The impregnation method for preparing catalysts often faces challenges such as prolonged preparation times and poor dispersion of active components due to the limited mobility of the impregnation liquid.The rotating p...The impregnation method for preparing catalysts often faces challenges such as prolonged preparation times and poor dispersion of active components due to the limited mobility of the impregnation liquid.The rotating packed bed(RPB)can break the precursor solution into fine droplets,enabling dynamic impregnation of active components onto the surface of activated carbon.This approach facilitates the uniform distribution of active components on the carrier and enhances the stability and performance of the catalyst.In this study,activated carbon catalysts were prepared using high-gravity technology.It was found that the preparation time for Co-MnO_(x)/GAC using the RPB method was reduced by 98%,the catalytic activity increased by 6.62%,and the loadings of active components increased by 13%and 17%,the catalytic activity remained stable after five cycles,with a significantly lower rate of metal dissolution.A suite of complementary analytical techniques demonstrates that Co-MnO_(x)/GAC(RPB)has higher homogeneity and dispersion.X-ray photoelectron spectroscopy(XPS)results indicate that Co(II)and Mn(IV)/Mn(III)are the primary active sites during the catalytic decomposition of ozone,elucidating the mechanism of synergistic catalytic ozonation by dual-active components.Finally,electron paramagnetic resonance(EPR)confirmed that hydroxyl radicals($OH)were the predominant reactive species in the reaction.展开更多
A plastic mixture construction technology using MBER （material becoming earth into rock） soil stabilizer is introduced and the water quality of a solidified soil cistern using the technology is analyzed. Rainwater w...A plastic mixture construction technology using MBER （material becoming earth into rock） soil stabilizer is introduced and the water quality of a solidified soil cistern using the technology is analyzed. Rainwater was harvested in July, 2012. Water quality of runoff and cistern water after storage was measured, including turbidity, chemical oxygen demand （COD）, total nitrogen, nitrate, and ammonia. Results show that pollutant concentrations in runoff decreased with time, indicating that runoff in the early time should be removed. Nitrate concentrations in cistern water increased after storage, while the remaining parameters decreased. Measured pollutant concentrations did not exceed the limit according to the standard for drinking water in China. It can be concluded that the solidified soil cistern with plastic mixture construction technology can provide available water for domestic use.展开更多
A multi-functional micro-arc plasma spraying system was developed according to aerodynamics and plasma spray theory. The soft switch IGBT （Insulated Gate Bipolar Transistor） invert technique, micro-computer control ...A multi-functional micro-arc plasma spraying system was developed according to aerodynamics and plasma spray theory. The soft switch IGBT （Insulated Gate Bipolar Transistor） invert technique, micro-computer control technique, convergent-divergent nozzle structure and axial powder feeding techniques have been adopted in the design of the micro-arc plasma spraying system. It is not only characterized by a small volume, a light weight, highly accurate control, high deposition efficiency and high reliability, but also has multi-functions in plasma spraying, welding and quenching. The experimental results showed that the system can produce a supersonic flame at a low power, spray Al2O3 particles at an average speed up to 430 m/s, and make nanostructured AT13 coatings with an average bonding strength of 42.7 MPa. Compared to conventional 9M plasma spraying with a higher power, the coatings with almost the same properties as those by conventional plasma spray can be deposited by multi-functional micro-arc plasma spraying with a lower power plasma arc due to an improved power supply design, spray gun structure and powder feeding method. Moreover, this system is suitable for working with thin parts and undertaking on site repairs, and as a result, the application of plasma spraying will be greatly extended.展开更多
In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor...In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure(EWP). By means of a threedimensional(3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system(TDS) widely used in China and its optimized drainage system(ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice,including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 k Pa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.展开更多
The stability control of longwall coalface is the key technology of large-cutting-height mining method.Therefore,a systematic study of the factors that affect coalface stability and its control technology is required ...The stability control of longwall coalface is the key technology of large-cutting-height mining method.Therefore,a systematic study of the factors that affect coalface stability and its control technology is required in the development of large-cutting-height mining method in China. After the practical field observation and years of study,it was found that the more than 95% of failures in coalface are shear failure. The shear failure analysis model of coalface has been established,that can perform systematic study among factors such as mining height,coal mass strength,roof load,support resistance,and face flipper protecting plate horizontal force. Meanwhile,sensitivity analysis of factors influencing coalface stability showed that improving support capacity,cohesion of coal mass and decreasing roof load of coalface are the key to improve coalface stability. Numerical simulation of the factors affecting coalface stability has been performed using UDEC software and the results are consistent with the theoretical analysis. The coalface reinforcement technology of large-cutting-height mining method using the grouting combined with coir rope is presented. Laboratory tests have been carried out to verify its reinforcement effect and practical application has been implemented in several coal mines with good results.It has now become the main technology to reduce longwall coalface failure of large-cutting-height mining method.展开更多
