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Magnitude, spatial patterns and drivers of methane fluxes from coastal salt marshes and mangrove forests in China

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Science China Earth Sciences 2025年第3期68卷 850-866页

作者： yixuan yU Derrick y.F.LAI Minjie hu Chuan TONG Key Laboratory of humid Subtropical Eco-geographical Process of Ministry of Education Fujian Normal University School of Geographical Sciences Fujian Normal University Department of Geography and Resource Management The Chinese University of Hong Kong

Methane（CH4） is a highly potent greenhouse gas due to its high radiative forcing and global warming *** the magnitude, spatial patterns, and drivers of CH4emission from wetlands at the regional scale is crucial for formulating suitable strategies to mitigate future climate change. In this study, we synthesized the CH4flux data reported for major plant communities in the coastal salt marshes and mangrove forests in China and produced a spatial map of CH4fluxes from the mangrove sediments and salt marshes in China based on the results of machine learning models. Moreover, we examined the main drivers of CH4flux from these coastal wetlands and estimated the annual CH4emissions from the salt marshes and mangrove forests in different coastal provinces of China using a bottom-up approach. Our results showed that the mean CH4fluxes from the salt marsh and mangrove ecosystems in China were 2.22±0.29 and 2.26±0.55 mg m-2h-1, respectively. Across China, the total annual CH4emission from salt marshes was 31,179.75 Mg CH4a-1, while that from mangroves was 5,533.97 Mg CH4a-1with the sediments contributing to 12.7%(701.64 Mg CH4a-1) of the total efflux. The salt marshes and mangroves in China accounted for 2.75% and 0.14%–0.15% of the global annual CH4emissions from these two ecosystems,respectively. Moreover, we found that CH4emissions from the salt marshes and mangroves could offset the cooling impact arising from net carbon dioxide uptake by 88% and 53%, respectively, over a 100-year time scale. Mean annual temperature, soil moisture, and soil organic carbon content were the main factors controlling CH4emissions from these coastal ***, we found that CH4fluxes from the salt marshes in China decreased with latitude, which implied a possible increase in marsh CH4emission in response to global warming that should be considered carefully when developing nature-based climate solutions to achieve national goals for carbon neutrality.

关键词： Salt marsh Mangrove Methane flux Spatial pattern Driving factors China

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Effects of sub-chronic aluminium intoxication on growth and morphological structure of spleen and bursa of fabricius in chickens——Preliminary study the effect of aluminium accumulation on immune system in chickens

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Effects of sub-chronic aluminium intoxication on growth and ...

东周时期内蒙古中南部人群和文化融合进程中的农业经济——以和林格尔大堡山墓地人骨C、N稳定同位素分析为例

中国畜牧兽医学会动物毒物学分会2009年学术研讨会

作者： hu C w,LI y F (College of Veterinary Medicine,Northeast Agricultural University Harbin 150030,China)

The model of different level’s sub-chronic aluminu m intoxication in chickens was estab lished by continuous peritoneal injec tion different gradient aluminum trichloride(AlCl).The growth index of spleen and bursa of Fabrici us were detected and the structures of them were observed by optical microscope and transmission electro n *** results showed that(1) the growth index of spleen and bursa of Fabricius of aluminium poisoned group was significant lower than the control group in chickens(Pwth index had dose-effect relationships with AlCl.(2) In fact of histopathol ogically,middle and low dose groups had no apparently pathologic al *** presented change s of apoptotic morphology and germi nal center of bursal nodule hyperplas yed in high dose group.(3) In the fact of ultrastructurally,low dose group had no apparently pathological *** middle and high dose groups,karyolemma broken,mitoch ondria swelled,cristae fragmentated or disappeared,rough endoplasmic reticulum dilated,cistemas widen, confluenced vacuole and presented typical mark shape of apoptosis in lymphocyte of spleen;karyolemma broken,caryolysised,myelin bodys appeared,the number of organelles within intracytoplasm decreased significantly in lymphocyte of bursa of *** results indicated that aluminum poisoning greatly hindered the development of spleen and bursa of Fabricius,as a consequ ence obvious pathological injury of spleen and bursa of Fabricius.

