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北京市自然保护区空间布局与三区二带理念

生态学报 2008年第12期28卷 6379-6384页

作者：孙立李俊清北京林业大学省部共建森林培育与保护教育部重点实验室北京100083

研究的主要目标是北京市自然保护区的空间布局,通过Arcgis软件,矢量化北京市保护区边界,使得自然保护区成为研究底图中的斑块,参照位置的不同,利用Fragstats软件计算聚集度指数(AI)从而提出三区划分的假设,将北京市分成3个大的保护区体... 详细信息

研究的主要目标是北京市自然保护区的空间布局,通过Arcgis软件,矢量化北京市保护区边界,使得自然保护区成为研究底图中的斑块,参照位置的不同,利用Fragstats软件计算聚集度指数(AI)从而提出三区划分的假设,将北京市分成3个大的保护区体系,在此基础之上,计算各个保护区之间的几何最近邻距离(ENN),证明三区划分的合理性。然后,通过小班数据,分析连接三区廊道之间的土地利用结构,为北京市划分出连接保护区体系的西部山脉廊道和东部水域廊道。最终形成北京市自然保护区分布格局三区二带规划理念。

关键词：保护区聚集度几何最近邻距离三区二带

A N-CoSe/CoSe_(2)-C@Cu hierarchical architecture as a current collector-integrated anode for potassium-ion batteries

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Rare Metals 2024年第8期43卷 3702-3712页

作者： Zi-Jie Mu Yan-jun Gao Wen-Shuai Dong Zong-You li qing-Yi Song Han-Jiao Huang li-Dong Xing Jian-Guo Zhang Wei Wang Qi-Yao Yu State Key Laboratory of Explosion Science and Technology School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type ***,we design a current collector-integrated electrode(N-CoSe/CoSe_(2)-C@Cu) as an advanced anode for potassium-ion battery(PIBs).The conductive CoSe/CoSe_(2) heterojunction with rich Se vacancy defects,conductive sp^2 N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural ***,the well-designed N-CoSe/CoSe_(2)-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g^(-1) at 0.1 A·g^(-1) after 200cycles),an exceptional rate capability(223.5 mAh·g^(-1) at2000 mA·g^(-1)),and an extraordinary long-term cycle stability(a capacity fading of only 0.019% per cycle over1200 cycles at 2000 mA·g^(-1)).Impressively,ex situ scanning electron microscopy(SEM) characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe_(2)-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process.

关键词： Potassium-ion battery Integrated collector electrode CoSe CoSe_2 Heterojunction Copper foil matrix N-doped carbon

Privacy Protection for Blockchain-Based Healthcare IoT Systems: A Survey

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1757-1776页

作者： Minfeng Qi Ziyuan Wang qing-Long Han jun Zhang Shiping Chen Yang Xiang School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyHawthorn3122VictoriaAustralia Faculty of Data Science City University of MacaoMacaoChina CSIRO Data61 SydneyNew South WalesAustralia

To enable precision medicine and remote patient monitoring,internet of healthcare things(IoHT)has gained significant interest as a promising *** the widespread use of IoHT,nonetheless,privacy infringements such as IoHT data leakage have raised serious public *** the other side,blockchain and distributed ledger technologies have demonstrated great potential for enhancing trustworthiness and privacy protection for IoHT *** this survey,a holistic review of existing blockchain-based IoHT systems is conducted to indicate the feasibility of combining blockchain and IoHT in privacy *** addition,various types of privacy challenges in IoHT are identified by examining general data protection regulation(GDPR).More importantly,an associated study of cutting-edge privacy-preserving techniques for the identified IoHT privacy challenges is ***,several challenges in four promising research areas for blockchain-based IoHT systems are pointed out,with the intent of motivating researchers working in these fields to develop possible solutions.

关键词： Blockchain internet of healthcare things(IoHT) privacy-preserving techniques(PPTs).

