei Jiang Zhi-jie Jiang ling Kang Bo li Chao li Jia-Wen li Xiao li Jie liu Shu-Bin liu Guang-Yuan Luan Chang-Jun Ning Bin-Bin Qi Jie Ren Zhi-Zhou Ren Xi-Chao Ruan Zhao-Hui Song Kang Sun Zhi-Xin Tan li-Jiao Wang Peng-Cheng Wang Zhao-Hui Wang Zhong-Wei Wen Xiao-Guang Wu Xuan Wu li-Kun Xie Yong-Ji Yu Guo-Hui Zhang lin-Hao Zhang Mo-Han Zhang Qi-Wei Zhang Xian-Peng Zhang Yu-liang Zhang Yue Zhang Zhi-Yong Zhang Mao-Yuan Zhao Lu-Ping Zhou Zhi-Hao Zhou Ke-Jun Zhu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第1期178-187,共10页
Nondestructive and noninvasive neutron assays are essential applications of neutron techniques.Neutron resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental compositi... Nondestructive and noninvasive neutron assays are essential applications of neutron techniques.Neutron resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental composition of an object.The back-streaming neutron line(Back-n)is a newly built time-of-flight facility at the China Spallation Neutron Source(CSNS)that provides neutrons in the eV to 300 MeV range.A feasibility study of the NRTA method for nuclide identification was conducted at the CSNS Back-n via two test experiments.The results demonstrate that it is feasible to identify different elements and isotopes in samples using the NRTA method at Back-n.This study reveals its potential future applications. 展开更多
关键词 CSNS White neutron beam NRTA Nuclide identification Nondestructive method
下载PDF
The BEL1-like transcription factor GhBLH5-A05 participates in cotton response to drought stress
13
作者 Jing-Bo Zhang Yao Wang +4 位作者 Shi-Peng Zhang Fan Cheng Yong Zheng yang li Xue-Bao li 《The Crop Journal》 SCIE CSCD 2024年第1期177-187,共11页
Drought stress impairs crop growth and development.BEL1-like family transcription factors may be involved in plant response to drought stress,but little is known of the molecular mechanism by which these proteins regu... Drought stress impairs crop growth and development.BEL1-like family transcription factors may be involved in plant response to drought stress,but little is known of the molecular mechanism by which these proteins regulate plant response and defense to drought stress.Here we show that the BEL1-like transcription factor GhBLH5-A05 functions in cotton(Gossypium hirsutum)response and defense to drought stress.Expression of GhBLH5-A05 in cotton was induced by drought stress.Overexpression of GhBLH5-A05 in both Arabidopsis and cotton increased drought tolerance,whereas silencing GhBLH5-A05 in cotton resulted in elevated sensitivity to drought stress.GhBLH5-A05 binds to cis elements in the promoters of GhRD20-A09 and GhDREB2C-D05 to activate the expression of these genes.GhBLH5-A05 interacted with the KNOX transcription factor GhKNAT6-A03.Co-expression of GhBLH5-A05 and GhKNAT6-A03 increased the transcription of GhRD20-A09 and GhDREB2C-D05.We conclude that GhBLH5-A05 acts as a regulatory factor with GhKNAT6-A03 functioning in cotton response to drought stress by activating the expression of the drought-responsive genes GhRD20-A09 and GhDREB2C-D05. 展开更多
关键词 Cotton(Gossypium hirsutum) BEL1-like transcription factor Drought stress Transcriptional regulation Drought tolerance
下载PDF
A digital twins enabled underwater intelligent internet vehicle path planning system via reinforcement learning and edge computing
14
作者 Jiachen yang Meng Xi +2 位作者 Jiabao Wen yang li Houbing Herbert Song 《Digital Communications and Networks》 SCIE CSCD 2024年第2期282-291,共10页
The Autonomous Underwater Glider(AUG)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential problem.Due to th... The Autonomous Underwater Glider(AUG)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential problem.Due to the complexity and variability of the ocean,accurate environment modeling and flexible path planning algorithms are pivotal challenges.The traditional models mainly utilize mathematical functions,which are not complete and reliable.Most existing path planning algorithms depend on the environment and lack flexibility.To overcome these challenges,we propose a path planning system for underwater intelligent internet vehicles.It applies digital twins and sensor data to map the real ocean environment to a virtual