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VISUAL OBSERBATION OF HCFC141b GAS HYDRATE FORMATION/DECOMPOSITION PROCESS OUTSIDE OF A TUBE 被引量:3
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作者 谢应明 郭开华 +2 位作者 樊栓狮 梁德青 顾建明 《化工学报》 EI CAS CSCD 北大核心 2003年第z1期91-97,共7页
In order to design a kind of heat exchanger suitable to the indirect-touched gas hydrate cool storage vessel, a visual observation of HCFC141b gas hydrate formation/decomposition process was presented through a self-d... In order to design a kind of heat exchanger suitable to the indirect-touched gas hydrate cool storage vessel, a visual observation of HCFC141b gas hydrate formation/decomposition process was presented through a self-designed small-scale visualization apparatus of gas hydrate cool storage. Based on the shooted photos and recorded temperatures, the formation/decomposition process of HCFC141b are described, some characteristics are concluded, and some suggestions of designing heat exchanger are indicated according to the specific characteristics of HCFC141b gas hydrate formation/decomposition process. 展开更多
关键词 into or form as it on HCFC VISUAL OBSERBATION OF HCFC141b GAS HYDRATE formation/decomposition PROCESS OUTSIDE OF A TUBE of heat that 化工学报 from be down rate
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Coastal ozone dynamics and formation regime in Eastern China:Integrating trend decomposition and machine learning techniques 被引量:1
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作者 Lei Tong Zhuoliang Gu +8 位作者 Xuchu Zhu Cenyan Huang Baoye Hu Yasheng Shi Yang Meng Jie Zheng Mengmeng He Jun He Hang Xiao 《Journal of Environmental Sciences》 2025年第9期597-612,共16页
Machine-learning is a robust technique for understanding pollution characteristics of surface ozone,which are at high levels in urban China.This study introduced an innovative approach combining trend decomposition wi... Machine-learning is a robust technique for understanding pollution characteristics of surface ozone,which are at high levels in urban China.This study introduced an innovative approach combining trend decomposition with Random Forest algorithm to investigate ozone dynamics and formation regimes in a coastal area of China.During the period of 2017–2022,significant inter-annual fluctuations emerged,with peaks in mid-2017 attributed to volatile organic compounds(VOCs),and in late-2019 influenced by air temperature.Multifaceted periodicities(daily,weekly,holiday,and yearly)in ozone were revealed,elucidating substantial influences of daily and yearly components on ozone periodicity.A VOC-sensitive ozone formation regime was identified,characterized by lower VOCs/NO_(x) ratios(average=0.88)and significant positive correlations between ozone and VOCs.This interplay manifested in elevated ozone duringweekends,holidays,and pandemic lockdowns.Key variables influencing ozone across diverse timescaleswere uncovered,with solar radiation and temperature driving daily and yearly ozone variations,respectively.Precursor substances,particularly VOCs,significantly shaped weekly/holiday patterns and long-term trends of ozone.Specifically,acetone,ethane,hexanal,and toluene had a notable impact on the multi-year ozone trend,emphasizing the urgency of VOC regulation.Furthermore,our observations indicated that NO_(x) primarily drived the stochastic variations in ozone,a distinguishing characteristic of regions with heavy traffic.This research provides novel insights into ozone dynamics in coastal urban areas and highlights the importance of integrating statistical and machinelearning methods in atmospheric pollution studies,with implications for targeted mitigation strategies beyond this specific region and pollutant. 展开更多
关键词 Time series decomposition Random forest VOC-sensitive Long-term trend Port area
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Learning intrinsic decomposition with semantic information fusion based on transformer
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作者 Pengjie ZHAO Hao SHA +1 位作者 Yongtian WANG Yue LIU 《虚拟现实与智能硬件(中英文)》 2025年第6期543-559,共17页
Intrinsic decomposition,the process of decomposing an image into reflectance and shading,is widely used in virtual and augmented reality tasks.Reflectance and shading often exhibit large gradients at the object edges,... Intrinsic decomposition,the process of decomposing an image into reflectance and shading,is widely used in virtual and augmented reality tasks.Reflectance and shading often exhibit large gradients at the object edges,and the intrinsic properties on the same object tend to be similar.This spatial coherence is closely related to semantic consistency because objects within the same semantic category often exhibit similar intrinsic properties.Therefore,incorporating semantic segmentation into a deep intrinsic decomposition framework helps the network distinguish between different object instances and understand high-level scene structures.To this end,we design an intrinsic decomposition network jointly trained