Role of adaptation measures in addressing heatwave exposure in China

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Advances in Climate Change Research 2024年第1期15卷 148-157页

作者： Qin-Mei HAN qing-Chen CHAO Shao SUN Pei-jun SHI National Climate Centre China Meteorological AdministrationBeijing 100081China State Key Laboratoryof Severe Weather Chinese Academy of Meteorological Sciences Beijing 0o08lChina Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China

Heatwave exposure has increased dramatically because of climate warming and population growth,along with their interactive ***,effective adaptation measures can reduce these ***,the dynamic changes,regional inequality in adaptive capacity and their potential contributions to reducing exposure in the future remain *** study quantifies the impact of adaptive capacity and underscores regional variations in heatwave magnitudes,population exposure and adaptation levels in *** projected the future adaptive capacity using air-conditioner penetration,factoring in climate cooling requirements and individuals'purchasing *** population and gross domestic product(GDP)data from four Shared Socioeconomic Pathways(SSP1,SSP2,SSP3 and SSP5)and daily temperature data from four SSP-based emission scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0 and SSP5-8.5),we estimated heatwave duration,population exposure and avoided impacts through adaptation across China and its *** show a substantial increase in heatwave duration in Southwest and Southern China,especially under the SSP5-8.5 scenario,with a projection of 163.2±36.7 d during *** the SSP3|SSP3-7.0 scenario,total exposure reaches 156.4±76.8 billion person d per year,which is the highest among all scenarios and 23 times greater than that in 1986-2005 without *** considering adaptation measures,a noteworthy reduction in population exposure is observed,especially in the SSP3|SSP3-7.0 and SSP5JSSP5-8.5 scenarios,with reductions of(62.6±3.9)%and(65.8±5.1)%,respectively,compared with the scenario without adaptation during *** regional disparities in avoided impacts are also evident,with variations of up to 50%across different *** implementation of effective and environmentally friendly adaptation measures can notably address climate change,thereby alleviating the profound threats posed to human well-being.

关键词： Heatwaves Population exposure Adaptation Future projection China

Improving the Short-Range Precipitation Forecast of Numerical Weather Prediction through a Deep Learning-Based Mask Approach

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Advances in Atmospheric Sciences 2024年第8期41卷 1601-1613页

作者： Jiaqi ZHENG qing liNG Jia li Yerong FENG School of Computer Science and Engineering/Guangdong Provincial Key Laboratory of Computational Science Sun Yat-Sen UniversityGuangzhou 510006China School of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction Guangzhou 510641China Shenzhen Institute of Meteorological Innovation Shenzhen 518038China

Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several *** correct the bias of an NWP model and improve the accuracy of short-range precipitation forecasting,we propose a deep learning-based approach called UNet Mask,which combines NWP forecasts with the output of a convolutional neural network called *** UNet Mask involves training the UNet on historical data from the NWP model and gridded rainfall observations for 6-hour precipitation *** overlap of the UNet output and the NWP forecasts at the same rainfall threshold yields a *** UNet Mask blends the UNet output and the NWP forecasts by taking the maximum between them and passing through the mask,which provides the corrected 6-hour rainfall *** evaluated UNet Mask on a test set and in real-time *** results showed that UNet Mask outperforms the NWP model in 6-hour precipitation prediction by reducing the FAR and improving CSI *** tests also showed that different small rainfall thresholds applied to the UNet and the NWP model have different effects on UNet Mask's forecast *** study shows that UNet Mask is a promising approach for improving rainfall forecasting of NWP models.

关键词： deep learning numerical weather prediction(NWP) 6-hour quantitative precipitation forecast

Physics of cavitation near particles

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Journal of Hydrodynamics 2024年第1期36卷 102-118页

作者： Jia-xin Yu Xiao-yu Wang jun-wei Shen Jin-sen Hu Xiang-qing Zhang Da-qing He Yu-ning Zhang Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China

The combined effect of cavitation and silt abrasion presents a great challenge and threat to secure the operation and the efficiency of hydraulic machineries working in sediment-laden *** present paper critically reviews the current research progress on the interaction mechanisms of the bubbles and the ***,the analytical models including boundary treatment methods for predicting the jet dynamics of the bubble collapse near particles are ***,the bubble collapsing dynamics,jet dynamics and shock wave characteristics near particles are revealed both experimentally and ***,the bubble-particle-wall system is investigated with a focus on microjets.