digital space,which provides a comprehensive and reliable environment for path simulation.We design a value-based reinforcement learning path planning algorithm and explore the optimal network structure parameters.The path simulation is controlled by a closed-loop model integrated into the terminal vehicle through edge computing.The integration of state input enriches the learning of neural networks and helps to improve generalization and flexibility.The task-related reward function promotes the rapid convergence of the training.The experimental results prove that our reinforcement learning based path planning algorithm has great flexibility and can effectively adapt to a variety of different ocean conditions. 展开更多
关键词 Digital twins Reinforcement learning Edge computing Underwater intelligent internet vehicle Path planning
下载PDF
Broadband bidirectional Brillouin–Raman random fiber laser with ultra-narrow linewidth
15
作者 杨茜 李阳 +3 位作者 邹辉 梅杰 徐恩明 张祖兴 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期371-376,共6页
We present a Brillouin–Raman random fiber laser(BRRFL)with full-open linear cavity structure to generate broadband Brillouin frequency comb(BFC)with double Brillouin-frequency-shift spacing.The incorporation of a reg... We present a Brillouin–Raman random fiber laser(BRRFL)with full-open linear cavity structure to generate broadband Brillouin frequency comb(BFC)with double Brillouin-frequency-shift spacing.The incorporation of a regeneration portion consisting of an erbium-doped fiber and a single-mode fiber enables the generation of broadband BFC.The dynamics of broadband BFC generation changing with the pump power(EDF and Raman)and Brillouin pump(BP)wavelength are investigated in detail,respectively.Under suitable conditions,the bidirectional BRRFL proposed can produce a flatamplitude BFC with 40.7-nm bandwidth ranging from 1531 nm to 1571.7 nm,and built-in 242-order Brillouin Stokes lines(BSLs)with double Brillouin-frequency-shift spacing.Moreover,the linewidth of single BSL is experimentally measured to be about 2.5 kHz.The broadband bidirectional narrow-linewidth BRRFL has great potential applications in optical communication,optical sensing,spectral measurement,and so on. 展开更多
关键词 random laser fiber laser stimulated Brillouin scattering(SBS) stimulated Raman scattering(SRS)
原文传递
Safe Efficient Policy Optimization Algorithm for Unsignalized Intersection Navigation
16
作者 Xiaolong Chen Biao Xu +3 位作者 Manjiang Hu Yougang Bian yang li Xin Xu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第9期2011-2026,共16页
Unsignalized intersections pose a challenge for autonomous vehicles that must decide how to navigate them safely and efficiently.This paper proposes a reinforcement learning(RL)method for autonomous vehicles to naviga... Unsignalized intersections pose a challenge for autonomous vehicles that must decide how to navigate them safely and efficiently.This paper proposes a reinforcement learning(RL)method for autonomous vehicles to navigate unsignalized intersections safely and efficiently.The method uses a semantic scene representation to handle variable numbers of vehicles and a universal reward function to facilitate stable learning.A collision risk function is designed to penalize unsafe actions and guide the agent to avoid them.A scalable policy optimization algorithm is introduced to improve data efficiency and safety for vehicle learning at intersections.The algorithm employs experience replay to overcome the on-policy limitation of proximal policy optimization and incorporates the collision risk constraint into the policy optimization problem.The proposed safe RL algorithm can balance the trade-off between vehicle traffic safety and policy learning efficiency.Simulated intersection scenarios with different traffic situations are used to test the algorithm and demonstrate its high success rates and low collision rates under different traffic conditions.The algorithm shows the potential of RL for enhancing the safety and reliability of autonomous driving systems at unsignalized intersections. 展开更多
关键词 Autonomous driving DECISION-MAKING reinforcement learning(RL) unsignalized intersection
下载PDF
