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Numerical Simulation Study of a Novel Horizontally Layered Enhanced Geothermal System:A Case Study of the Qiabuqia Geothermal Area,Qinghai Province,China

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Journal of Thermal Science 2021年第4期30卷 1328-1340页

作者： gao kun LIU Weiqun MA Tianran HU Yang FANG Tian YE Lei School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China

Hot dry rock,as a renewable and sustainable energy source,can alleviate resource shortages and environmental *** on data from the Qiabuqia geothermal field and an established thermal-hydrological-mechanical coupled mathematical model,a novel horizontally layered enhanced geothermal system(EGS)is proposed and compared with the conventional double vertical well *** the simulated conditions in this paper,the comprehensive heat recovery performance of the horizontally layered EGS is significantly better than that of the double vertical well ***,although the average production temperature of the double vertical well EGS is higher than that of the horizontally layered EGS in the attenuation stage,the heat power output of the horizontally layered EGS ranges from 6.10 MW to 12.25 MW,which is 1.36 to 1.67 times that of the double vertical well ***,the heat recovery rate of the horizontally layered EGS is 6.63%higher than that of the double vertical well EGS and is thus more ***,parametric analysis was performed to investigate the influence of the controllable parameters on heat recovery for the horizontally layered *** heat power output and heat extraction ratio are proportional to the pressure difference and well spacing and inversely proportional to the injection fluid *** thermal power output is most greatly influenced by the pressure difference,followed by the well spacing and injection fluid *** effects of the pressure difference and well spacing on the heat recovery rate are almost the same,and the injection fluid temperature has no effect.

关键词： hot dry rock enhanced geothermal system thermal-hydrological-mechanical coupling numerical simulation parameter analysis

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Hot pressing sintering process and sintering mechanism of W-La_(2)O_(3)-Y_(2)O_(3)-ZrO_(2)

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Rare Metals 2021年第7期40卷 1949-1956页

作者： Bao-Gang Fu Jian-Can Yang Zhi-kun gao Zuo-Ren Nie College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China

The W-La_(2)O_(3)-Y_(2)O_(3)-ZrO_(2)materials were prepared by vacuum hot pressing sintering *** microstructure was characterized by scanning electron microscopy(SEM).The effects of sintering temperature,sintering pressure,holding time and heating rate on relative density,hardness and microstructure were *** sintering activation energy of the powder was *** on the result,the best sintering parameters by vacuum hot pressing sintering are as follows:sintering temperature of 1600℃,sintering pressure of 60 MPa and holding time of 60 *** heating rate is 10℃·min^(-1)from room temperature to 1000℃and 4℃·min^(-1)from1000 to 1600℃.Using this process,the grain size is about3 lm in diameter with relative density at 99.7%,and the hardness is HV *** sintering characteristic index(n)of the specimen is 4,and the sintering mechanism mainly depends on the diffusion from the surface to the intragranular in the volume *** sintering activation energy of W-La_(2)O_(3)-Y_(2)O_(3)-ZrO_(2)material is286.2 k J·mol^(-1),which indicates that the powder has higher activity in sintering process.

关键词： W-La_(2)O_(3)-Y_(2)O_(3)-ZrO_(2) Hot pressing sintering Relative density Tungsten electrode Sintering mechanism

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Two New Butenolide Derivatives from Erigeron acer

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Chemical Research in Chinese Universities 2006年第1期22卷 33-35页

作者： WU Gang FEI Dong-qing gao kun State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000 P.R. China

Two new butenolide derivatives, named as erigeracerin A and efigeracefin B, which are a pair of epimers, were isolated from Erigeron acer. Their structures were elucidated by spectroscopic analysis including 2D NMR an... 详细信息

关键词： Erigeron acer Compositae Erigeracerin Butenolide derivatives

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Multisensor information fusion:Future of environmental perception in intelligent vehicles

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Journal of Intelligent and Connected Vehicles 2024年第3期7卷 163-176页

作者： Yongsheng Zhang Chen Tu kun gao Liang Wang CRRC Qishuyan Institute Co. Ltd.Changzhou 213011China School of Information Science and Engineering Southeast UniversityNanjing 211189China Department of Architecture and Civil Engineering Chalmers University of TechnologyGothenburg SE-41296Sweden School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China

As urban transportation increasingly impacts daily life,efficiently utilizing traffic resources and developing public transportation have become crucial for addressing issues such as congestion,frequent accidents,and noise *** rapid advancement of intelligent autonomous driving technologies,particularly environmental perception technologies,offers new directions for solving these *** review discusses the application of multisensor information fusion technology in environmental perception for intelligent vehicles,analyzing the components and performance of various sensors and their specific applications in autonomous *** multisensor information fusion,the accuracy of environmental perception is enhanced,optimizing decision support for autonomous driving systems and thereby improving vehicle safety and driving *** study also discusses the challenges faced by information fusion technology and future development trends,providing references for further research and application in intelligent transportation systems.

