检索结果-南通市图书馆

维普期刊数据库

Domain generalization with semi-supervised learning for people-centric activity recognition

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2025年第1期68卷 171-188页

作者： Jing liU wei ZHU Di li Xing HU liang SONG Academy for Engineering & Technology Fudan University Shanghai East-bund Research Institute on Networking Systems of AI School of Optoelectronic Information and Computer Engineering University of Shanghai for Science & Technology

People-centric activity recognition is one of the most critical technologies in a wide range of real-world applications,including intelligent transportation systems, healthcare services, and brain-computer interfaces. Large-scale data collection and annotation make the application of machine learning algorithms prohibitively expensive when adapting to new tasks. One way of circumventing this limitation is to train the model in a semi-supervised learning manner that utilizes a percentage of unlabeled data to reduce the labeling burden in prediction tasks. Despite their appeal, these models often assume that labeled and unlabeled data come from similar distributions, which leads to the domain shift problem caused by the presence of distribution gaps. To address these limitations, we propose herein a novel method for people-centric activity recognition,called domain generalization with semi-supervised learning(DGSSL), that effectively enhances the representation learning and domain alignment capabilities of a model. We first design a new autoregressive discriminator for adversarial training between unlabeled and labeled source domains, extracting domain-specific features to reduce the distribution gaps. Second, we introduce two reconstruction tasks to capture the task-specific features to avoid losing information related to representation learning while maintaining task-specific consistency. Finally, benefiting from the collaborative optimization of these two tasks, the model can accurately predict both the domain and category labels of the source domains for the classification task. We conduct extensive experiments on three real-world sensing datasets. The experimental results show that DGSSL surpasses the three state-of-the-art methods with better performance and generalization.

关键词： activity recognition deep learning domain generalization semi-supervised learning adversarial training

同方期刊数据库

Fabrication of Ni-Zn spinel ferrite with superior magnetic performance from electric arc furnace dust and iron scale

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2025年第1期32卷 105-114页

作者： Yang li wei-zhe Jie Chang Chen Yi Su Wu Zhou Hua Zhang Hong-wei Ni The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina The Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan430081HubeiChina

The Ni-ZnFe_(2)O_(4)(NixZn_(1-x)Fe_(2)O_(4),x=0.4-0.7)spinel was synthesized using Zn2+extracted from electric arc furnace dust(EAFD),nickel chloride hexahydrate,and Fe^(3+)extracted from iron scale as raw *** zinc was selectively extracted from EAFD using CaO roasting followed by NH_(4)Cl solution *** ferric ion was leached from iron scale using HCl solution as acid *** experimental results demonstrate a high level of efficiency in the extraction of zinc,with a rate of 97.5%,and the leaching rate of ferric ion is 96.89%.The composition of the leaching solution is primary zinc and iron with low calcium,which is beneficial to the preparation of spinel *** influence of Ni content(x)and calcination temperature on the synthesis and magnetic properties of NixZn_(1-x)Fe_(2)O_(4)compounds was investigated by X-ray diffraction,scanning electron microscopy,and vibrating sample *** results revealed that both Ni content and calcination temperature significantly affect the synthesis and magnetic properties of spinel NixZn_(1-x)Fe_(2)O_(4).Under the conditions of Ni content set at x=0.6,calcination temperature of 1100℃,and a duration of 2 h,a spinel NixZn_(1-x)Fe_(2)O_(4)with high saturation magnetization(Ms=65.7 A m2 kg-1)and low coercivity(Hc=0.056 A m^(-1))was obtained.

