The inexhaustible heat deposit in great depths （5-10 km） is a scientific fact. Such deposit occurs around the globe. Thereby, everybody is enabled to generate autonomously clean and renewable energy, ample electrici...The inexhaustible heat deposit in great depths （5-10 km） is a scientific fact. Such deposit occurs around the globe. Thereby, everybody is enabled to generate autonomously clean and renewable energy, ample electricity and heat. The economical exploration and exploitation of this superdeep geothermal heat deposit requires a novel drilling technique, because the currently only deep drilling method （Rotary） is limited to about 5 km, due to the rising costs, depending exponentially on depth. Electro-pulse-boring （EPB） is a valuable option to Rotary drilling. EPB, originally investigated in Russia, is ready to be developed for industrialization. The feasibility of EPB is proven by many boreholes drilled up to 200 m in granite （crystalline）. Estimates show outstanding low costs for drilling by EPB： 100 E/m for a borehole with a large diameter （φ） such as 20 （50 cm）, independent on depth and applicable likewise for sediments and crystalline rocks, such as granite. The current rate of penetration （ROP） of 3 m per hour is planned to be augmented up to 35 m per hour, and again, irrespective whether in sedimentary or crystalline formations. Consequently, a 10 km deep borehole with φ 50 cm will ultimately be drilled within 12 days. EPB will create new markets, such as： （i） EPB shallow drilling for geotechnics, energy piles, measures in order to mitigate natural hazards, etc., （ii） EPB deep drilling （3-5 km） for hydro-geothermics, exploration campaigns etc. and （iii） EPB super-deep drilling （5-10 km） for petro-geothermies, enabling the economic generation of electricity. The autonomous and unlimited supply with cost efficient electricity, besides ample heat, ensures reliably clean and renew- able energy, thus, high supply security. Such development will provide a substantial relief to cope with the global challenge to limit the climate change below 2 ℃. The diminution of fossil fuels, due to the energy transition in order to mitigate the climate change, implies likewise 展开更多
Air-gun is an important active seismic source.With the development of the theory about air-gun array,the technique for air-gun array design becomes mature and is widely used in petroleum exploration and geophysics.In ...Air-gun is an important active seismic source.With the development of the theory about air-gun array,the technique for air-gun array design becomes mature and is widely used in petroleum exploration and geophysics.In order to adapt it to different research domains,different combination and fired models are needed.At the present time,there are two fired models of air-gun source,namely,reinforced initial pulse and reinforced first bubble pulse.The fired time,space between single guns,frequency and resolution of the two models are different.This comparison can supply the basis for its extensive application.展开更多
Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a ...Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a sealant,coupled with an air seepage evaluation model that incorporates Knudsen diffusion.Moreover,the initial coating application methods were outlined,and the advantages of using NOSP compared to other sealing materials,particularly regarding cost and construction techniques,were also examined and discussed.Experimental results indicated a significant reduction in permeability of rock specimens coated with a 7–10μm thick NOSP layer.Specifically,under a 0.5 MPa pulse pressure,the permeability decreased to less than 1 n D,and under a 4 MPa pulse pressure,it ranged between4.5×10^(-6)–5.5×10^(-6)m D,marking a 75%–80%decrease in granite permeability.The sealing efficacy of NOSP surpasses concrete and is comparable to rubber materials.The optimal viscosity for application lies between 95 and 105 KU,and the coating thickness should ideally range from 7 to 10μm,applied to substrates with less than 3%porosity.This study provides new insights into air transport and sealing mechanisms at the pore level,proposing NOSP as a cost-effective and simplified solution for CAES applications.展开更多
Dielectric barrier discharge （DBD） between two cylindrical glass containers with salt water generated by a nanosecond repetitively pulsed power generator is reported. The electrical parameters, luminous images and s...Dielectric barrier discharge （DBD） between two cylindrical glass containers with salt water generated by a nanosecond repetitively pulsed power generator is reported. The electrical parameters, luminous images and spectrum diagnosis are presented. It is shown that the DBD possesses a large discharge current and an intense optical emission from the nitrogen second positive system below 400 nm. The gas temperature remains very close to room temperature regardless of pulse polarity. Luminous photographs with a short exposure time down to 2 ns indicate that no filament is observed and the discharge is homogeneous.展开更多