with a dedicated semantic segmentation module,allowing semantic cues to enhance the decomposition of reflectance and shading.The semantic module provides guidance during training but is removed during inference,improving performance without increasing the inference cost.Additionally,to capture the global contextual dependencies critical for intrinsic decomposition,we adopt a Transformer-based backbone.The proposed backbone enables the model to associate distant regions with similar material properties,thereby maintaining consistency in reflectance and learning smooth illumination patterns across a scene.A convolutional decoder is also designed to output predictions with improved details.Experiments demonstrate that our approach achieves state-of-the-art performance in the quantitative evaluations on the Intrinsic Images in the Wild(IIW)and Shading Annotations in the wild(SAW)datasets. 展开更多
关键词 Intrinsic image decomposition Augmented reality Semantic segmentation Detachable decoder Joint learning
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Preparation of fibrous nickel powder by precipitation transformation coupled with thermal decomposition 被引量:3
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作者 邬建辉 刘刚 +3 位作者 苏涛 张文宏 罗妹妹 魏涛 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第8期2653-2660,共8页
Fibrous particulate precursor was obtained by precipitation transformation in the ternary solution system of ammonium oxalate, nickel chloride and ammonia. The composition and morphology of precursor were characterize... Fibrous particulate precursor was obtained by precipitation transformation in the ternary solution system of ammonium oxalate, nickel chloride and ammonia. The composition and morphology of precursor were characterized by XRD, SEM, IR and DTA/TGA analyses. The results show that the chemical composition and morphology of precursor precipitates at pH=8.4?8.8 are different from those of precursor precipitates at pH=6.0, and the mechanisms of the thermal decomposition of the precursors are different. The effects of various conditions in the process of thermal decomposition, including precursor morphology, atmosphere, temperature and time on the morphology and dispersion degree of obtained nickel powders were studied in detail. The final product inherits the morphology of precursor when the thermal decomposition is conducted under a weakly reducing atmosphere at temperature range of 400?440 °C for 30 min. Fibrous nickel powder can be produced with good dispersion, and its shape changes from smooth, straight and compact fiber into loose and curved fiber with rough surface. 展开更多
关键词 PRECURSOR fibrous nickel powder precipitation transformation thermal decomposition
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Thermal decomposition and kinetics of diisopropyl methylphosphonate(DIMP),a chemical warfare agent simulant
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作者 Natalie Gese Hergen Eilers 《Defence Technology(防务技术)》 2026年第1期40-51,共12页
Chemical warfare agents(CWAs)remain a persistent hazard in many parts of the world,necessitating a deeper exploration of their chemical and physical characteristics and reactions under diverse conditions.Diisopropyl m... Chemical warfare agents(CWAs)remain a persistent hazard in many parts of the world,necessitating a deeper exploration of their chemical and physical characteristics and reactions under diverse conditions.Diisopropyl methylphosphonate(DIMP),a commonly used CWA surrogate,is widely studied to enhance our understanding of CWA behavior.The prevailing thermal decomposition model for DIMP,developed approximately 25 years ago,is based on data collected in nitrogen atmospheres at temperatures ranging from 700 K to 800 K.Despite its limitations,this model continues to serve as a foundation for research across various thermal and reactive environments,including combustion studies.Our recent experiments have extended the scope of decomposition analysis by examining DIMP in both nitrogen and zero air across a lower temperature range of 175℃ to 250℃.Infrared spectroscopy results under nitrogen align well with the established model;however,we observed that catalytic effects,stemming from decomposition byproducts and interactions with stainless steel surfaces,alter the reaction kinetics.In zero air environments,we observed a novel infrared absorption band.Spectral fitting suggests this band may represent a combination of propanal and acetone,while GCMS analysis points to vinyl formate and acetone as possible constituents.Although the precise identity of these new products remains unresolved,our findings clearly indicate that the existing decomposition model cannot be reliably extended to lower temperatures or non-nitrogen environments without further revisions. 展开更多
关键词 Chemical warfare agents Simulants Diisopropyl methylphosphonate Thermal decomposition decomposition model PROPANAL Vinyl formate ACETONE
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Optimal Reconfiguration Trajectory of Multi-satellite Electromagnetic Formation System