关键词： Chickens Aluminum poisoning Spleen Bursa of Fabricius

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中国科学：地球科学 2018年第2期48卷 200-209页

作者：张昕煜张旭索明杰魏东胡耀武中国科学院大学考古与人类学系北京100049 中国科学院古脊椎动物与古人类研究所中国科学院脊椎动物演化与人类起源重点实验室北京100044 中国社会科学院考古研究所北京100710 内蒙古师范大学历史文化学院呼和浩特010022 吉林大学边疆考古研究中心长春130012

东周时期,内蒙古中南部是农耕文化与游牧文化竞相角逐的舞台.在该地存在的多人群并存、文化并举的基本格局,随着战国中晚期赵、秦等诸侯国势力的北扩,转变为中原文化日益繁盛之势.中原地区特有的农耕经济(如粟作农业),究竟对内蒙古中南... 详细信息

东周时期,内蒙古中南部是农耕文化与游牧文化竞相角逐的舞台.在该地存在的多人群并存、文化并举的基本格局,随着战国中晚期赵、秦等诸侯国势力的北扩,转变为中原文化日益繁盛之势.中原地区特有的农耕经济(如粟作农业),究竟对内蒙古中南部的人群和文化融合是否产生了怎样的影响,仍缺乏较为细致的研究.为此,本文以和林格尔地区战国晚期大堡山墓地出土的41例人骨为研究对象,开展了C、N稳定同位素分析.结果表明,总体上先民的食物中包含了较大量的C_4类动物蛋白.结合考古资料可以看出,大堡山先民以粟作农业(包括粟类作物和以粟类作物副产品为食的动物)为基础,兼营牧业生产,其生活方式体现了战国晚期中原农业文明对内蒙古中南部的全面影响.尤其值得一提的是,通过对比不同时期已发表的人骨胶原C、N稳定同位素数据发现,粟作农业在东周时期和林格尔地区人群与文化融合的进程中始终发挥着积极作用.

关键词：大堡山墓地内蒙古中南部粟作农业碳、氮稳定同位素分析

陕北神圪垯墚遗址4000a BP前后生业经济的稳定同位素记录

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中国科学：地球科学 2017年第1期47卷 95-103页

作者：陈相龙郭小宁王炜林胡松梅杨苗苗吴妍胡耀武中国社会科学院考古研究所北京100710 陕西省考古研究院西安710043 中国科学院脊椎动物演化与人类起源重点实验室北京100044 中国科学院大学北京100049

为深入探讨陕北地区距今4000a前后生业经济的面貌,本文以神木神圪垯墚遗址出土28例人骨与24例动物骨骼为研究对象,运用碳氮稳定同位素分析方法重建了该遗址居民的食物结构与家畜饲养策略.人骨胶原的碳氮同位素表明,遗址存在个别食用了大... 详细信息

为深入探讨陕北地区距今4000a前后生业经济的面貌,本文以神木神圪垯墚遗址出土28例人骨与24例动物骨骼为研究对象,运用碳氮稳定同位素分析方法重建了该遗址居民的食物结构与家畜饲养策略.人骨胶原的碳氮同位素表明,遗址存在个别食用了大量C_3类食物的个体,但大多数居民基本以C_4类食物(粟作农业产品)为食,肉食消费程度个体间有差异.家畜中,家猪主要以粟类食物为食,部分黄牛食用了较多的粟类食物,而其余个体则与羊一样主要以采食野生C_3植物为生.结合陕北及相邻地区相关研究成果,本文认为4000a BP前后粟作农业生产是陕北生业经济的主要内容,草原畜牧经济(黄牛和羊的牧养)在本地多元化生业经济结构中的重要程度较低.繁荣的粟作农业经济为陕北地区社会发展提供了稳定的食物供给,保证了财富的积累和人群的增长,加速了社会分工和人群分化的速率,这可能是本地区文明化进程在4000a BP前后骤然提速的重要原因.

