检索结果-南通市图书馆

Assessing effectiveness of nature-based solution with big earth data:60 years mangrove plantation program in Bangladesh coast

引用

Ecological Processes 2023年第1期12卷 165-192页

作者： Riffat Mahmood Li Zhang guoqing Li Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100094China College of Resources and Environmental Studies University of Chinese Academy of SciencesBeijing 100094China Department of Geography and Environment Faculty of Life and Earth SciencesJagannath UniversityDhaka 1100Bangladesh International Research Center of Big Data for Sustainable Development Goals Beijing 100094China

Background In the climate change context,nature-based solution(NBS)is considered one of the effective tools to increase the resilience of socio-ecological *** concept coincides with the government’s attempts of afforestation and reforestation programs that have been going on for 60 years in *** study,therefore,envisaged understanding how NBS(mangrove afforestation and reforestation)works to promote climate change resilience through the synthetization of remote sensing-based big earth data,statistical tools,and *** study took the entire coast of Bangladesh except for Sundarbans Reserve Forest and rolled back to 1962 to work on 60 years’time series *** CORONA satellite imagery along with Landsat satellite imagery was used,which is the first-ever attempt in the remote sensing-based ecosystem work in *** The study’s main innovation is to spatially establish the effectiveness of the *** study critically assessed and estimated stable lands and their socio-economic benefits as part of the effectiveness of the *** part of the NBS-derived benefits in the context of climate change,it estimated the sequestrated carbon in mangrove forests.A significant positive relationship was observed between the increase of mangroves and stable *** about 448,011 ha of agricultural land was stabilized due to the NBS intervention whose economic value is 18,837 million *** addition,29,755.71 kt of carbon have been sequestrated due to NBS *** The concept of NBS is still in the development stage and very little or no work has been done so far in measuring and labeling the effectiveness of the ***,our study can innovatively contribute to the scientific community to show the effectiveness of the NBS in three domains(social,economic and ecological)in the changing climatic scenario.

关键词： Nature-based solution(NBS) Mangrove afforestation program Coast Geographic Information System Remote sensing CORONA satellite image Land stabilization Sequestrated carbon Climate change

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Small interplanetary magnetic flux rope

引用

Science China(Technological Sciences) 2020年第2期63卷 183-194页

作者： FENG HengQiang ZHAO guoqing WANG JieMin Institute of Space Physics Luoyang Normal UniversityLuoyang 471934China Henan Key Laboratory of Electromagnetic Transformation and Detection Luoyang Normal UniversityLuoyang 471934China

Small interplanetary magnetic flux ropes(SIMFRs) are often detected by space satellites in the interplanetary space near 1 *** ropes can be fitted by a cylindrically symmetric magnetic model. The durations of SIMFRs are usually 700 km/s). Some SIMFRs demonstrate abnormal heavy ion compositions, such as abnormally high He abundance, abnormally high average iron ionization, and enhanced O7+abundance. These SIMFRs originate from remarkably hot coronal origins. Approximately 74.5% SIMFRs exhibit counterstreaming suprathermal electron signatures. Given their flux rope configuration, SIMFRs are potentially more effective for substorms. SIMFRs and magnetic clouds have many similar observational properties but also show some different *** similar properties may indicate that SIMFRs are the interplanetary counterparts of small coronal mass ejections. Some direct bodies of evidence have confirmed that several SIMFRs are interplanetary counterparts of CMEs. However, their different properties may imply that some SIMFRs have interplanetary origins. Therefore, one of the main aims of future research on SIMFRs is to determine whether SIMFRs originate from two different sources, that is, some events are formed in the solar coronal atmosphere, whereas others originate from the interplanetary space. Finally, in this paper, we offer some prospects that should be addressed in the future.

