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Journal of Thermal Science 2019年第3期28卷 494-504页

作者： LIU Peng SHU Gequn tian hua State Key Laboratory of Engines Tianjin University

In consideration of the high-temperature characteristic of engine's waste heat and stricter environmental regulations, natural substance, including CO_2 and hydrocarbons, have been treated as promising working fluid for diesel engine waste heat recovery due to its environment friendly and excellent physical and chemical properties. This paper presented a comprehensive performance analysis on transcritical Rankine cycles for diesel engine multiple waste heat recovery using hydrocarbons and CO_2 as working fluid. The optimal turbine inlet pressures corresponding to maximum net power output, maximum exergy efficiency and minimum electricity production cost(EPC) were obtained. The effect of working fluid on these optimal pressures has been discussed. For fluids with low critical temperature, the optimal pressure corresponding to maximum net power output is lower than the one for maximum exergy efficiency, while the opposite results can be found for fluid with high critical temperature. Then, the effect of various working fluid properties in transcritical cycle performance is discussed. Comparison results show that CO_2 obtains only more power output than Ethane, Propane and Propene, but CO_2 is capable of absorbing more energy from engine coolant and regeneration heat with comparable total heat transfer areas and has an advantage in turbine size, particularly for hydrocarbons with high critical temperature.

关键词： transcritical Rankine cycle natural working fluid multiple waste heat performance comparison

Study of DDT and its derivatives DDD, DDE adsorption and degradation over Fe-SBA-15 at low temperature

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Journal of Environmental Sciences 2012年第3期24卷 536-540页

作者： Hailin Wang hua tian Zhengping Hao Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100190China

Mesoporous SBA-15 with different Fe2O3 loading were synthesized by an in-situ coating progress for removals of dichlorodiphenyl- trichloroethane （DDT） and its derivatives, i.e., 1,1-dichloro-2,2-bis-（p-chlorophenyl）ethane （DDD） and 1,1-dichloro-2,2-bis-（4-chloro -phenyl） ethane （DDE）. The results from XRD （X-ray diffractometer）, TEM （transmission electron microscopy） indicated that the iron could be well dispersed on SBA-15 within 6 wt.% Fe2O3 loading. Nitrogen adsorption-desorption tests indicated that the synthesized materials were characterized by ordered meso-structure, high surface area and large pore volume. DDTs were removed from aqueous media in 12-hr treatment and high removal efficiency of DDTs was achieved at over 94%. DDTs could be completely degraded at 350°C under the existence of SBA-15 with 4 wt.% Fe2O3 loading. The final degradation products of DDT were dichlorobenzophenone （DCB） and bis-（4-chloro-phenyl） methane （DDM）, suggesting a complete dechlorination from trichloromethyl.

关键词： DDTs SBA-15 iron adsorption catalytic dechlorination

Application and prospective of 3D printing in rock mechanics: A review

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International Journal of Minerals,Metallurgy and Materials 2021年第1期28卷 1-17页

作者： Yong-tao Gao tian-hua Wu Yu Zhou Key Laboratory of Ministry for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China

This review aims to discuss the application and development of three-dimensional printing(3DP) technology in the field of rock mechanics and the mechanical behaviors of 3D-printed specimens on the basis of various available printing *** review begins with a brief description of the concepts and principles associated with 3DP, and then systematically elaborates the five major applications of 3DP technology in the field of rock mechanics, namely, the preparation of rock(including pre-flawed rock) specimens, preparation of joints, preparation of geophysical models, reconstruction of complex rock structures, and performance of bridging experimental testing and numerical ***, the mechanical performance of 3D-printed specimens created using six different printing materials, such as polymers, resin,gypsum, sand, ceramics, and rock-like geological materials, is reviewed in ***, some improvements that can make these 3D-printed specimens close to natural rocks and some limitations of 3DP technology in the application of rock mechanics are *** prospects that are required to be investigated in the future are also ***, a brief summary is *** review suggests that 3DP technology, especially when integrated with other advanced technologies, such as computed tomography scanning and 3D scanning, has great potential in rock mechanics field.