关键词： intelligent vehicles environmental perception multisensor information fusion autonomous driving traffic safety

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Evaluation of Genetic and Epigenetic Modification in Rapeseed(Brassica napus)Induced by Salt Stress

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Journal of Integrative Plant Biology 2007年第11期49卷 1599-1607页

作者： Guangyuan Lu Xiaoming Wu Biyun Chen Guizhen gao kun Xu Brassica Germplasm Division Oil Crops Research Institute Chinese Academy of Agricultural Science Wuhan 430062 China

Salinity is an important limiting environmental factor for rapeseed production worldwide. In this study, we assessed the extent and pattern of DNA damages caused by salt stress in rapeseed plants. Amplified fragment length polymorphism （AFLP） analysis revealed dose-related increases in sequence alterations in plantlets exposed to 10-1000 mmol/L sodium chloride. In addition, individual plantlets exposed to the same salt concentration showed different AFLP and selected region amplified polymorphism banding patterns. These observations suggested that DNA mutation in response to salt stress was random in the genome and the effect was dose-dependant. DNA methylation changes in response to salt stress were also evaluated by methylation sensitive amplified polymorphism （MSAP）. Three types of MSAP bands were recovered. Type Ⅰ bands were observed with both isoschizomers Hpa Ⅱ and Msp Ⅰ, while type Ⅱ and type Ⅲ bands were observed only with Hpa Ⅱ and Msp Ⅰ, respectively. Extensive changes in types of MSAP bands after NaCI treatments were observed, including appearance and disappearance of type Ⅰ, Ⅱ and Ⅲ bands, as well as exchanges between either type Ⅰand type Ⅱ or type Ⅰ and type Ⅲ bands. An increase of 0.2-17.6% cytosine methylated CCGG sites were detected in plantlets exposed to 10- 200 mmol/L salt compared to the control, and these changes included both de novo methylation and demethylation events. Nine methylation related fragments were also recovered and sequenced, and one sharing a high sequence homology with the ethylene responsive element binding factor was identified. These results demonstrated clear DNA genetic and epigenetic alterations in planUets as a response to salt stress, and these changes may suggest a mechanism for plants adaptation under salt stress.

关键词： Brassica napus DNA-methylation genetic variation methylation sensitive amplified polymorphism salt stress.

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Preparation and characterization of Al/B/Fe_2O_3 nanothermites

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Science China Chemistry 2014年第6期57卷 797-802页

作者： SHEN LianHua LI GuoPing LUO YunJun gao kun GE Zhen School of Materials and Engineering Beijing Institute of Technology

A sol-gel synthetic approach combined with an ultrasonic method was utilized to prepare Al/B/Fe2O3 *** structure and properties of the prepared nanothermites were characterized by thermogravimetric analysis,differential scanning calorimetry,scanning electron microscopy,X-ray diffraction,and an impact sensitivity *** results verified that the nano-aluminum and the micro-boron were uniformly dispersed in the pores of the iron oxide *** heat of the prepared Al/B/Fe2O3 nanothermites was 1.3 times that of the simple physically mixed *** addition,the heat of the combustion test showed that these materials were indeed ***-scale safe experiments also showed that the prepared materials through sol-gel were relatively insensitive to standard impact.

关键词： sol-gel nanothermites energetic materials properties

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Characteristic mode analysis of wideband high-gain and low-profile metasurface antenna

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Chinese Physics B 2021年第6期30卷 275-281页

作者： kun gao Xiang-Yu Cao Jun gao Huan-Huan Yang Jiang-Feng Han Information and Navigation College of Air Force Engineering University Xi'an 710077China

A wideband high-gain and low-profile metasurface antenna is proposed by analyzing characteristic quantities and parameters in the characteristic modes(CMs). The detailed modal current and modal weighting coefficient are analyzed to explain the broadband operation and high gain. A dominant characteristic mode is well excited, leading to a broadband operation. The mode behaviors of the excitation are changed to suppress the unwanted higher-order modes and improve the radiation performance by changing the widths of two patches. The measured impedance bandwidth for-10 dB is 39.8%(5.3 GHz–7.94 GHz) with a gain of 7.8 dBi–10.04 dBi over the operating bandwidth.