关键词：陕北 4000a BP前后神圪垯墚碳氮稳定同位素生业经济

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

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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

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High-precision tip positioning composite feedforward control of linear colocated motion systems with Bi-Loop iterative feedforward tuning

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Science China(Technological Sciences) 2025年第2期68卷 153-166页

作者： Junyu hu yourui TAO Shanhu LI Xu HAN College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of TechnologyTianjin 300130China

To enhance the tip positioning accuracy and robustness against disturbances of linear colocated motion systems,a novel composite feedforward(COMFF)control with Bi-Loop iterative feedforward tuning(IFFT)is *** tip positioning error consists of the coupled tip residual vibration and linear motor tracking *** the influence of nonlinear friction and load flexibility,the topology of COMFF is designed as decoupled structures so that COMFF can suppress the tip residual vibration and compensate for the linear motor tracking error ***,Bi-Loop IFFT is built to improve the robustness of COMFF in high-precision motor tracking *** the state space of the linear motor tracking error based on the projection theorem,two loops are performed in parallel along the iteration *** is the P-type iteration loop that drives linear motor tracking errors to converge to the zero *** other is the observation loop constructed by the recursive least square with forgetting factors to accelerate the P-type iteration *** by the P-type iteration loop with the aid of the observation loop,the proposed COMFF is integrated with fast convergence and high robustness when confronted with model *** effectiveness of the proposed COMFF combined with Bi-Loop IFFT is validated by experiments.

关键词： composite feedforward(COMFF)control Bi-Loop iterative feedforward tuning(Bi-Loop IFFT) colocated motion systems nonlinear friction flexible load

Nighttime reactions of a series of unsaturated alcohols with NO_(3)•:Kinetics,products and mechanisms study

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Journal of Environmental Sciences 2025年第5期151卷 331-346页

作者： yanyong Xu Shengrui Tong weiran Li Meifang Chen Lin hu Hailiang Zhang Sufan wang Maofa Ge State Key Laboratory for Structural Chemistry of Unstable and Stable Species Chinese Academy of Sciences Research/Education Center for Excellence in Molecular SciencesInstitute of Chemistry Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China College of Chemistry and Material Science Anhui Normal UniversityWuhu 241000China College of Ecology and Environment Xinjiang UniversityUrumqi 830017China

Unsaturated alcohols are a class of Biogenic volatile organic compounds(BVOCs)emitted in large quantities by plants when damaged or under adverse environmental conditions,and studies on their atmospheric degradation at night are still *** used chamber experiments to study the gas-phase reactions of three unsaturated alcohols,E-2-penten-1-ol,Z-2-hexen-1-ol and Z-3-hepten-1-ol,with NO_(3)radicals(NO_(3)•)during the *** rate constants of these reactions were(11.7±1.76)×10^(−13),(8.55±1.33)×10^(−13)and(6.08±0.47)×10^(−13)cm^(3)/(molecule·s)at 298K and 760 Torr,*** contrast,the reaction rate of similar substances with ozone was about 10^(−18)cm^(3)/(molecule·s),which indicates that the reaction with NO_(3)•is themain oxidation pathway for unsaturated alcohols at *** molecule aldehydes and ketones were the main gas-phase organic products of the reaction of three aldehydes and ketones with NO_(3)•,and the total small molecule aldehydes and ketones yields can reach between 45%-60%.They mainly originate from the breakage of alkoxy radicals,and different breakage sites determine different product *** addition,the SOA yields of the three unsaturated alcohols with NO_(3)•were 7.1%±1.0%,12.5%±1.9%and 30.0%±4.5%,respectively,whichweremuch higher than those of similarly structured substances with O_(3)or OH radicals(•OH).The results of high-resolution mass spectrometry shows that the main components of Secondary organic aerosol(SOA)of the three unsaturated alcohols are dimeric compounds containing several nitrate groups,which are formed through the polymerization of oxyalkyl radicals.

