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Modeling Hydrothermal Transfer Processes in Permafrost Regions of Qinghai-Tibet Plateau in China

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Chinese Geographical Science 2015年第6期25卷 713-727页

作者： hu guojie ZHAO Lin LI Ren WU Tonghua WU Xiaodong PANG Qiangqiang XIAO Yao QIAO Yongping SHI Jianzong Cryosphere Research Station on Qinghai-Xizang Plateau State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Hydrothermal processes are key components in permafrost dynamics; these processes are integral to global warming. In this study the coupled heat and mass transfer model for(Coup Model) the soil-plant-atmosphere-system is applied in high-altitude permafrost regions and to model hydrothermal transfer processes in freeze-thaw cycles. Measured meteorological forcing and soil and vegetation properties are used in the Coup Model for the period from January 1, 2009 to December 31, 2012 at the Tanggula observation site in the Qinghai-Tibet Plateau. A 24-h time step is used in the model simulation. The results show that the simulated soil temperature and water content, as well as the frozen depth compare well with the measured data. The coefficient of determination(R2) is 0.97 for the mean soil temperature and 0.73 for the mean soil water content, respectively. The simulated soil heat flux at a depth of 0–20 cm is also consistent with the monitored data. An analysis is performed on the simulated hydrothermal transfer processes from the deep soil layer to the upper one during the freezing and thawing period. At the beginning of the freezing period, the water in the deep soil layer moves upward to the freezing front and releases heat during the freezing process. When the soil layer is completely frozen, there are no vertical water exchanges between the soil layers, and the heat exchange process is controlled by the vertical soil temperature gradient. During the thawing period, the downward heat process becomes more active due to increased incoming shortwave radiation at the ground surface. The melt water is quickly dissolved in the soil, and the soil water movement only changes in the shallow soil layer. Subsequently, the model was used to provide an evaluation of the potential response of the active layer to different scenarios of initial water content and climate warming at the Tanggula site. The results reveal that the soil water content and the organic layer provide protection against active layer deepening in summer, s

关键词：过程模拟西藏高原高原多年冻土区土壤-植物-大气系统 CoupModel 青海传热传质模型垂直温度梯度

An analytical model for estimating soil temperature profiles on the Qinghai-Tibet Plateau of China

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Journal of Arid Land 2016年第2期8卷 232-240页

作者： hu guojie ZHAO Lin WU Xiaodong LI Ren WU Tonghua XIE Changwei QIAO Yongping SHI Jianzong CHENG Guodong Cryosphere Research Station on Qinghai-Xizang Plateau State Key Laboratory of Cryospheric SciencesCold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Soil temperature is a key variable in the control of underground hydro-thermal processes. To estimate soil temperature more accurately, this study proposed a solution method of the heat conduction equation of soil temperature （improved heat conduction model） by applying boundary conditions that incorporate the annual and diurnal variations of soil surface temperature and the temporal variation of daily temperature amplitude, as well as the temperature difference between two soil layers in the Tanggula observation site of the Qinghai-Tibet Plateau of China. We employed both the improved heat conduction model and the classical heat conduction model to fit soil temperature by using the 5 cm soil layer as the upper boundary for soil depth. The results indicated that the daily soil temperature amplitude can be better described by the sinusoidal function in the improved model, which then yielded more accurate soil temperature simulating effect at the depth of 5 cm. The simulated soil temperature values generated by the improved model and classical heat conduction model were then compared to the observed soil temperature values at different soil depths. Statistical analyses of the root mean square error （RMSE）, the normalized standard error （NSEE） and the bias demonstrated that the improved model showed higher accuracy, and the average values of RMSE, bias and NSEE at the soil depth of 10-105 cm were 1.41℃, 1.15℃ and 22.40%, respectively. These results indicated that the improved heat conduction model can better estimate soil temperature profiles compared to the traditional model.

关键词： soil temperature heat conduction equation daily amplitude boundary condition

Modeling permafrost properties in the Qinghai-Xizang(Tibet) Plateau

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Science China Earth Sciences 2015年第12期58卷 2309-2326页

作者： hu guojie ZHAO Lin WU XiaoDong LI Ren WU Tonghua XIE ChangWei PANG QiangQiang XIAO Yao LI WangPing QIAO YongPing SHI JianZong Cryosphere Research Station on Qinghai-Xizang Plateau State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Water and heat dynamics in the active layer at a monitoring site in the Tanggula Mountains, located in the permafrost region of the Qinghai-Xizang(Tibet) Plateau(QXP), were studied using the physical-process-based COUPMODEL model, including the interaction between soil temperature and moisture under freeze-thaw cycles. Meteorological, ground temperature and moisture data from different depths within the active layer were used to calibrate and validate the model. The results indicate that the calibrated model satisfactorily simulates the soil temperatures from the top to the bottom of the soil layers as well as the moisture content of the active layer in permafrost regions. The simulated soil heat flux at depths of 0 to 20 cm was consistent with the monitoring data, and the simulations of the radiation balance components were reasonable. Energy consumed for phase change was estimated from the simulated ice content during the freeze/thaw processes from 2007 to 2008. Using this model, the active layer thickness and the energy consumed for phase change were predicted for future climate warming scenarios. The model predicts an increase of the active layer thickness from the current 330 cm to approximately 350–390 cm as a result of a 1–2°C warming. However, the effect active layer thickness of more precipitation is limited when the precipitation is increased by 20%–50%. The COUPMODEL provides a useful tool for predicting and understanding the fate of permafrost in the QXP under a warming climate.