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作者 CHU Wenbo ZHOU Qingrui +1 位作者 LIU Zhongxin NI Yuanhua 《空间控制技术与应用(中英文)》 北大核心 2026年第1期37-47,共11页
The multi-satellite electromagnetic formation flight system is nonlinear and strongly coupled,which makes modeling and optimization challenging.To simplify electromagnetic force evaluation and dynamics modeling,we int... The multi-satellite electromagnetic formation flight system is nonlinear and strongly coupled,which makes modeling and optimization challenging.To simplify electromagnetic force evaluation and dynamics modeling,we introduce a reference frame consistent with each satellite body frame,in which the electromagnetic dipoles and electromagnetic forces are represented as two-dimensional vectors.Then,the maneuver time is divided into time intervals,and different satellite sets are activated in each interval,converting the multi-satellite formation reconfiguration problem into an optimal trajectory problem of each two-satellite subsystem.To this end,a token-based dynamic programming method with a switching penalty of active satellite sets is proposed to determine the sequence of satellite sets participating in each time interval,thereby enabling all satellites to reach their desired states.For the two-satellite subsystem with the objectives of minimizing maneuver time and energy consumption,the Gauss pseudo-spectral method is employed to generate the optimal reconfiguration trajectory.Numerical simulations verify the effectiveness of the proposed optimization method. 展开更多
关键词 electromagnetic formation flight Gauss pseudo-spectral method token-based dynamic programming
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Prescribed-Time Active Disturbance Rejection Control for Electromagnetic Formation Flight Under Model Uncertainties and Disturbances
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作者 SHEN Xixi MENG Bin HU Jiangping 《空间控制技术与应用(中英文)》 北大核心 2026年第1期94-102,共9页
This study investigates prescribed-time position tracking control for electromagnetic satellite formations subject to model uncertainties and external disturbances.Using the Clohessy-Wiltshire equations as the relativ... This study investigates prescribed-time position tracking control for electromagnetic satellite formations subject to model uncertainties and external disturbances.Using the Clohessy-Wiltshire equations as the relative motion dynamics model,a prescribed time output feedback control strategy is proposed.A prescribed-time extended state observer is designed to estimate the relative velocity and external disturbances.The disturbance estimates are then used as the feedforward component of the controller.Building on this framework,a novel prescribed-time active disturbance rejection control strategy for position tracking is developed via a backstepping control design.The convergence of the extended state observer and the stability of the closed-loop system are rigorously analyzed using Lyapunov stability theory.Numerical simulations are performed to validate the effectiveness of the proposed controller. 展开更多
关键词 electromagnetic formation prescribed time active disturbance rejection control output feedback control
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The role of Zr in modulating the electronic and structural properties of supported Ni catalysts for catalytic decomposition of methane
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作者 LIU Lu REN Shenyong +2 位作者 YAO Chengshu SHEN Baojian XU Chunming 《燃料化学学报(中英文)》 北大核心 2026年第2期88-101,共14页
Catalytic decomposition of methane,which produces high-purity hydrogen and high-value-added carbon nanomaterials,has shown considerable potential for development and is expected to yield significant economic benefits ... Catalytic decomposition of methane,which produces high-purity hydrogen and high-value-added carbon nanomaterials,has shown considerable potential for development and is expected to yield significant economic benefits in the future.However,designing catalysts that simultaneously exhibit high activity and long-term stability remains a significant challenge.Tuning the catalyst’s structure and electronic properties is an effective strategy for enhancing the reaction performance.In this work,a series of NixZr/ZSM-5 catalysts were prepared using the incipient wetness impregnation method,and the effect of Zr loadings on catalyst properties and performance was systematically investigated.The calcined and reduced catalysts were characterized by low-temperature N_(2)adsorption-desorption,XRD,SEM,H_(2)-TPR and XPS.The results showed that the addition of Zr significantly increased the specific surface area of the catalyst and reduced the metal particle size.Smaller NiO particles were found to enter the pores of the HZSM-5 support,and electronic interactions between NiO and ZrO_(2)markedly enhanced the metal-support interaction.The catalyst exhibited optimal catalytic performance at a Zr loading of 5%,achieving a maximum methane conversion of 68%at 625℃,maintaining activity for 900 min,and delivering a carbon yield of 1927%.Further increasing the Zr loading yielded only limited improvements in catalytic performance.Characterization of the spent catalysts and carbon products via TEM,Raman spectroscopy,and TGA revealed that the introduction of ZrO_(2)reduced metal sintering and promoted a shift in carbon nanofibers growth mode from tip-growth to base-growth.The mechanism of base-growth enabled the catalyst to maintain reaction activity for an extended period. 展开更多