Based on existing low-frequency water-filled impedance tube testing facilities, which is a part of the Low Frequency Facility of the Naval Undersea Warfare Center in Beijing, an improved water-filled pulse tube method...Based on existing low-frequency water-filled impedance tube testing facilities, which is a part of the Low Frequency Facility of the Naval Undersea Warfare Center in Beijing, an improved water-filled pulse tube method is presented in this short paper. This proposed study is significantly different from the conventional pulse tube method because of the capability for a single plane damped sine pulse wave to generate in the water-filled pulse tube with a regular waveform and short duration time of about 1ms. During the generation process of the pulse, an inverse filter principle was adopted to compensate the transducer response. The effect of the characteristics of tube termination can be eliminated through the generation process of the pulse. Reflection coefficient from a water/air interface was measured to verify the proposed method. When compared with the expected theoretical values, a relatively good agreement can be obtained in the low frequency range of 500-2 000 Hz.展开更多
AuPt nano particles are bi-functional catalysts for Oxygen Reduction Reaction （ORR） and Oxygen Evolution Reaction （OER） that were taken place on air electrodes in lithium air batteries. Magnetic field has been app...AuPt nano particles are bi-functional catalysts for Oxygen Reduction Reaction （ORR） and Oxygen Evolution Reaction （OER） that were taken place on air electrodes in lithium air batteries. Magnetic field has been applied during electrodeposition for the preparation of AuPt particles. With the increase of the magnetic flux density under constant current density, the grain size decreases from - 1μm to 200nm and the activity of the AuPt catalyst increases. The magnetic field oriented vertical to the electric field has a promotion effect on increasing the catalytic ability of AuPt/carbon electrode. By pulse plating, the grain size decreases to about 100nm. By adjusting parameters of the electric field and the magnetic field, controllable in-situ preparation of AuPt catalyst with various morphology and catalytic activity could be achieved.展开更多
Experimental studies were conducted in order to improve the understanding of the thrust generation and the pressure/flame reverse propagation of the air-breathing pulse detonation engines(APDEs)with self-designed inle...Experimental studies were conducted in order to improve the understanding of the thrust generation and the pressure/flame reverse propagation of the air-breathing pulse detonation engines(APDEs)with self-designed inlets and valves structures.The present experimental research utilized a gasoline/air APDE(with 68 mm inner-diameter,2050 mm length and maximum operating frequency not less than 40 Hz which was as a benchmark structure)at different operating frequencies,with freestream air inflow of 1.1 atm and 0℃.The theoretical equivalence ratio of gasoline/air was 1.Two kinds of inlets with centerbody or without were considered and combined with two kinds of self-designed valves(the elastic-valve and the convergent aero-valve)specially designed for comparative experiments.During the test,the inflow parameters,the pressure along the longitudinal direction inside the engine and the thrust force were measured for the APDE operating characteristic analysis,including the detonation combustion,the aerodynamic drag,the pressure/flame reverse propagation and the thrust generation.The research results indicate that:The inlet centerbody does not increase drag but plays a positive effect on airflow stability and operation matching.The elastic-valve and the convergent aero-valve,though increase the inlet aerodynamic drag,have obvious effects on suppressing the detonation wave and pressure forward propagation,resulting in effective thrust increase.Effects of the convergent aero-valve are the best when the flow choked,while the effects of elastic-valve are better and continuously stable in a wider range of frequency.The wmaximum nondimensional thrust increases with the elastic-valve is reached about 1.12 at the frequency of 8-9 Hz,and about 0.97 with the convergent aero-valve at the frequency of 7 Hz.The maximum fuel specific impulse is 2514.6 s when using the convergent aerovalve.And this study provides technical reserve for the APDE optimization design.展开更多