关键词： magnetic flux ropes magnetic cloud coronal mass ejection heliospheric current sheet

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Coordination Control Method for Preventing Sub/Super Synchronous Oscillations of Multi-wind Farm Systems

引用

CSEE Journal of Power and Energy Systems 2023年第5期9卷 1655-1665页

作者： guoqing He Weisheng Wang Haijiao Wang China Electric Power Research Institute Beijing 100192China

In recent years,sub/super-synchronous oscillations occur frequently in large-scale wind power bases throughout *** the oscillation frequencies are close to the fundamental frequency,the current components can spread over a large area,and may destroy the shafting of rotating devices in the power *** the control strategy and parameters of wind turbines can prevent this problem to some extent,however,due to complex operational conditions and continuous development of wind power,the off-line improvement measures on wind turbines cannot eliminate the potential oscillation *** paper proposes an oscillation risk screening and stability assessment method,and develops a coordination control method for large-scale wind farm systems to prevent sub/supersynchronous *** Nyquist criterion and the modal analysis method are combined to generate quantitative factors for the stability assessment and the control strategy *** coordination control method consists of minute-level power coordinated allocation and second-level fast power control to prevent and eliminate the oscillations.A detailed simulation model of a multiple wind farms system originated from an actual wind power base in China is presented to verify the effectiveness of the proposed method.

关键词： Coordination control prevention sequence impedance sub/super-synchronous oscillations wind farm

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Non-centrosymmetric topological phase probed by non-linear Hall effect

引用

National Science Review 2024年第6期11卷 180-188页

作者： Naizhou Wang Jing-Yang you Aifeng Wang Xiaoyuan Zhou Zhaowei Zhang Shen Lai Yuan-Ping Feng Hsin Lin guoqing Chang Wei-bo Gao Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Department of Physics National University of Singapore Low Temperature Physics Laboratory College of Physics and Center for Quantum Materials and Devices Chongqing University Centre for Advanced 2D Materials National University of Singapore Institute of Physics Academia Sinica The Photonics Institute and Centre for Disruptive Photonic Technologies Nanyang Technological University

Non-centrosymmetric topological material has atracted intense atention due to its superior characteristics as compared with the centrosymmetric one, although probing the local quantum geometry in non-centrosymmetric topological material remains challenging. The non-linear Hall（NLH） effect provides an ideal tool to investigate the local quantum geometry. Here, we report a non-centrosymmetric topological phase in ZrTe5, probed by using the NLH effect. The angle-resolved and temperature-dependent NLH measurement reveals the inversion and ab-plane mirror symmetries breaking at <30 K, consistently with our theoretical calculation. Our findings identify a new non-centrosymmetric phase of ZrTe5and provide a platform to probe and control local quantum geometry via crystal symmetries.

关键词： non-linear Hall effect topological insulator ZrTe5

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Suicide Prevention:More Actions Are Needed

引用

China CDC weekly 2023年第25期5卷 545-546页

作者： guoqing Hu Department of Epidemiology and Health Statistics Hunan Provincial Key Laboratory of Clinical EpidemiologyXiangya School of Public HealthCentral South UniversityChangsha CityHunan ProvinceChina National Clinical Research Center for Geriatric Disorders(Xiangya Hospital) Central South UniversityChangsha CityHunan ProvinceChina

Suicide has long been a significant global public health ***,approximately 800,000 individuals succumb to suicide worldwide,resulting in more fatalities than those caused by malaria,breast cancer,or war and homicide(1).A striking 79%of these suicide-related deaths transpire in low-and middle-income countries(LMICs)(1).Remarkably,suicide ranks as the second leading cause of death among young individuals aged 15–29 years for both males and females,with 90%of adolescents who died by suicide originating from LMICs(1).