Technological advancement and industrialization path of Sinopec in carbon capture,utilization and storage,China
17
作者 yang li Rui Wang +1 位作者 Qingmin Zhao Zhaojie Xue 《Energy Geoscience》 EI 2024年第1期204-211,共8页
Carbon capture,utilization and storage(CCUS)technology is an important means to effectively reduce carbon emissions from fossil energy combustion and industrial processes.With the crisis of climate change,CCUS has att... Carbon capture,utilization and storage(CCUS)technology is an important means to effectively reduce carbon emissions from fossil energy combustion and industrial processes.With the crisis of climate change,CCUS has attracted increasing attention in the world.CCUS technology as developed rapidly in China is technically feasible for large-scale application in various industries.The R&D and demonstration of CCUS in China Petroleum&Chemical Corporation(Sinopec)are summarized,including carbon capture,carbon transport,CO_(2)enhanced energy recovery(including oil,gas,and water,etc.),and comprehensive utilization of CO_(2).Based on the source-sink matching characteristics in China,two CCUS industrialization scenarios are proposed,namely,CO_(2)-EOR,CO_(2)-driven enhanced oil recovery using centralized carbon sinks in East China and CO_(2)-EWR,CO_(2)-driven enhanced water recovery(EWR)using centralized carbon sources from the coal chemical industry in West China.Finally,a CCUS industrialization path from Sinopec's perspective is suggested,using CO_(2)-EOR as the major means and CO_(2)-EWR,CO_(2)-driven enhanced gas recovery(CO_(2)-EGR)and other utilization methods as important supplementary means. 展开更多
关键词 Carbon capture TRANSPORT Enhanced energy recovery Comprehensive utilization Industrialization path
下载PDF
Establishment of a cholangiocarcinoma risk evaluation model based on mucin expression levels
18
作者 Chun-Yuan yang li-Mei Guo +5 位作者 yang li Guang-Xi Wang Xiao-Wei Tang Qiu-Lu Zhang ling-Fu Zhang Jian-Yuan Luo 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第4期1344-1360,共17页
BACKGROUND Cholangiocarcinoma(CCA)is a highly malignant cancer,characterized by frequent mucin overexpression.MUC1 has been identified as a critical oncogene in the progression of CCA.However,the comprehensive underst... BACKGROUND Cholangiocarcinoma(CCA)is a highly malignant cancer,characterized by frequent mucin overexpression.MUC1 has been identified as a critical oncogene in the progression of CCA.However,the comprehensive understanding of how the mucin family influences CCA progression and prognosis is still incomplete.AIM To investigate the functions of mucins on the progression of CCA and to establish a risk evaluation formula for stratifying CCA patients.METHODS Single-cell RNA sequencing data from 14 CCA samples were employed for elucidating the roles of mucins,complemented by bioinformatic analyses.Subse-quent validations were conducted through spatial transcriptomics and immuno-histochemistry.The construction of a risk evaluation model utilized the least absolute shrinkage and selection operator regression algorithm,which was further confirmed by independent cohorts and diverse data types.RESULTS CCA tumor cells with elevated levels of MUC1 and MUC4 showed activated nucleotide metabolic pathways and increased invasiveness.MUC5AC-high cells were found to promote CCA progression through WNT signaling.MUC5B-high cells exhibited robust cellular oxidation activities,leading to resistance against antitumoral treatments.MUC13-high cells were observed to secret chemokines,recruiting and transforming macrophages into the M2-polarized state,thereby suppressing antitumor immunity.MUC16-high cells were found to promote tumor progression through interleukin-1/nuclear factor kappa-light-chain-enhancer of activated B cells signaling upon interaction with neutrophils.Utilizing the expression levels of these mucins,a risk factor evaluation formula for CCA was developed and validated across multiple cohorts.CCA samples with higher risk factors exhibited stronger metastatic potential,chemotherapy resistance,and poorer prognosis.CONCLUSION Our study elucidates the functional mechanisms through which mucins contribute to CCA development,and provides tools for risk stratification in CCA. 展开更多