关键词 promoter ZrO_(2) Ni/HZSM-5 catalytic decomposition of methane carbon nanofibers
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Quorum sensing:its roles in mediating biofilm and viable but non-culturable state formation,and strategies for the prevention and control of foodborne bacteria via quorum quenching
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作者 Ting Ding Xuchen Li +3 位作者 Hongwei Zhan Yanqing Li Zhenqing Li Yang Deng 《Food Science and Human Wellness》 2026年第2期520-537,共18页
Foodborne bacteria produce biofilms and their viable but non-culturable(VBNC)formation,can affect food quality and safety.Studies have shown that these characteristics are regulated by the bacterial quorum sensing(QS)... Foodborne bacteria produce biofilms and their viable but non-culturable(VBNC)formation,can affect food quality and safety.Studies have shown that these characteristics are regulated by the bacterial quorum sensing(QS)system.Quenching the QS system of foodborne bacteria and blocking the expression of the corresponding genes may be an effective way to improve food quality and safety.Therefore,this article reviews the QS systems for foodborne bacteria,the regulatory mechanisms of QS systems in biofilm and VBNC formation and resuscitation,the research progress on quorum sensing inhibitors(QSIs)for Gram-negative and Gram-positive bacteria,and introduces QSIs from various sources.In addition,we have also summarized the current research issues on QS regulation of biofilms and VBNC formation.The systematic study of the QS phenomenon of foodborne bacteria in practical situations,the mechanism of bacterial QS cooperation-cheating,the screening of novel and highly active QSIs,the combination of QSIs and other technologies to improve their bioavailability,and the regulatory network between biofilm and VBNC formation and resuscitation are research directions that need to be paid attention to in the future. 展开更多
关键词 Foodborne bacteria Quorum sensing Biofilm formation Viable but non-culturable state formation Food quality
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Advanced isoconversional kinetic analysis of lepidolite sulfation product decomposition reactions for selectively extracting lithium
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作者 Yubo Liu Baozhong Ma +4 位作者 Jiahui Cheng Xiang Li Hui Yang Chengyan Wang Yongqiang Chen 《International Journal of Minerals,Metallurgy and Materials》 2026年第1期217-227,共11页
The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.A... The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.Accordingly,comprehensive kinetic study by employing thermalgravimetric analysis at various heating rates was presented in this paper.Two main weight loss regions were observed during heating.The initial region corresponded to the dehydration of crystal water,whereas the subsequent region with overlapping peaks involved complex decomposition reactions.The overlapping peaks were separated into two individual reaction peaks and the activation energy of each peak was calculated using isoconversional kinetics methods.The activation energy of peak 1 exhibited a continual increase as the reaction conversion progressed,while that of peak 2 steadily decreased.The optimal kinetic models,identified as belonging to the random nucleation and subsequent growth category,provided valuable insights into the mechanism of the decomposition reactions.Furthermore,the adjustment factor was introduced to reconstruct the kinetic mechanism models,and the reconstructed models described the kinetic mechanism model more accurately for the decomposition reactions.This study enhanced the understanding of the thermochemical behavior and kinetic parameters of the lepidolite sulfation product decomposition reactions,further providing theoretical basis for promoting the selective extraction of lithium. 展开更多
关键词 LITHIUM LEPIDOLITE decomposition reactions KINETICS isoconversional analysis
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Promoting osteoblast-mediated bone formation:a more promising approach for natural products to treat osteoporosis
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作者 Peixuan Hu Meipeng Zhu +1 位作者 Feng Li Jian Liu 《Chinese Journal of Natural Medicines》 2026年第2期156-170,共15页