关键词： Suicide death striking

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Online Learning Control for Hybrid Electric Vehicle

引用

Chinese Journal of Mechanical Engineering 2012年第1期25卷 98-106页

作者： LI Weimin XU guoqing XU Yangsheng Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055China Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

Improvements in hybrid electric vehicle (HEV) fuel economy and emissions heavily depend on an efficient energy management strategy (EMS). However, the uncertainty of future driving conditions generally cannot be easily tackled in EMS design. Most existing EMSs act upon fixed parameters and cannot adapt to varying driving conditions. Therefore, they usually fail to fully explore the potential of these advanced vehicles. In this paper, a novel EMS design procedure based on neural dynamic programming (NDP) is proposed. The NDP is a generic online learning algorithm, which combines stochastic dynamic programming (SDP) and the temporal difference (TD) method. Instead of computing the utility function and optimal control actions through Bellman equations, the NDP algorithm uses two neural networks to approximate them. The weights of these neural networks are updated online by the TD method. It avoids the high computational cost that SDP suffers from and is suitable for real-time implementation. The main advantages of NDP EMS is that it does not rely on prior information related to future driving conditions, and can self-tune with a wide variance in operating conditions. The NDP EMS has been applied to “Qianghua-I”, a prototype of a parallel HEV, using a revolving drum test bench for verification. Experiment results illustrate the potential of the proposed EMS in terms of fuel economy and in keeping state of charge (SOC) deviations at a low level. The proposed research ensures the optimality of NDP EMS, as well as real-time applicability.

关键词： hybrid electric vehicle neural dynamic programming energy management strategy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

27.3-day and 13.6-day atmospheric tide

引用

Science China Earth Sciences 2007年第9期50卷 1380-1395页

作者： LI guoqing ZONG HaiFeng Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

An analysis of time variations in the earth's length of day (LOD) for 25 years (1973-1998) versus at- mospheric circulation changes and lunar phase is presented. It is found that, on the average, there is a 27.3-day and 13.6-day period oscillation in global zonal wind speed, atmospheric geopotential height, and LOD following alternating changes in lunar phase. Every 5-9 days (6.8 days on average), the fields of global atmospheric zonal wind and geopotential height and LOD undergo a sudden change in rela- tion to a change in lunar declination. The observed atmospheric oscillation with this time period may be viewed as a type of atmospheric tide. Ten atmospheric tidal cases have been analyzed by comparing changes in LOD, global zonal wind speed and atmospheric geopotential height versus change in lunar declination. Taken together these cases reveal prominent 27.3-day and 13.6-day tides. The lunar forcing on the earth's atmosphere is great and obvious changes occur in global fields of zonal wind speed and atmospheric geopotential height over the equatorial and low latitude areas. The driving force for the 27.3-day and 13.6-day atmospheric tides is the periodic change in lunar forcing during the moon's revolution around the earth. When the moon is located on the celestial equator the lunar declination equals zero and the lunar tidal forcing on the atmosphere reaches its maximum, at this time the global zonal wind speed increases and the earth's rotation rate decreases and LOD increases. Conversely, when the moon reaches its most northern or southern positions the lunar declination is maximized, lunar tidal forcing decreases, global zonal wind speed decreases, earth's rotation rate increases and LOD decreases. 27.3-day and 13.6-day period atmospheric tides deserve deeper study. Lunar tidal forcing should be considered in models of atmospheric circulation and in short and medium range weather forecasting.

关键词： atmospheric tide, earth's rotation, subseasonal oscillation, atmospheric circulation, lunar forcing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Adaptive robust cubature Kalman filtering for satellite attitude estimation

引用

Chinese Journal of Aeronautics 2018年第4期31卷 806-819页

作者： Zhenbing QIU Huaming QIAN guoqing WANG College of Automation Harbin Engineering University