关键词 MUCIN CHOLANGIOCARCINOMA Single-cell RNA sequencing Spatial transcriptomics PROGNOSIS
下载PDF
Knowledge mapping of research on sustainable utilization of landscape resources:a case study of Guilin National Innovation Demonstration Zone for sustainable development in China
19
作者 Xiuxiu Gao yang li +1 位作者 Yijue li Zheng He 《Chinese Journal of Population,Resources and Environment》 2024年第3期326-333,共8页
Worldwide interest has increasingly focused on the sustainable utilization of landscape as a resource in urban areas,emphasizing its ecological,cultural and social significance.This study examines Guilin City,China,as... Worldwide interest has increasingly focused on the sustainable utilization of landscape as a resource in urban areas,emphasizing its ecological,cultural and social significance.This study examines Guilin City,China,as a representative case study due to its rich landscape resources and status as a national innovation demonstration zone for implementing the 2030 Agenda for Sustainable Development.This study uses bibliometric visualization tools like CiteSpace and VOSviewer to analyze research trends from 1980 to 2021 in the Chinese Academic Journal Network Publishing Database(CNKI).The results show increasing academic interest over three stages:initiation(1982-1997),exploration(1998-2004),and diversified development(2005-2021).Contributions are predominantly from local academic and tourism sectors,indicating a strong regional influence;however,relatively weak interinstitutional collaboration occurs,suggesting potential for more integrated research efforts.Primary research is also concentrated within economic disciplines,particularly tourism-related ones.The evolution of research frontiers reveals three main paths:urban development strategies,industrial economic theories and empirical validation,and ecosystem analysis and evaluation.A multidisciplinary approach and stronger collaborative efforts are crucial to enhance research on ecological values and empirical models while supporting evidence-based urban development strategies in Guilin City and comparable cities globally. 展开更多
关键词 Sustainable development Landscape resources Bibliometric analysis Knowledge mapping
下载PDF
The role of exercise in modulating the HP pathway to reduce glioma-induced epilepsy
20
作者 Fu-Jun Shi Wei Cai +1 位作者 Nan Wu yang li 《Traditional Medicine Research》 2024年第12期66-74,共9页
Background:Glioma-induced refractory epilepsy can be alleviated through conventional exercise,providing a potential therapeutic approach to manage this condition.This study aims to investigate the underlying mechanism... Background:Glioma-induced refractory epilepsy can be alleviated through conventional exercise,providing a potential therapeutic approach to manage this condition.This study aims to investigate the underlying mechanisms.Methods:Bioinformatics methodologies were employed to scrutinize gene expression data from public repositories such as GEO,with a specific focus on mobility-related genes in epilepsy.Through differential and enrichment analyses,differentially expressed genes(DEGs)were identified,while protein-protein interaction networks elucidated pivotal hub genes.Results:Our analysis revealed 32 DEGs,comprising 23 upregulated and 9 downregulated genes.Enrichment analysis underscored significant alterations in immune pathways in epilepsy.Two central hub genes,haptoglobin(HP)and prostaglandin-endoperoxide synthase 2(PTGS2),were found to be modulated by Arginase 1(ARG1)and Chemokine(C-X-C motif)ligand 8(CXCL8).GSVA analysis associated elevated PTGS2 expression with metabolic pathways,while increased HP expression was correlated with angiogenesis and inflammation.Subsequent experiments validated HP’s role in tumor cell proliferation,emphasizing its potential as a therapeutic target.Conclusion:This study highlights the crucial involvement of HP and PTGS2 genes in the etiology of epilepsy,linked to discrepancies in the immune system.These findings offer fresh perspectives on the management of epilepsy,emphasizing the neuroprotective possibilities of targeting specific gene pathway. 展开更多
关键词 EPILEPSY gene expression BIOINFORMATICS immune pathways protein-protein interaction hub genes
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部