Osteoporosis is a systemic skeletal disorder characterized by reduced bone mass,compromised bone microstructure,and an increased risk of fractures,primarily due to excessive osteoclast-mediated bone resorption relativ... Osteoporosis is a systemic skeletal disorder characterized by reduced bone mass,compromised bone microstructure,and an increased risk of fractures,primarily due to excessive osteoclast-mediated bone resorption relative to osteoblast-mediated bone formation.While current anti-osteoporosis drugs,such as bisphosphonates and denosumab,predominantly focus on reducing bone resorption,osteoanabolic approaches are essential for restoring bone microarchitecture and ultimately reducing fracture risk.Traditional Chinese medicines(TCMs)and their active ingredients have long been used in China for osteoporosis prevention and treatment.This review provides a comprehensive evaluation of the effects and molecular mechanisms of 65 natural products across 24 categories on osteoblast-mediated bone formation.These compounds promote bone formation by regulating key transcription factors(RUNX2 and Osterix)and signaling pathways,including WNT/β-catenin,bone morphogenic protein(BMP),mitogen-activated protein kinase(MAPK),phosphoinositide 3-kinase/protein kinase B(PI3K/AKT),oxidative stress,autophagy,and epigenetic regulation.Notably,certain natural products[e.g.,icariin(ICA)]exert their effects through multiple targets and pathways.Many of these natural products have demonstrated significant therapeutic efficacy in animal models,such as ovariectomized(OVX)mice.Our findings suggest that natural products with kidney-tonifying,anti-inflammatory,and antioxidant properties,as well as those inhibiting adipocyte differentiation,may hold promise for osteoporosis treatment.Additionally,we highlight current research gaps and propose future directions,including high-throughput screening and validation in diverse animal models,development of novel bone-targeting delivery systems,and identification of natural compounds targeting osteocytes. 展开更多
关键词 Natural products OSTEOBLASTS Bone formation OSTEOPOROSIS
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Three-step formation of diamonds in shock-compressed hydrocarbons:Dissociation,species separation,and nucleation
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作者 Bo Chen Qiyu Zeng +4 位作者 Xiaoxiang Yu Jiahao Chen Shen Zhang Dongdong Kang Jiayu Dai 《Matter and Radiation at Extremes》 2026年第1期58-67,共10页
The accumulation and circulation of carbon and hydrogen contribute to the chemical evolution of ice giant planets.Species separation and diamond precipitation have been reported in carbon-hydrogen systems and have bee... The accumulation and circulation of carbon and hydrogen contribute to the chemical evolution of ice giant planets.Species separation and diamond precipitation have been reported in carbon-hydrogen systems and have been verified by static and shock compression experiments.Nevertheless,the dynamic formation processes underlying these phenomena remain insufficiently understood.In combination with a deep learning model,we demonstrate that diamonds form through a three-step process involving dissociation,species separation,and nucleation processes.Under shock conditions of 125 GPa and 4590 K,hydrocarbons decompose to give hydrogen and low-molecular-weight alkanes(CH_(4) and C_(2)H_(6)),which escape from the carbon chains,resulting in C/H species separation.The remaining carbon atoms without C-H bonds accumulate and nucleate to form diamond crystals.The process of diamond growth is associated with a critical nucleus size at which the dynamic energy barrier plays a key role.These dynamic processes of diamond formation provide insight into the establishment of a model for the evolution of ice giant planets. 展开更多
关键词 diamond formation formation processes ice giant planetsspecies separation DISSOCIATION deep learning modelwe carbon hydrogen static shock compression experimentsneverthelessthe chemical evolution
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Ultrastructural Observation of Quantonenpollenites,a Characteristic Pollen of the Quantou Formation in the Songliao Basin,and its Taxonomic Clarification
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作者 LIAO Cuijing ZHANG Chaoyu +1 位作者 LI Suping LIU Weiqing 《Acta Geologica Sinica(English Edition)》 2026年第1期20-32,共13页
Quantonenpollenites,a pollen taxon which was assumed to be angiosperm,is of great significance in confirming the geological age of its bearing strata.Aims to clarify the taxonomic affiliation of Quantonenpollenites,we... Quantonenpollenites,a pollen taxon which was assumed to be angiosperm,is of great significance in confirming the geological age of its bearing strata.Aims to clarify the taxonomic affiliation of Quantonenpollenites,we investigated the external morphology and internal structure using Light Microscopy(LM),Scanning Electron Microscopy(SEM),and Transmission Electron Microscopy(TEM).According to TEM observations,the exine of Quantonenpollenites pollen is unstratified with the absence of a columellar layer,and the exine is tightly connected with the intine.Based on comprehensive morphological