This paper is concerned with the adaptive robust cubature Kalman filtering problem for the case that the dynamics model error and the measurement model error exist simultaneously in the satellite attitude estimation system. By using Hubel-based robust filtering methodology to correct the measurement covariance formulation of cubature Kalman filter, the proposed filtering algorithm could effectively suppress the measurement model error. To further enhance this effect and reduce the impact of the dynamics model error, two different adaptively robust filtering algorithms,one with the optimal adaptive factor based on the estimated covariance matrix of the predicted residuals and the other with multiple fading factors based on strong tracking algorithm, are developed and applied for the satellite attitude estimation. The quaternion is employed to represent the global attitude parameter, and three-dimensional generalized Rodrigues parameters are introduced to define the local attitude error. A multiplicative quaternion error is derived from the local attitude error to maintain quaternion normalization constraint in the filter. Simulation results indicate that the proposed novel algorithm could exhibit higher accuracy and faster convergence compared with the multiplicative extended Kalman filter, the unscented quaternion estimator, and the adaptive robust unscented Kalman filter.

关键词： Attitude estimation Cubature Kalman filter Multiple fading factors Optimal adaptive factor Robust filtering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Parametric analyses on dynamic stall control of rotor airfoil via synthetic jet

引用

Chinese Journal of Aeronautics 2017年第6期30卷 1818-1834页

作者： Qijun ZHAO Yiyang MA guoqing ZHAO National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

The effects of synthetic jet control on unsteady dynamic stall over rotor airfoil are investigated numerically. A moving-embedded grid method and an Unsteady Reynolds Averaged Navier-Stokes（URANS） solver coupled with k-x Shear Stress Transport（SST） turbulence model are established for predicting the complex flowfields of oscillatory airfoil under jet control. Additionally, a velocity boundary condition modeled by sinusoidal function has been developed to fulfill the perturbation effect of periodic jet. The validity of present CFD method is evaluated by comparisons of the calculated results of baseline dynamic stall case for rotor airfoil and jet control case for VR-7 B airfoil with experimental data. Then, parametric analyses are conducted emphatically for an OA212 rotor airfoil to investigate the effects of jet control parameters（jet location, dimensionless frequency, momentum coefficient, jet angle, jet type and dual-jet） on dynamic stall characteristics of rotor airfoil. It is demonstrated by the calculated results that efficiency of jet control could be improved with specific momentum coefficient and jet angle when the jet is located near separation point of rotor airfoil. Furthermore, the dual-jet could improve control efficiency more obviously on dynamic stall of rotor airfoil with respect to the unique jet, and the influence laws of dual-jet＇s angles and momentum coefficients on control effects are similar to those of the unique jet. Finally,unsteady aerodynamic characteristics of rotor via synthetic jet which is located on the upper surface of rotor blade in forward flight are calculated, and as a result, the aerodynamic characteristics of rotor are improved compared with the baseline. The results indicate that synthetic jet has the capability in improving aerodynamic characteristics of rotor.

关键词： Airfoil Dynamic stall characteristics:Flow control Moving-embedded gridmethodology Navier-Stokes equations Parametric analyses Rotor Synthetic jet

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microstructure and wear properties of the electroslag remelting layer reinforced by TiC particles

引用

Journal of University of Science and Technology Beijing 2008年第6期15卷 769-774页

作者： Qianlin Wu Yangshan Sun guoqing Li School of Material Science and Engineering Southeast University Nanjing 211189 China

The electroslag remelting （ESR） layer reinforced by TiC particles was obtained by electroslag remelting. The microstructure and wear properties of the ESR layer were studied by means of scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and wear test. The results indicate that TiC particles are synthesized by self-propagating high-temperature synthesis （SHS） reaction during the electroslag remelting process. The size of TiC particles is in the range of 1-10 μm, and the distribution of TiC particles is uniform, from outside to inside of the ESR layer, and the volume fraction and the size of TiC particles decrease gradually. Molten iron and slag flow into porosity due to the SHS process leading to rapid densification and the elimination of porosity in the ESR layer during the ESR process. TiC particles enhance the wear resistance of the ESR layer, whereas CaF2 can improve the high temperature lubricating property of the ESR layer.

关键词： electroslag remelting (ESR) TiC particles porosity wear resistance lubricating property

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：