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Tradeoff between productivity and stability across above-and below-ground communities

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Journal of Integrative Plant Biology 2024年第11期66卷 2321-2324页

作者： Zonghao Hu Haiyan Liu Junjie Yang Bin Hua Michael Bahn Shuang Pang Tingting Li Wei Yang Honghui Wu Xingguo Han Ximei Zhang State Key Laboratory of Efﬁcient Utilization of Agricultural Water Resources Institute of Environment and Sustainable Development in AgricultureChinese Academy of Agricultural SciencesBeijing 100081China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China College of Forestry Henan Agricultural UniversityZhengzhou 450002China Department of Ecology University of InnsbruckInnsbruck 6020Austria State Key Laboratory of Efﬁcient Utilization of Arid and Semi-arid Arable Land in Northern China Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China Key Laboratory of Arable Land Quality Monitoring and Evaluation Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China

Because of the aggravated agricultural fertilization and combustion of fossil fuels,the nitrogen(N)deposition rate has increased from the pre-industrial levels of about 0.1–0.3 to as high as 10 g N m^(-2)year^(-1)in some developed countries,and it is predicted to increase similarly over the next 50 years in many developing countries(Galloway et al.,2004).

关键词： Trade stability ground

Variational-Iterative Solution of ground State for Central Potential

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Communications in Theoretical Physics 2002年第7期38卷 15-18页

作者： ZHAO Wei-Qin China Center of Advanced Science and Technology CCAST World Lab. P.O. Box 8730 Beijing 100080 China Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 9184-1 Beijing 100039 China

The newly developed iterative method based on Green function defined by quadratures along a single trajectory is combined with the variational method to solve the ground state quantum wave function for central *** an example, the method is applied to discuss the ground state solution of Yukawa potential, using Hulthen solution as the trial function.

关键词： iterative solution, variantional method, ground state

Guest editorial-special issue on ground control in mining in 2018

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International Journal of Mining Science and Technology 2019年第1期29卷 1-2页

作者： Michael M.Murphy Ted Klemetti Heather Lawson Brijes Mishra Kyle Perry Pittsburgh Mining Research Division NIOSH Spokane Mining Research Division NIOSH Mining Engineering West Virginia University Mining&Nuclear Engineering Missouri S&T

ground control is the science of studying and controlling the behavior of rock strata in response to mining operations. ground control-related research has seen significant advancements over the last 37 years, and these accomplishments are well documented in the proceedings of the annual International Conference on ground Control in Mining (ICGCM)(1)The ICGCM is a forum to promote closer communication among researchers, consultants。

关键词： NIOSH Guest editorial-special issue on ground control in mining in 2018

ground Temperature-increase Anomalies Before 1976 Tangshan Earthquake

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Chinese Science Bulletin 1993年第11期38卷 940-946页

作者：强祖基徐秀登赁常恭王弋平 Institute of Geology State Seismological BureauBeijing 100029 PRC Department of Geography Zhejiang Normal University Jinhua 321004 PRC Satellite Meteorological Center State Meteorological Administration Beijing 100081 PRC Institute of Geology State Seismological Bureau Beijing 100029 PRC

Earthquakes are the results of rapid tectonic motion and last release of strain energy. Heat is the general expression of various motions and energies. The comprehensive analysis on the data of the ground temperature and satellite thermal infrared pattern of more than 20 earthquakes with M_s>5.0 that occurred in China since 1989 shows that there

关键词： Tangshan earthquake ground temperature-increase anomalies plate movement.

Heating performance of a ground source heat pump system installed in a school building

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Science China(Technological Sciences) 2010年第1期53卷 80-84页

作者： Jaedo SONG Kwangho LEE Youngman JEONG Seongir CHEONG Jaekeun LEE Yujin HWANG Yeongho LEE Donghyuk LEE School of Mechanical Engineering Pusan National UniversitySan 30Jangjeon DongGeumjeong GuBusan 609-735Pepublic of Korea LG Electronics 391-2 Gaeumjeong-dongChangwon CityGyeongnam 641-711Pepublic of Korea

The heating performance of a water-to-refrigerant type ground source heat pump system is represented in this paper under the actual working conditions of the GSHP(ground source heat pump) system during the winter season of *** heat pump equipments with the capacity of 10 HP each and a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth were *** investigated a variety of working conditions,including the outdoor temperature,the ground temperature,and the water temperature of inlet and outlet of the ground heat exchanger in order to examine the heating performance of the GSHP ***,the heating capacity and the input power were investigated to determine the heating performance of the GSHP *** average heating coefficient of performance(COP) of the heat pump was noted to be 5.1 at partial load of 47%,while the overall system COP was found to be ***,performance of the GSHP system was compared with that of air source heat pump.