关键词：高原冻土西藏青海 CoupModel 活动层厚度高原多年冻土区建模特性

基于DEMATEL-ISM模型的装配式建筑施工质量控制体系的构建

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黑龙江科学 2024年第6期15卷 56-59页

作者：李旺超胡国杰辽宁工业大学辽宁锦州121001

装配式建筑是建筑业的未来发展趋势,其施工质量直接关乎人民群众的利益。为提高装配式建筑施工质量,从人员、材料、机械、方法和环境5个层面分析得到15个影响因素,构建装配式建筑施工质量评价指标体系,基于DEMATEL-ISM模型对各指标之间... 详细信息

装配式建筑是建筑业的未来发展趋势,其施工质量直接关乎人民群众的利益。为提高装配式建筑施工质量,从人员、材料、机械、方法和环境5个层面分析得到15个影响因素,构建装配式建筑施工质量评价指标体系,基于DEMATEL-ISM模型对各指标之间的因果关系进行分析。结果表明,管理人员水平是影响装配式建筑施工质量的主要因素,预制构件存储状况、施工器具误差、预制构件安装方案合理性、工程质量管理环境是影响装配式建筑施工质量的次要因素,根据分析结果为装配式建筑施工质量控制提供合理建议。

关键词：施工质量评价指标体系交叉影响矩阵相乘法 DEMATEL-ISM模型直接影响矩阵

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建筑施工安全风险影响因素模型的构建

黑龙江科学 2024年第8期15卷 106-109页

作者：刘洋阳胡国杰辽宁工业大学辽宁锦州121001

为了降低施工安全风险,通过文献分析和专家访谈,从5个层面确定了15个风险影响因素,构建了DEMATEL-ISM模型,分析各风险因素之间的关系,确定关键性因素,对风险因素进行层级划分。结果表明,安全意识、安全管理、安全规章制度规定和监管力... 详细信息

为了降低施工安全风险,通过文献分析和专家访谈,从5个层面确定了15个风险影响因素,构建了DEMATEL-ISM模型,分析各风险因素之间的关系,确定关键性因素,对风险因素进行层级划分。结果表明,安全意识、安全管理、安全规章制度规定和监管力度为根本因素,施工现场周边环境、设备操作规范、材料质量、材料堆放环境和材料安全防护设施为直接因素,由此提出相应建议。

关键词：建筑施工风险因素 DEMATEL ISM

基于ISM-MICMAC的建筑工程项目成本管理研究

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黑龙江科学 2024年第7期15卷 143-147页

作者：张春美胡国杰辽宁工业大学经济管理学院辽宁锦州121001

建筑工程项目建造过程中的成本管理受诸多因素影响,了解各因素间的内在联系可实现更有效的成本管理。以建筑工程项目为研究对象,通过文献分析法,结合专家访谈确定建筑工程5个阶段共19个成本管理影响因素,借助ISM方法对影响因素进行层级... 详细信息

建筑工程项目建造过程中的成本管理受诸多因素影响,了解各因素间的内在联系可实现更有效的成本管理。以建筑工程项目为研究对象,通过文献分析法,结合专家访谈确定建筑工程5个阶段共19个成本管理影响因素,借助ISM方法对影响因素进行层级划分,分析建筑工程项目成本影响因素间的等级关系与关联路径。利用MICMAC方法分析因素驱动力与依赖性,进一步对影响因素分类。结果显示,独立要素属于多层递阶结构图中的深层因素,其中市场调整与投资决策分析、投资估算精度为根本性因素,设计人员专业水平与设计质量这一因素具有较强驱动力,是成本管理的重点所在。应针对这些影响因素进行改进和优化,以期为建筑施工企业成本管理提供借鉴。

关键词： ISM-MICMAC模型成本管理层级关系建筑工程项目

Secure Transmission in Cognitive Radio Networks Using Full-Duplex Technique with Outdated CSI

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China Communications 2023年第1期20卷 230-245页