关键词： characteristic mode analysis wideband high gain metasurface antenna

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Revealing driver psychophysiological response to emergency braking in distracted driving based on field experiments

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Journal of Intelligent and Connected Vehicles 2022年第3期5卷 270-282页

作者： Ying Li Li Zhao kun gao Yisheng An Jelena Andric School of Information Engineering Chang’an UniversityXi’anChina Nebraska Transportation Center University of Nebraska-LincolnLincolnNebraskaUSA Department of Architecture and Civil Engineering Chalmers University of TechnologyGothenburgSweden Volvo Group Trucks Technology GothenburgSweden

Purpose–The purpose of this paper is to characterize distracted driving by quantifying the response time and response intensity to an emergency stop using the driver’s physiological ***/methodology/approach–Field tests with 17 participants were conducted in the connected and automated vehicle test *** participants were required to prioritize their primary driving tasks while a secondary nondriving task was asked to be *** data,vehicle trajectory data and various physiological data were recorded through a biosignalsplux signal data acquisition toolkit,such as electrocardiograph for heart rate,electromyography for muscle strength,electrodermal activity for skin conductance and force-sensing resistor for braking ***–This study quantified the psychophysiological responses of the driver who returns to the primary driving task from the secondary nondriving task when an emergency *** results provided a prototype analysis of the time required for making a decision in the context of advanced driver assistance systems or for rebuilding the situational awareness in future automated vehicles when a driver’s take-over maneuver is ***/value–The hypothesis is that the secondary task will result in a higher mental workload and a prolonged reaction ***,the driver states in distracted driving are significantly different than in regular driving,the physiological signal improves measuring the brake response time and distraction levels and brake intensity can be expressed as functions of driver *** the best of the authors’knowledge,this is the first study using psychophysiological measures to quantify a driver’s response to an emergency stop during distracted driving.

关键词： Mobile phones Driver distraction Emergency braking Psychophysiological Response time Psychophysiological measure

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Modified B-ultrasound method for measurement of antral section only to assess gastric function and guide enteral nutrition in critically ill patients

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World Journal of Gastroenterology 2017年第28期23卷 5229-5236页

作者： Ying Liu Ya-kun gao Lei Yao Li Li Department of Ultrasound Cangzhou Central Hospital

AIM To establish a modified B-ultrasound method of measuring the antral section only to assess gastric motility in healthy people,and evaluate its application in guiding enteral nutrition(EN) in critically ill patients. METHODS First,30 healthy volunteers were selected. The modified B-ultrasound method and the traditional B-ultrasound method were applied to assess gastric function. The correlation of indices of gastric function between the two groups was analyzed statistically. In addition,64 critically ill patients were selected,and the modified B-ultrasound method and the gastric juice withdrawal method were applied to guide the implementation of EN. Daily caloric value,the time required to achieve complete EN,ICU stay,hospitalization time,and serum prealbumin and albumin levels were recorded and compared between the two groups. Kaplan-Meier survival curve was used to compare the complications of EN between the two groups. RESULTS In healthy subjects,there was a good correlation among gastric emptying time,antral contraction frequency andantral motility index between the two groups(r = 0.57,0.61 and 0.54,respectively). The study on critically ill patients also revealed that a better effect of EN was achieved in the modified B-ultrasound method group,in which patients had shorter ICU stay and hospitalization time and higher levels of serum prealbumin and albumin. The Kaplan-Meier survival analysis revealed that the improved B-ultrasound method was associated with significantly fewer EN complications(P = 0.031).CONCLUSION The modified B-ultrasound method can provide a good real-time assessment of gastric function and has a better effect than the traditional method in guiding EN in critically ill patients.

关键词： Gastric emptying Real-time ultrasound Critically ill patients Enteral nutrition

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Cell Production and Expansion in the Primary Root of Maize in Response to Low-Nitrogen Stress

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Journal of Integrative Agriculture 2014年第11期13卷 2508-2517页

作者： gao kun CHEN Fan-jun YUAN Li-xing MI Guo-hua Key Laboratory of Plant-Soil Interaction Ministry of Agriculture/Center for Resources Environment and Food Security College of Resources and Environmental Sciences China Agricultural University

Maize plants respond to low-nitrogen stress by enhancing root elongation. The underlying physiological mechanism remains unknown. Seedlings of maize （Zea mays L., cv. Zhengdan 958） were grown in hydroponics with the control （4 mmol L-1） or low-nitrogen （40 μmol L-1） for 12 d, supplied as nitrate. Low nitrogen enhanced root elongation rate by 4.1-fold, accompanied by increases in cell production rate by 2.2-fold, maximal elemental elongation rate （by 2.5-fold）, the length of elongation zone （by 1.5-fold）, and ifnal cell length by 1.8-fold. On low nitrogen, the higher cell production rate resulted from a higher cell division rate and in fact the number of dividing cells was reduced. Consequently, the residence time of a cell in the division zone tended to be shorter under low nitrogen. In addition, low nitrogen increased root diameter, an increase that occurred speciifcally in the cortex and was accompanied by an increase in cell number. It is concluded that roots elongates in response to low-nitrogen stress by accelerating cell production and expansion.

关键词： cell length elemental expansion kinematic analysis root diameter root elongation Zea mays L

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