evidence,especially the lack of columellar layer which is typical characteristics existing in almost all angiosperm pollen,the botanical affinity of Quantonenpollenites should be attributed to gymnosperms rather than angiosperms as previously thought.Through comparative analysis,it may have a close affinity with Ephedra,but further analytical data are still needed for verification.As a characteristic palynological type of the Quantou Formation in the Songliao Basin,the occurrence of Quantonenpollenites has indicative significance for determining the age of the hosting strata.By systematically clarifying the phylogenetic affiliation of Quantonenpollenites,together with the other associated palynomorphs,this study provides crucial reference materials for defining the stratigraphic age range of the Quantou Formation(Cenomanian to early Turonian),improves the resolution of stratigraphic age calibration of the Quantou Formation,and provides key paleontological evidence for the refined division of the terrestrial Cretaceous chronostratigraphic framework in the Songliao Basin. 展开更多
关键词 Quantonenpollenites pollen morphology ULTRASTRUCTURE Quantou formation CRETACEOUS
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Formation control for multiple spacecraft with disturbances and sensor failures
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作者 Yufei LYU Yuezu PENG Wenliang 《Journal of Systems Engineering and Electronics》 2026年第1期18-25,共8页
Formation control of multiple spacecraft has attracted extensive research attention.However,achieving reliable performance under sensor failures remains a significant challenge.This paper develops an integrated framew... Formation control of multiple spacecraft has attracted extensive research attention.However,achieving reliable performance under sensor failures remains a significant challenge.This paper develops an integrated framework that jointly designs distributed observers and local controllers to ensure robust formation control in the presence of external disturbances and sensor malfunctions.Treating the spacecraft formation as a single interconnected system,each spacecraft constructs a distributed observer that estimates the overall system state by incorporating both its own measurements and the predicted control information shared among the spacecraft.Based on the observer estimates,a local control law is synthesized to maintain the desired formation.Rigorous theoretical analysis and numerical simulations demonstrate that the proposed integrated approach effectively guarantees formation stability and resilience against sensor failures and disturbances. 展开更多
关键词 formation control multiple spacecraft DISTURBANCE sensor failure
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Additional small theropod remains from the Upper Cretaceous Nenjiang Formation in Songliao Basin,Northeast China
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作者 HUANG Yuqi WU Wenhao +1 位作者 Ivan Bolotsky YU Kaifeng 《Global Geology》 2026年第1期1-12,共12页
Five new small theropod teeth and one manual ungual have recently been recovered from the Upper Cretaceous Nenjiang Formation in the Songliao Basin.The specimens were examined for their morphological characteristics,l... Five new small theropod teeth and one manual ungual have recently been recovered from the Upper Cretaceous Nenjiang Formation in the Songliao Basin.The specimens were examined for their morphological characteristics,leading to the identification of four distinct taxa.The first taxon consists of three foliodont teeth characterized by a pronounced basal constriction and large hook-like distal denticles,which can be attributed to Troodontidae.The second taxon is represented by an elongated tooth featuring prominent longitudinal ridges,allowing for its assignment to Paronychodon.The third taxon is a bladelike tooth with notably small distal denticles,corresponding to Richardoestesia.The fourth taxon comprises a manual ungual characterized by a transversely wide and nearly symmetrical proximal articular surface,fully enclosed ventral foramina,a flattened ventral surface,and the absence of a flexor tubercle,resembling Alvarezsauridae.These specimens significantly enhance the known dinosaur diversity of the Nenjiang Formation and provide crucial insights for understanding the terrestrial ecosystem in Northeast Asia during the Late Cretaceous. 展开更多
关键词 THEROPODA biodiversity Nenjiang formation CAMPANIAN Late Cretaceous Songliao Basin
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FDEFusion:End-to-End Infrared and Visible Image Fusion Method Based on Frequency Decomposition and Enhancement
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作者 Ming Chen Guoqiang Ma +3 位作者 Ping Qi Fucheng Wang Lin Shen Xiaoya Pi 《Computers, Materials & Continua》 2026年第4期817-839,共23页