关键词： Unsaturated alcohols Reaction rate Aldehyde and ketone products Secondary organic aerosol components Reaction mechanism

Catalytic production of high-energy-density spiro polycyclic jet fuel with biomass derivatives

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Journal of Energy Chemistry 2025年第2期101卷 760-768页

作者： wen-Jing Zhang yan-Cheng hu yan-Hong Tan Jia Li Ning Li Jing-Pei Cao School of Chemical Engineering and Technology China University of Mining and Technology CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

High-energy-density（HED） fuel（*** used JP-10 and RJ-4）,featuring compact 3D polycyclic structure with high strain,is of critical importance for volume-limited military aircraft,since their high density and combustion heat can provide more propulsion *** reduce the reliance on petroleum source,it is highly desirable to develop renewable alternatives for the production of strained polycyclic HED fuel,but which remains a big challenge because of the inaccessibility caused by the high strain,we herein demonstrate a three-step catalytic route towards highly strained C17and C18spirofuel with biomass *** process includes catalytic aldol condensation of renewable cyclohexanone/cyclopentanone with benzaldehyde,catalytic spiro Diels-Alder（D-A） reaction of aldol adduct with isoprene,and catalytic *** key spiro D-A reaction is enabled by the catalysis of heterogeneous Lewis acidic ionic *** chloroaluminate IL,formed by benign urea and AICl3,exhibits good catalytic performance and reusability for this *** eventual hydrodeoxygenation（HDO）over Pd/C and H-y produces strained tricyclic spirofuel with density>0.93 g/mL,combustion heat>41 MJ/L and freezing point which are better than the properties of tactical fuel ***,it is anticipated that the as-prepared renewable fuels have the potential to replace traditional petroleum-derived HED fuels.

关键词： Biomass derivatives Cycloaddition High-energy-density Lewis acidic ionic liquid Spiro polycyclic fuel

Record-high heat transfer performance of spray cooling on 3D-printed hierarchical micro/nano-structured surface

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Science Bulletin 2025年第2期70卷 223-231页

作者： yongyan hu yifan Lei Xiuliang Liu Ronggui yang School of Energy and Power Engineering Huazhong University of Science and TechnologyWuhan 430074China College of Engineering Peking UniversityBeijing 100871China

Managing high-flux waste heat with controllable device working temperature is becoming challenging and critical for the artificial intelligence,communications,electric vehicles,defense and aerospace *** cooling,which combines forced convection with phase-change latent heat of working fluids,is promising for high flux heat *** of the previous studies on spray cooling enhancement adopted high spray flow rates to strengthen forced convection for high critical heat flux(CHF),leading to a low heat transfer coefficient(HTC).Micro/nanostructured surfaces can enhance boiling,but bubbles inside the structures tend to form a vapor blanket,which can deteriorate heat *** work demonstrates simultaneous enhancement of CHF and HTC in spray cooling by improving both evaporation and liquid film boiling on three-dimensional(3D)ordered hierarchical micro/nano-structured *** hierarchical micro/nano-structured surface is designed to coordinate the transport of spray droplets,capillary liquid films,and boiling bubbles to enhance spray cooling *** inversion where superheat decreases with increasing heat flux is observed,leading to an ultra-high HTC due to the simultaneous promotion of bubble nucleation and *** CHF is obtained by overcoming the liquid–vapor counterflow,i.e.,synergistically facilitating bubble escape and liquid permeation.A record-breaking heat transfer performance of spray cooling is achieved with a maximum heat flux of1273 w/cm^(2)and an HTC of 443.7 kw/(m^(2)K)over a 1 cm^(2)heating area.?2024 Science China *** by Elsevier *** Science China *** rights are reserved,including those for text and data mining,AI training,and similar technologies.

关键词： Spray cooling Liquid film boiling Liquid film evaporation Hierarchical structure Thermal management