文摘The inexhaustible heat deposit in great depths （5-10 km） is a scientific fact. Such deposit occurs around the globe. Thereby, everybody is enabled to generate autonomously clean and renewable energy, ample electricity and heat. The economical exploration and exploitation of this superdeep geothermal heat deposit requires a novel drilling technique, because the currently only deep drilling method （Rotary） is limited to about 5 km, due to the rising costs, depending exponentially on depth. Electro-pulse-boring （EPB） is a valuable option to Rotary drilling. EPB, originally investigated in Russia, is ready to be developed for industrialization. The feasibility of EPB is proven by many boreholes drilled up to 200 m in granite （crystalline）. Estimates show outstanding low costs for drilling by EPB： 100 E/m for a borehole with a large diameter （φ） such as 20 （50 cm）, independent on depth and applicable likewise for sediments and crystalline rocks, such as granite. The current rate of penetration （ROP） of 3 m per hour is planned to be augmented up to 35 m per hour, and again, irrespective whether in sedimentary or crystalline formations. Consequently, a 10 km deep borehole with φ 50 cm will ultimately be drilled within 12 days. EPB will create new markets, such as： （i） EPB shallow drilling for geotechnics, energy piles, measures in order to mitigate natural hazards, etc., （ii） EPB deep drilling （3-5 km） for hydro-geothermics, exploration campaigns etc. and （iii） EPB super-deep drilling （5-10 km） for petro-geothermies, enabling the economic generation of electricity. The autonomous and unlimited supply with cost efficient electricity, besides ample heat, ensures reliably clean and renew- able energy, thus, high supply security. Such development will provide a substantial relief to cope with the global challenge to limit the climate change below 2 ℃. The diminution of fossil fuels, due to the energy transition in order to mitigate the climate change, implies likewise
基金The research was funded under the project of NSFC(Grant number:NSFC40234038)Joint Earthquake Science Foundation,China(Grant No.105108)
文摘Air-gun is an important active seismic source.With the development of the theory about air-gun array,the technique for air-gun array design becomes mature and is widely used in petroleum exploration and geophysics.In order to adapt it to different research domains,different combination and fired models are needed.At the present time,there are two fired models of air-gun source,namely,reinforced initial pulse and reinforced first bubble pulse.The fired time,space between single guns,frequency and resolution of the two models are different.This comparison can supply the basis for its extensive application.
基金supported by the National Natural Science Foundation of China(No.42272321)Hubei Provincial Key Research Projects(Nos.2022BAA093 and 2022BAD163)+1 种基金Major Scientific and Technological Special Project of Jiangxi Province(No.2023ACG01004)WSGRI Engineering&Surveying Incorporation Limited(No.6120230256)。
文摘Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a sealant,coupled with an air seepage evaluation model that incorporates Knudsen diffusion.Moreover,the initial coating application methods were outlined,and the advantages of using NOSP compared to other sealing materials,particularly regarding cost and construction techniques,were also examined and discussed.Experimental results indicated a significant reduction in permeability of rock specimens coated with a 7–10μm thick NOSP layer.Specifically,under a 0.5 MPa pulse pressure,the permeability decreased to less than 1 n D,and under a 4 MPa pulse pressure,it ranged between4.5×10^(-6)–5.5×10^(-6)m D,marking a 75%–80%decrease in granite permeability.The sealing efficacy of NOSP surpasses concrete and is comparable to rubber materials.The optimal viscosity for application lies between 95 and 105 KU,and the coating thickness should ideally range from 7 to 10μm,applied to substrates with less than 3%porosity.This study provides new insights into air transport and sealing mechanisms at the pore level,proposing NOSP as a cost-effective and simplified solution for CAES applications.
基金supported by National Natural Science Foundation of China (Nos. 50707032, 11076026)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KGCX2-YW-339)+1 种基金the National Basic Research Program of China (No. 2011CB209405)the State Key Laboratory of Control and Simulation of Power Systems and Generating Equipment in Tsinghua University (No. SKLD09KZ05)
文摘Dielectric barrier discharge （DBD） between two cylindrical glass containers with salt water generated by a nanosecond repetitively pulsed power generator is reported. The electrical parameters, luminous images and spectrum diagnosis are presented. It is shown that the DBD possesses a large discharge current and an intense optical emission from the nitrogen second positive system below 400 nm. The gas temperature remains very close to room temperature regardless of pulse polarity. Luminous photographs with a short exposure time down to 2 ns indicate that no filament is observed and the discharge is homogeneous.