关键词： Cavitation bubble particle jet shock wave

Expression of Mcm7 and Cdc6 and its significance in oral cancer and precancerous lesion

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中国口腔颌面外科杂志 2008年第B5期6卷 142-143页

作者： Chong Jin Feng Hui jun li Gui qing liao Deprtment of Stomatology The First Affiliated Hospital andAffiliated Dental Hospital Sun Yat-sen University Guangzhou510080 China

Purpose: To evaluate the expression of minichromosome maintenance protein7 (Mcm7) and Cell Division Cycle gene 6 (Cdc6) and to determine its significance in oral precancerous lesions and oral squamous cell carcinoma (OSCC)。Methods: Mcm7 and Cdc6 expression was detected by immunochemistry in 10 normal oral mucosa tissues, 34 oral precancerous lesion tissues and 54 OSCC tissues。Then their relationships with the histology, clinical stage and lymph node metastasis were analyzed。Results: Mcm7 was expressed in each kind of tissues。The positive labeling indexes were 3.6% ,22.3% ,45.9% , separately in normal oral mucosa tissues, oral precancerous lesion tissues and OSCC tissues。And there were significant differences among each group (Pling indexes of both Mcm7 and Cdc6 in the group with lymph node metastasis were higher than those in the group without lymph node metastasis (P<0.01)。

关键词：口腔癌治疗方法临床分析癌前病变

Geochronology and Geochemistry of the Xingxingxia Triassic A-type Granites in Central Tianshan,NW China:Petrogenesis and Tectonic Implications

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 337-351页

作者： HUANG Zengbao li Xiyao ZHAO Hao LU qing Geological Survey of Gansu Province Lanzhou 735000China Key Laboratory of Submarine Geosciences and Prospecting Techniques MOE and College of Marine GeosciencesOcean University of ChinaQingdaoShandong 266100China Research Institute of Petroleum Exploration and Development Shengli OilfieldSINOPECDongyingShandong 257000China

The Triassic granitoids in Central Tianshan play a key role in determining the petrogenesis and tectonic evolution on the southern margin of the Central Asian orogenic *** this study,we present SHRIMP zircon U-Pb ages,Hf isotopic and geochemical data on the Xingxingxia biotite granite,amazonite granite and granitic pegmatite in Central Tianshan,NW *** U-Pb dating yielded formation ages of 242 Ma for the biotite granite and 240 Ma for the amazonite *** granitoid rocks have high K_(2)O with low MgO and CaO *** are enriched in Nb,Ta,Hf and Y,while being depleted in Ba and Sr,showing flat HREE patterns and negative Eu *** have typical A-type granite geochemical signatures with high Ga/A_(1)(8–13)and TFeO/(TFeO+MgO)ratios,showing an A_(2) affinity for biotite granite and an A_(1) affinity for amazonite granite and granitic *** ε_(Hf)(t)values of the granitoids are 0.45–2.66,with Hf model ages of 0.99–1.17 *** suggests that these A-type granites originated from partial melting of the lower *** propose that Xingxingxia Triassic A-type granites formed under lithospheric extension from post-orogenic to anorogenic intraplate settings and NE-trending regional strike-slip fault-controlled magma emplacement in the upper crust.

关键词： Triassic A-type granite Xingxingxia Central Tianshan Central Asian orogenic belt

Macroscopic model and statistical model to characterize electromagnetic information of a digital coding metasurface

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National Science Review 2024年第3期11卷 159-171页

作者： Rui Wen Shao jun Wei Wu Zheng Xing Wang Hui Xu Han qing Yang Qiang Cheng Tie jun Cui Institute of Electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University Peng Cheng Laboratory Pazhou Laboratory(Huangpu)

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

关键词： electromagnetic information theory current entropy current space digital coding metasurface macroscopic model statistical model