关键词： Electric furnace arc dust Iron scale Spinel ferrite Magnetic performance Calcination temperature

Intrahepatic HBV DNA as a predictor of antivirus treatment efficacy in HBeAg-positive chronic hepatitis B patients

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第20期13卷 2878-2882页

作者： Hai-Ying Lu li-wei zhuang Yan-Yan Yu Hadad Ivan Chong-Wen Si Zheng Zeng Jun li Dong-Ming Hou Xin-Yue Chen Zhong-Hou Han Yong Chen Department of Infectious Diseases Peking University First Hospital Beijing 100034 China Indiana University School of Medicine Indianapolis IN 46202 United States Beijing You'an Hospital Beijing 100054 China Qinhuangdao Third Hospital Qinhuangdao 066000 Hebei Province China Huai'an Infectious Disease Hospital Huai'an 223300 Jiangsu Province China

AIM： To evaluate the effect of antiviral agents on intrahepatic HBV DNA in HBeAg-positive chronic hepatitis B patients. METHODS： Seventy-one patients received treatment with lamivudine, interferon alpha （IFN-α2b） or sequential therapy with lamivudine-IFN-α2b for 48 wk. All subjects were followed up for 24 wk. Serum and intrahepatic HBV DNA were measured quantitatively by PCR. HBV genotypes were analyzed by PCR-RFLP. RESULTS： At the end of treatment, the intrahepatic HBV DNA level in 71 patients decreased from a mean of （6.1 ± 1.0） Iog10 to （4.9± 1.4） Iog10. Further, a larger decrease was seen in the intrahepatic HBV DNA level in patients with HBeAg seroconversion. Intrahepatic HBV DNA level （before and after treatment） was not significantly affected by the patients＇ HBV genotype, or by the probability of virological flare after treatment. CONCLUSION： Intrahepatic HBV DNA can be effectively lowered by antiviral agents and is a significant marker for monitoring antivirus treatment. Low intrahepatic HBV DNA level may achieve better efficacy of antivirus treatment.

关键词： Intrahepatic HBV DNA Histology Antivira therapy HBV genotype

Recent advances in semi-heterogenous photocatalysis in organic synthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2025年第2期36卷 94-117页

作者： Jia-Cheng Hou wei Cai Hong-Tao Ji li-Juan Ou wei-Min He School of Chemistry and Chemical Engineering University of South China School of Pharmaceutical Sciences Hunan University of Medicine School of Materials Science and Engineering Hunan Institute of Technology

Semi-heterogeneous photocatalysis has emerged as a powerful and productive platform in organic chemistry, which provides mild and eco-friendly conditions for a diverse range of bond-forming *** synergy of homogeneous catalysts and heterogeneous catalysts inherits their main advantages, such as higher activities, easy separation and superior recyclability. In this review, we summarize the recent advances in recyclable semi-heterogenous protocols for the light promoted bond-forming reactions and identify directions for future research according to the different photocatalysts/metal/redox catalysts involved. Notably, this review is not a comprehensive description of reported literature but aim to highlight and illustrate key concepts, strategies, reaction model, reaction conditions and mechanisms.

关键词： Bond-forming Organic synthesis Photocatalysis Recyclable Semi-heterogeneous

The role of sulfur cycle in new particle formation:Cycloaddition reaction of SO_(3)to H_(2)S

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2025年第2期148卷 489-501页

作者： Haijie Zhang wei Wang liang Fan Junling li Yanqin Ren Hong li Rui Gao Yisheng Xu State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Key Laboratory of Cluster Science Ministry of Education of ChinaSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China

The chemistry of sulfur cycle contributes significantly to the atmospheric nucleation process,which is the first step of new particle formation(NPF).In the present study,cycloaddition reaction mechanism of sulfur trioxide(SO_(3))to hydrogen sulfide(H_(2)S)which is a typical air pollutant and toxic gas detrimental to the environment were comprehensively investigate through theoretical calculations and Atmospheric Cluster Dynamic Code ***-phase stability and nucleation potential of the product thiosulfuric acid(H_(2)S_(2)O_(3),TSA)were further analyzed to evaluate its atmospheric *** any catalysts,the H_(2)S+SO_(3)reaction is infeasible with a barrier of 24.2 kcal/*** nucleation precursors formic acid(FA),sulfuric acid(SA),and water(H_(2)O)could effectively lower the reaction barriers as catalysts,even to a barrierless reaction with the efficiency of cis-SA>trans-FA>trans-SA>H_(2)***,the gas-phase stability of TSA was investigated.A hydrolysis reaction barrier of up to 61.4 kcal/mol alone with an endothermic isomerization reaction barrier of 5.1 kcal/mol under the catalytic effect of SA demonstrates the sufficient stability of ***,topological and kinetic analysis were conducted to determine the nucleation potential of *** clusters formed by TSA and atmospheric nucleation precursors(SA,ammonia NH_(3),and dimethylamine DMA)were thermodynamically ***,the gradually decreasing evaporation coefficients for TSA-base clusters,particularly for TSA-DMA,suggests that TSA may participate in NPF where the concentration of base molecules are relatively *** present new reaction mechanismmay contributes to a better understanding of atmospheric sulfur cycle and NPF.