In the image fusion field,fusing infrared images(IRIs)and visible images(VIs)excelled is a key area.The differences between IRIs and VIs make it challenging to fuse both types into a high-quality image.Accordingly,eff... In the image fusion field,fusing infrared images(IRIs)and visible images(VIs)excelled is a key area.The differences between IRIs and VIs make it challenging to fuse both types into a high-quality image.Accordingly,efficiently combining the advantages of both images while overcoming their shortcomings is necessary.To handle this challenge,we developed an end-to-end IRI andVI fusionmethod based on frequency decomposition and enhancement.By applying concepts from frequency domain analysis,we used the layering mechanism to better capture the salient thermal targets from the IRIs and the rich textural information from the VIs,respectively,significantly boosting the image fusion quality and effectiveness.In addition,the backbone network combined Restormer Blocks and Dense Blocks;Restormer blocks utilize global attention to extract shallow features.Meanwhile,Dense Blocks ensure the integration between shallow and deep features,thereby avoiding the loss of shallow attributes.Extensive experiments on TNO and MSRS datasets demonstrated that the suggested method achieved state-of-the-art(SOTA)performance in various metrics:Entropy(EN),Mutual Information(MI),Standard Deviation(SD),The Structural Similarity Index Measure(SSIM),Fusion quality(Qabf),MI of the pixel(FMI_(pixel)),and modified Visual Information Fidelity(VIF_(m)). 展开更多
关键词 Infrared images visible images frequency decomposition restormer blocks global attention
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The effect of forest microenvironment on litter decomposition in the Andean tropical mountains
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作者 Dennis Castillo-Figueroa 《Journal of Forestry Research》 2026年第1期152-168,共17页
Upper Andean tropical forests are renowned for their extraordinary biodiversity and heterogeneous environmental conditions.Despite the critical role of litter decomposition in carbon and nutrient cycles,its dynamics i... Upper Andean tropical forests are renowned for their extraordinary biodiversity and heterogeneous environmental conditions.Despite the critical role of litter decomposition in carbon and nutrient cycles,its dynamics in this region remains unexplored at finer scales.This study investigates how micro site conditions influence litter decomposition of 15 upper Andean species over time.A reciprocal translocation field experiment was conducted over 18 months in 14 permanent plots within four sites in Colombian Andean mountain forests.Each plot contained three litterbeds(microsites),each with the 15 species,harvested at 3,6,12 and 18 months,totaling 2520 litterbags.Different forest variables,including canopy openness,leaf area index,slope and depth of litter,were measured in each litterbed.ANOVAs and linear mixed models were used to assess variation between sites and plots respectively,while multiple linear regression analyses evaluated the effects of forest variables on decay rates over time at the micro site scale.Results showed differences in absolute decay rates between sites but consistent relative decay rates,indicating varying magnitudes of decomposition,yet maintaining the same order based on their litter quality.Decay rates varied between species,with more variation in labile species compared to recalcitrant ones.Despite substantial variation in forest characteristics within sites,their influence on litter decomposition was minimal and declined over time.This suggests that,at finer spatial scales,the forest microenvironment plays a lesser role in litter decomposition,with litter quality emerging as the primary driver.This study is a step towards understanding the fine-scale dynamics of litter decomposition in upper Andean tropical forests,highlighting the intricate interplay between microenvironmental factors and decomposition processes. 展开更多
关键词 decomposition Tropical montane forests Forest structure Microenvironmental conditions Microsite scale
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Late Permian Mixed Carbonate-Siliciclastic Sedimentary Succession on the Northwestern Margin of the Indian Plate,Pakistan:Insights into Facies Evolution and Paleoenvironmental Reconstruction of the Chhidru Formation
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作者 Jabir HUSSAIN Ali Khan MUMTAZ +4 位作者 Mamoon Siyar SYED Zarkogiannis D.STERGIOS Mehrangiz NADERI Syed Osja MEHDI Muhammad BILAL 《Acta Geologica Sinica(English Edition)》 2026年第1期33-53,共21页