关键词： ground source heat pump(GSHP) water-to-refrigerant heating performance coefficient of performance(COP) air source heat pump(ASHP)

A New Method of Desired Gait Synthesis for Biped Walking Robot Based on ground Reaction Force

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High Technology Letters 2000年第4期6卷 33-38页

作者：张永学 Harbin Inst of Technology Harbin China

A new method of desired gait synthesis for biped walking robot based on the ground reaction force was proposed. The relation between the ground reaction force and joint motion is derived using the D’Almbert principle. In view of dynamic walking with high stability, the ZMP(Zero Moment Point)stability criterion must be considered in the desired gait synthesis. After that, the joint trajectories of biped walking robot are decided by substituting the ground reaction force into the aforesaid relation based on the ZMP criterion. The trajectory of desired ZMP is determined by a fuzzy logic based upon the body posture of biped walking robot. The proposed scheme is simulated and experimented on a 10 degree of freedom biped walking robot. The results indicate that the proposed method is feasible.

关键词： Biped walking robot Desired gait synthesis ZMP ground reaction force Fuzzy logic

Walking Stability Control Method for Biped Robot on Uneven ground Based on Deep Q-Network

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Journal of Beijing Institute of Technology 2019年第3期28卷 598-605页

作者： Baoling Han Yuting Zhao Qingsheng Luo School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China School of Mechatronic Engineering Beijing Institute of TechnologyBeijing 100081China

A gait control method for a biped robot based on the deep Q-network (DQN) algorithm is proposed to enhance the stability of walking on uneven ground. This control strategy is an intelligent learning method of posture adjustment. A robot is taken as an agent and trained to walk steadily on an uneven surface with obstacles, using a simple reward function based on forward progress. The reward-punishment (RP) mechanism of the DQN algorithm is established after obtaining the offline gait which was generated in advance foot trajectory planning. Instead of implementing a complex dynamic model, the proposed method enables the biped robot to learn to adjust its posture on the uneven ground and ensures walking stability. The performance and effectiveness of the proposed algorithm was validated in the V-REP simulation environment. The results demonstrate that the biped robot's lateral tile angle is less than 3° after implementing the proposed method and the walking stability is obviously improved.

关键词： deep Q-network (DQN) biped robot uneven ground walking stability gait control

Discussions on rockburst and dynamic ground support in deep mines

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第5期11卷 1110-1118页

作者： Charlie C.Li Peter Mikula Brad Simser Bruce Hebblewhite William Joughin Xiaowei Feng Nuwen Xu Norwegian University of Science and Technology (NTNU) Trondheim Norway Mikula Geotechnics Pty. Ltd. Kalgoorlie Australia Glencore Company Sudbury Canada The University of New South Wales (UNSW) Sydney Australia SRK Consulting Johannesburg South Africa China University of Mining and Technology Xuzhou China Sichuan University Chengdu China

The paper is a summary of discussions on four topics in rockburst and dynamic ground *** 1 is the mechanisms of *** events are classified into two categories in accordance with the triggering mechanisms,*** burst and fault-slip *** burst occurs on rock surfaces when the tangential stress exceeds the rock strength in hard and brittle ***-slip burst is triggered by fault-slip induced *** 2 is prediction and forecasting of rockburst *** for a rockburst event must tell the location,timing and magnitude of the *** could simply foresee the probability of some of the three *** is extremely challenging to predict rockbursts and large seismic events with current knowledge and technologies,but forecasting is possible,for example the possible locations of strain burst in an underground *** present,the approach using seismic monitoring and numerical modelling is a promising forecasting *** 3 is preconditioning *** current preconditioning methods are blasting,relief-hole drilling and *** fault-slip seismicity is difficult and challenging but has been *** very deep locations(>3000 m),the fracturing could extend from the excavation face to a deep location ahead of the face and therefore preconditioning is usually not *** 4 is dynamic ground support against *** ground support requires that the support system be strong enough to sustain the momentum of the ejecting rock on one hand and tough enough on the other hand to absorb the strain and seismic energies released from the rock *** current dynamic support systems in underground mining are composed of yielding tendons and flexible surface retaining elements like mesh/screen and *** props and engineered timber props are also used for dynamic support.

关键词： Rockburst Seismic event Dynamic ground support Forecasting Preconditioning

A ground HYDROLOGIC MODEL WITH INCLUSION OF A LAYER OF VEGETATION CANOPY THAT CAN INTERACT WITH GENERAL CIRCULATION MODEL

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Science China Chemistry 1990年第3期33卷 334-344页

作者：孙(艹叔)芬卢志泊 Institute of Mechanics Academia Sinica Beijing 100080 PRC

In this paper, a ground hydrologic model(GHM) is presented in which the vapor, heat and momentum exchanges between ground surface covers (including vegetation canopy) and atmosphere is described more realistically. The model is used to simulate three sets of field data and results from the numerical simulation agree with the field data well. GHM has been tested using input data generated by general circulation model (GCM) runs for both the North American regions and the Chinese regions, The results from GHM are quite different from those of GHMs in GCMs. It shows that a more active concerted effort on the land surface process study to provide a physically realistic GHM for predicting the exchange between land and atmosphere is important and necessary.

关键词： general circulation model (GCM) ground hydrolosic model (GHM) heat and vapor exchange between land and atmosphere.