关键词： New particle formation(NPF) Atmospheric sulfur cycle Nucleation process Reaction mechanism Hydrogen sulfide(H_(2)S) Atmospheric Cluster Dynamic Code (ACDC)

Investigation on coal damage and fracture extension law of liquid nitrogen injection pre-cooling and fracturing under true triaxial stress

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2025年第2期35卷 213-229页

作者： Botao li Haifei lin Jianping wei Hongtu Zhang Shugang li Zongyong wei Lei Qin Pei Wang Rongwei Luo Zeran liu School of Safety Science and Engineering Henan Polytechnic UniversityJiaozuo 454003China State Key Laboratory Cultivation Base for Gas Geology and Gas Control Henan Polytechnic UniversityJiaozuo 454003China State Collaborative Innovation Center of Coal Work Safety and Clean-efficiency Utilization Henan Polytechnic UniversityJiaozuo 454003China College of Safety Science and Engineering Xi’an University of Science and TechnologyXi’an 710054China Key Laboratory of Shaanxi Province Universities of Gas Disaster Prevention and Control in Western Coal Mines Xi’an 710054China

To more accurately describe the coal damage and fracture evolution law during liquid nitrogen(LN_(2))fracturing under true triaxial stress,a thermal-hydraulic-mechanical-damage(THMD)coupling model for LN_(2) fracturing coal was developed,considering the coal heterogeneity and thermophysical parameters of *** accuracy and applicability of model were verified by comparing with LN_(2) injection pre-cooling and fracturing experimental *** effects of different pre-cooling times and horizontal stress ratios on coal damage evolution,permeability,temperature distribution,and fracture characteristics were *** results show that the permeability and damage of the coal increase exponentially,while the temperature decreases exponentially during the fracturing *** the pre-cooling time increases,the damage range of the coal expands,and the fracture propagation becomes more *** initiation pressure and rupture pressure decrease and tend to stabilize with longer precooling *** the horizontal stress ratio increases,fractures preferentially extend along the direction of maximum horizontal principal stress,leading to a significant decrease in both initiation and rupture *** a horizontal stress ratio of 3,the initiation pressure drops by 48.07%,and the rupture pressure decreases by 41.36%.The results provide a theoretical basis for optimizing LN_(2) fracturing techniques and improving coal seam modification.

关键词： liquid nitrogen fracturing Thermal–hydraulic-mechanical-damage coupling Heterogeneous coal True triaxial stress Fracture morphology

The Teleconnection between Rainfall over the Northeastern Slope of the Tibetan Plateau and Downstream Regions:Insights from 20 Years of Heavy Rainfall Events

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2025年第2期42卷 327-341页

作者： wei SUN Rucong YU Jian li Zewen li State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Institute of Tibetan Plateau Meteorology China Meteorological AdministrationChengdu 610072China Department of Atmospheric Science Yunnan UniversityKunming 650091China Inner Mongolia Autonomous Region Mete-orological Service Center Hohhot 010051China