This study investigates the facies development and sedimentology of the Late Permian Chhidru Formation,a mixed carbonate-siliciclastic unit exposed in the Western Salt Range,Potwar Basin,Pakistan.The formation is subd... This study investigates the facies development and sedimentology of the Late Permian Chhidru Formation,a mixed carbonate-siliciclastic unit exposed in the Western Salt Range,Potwar Basin,Pakistan.The formation is subdivided into four lithological units reflecting lateral variability,with thicknesses and lithologies ranging from fossiliferous sandy limestone to interbedded limestone and sandstone.These successions record a depositional shift from a carbonate platform to mixed carbonate-clastic,and ultimately,clastic-dominated environments.Lithostratigraphy suggests deposition on the underlying Wargal Limestone carbonates during a Late Permian sea-level fall on the northwest Indian margin of Gondwana.Similar Permian successions with identical lithological characteristics are documented in the Persian Gulf(Dalan Formation),Arabian Platform(Khuff Formation),and Iran(Nesen and Hambust formations).Petrographic analysis reveals deposition in the distal middle to proximal inner shelf settings of a carbonate-siliciclastic mixed,unrimmed platform.Based on identified foraminiferal assemblages,the Chhidru Formation's age is estimated to range from the late Wuchiapingian to Changhsingian stages of the Lopingian epoch. 展开更多
关键词 facies analysis depositional setting Chhidru formation Salt Range Pakistan
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Air-road cross domain collaborative hierarchical reinforcement learning for real-time formation control:A network signal generator approach
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作者 Xinhai ZHUANG Hengyu LI +2 位作者 Yueying WANG Huaicheng YAN Jun LUO 《Science China(Technological Sciences)》 2026年第2期324-337,共14页
In this paper,a hierarchical reinforcement learning(HRL)based real-time formation control approach is proposed for heterogeneous aerial-ground agents(HAGAs).Initially,to address the issue of imprecise modeling of HAGA... In this paper,a hierarchical reinforcement learning(HRL)based real-time formation control approach is proposed for heterogeneous aerial-ground agents(HAGAs).Initially,to address the issue of imprecise modeling of HAGAs,a unified heterogeneous chained system model is constructed using the hand-position method.Subsequently,a hierarchical framework is designed:(1)To decouple multi-agent collaborative interactions and individual dynamic rules through hierarchical resolution,which enables controller design to be independent of direct reliance on neighborhood collaborative errors.(2)By adopting a dual-layer framework that separates collaborative topology management from individual control strategies,seamless switching between multiple task scenarios can be achieved simply by reconstructing the collaborative topology of the first layer.Moreover,to overcome the issue of non-asymptotic stability of tracking errors caused by the discount factor in traditional optimal control,a cost function based on the derivative of the tracking error is introduced.This not only addresses the error issue caused by the discount factor but also effectively resolves the problem of the unboundedness of the quadratic cost function.Finally,the efficacy of the proposed algorithm is substantiated through simulation experiments. 展开更多
关键词 air-road heterogeneous agents formation control reinforcement learning layered design
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Research on the Mechanism of“Cold Tumor”Formation and Immunotherapy for Its Transformation into“Hot Tumor”
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作者 Liang Zhou Jia Zhou Zhengyi Wang 《Oncology Research》 2026年第3期295-337,共43页
A clear goal in cold tumor research is to identify strategies for converting them into immunologically‘hot’tumors with enhanced immune cell infiltration and activity,thereby improving their responsiveness to immunot... A clear goal in cold tumor research is to identify strategies for converting them into immunologically‘hot’tumors with enhanced immune cell infiltration and activity,thereby improving their responsiveness to immunotherapy.The genesis of cold tumors is exceedingly intricate.In recent times,as the analysis of this phenomenon has been pursued with greater depth,a suite of advanced diagnostic and therapeutic technologies has surfaced.These novel approaches and tactics are anticipated to modulate the tumor immune microenvironment across various dimensions,thereby facilitating the advancement of personalized and precise treatment modalities for cold tumors.The present article addresses the challenge of diminished therapeutic responsiveness to“cold tumors”within clinical settings.It systematically elucidates the multi-faceted regulatory mechanisms underlying immune evasion in cold tumors and offers a detailed analysis of advanced therapeutic strategies that incorporate nanotechnology,gene editing,and artificial intelligence methodologies.Furthermore,the future development trends of immunotherapy were explored in greater depth.It was posited that the convergence of artificial intelligence,multidimensional genomics,and emerging biotechnologies has presented positive prospects for the treatment of cold tumors,and has offered a theoretical foundation and technical framework for the transformation of cold tumors into“hot tumors”. 展开更多
关键词 Cold tumor immunosuppressive factors formation mechanism clinical treatment strategies
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