基金Supported by the National Natural Science Foundation of China under Grant No. 11204242 China Postdoctoral Foundation under Grant No. 2011M501477
文摘Based on existing low-frequency water-filled impedance tube testing facilities, which is a part of the Low Frequency Facility of the Naval Undersea Warfare Center in Beijing, an improved water-filled pulse tube method is presented in this short paper. This proposed study is significantly different from the conventional pulse tube method because of the capability for a single plane damped sine pulse wave to generate in the water-filled pulse tube with a regular waveform and short duration time of about 1ms. During the generation process of the pulse, an inverse filter principle was adopted to compensate the transducer response. The effect of the characteristics of tube termination can be eliminated through the generation process of the pulse. Reflection coefficient from a water/air interface was measured to verify the proposed method. When compared with the expected theoretical values, a relatively good agreement can be obtained in the low frequency range of 500-2 000 Hz.
基金This work was supported by the National Natural Science Foundation of China （No.51304056）, the China Postdoctoral Science Foundation （No.2013M531049）, the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, and the Fundamental Research Funds for the Central Universities （No.HIT.NSRIF.2011021）.
文摘AuPt nano particles are bi-functional catalysts for Oxygen Reduction Reaction （ORR） and Oxygen Evolution Reaction （OER） that were taken place on air electrodes in lithium air batteries. Magnetic field has been applied during electrodeposition for the preparation of AuPt particles. With the increase of the magnetic flux density under constant current density, the grain size decreases from - 1μm to 200nm and the activity of the AuPt catalyst increases. The magnetic field oriented vertical to the electric field has a promotion effect on increasing the catalytic ability of AuPt/carbon electrode. By pulse plating, the grain size decreases to about 100nm. By adjusting parameters of the electric field and the magnetic field, controllable in-situ preparation of AuPt catalyst with various morphology and catalytic activity could be achieved.
基金the National Natural Science Foundation of China(91441201)the Fundamental Research Funds for the Central Universities(5003123003)for financial supports of this work.
文摘Experimental studies were conducted in order to improve the understanding of the thrust generation and the pressure/flame reverse propagation of the air-breathing pulse detonation engines(APDEs)with self-designed inlets and valves structures.The present experimental research utilized a gasoline/air APDE(with 68 mm inner-diameter,2050 mm length and maximum operating frequency not less than 40 Hz which was as a benchmark structure)at different operating frequencies,with freestream air inflow of 1.1 atm and 0℃.The theoretical equivalence ratio of gasoline/air was 1.Two kinds of inlets with centerbody or without were considered and combined with two kinds of self-designed valves(the elastic-valve and the convergent aero-valve)specially designed for comparative experiments.During the test,the inflow parameters,the pressure along the longitudinal direction inside the engine and the thrust force were measured for the APDE operating characteristic analysis,including the detonation combustion,the aerodynamic drag,the pressure/flame reverse propagation and the thrust generation.The research results indicate that:The inlet centerbody does not increase drag but plays a positive effect on airflow stability and operation matching.The elastic-valve and the convergent aero-valve,though increase the inlet aerodynamic drag,have obvious effects on suppressing the detonation wave and pressure forward propagation,resulting in effective thrust increase.Effects of the convergent aero-valve are the best when the flow choked,while the effects of elastic-valve are better and continuously stable in a wider range of frequency.The wmaximum nondimensional thrust increases with the elastic-valve is reached about 1.12 at the frequency of 8-9 Hz,and about 0.97 with the convergent aero-valve at the frequency of 7 Hz.The maximum fuel specific impulse is 2514.6 s when using the convergent aerovalve.And this study provides technical reserve for the APDE optimization design.