The connection between rainfall over topographic regions and their downstream areas represents a phenomenon of great concern in atmospheric *** on the rainfall events of the past two decades,we analyzed the impact of rainfall over the Northeastern Slope of the Tibetan Plateau(NSTP)on rainfall in downstream *** discovered that rainfall followed two propagation routes,guided by two modes related to the three-dimensional circulation *** the first mode,dominated by cold(warm)anomalies along the west(east)direction,rainfall over the NSTP was concentrated between an upstream cyclonic and a downstream anti-cyclonic anomalous circulation(an upstream trough and a downstream ridge).This pattern was accompanied by upper-level divergence,low-level convergence,a deep moist layer,and a vertical *** a consequence of the eastward movement of the trough-ridge system associated with the coldwarm anomalies,the rainfall over the NSTP moved eastward along 37°-40°N,reaching North China after about 36 *** the second mode,the circulation structure was also dominated by cold-warm anomalies but rotated clockwise,introducing cold anomalies to the northeast and warm anomalies to the east of the *** the southeastward movement of the circulation structure,rainfall concentrated upstream of the anti-cyclonic circulation around the warm center before moving southeastward to the Sichuan Basin along the eastern edge of the plateau after 30-36 *** findings of this study could broaden the understanding of rainfall-related teleconnection between two distant regions and offer helpful guidance for identifying early signals of rainfall disasters over the Chinese mainland.

关键词： teleconnection rainfall propagation three-dimensional circulation structure upper-tropospheric temperature anomaly

Effect of pseudo-random number on the security of quantum key distribution protocol

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2025年第2期34卷 41-46页

作者： Xiao-liang Yang Yu-Qing li Hong-wei li Henan Key Laboratory of Quantum Information and Cryptography SSF IEUZhengzhou 450000China

In the process of quantum key distribution(QKD), the communicating parties need to randomly determine quantum states and measurement bases. To ensure the security of key distribution, we aim to use true random sequences generated by true random number generators as the source of randomness. In practical systems, due to the difficulty of obtaining true random numbers, pseudo-random number generators are used instead. Although the random numbers generated by pseudorandom number generators are statistically random, meeting the requirements of uniform distribution and independence,they rely on an initial seed to generate corresponding pseudo-random sequences. Attackers may predict future elements from the initial elements of the random sequence, posing a security risk to quantum key distribution. This paper analyzes the problems existing in current pseudo-random number generators and proposes corresponding attack methods and applicable scenarios based on the vulnerabilities in the pseudo-random sequence generation process. Under certain conditions, it is possible to obtain the keys of the communicating parties with very low error rates, thus effectively attacking the quantum key system. This paper presents new requirements for the use of random numbers in quantum key systems, which can effectively guide the security evaluation of quantum key distribution protocols.

关键词： quantum key distribution pseudo-random security

Adaptive-basis decomposition-based low-rank network for efficient non-uniform motion deblurring

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics Letters 2025年第1期21卷 43-50页

作者： CHEN Lei XIONG Qingbo ZHANG wei li Runde School of Software Henan UniversityKaifeng 475004China School of Applied Technology China University of Labor RelationsBeijing 100048China

In this study,we present a unified sparsity-driven framework that significantly enhances motion deblurring performance by integrating two key components:a custom-designed dataset and a low-rank module(LRM).This framework leverages the inherent sparsity of per-pixel blur kernels to bolster both deblurring accuracy and model ***,we propose an adaptive-basis decomposition-based deblurring(ADD)approach,which constructs a tailored training dataset to enhance the generalization capacity of the deblurring *** ADD framework adaptively decomposes motion blur into sparse basis elements,effectively addressing the intricacies associated with non-uniform ***,an LRM is proposed to improve the interpretability of deblurring models as a plug-and-play module,primarily designed to identify and harness the intrinsic sparse features in sharp images.A series of ablation studies have been conducted to substantiate the synergistic advantages of combining the proposed ADD with the LRM for overall improvement in deblurring ***,we empirically demonstrate through rigorous experimentation that incorporating the LRM into an existing Uformer network leads to substantial enhancement in reconstruction *** integration yields a sparsity-guided low-rank network(SGLRN).Operating under the overarching principle of sparsity,SGLRN consistently outperforms state-of-the-art methods across multiple standard deblurring *** experimental results,assessed through quantitative metrics and qualitative visual evaluations,provide compelling evidence of its *** overall deblurring results are available at Google Drive.

关键词： network motion uniform

维普期刊数据库