关键词： three-dimensional printing(3DP) rock mechanics 3DP material rock analogue 3DP geotechnical model numerical simulation

Heat transfer characteristics for double-jet in different flow regions on a thick plate

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Journal of Iron and Steel Research International 2021年第11期28卷 1400-1407页

作者： Xiu-hua tian tian-liang Fu Zhao-dong Wang Guo-dong Wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina

During multi-jet cooling,the complex hydrodynamic characteristics caused by the interaction between jets will affect the heat transfer of the *** further clarify the heat transfer characteristics in different flow regions,the double-jet cooling experiments were completed on a 50-mm-thick plate with the initial cooling temperature and jet angle in the range of 300–900°C and 0°–60°,*** inverse heat conduction was used to calculate the surface temperature and heat ***,the rewetting phenomenon,maximum heat flux and maximum cooling speed were *** results show that increasing the angle between jet and wall normal would increase the wetting front’s width downstream of the jet *** the jet angle was 60°,the maximum value increased by 37.29 mm compared with that when the angle was *** correlation between the width of the wetting front and the radial temperature gradient was further *** addition,it was found that the maximum heat flux would be affected by the duration of transition boiling,but not affected by complete wetting *** results clarified the heat transfer mechanisms under various initial cooling temperature and inclination angle conditions on plate cooling in different flow regions,and provided valuable data for controlling heat transfer efficiency and improving cooling uniformity.

关键词： Double-jet Thick plate Rewetting phenomenon Flow region Heat flux

Controversies about the use of serological markers indiagnosis of in flammatory bowel disease

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World Journal of Gastroenterology 2010年第2期16卷 279-280页

作者： Xie, Qin Gan, hua-tian Sichuan Univ Dept Geriatr W China Hosp Chengdu 610041 Sichuan Peoples R China Sichuan Univ Dept Gastroenterol W China Hosp Chengdu 610041 Sichuan Peoples R China

The serological markers are increasingly used in diagnosis of inflammatory bowel disease(IBD).D-lactate and diamine oxidase are new indicators that can be used to reveal the damage to intestinal mucosa and permeability alteration in *** the two biological markers seem more sensitive,recent clinical trials and animal experiments have shown controversies about the use of them in diagnosis of ***, these markers should be interpreted cautiously and further prospective studies are needed to establish their clinical role in diagnosis of IBD.

关键词： Inflammatory bowel diseases D-lactate Diamine oxidase Intestinal permeability Diagnosis

Experimental investigation on diesel engine's waste heat capacity under mapping characteristics

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Science China(Technological Sciences) 2015年第1期58卷 9-18页

作者： tian hua ZHANG ChengYu LI XiaoNing SHU GeQun State Key Laboratory of Engines Tianjin University

Waste heat recovery for internal combustion engine(ICE)has been considered as an important strategy to improve efficiency and promote fuel economy,thus alleviating the problems of energy shortage and environmental *** paper investigates the characteristics of various kinds of waste heat energy,namely,waste heat in exhaust,cooling water and charge air,over the engine’s whole operating *** on the energy balance experiments,the energy distribution of a conventional heavy-duty diesel engine is obtained under mapping *** to exergy analysis,the energy recovery potential for waste heat is studied as *** experimental results indicate that exhaust energy increases with engine speed and load,while cooling water energy is more sensitive to load,especially at low and middle *** air energy,on the other hand,mainly counts on speed rather than *** energy possesses the highest recovery potential in terms of both quantity and *** waste heat recovery,a dramatic improvement in engine efficiency is achievable,actually,the maximum value can amount to 60%or even more.

关键词： waste heat recovery mapping characteristics diesel engine energy balance exergy analysis

Pathogenesis of pancreatic encephalopathy in severe acute pancreatitis

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Hepatobiliary & Pancreatic Diseases International 2007年第2期6卷 134-140页

作者： Zhang, Xi-Ping tian, hua Hangzhou First Peoples Hosp Dept Gen Surg Hangzhou 310006 Peoples R China Zhejiang Univ Sch Med Second Affiliated Hosp Dept Gen Surg Hangzhou 310003 Peoples R China