作者： Zhihui Shang Tao Zhang guojie hu Yueming Cai Weiwei Yang College of Medical Information Engineering Zunyi Medical UniversityGuizhou 563006China College of Communication Engineering Army Engineering University of PLANanjing 210007China The Sixty-third Research Institute National University of Defense TechnologyNanjing 210007China Department of Communication Engineering Rocket Force University of EngineeringXi’an 710025China

This paper investigates the effects of the outdated channel state information(CSI)on the secrecy performance of an underlay spectrum sharing cognitive radio networks(CRNs),where the secondary user(SU)source node(Alice)aims to transmit the trusted messages to the full-duplex(FD)aided SU receiver(Bob)with the assistance of cooperative relay(Relay).Considering the impact of feedback delay,outdated CSI will aggravate the system performance.To tackle such challenge,the collaborative zero-forcing beamforming(ZFB)scheme of FD technique is further introduced to implement jamming so as to confuse the eavesdropping and improve the security performance of the system.Under such setup,the exact and asymptotic expressions of the secrecy outage probability(SOP)under the outdated CSI case are derived,respectively.The results reveal that i)the outdated CSI of the SU transmission channel will decrease the diversity gain from min(NANR,NRNB)to NRwith NA,NRand NBbeing the number of antennas of Alice,Relay and Bob,respectively,ii)the introduction of FD technique can improve coding gain and enhance system performance.

关键词： cognitive radio network physical layer security full-duplex multiple antennas relay secrecy outage probability outdated CSI

Robust Trajectory and Communication Design for Angle-Constrained Multi-UAV Communications in the Presence of Jammers

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China Communications 2022年第2期19卷 131-147页

作者： Yufang Gao Yang Wu Zhichao Cui Wendong Yang guojie hu Shiming Xu The College of Communications Engineering Army Engineering University of PLANanjing 210007China The College of Communications Engineering Rocket Force University of EngineeringXi’an 710025China

This paper studies a multi-unmanned aerial vehicle(UAV)enabled wireless communication system,where multiple UAVs are employed to communicate with a group of ground terminals(GTs)in the presence of potential jammers.We aim to maximize the throughput overall GTs by jointly optimizing the UAVs’trajectory,the GTs’scheduling and power allocation.Unlike most prior studies,we consider the UAVs’turning and climbing angle constraints,the UAVs’three-dimensional(3D)trajectory constraints,minimum UAV-to-UAV(U2U)distance constraint,and the GTs’transmit power requirements.However,the formulated problem is a mixed-integer non-convex problem and is intractable to work it out with conventional optimization methods.To tackle this difficulty,we propose an efficient robust iterative algorithm to decompose the original problem be three sub-problems and acquire the suboptimal solution via utilizing the block coordinate descent(BCD)method,successive convex approximation(SCA)technique,and S-procedure.Extensive simulation results show that our proposed robust iterative algorithm offers a substantial gain in the system performance compared with the benchmark algorithms.

关键词： anti-jamming angle constraints robust design multi-UAV communications 3D trajectory optimization

The Surface Energy Budget and Its Impact on the Freeze-thaw Processes of Active Layer in Permafrost Regions of the Qinghai-Tibetan Plateau

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Advances in Atmospheric Sciences 2022年第1期39卷 189-200页

作者： Junjie MA Ren LI Hongchao LIU Zhongwei huANG Tonghua WU guojie hu Yao XIAO Lin ZHAO Yizhen DU Shuhua YANG Cryosphere Research Station on the Qinghai-Tibet Plateau State Key Laboratory of Cryospheric ScienceNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou UniversityLanzhou 730000China School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing 210044China

The surface energy budget is closely related to freeze-thaw processes and is also a key issue for land surface process research in permafrost regions.In this study,in situ data collected from 2005 to 2015 at the Tanggula site were used to analyze surface energy regimes,the interaction between surface energy budget and freeze-thaw processes.The results confirmed that surface energy flux in the permafrost region of the Qinghai-Tibetan Plateau exhibited obvious seasonal variations.Annual average net radiation(R_(n))for 2010 was 86.5 W m^(-2),with the largest being in July and smallest in November.Surface soil heat flux(G_(0))was positive during warm seasons but negative in cold seasons with annual average value of 2.7 W m^(-2).Variations in R_(n) and G_(0) were closely related to freeze-thaw processes.Sensible heat flux(H)was the main energy budget component during cold seasons,whereas latent heat flux(LE)dominated surface energy distribution in warm seasons.Freeze-thaw processes,snow cover,precipitation,and surface conditions were important influence factors for surface energy flux.Albedo was strongly dependent on soil moisture content and ground surface state,increasing significantly when land surface was covered with deep snow,and exhibited negative correlation with surface soil moisture content.Energy variation was significantly related to active layer thaw depth.Soil heat balance coefficient K was>1 during the investigation time period,indicating the permafrost in the Tanggula area tended to degrade.

关键词： Qinghai-Tibetan Plateau permafrost energy budget freeze-thaw process thawing depth