BACKGROUND: Pancreatic encephalopathy (PE) is a serious complication of severe acute pancreatitis (SAP). In recent years, more and more PE cases have been reported worldwide, and the onset PE in the early stage was regarded as a poor prognosis sign of SAP, but the pathogenesis of PE in SAP still has not been clarified in the past decade. The purpose of this review is to elucidate the possible pathogenesis of PE in SAP. DATA SOURCES: The English-language literature concerning PE in this review came from the Database of MEDLINE (period of 1991-2005), and the keywords of severe acute pancreatitis and pancreatic encephalopathy were used in the searching. RESULTS: Many factors were involved in the pathogenesis of PE in SAP. Pancreatin activation, excessive release of cytokines and oxygen free radicals, microcirculation abnormalities of hemodynamic disturbance, ET-1/NO ratio, hypoxemia, bacterial infection, water and electrolyte imbalance, and vitamin B1 deficiency participated in the development of PE in SAP. CONCLUSIONS: The pathogenesis of PE in SAP has not yet been fully understood. The development of PE in SAP may be a multi-factor process. To find out the possible inducing factor is essential to the clinical management of PE in SAP.

关键词： severe acute pancreatitis pancreatic encephalopathy pathogenesis microcirculation cytokines phospholipase A(2) oxygen free radicals vitamin B1 deficiency

Effects of synthesis conditions on the structural and electrochemical properties of layered LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 cathode material via oxalate co-precipitation method

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Rare Metals 2008年第6期27卷 575-579页

作者： tian hua YE Naiqing LIU Dan LI Wenqun Key Laboratory of New Processing Technology for Nonferrous Metals and Materials Ministry of Education of China Guilin 541004 China Department of Materials and Chemistry Engineering Guilin University of Technology Guilin 541004 China

The uniform layered LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries was prepared by using （Ni1/3Co1/3Mn1/3）C2O4 as precursor synthesized via oxalate co-precipitation method in air. The effects of calcination temperature and time on the structure and electrochemical properties of the LiNi1/3Co1/3Mn1/3O2 were systemically studied. XRD results revealed that the optimal calcination conditions to prepare the layered LiNi1/3Co1/3Mn1/302 were 950℃ for 15 h. Electrochemical measurement showed that the sample prepared under the such conditions has the highest initial discharge capacity of 160.8 mAh/g and the smallest irreversible capacity loss of 13.5% as well as stable cycling performance at a constant current density of 30 mA/g between 2.5 and 4.3 V versus Li at room temperature.

关键词： lithium ion batteries oxalate co-precipitation method cathode materials electrochemical performance

Phosphine oxide-Sc(OTf)3catalyzed enantioselective bromoaminocyclization of tri-substituted allyl N-tosylcarbamates

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Science China Chemistry 2018年第6期61卷 656-659页

作者： Xiangyu Tan Hongjie Pan hua tian Yian Shi Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Recognition and Function Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Institute of Natural and Synthetic Organic Chemistry Changzhou University Changzhou 213164 China Department of Chemistry Colorado State University Fort Collins Colorado 80523 USA

Phosphine oxide-Sc(OTf)3 catalyzed regio-and enantioselective bromoaminocyclization of tri-substituted allyl N-tosylcarbamates is described. Awide variety of optically active tertiary 5-bromo-1,3-oxazinan-2-ones can b... 详细信息

关键词： asymmetric bromonation bromoaminocyclization phosphine oxide-Sc(OTf)3 5-bromo-1,3-oxazinan-2-ones

A HYBRID MODEL FOR SIMULATING VELOCITY FIELD OF A RIVER WITH COMPLEX GEOMETRY PLUNGED BY MULTIPLE JETS

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Journal of Hydrodynamics 2006年第6期18卷 752-759页

作者： LI Lian-xia LIAO hua-sheng LI tian-xiang State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065China

A hybrid model that combines both physical and numerical models was employed to simulate the velocity field in a river area in complex geometry with multiple plunging jets. The simulation was based on experiments concerning energy dissipation and scour prevention at the Xiluodu Hydropower Station on the Yangtze River. The calculated results indicate that the complex geometry of the river area has a significant influence on the velocity field, especially on the circulation flow pattern at upstream and downstream of the plunging area and on the asymmetric characteristics of the spiral flow near both banks. The scour characteristics of the downstream river bed caused by the multiple jets were also predicted and analyzed according to the characteristics of the calculated velocity field. The good agreement between the simulated and experimental results indicates that the hybrid model can be used to effectively solve complicated 3-D problems with complex geometric and inlet conditions. Such problems may not easily be solved by using either a physical or a numerical model alone, and therefore the method presented in this article is considered to be a practical and effective way of dealing with this kind of problems.

关键词： hybrid models turbulence model scour multiple jets