A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL...A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.展开更多
To ameliorate the defects of insufcient support resistance of traditional roadside flling bodies for gob-side entry retaining(GER),overcome the inability to adapt to the deformation of surrounding rock,and isolate the...To ameliorate the defects of insufcient support resistance of traditional roadside flling bodies for gob-side entry retaining(GER),overcome the inability to adapt to the deformation of surrounding rock,and isolate the goaf efectively,a new type of high-water material as a roadside flling body for GER technology with double roadways was proposed.The instability analysis and control technology of GER with double roadways by flling high-water material into a gently inclined coal seam were studied.The basic mechanical properties of the new high-water material were investigated through laboratory experiments,and their main advantages were identifed.The reasonable width of the roadside flling wall of a high-water material was obtained by combining ground pressure observation and theoretical calculations.The distribution characteristics of the stress and plastic zone of surrounding rock of GER after being stabilized by the disturbance of the working face were studied using numerical simulations,and the failure range of GER by flling with high-water material was revealed.Based on this,a coupling control technology of anchor cables and bolts+single props+metal mesh+anchor bolts is proposed.Through the coupling methods of arranging borehole peeping and observing the convergences of surrounding rock,the results demonstrate that GER with double roadways by flling with a 1.8-m-wide high-water material has a good control efect.The above research will play an active role in promoting the application of high-water materials in GER roadside flling.展开更多
Five experimental self-shielded flux cored wires are fabricated withdifferent amount of Fe_2O_3 in the flux. The effect of Fe_2O_3 on welding technology and mechanicalproperties of weld metals deposited by these wires...Five experimental self-shielded flux cored wires are fabricated withdifferent amount of Fe_2O_3 in the flux. The effect of Fe_2O_3 on welding technology and mechanicalproperties of weld metals deposited by these wires are studied. The results show that with theincrease of Fe_2O_3 in the mix, the melting point of the pretreated mix is increased. LiBaF_3 andBaFe_(12)O_(19), which are very low in inherent moisture, are formed after the pretreatment. Themechanical properties are evaluated to the weld metals. The low temperature notch toughness of theweld metals is increased linearly with the Fe_2O_3 content in the flux due to the balance betweenFe_2O_3 and residual Al in the weld metal. The optimum Fe_2O_3 content in flux is 2.5 percent approx3.5 percent.展开更多
The number of hazardous waste in our country increased dramatically in recent years,stabilization/solidification technology begins to attract a wide spread attention by domestic scholars.Based on the domestic related ...The number of hazardous waste in our country increased dramatically in recent years,stabilization/solidification technology begins to attract a wide spread attention by domestic scholars.Based on the domestic related literature,this paper discussed the present situation about the treatment of the solid waste using stabilization/solidification technology;meanwhile we have a variety of outlooks on the future of the stabilization/solidification technology.展开更多
With the development of the production scale and the increasing of the process technologies and facilities,product quality and the requirement of water supply continuously put forward new requirements to water treatme...With the development of the production scale and the increasing of the process technologies and facilities,product quality and the requirement of water supply continuously put forward new requirements to water treatment technology.The practice of the water saving technology should ensure the safe of water using and the innovation of technique data.Especially the stabilization of water quality should also meet the production at full capacity,reduce equipment failure rate and maintain the sustainable development under the condition of the minimal resource consumption.This article describes the practice of Baosteel saving technology,water-saving ideas from the system to start,according to Baosteel raw water intake requirements and process water and drainage characteristics,water and salt water tidal according to changes in the Yangtze River and the Yangtze River upstream and downstream trends in water discharge on water quality factors,established the electrical conductivity,chloride ion indicators for the control of the Yangtze River water,the implementation of'avoid salt build light'water at the same time,combined with the actual situation of water pollution in the Yangtze River,the use of force coefficient correlation theory,the implementation of'avoid taking clear pollution'to ensure the quality of raw water intake.System and cascade utilization of water,process water,based on whole plant water balance testing,analysis,technical parameters of the system and processes the user running the pressure balance pipe network,and implemented a stabilization system to adjust water pressure,reducing the water supply network systemwater loss;application of electrochemical principles,the implementation of the protection of underground pipes Baosteel,implemented a water use,steps to use,the operating mode of water supply in series to increase water reuse,reduce wastewater discharge system.Water quality stability and water-saving in the process;carry out water quality stability technology in the different complicated processes of the steel industry;apply the environmental protection and water quality,sterilization,non-phosphorus and low phosphorus technologies which are suitable for high concentration of circulating water.By these technologies,we achieved the water-saving in the process in different seasons and solved the technical problems affecting production such as equipment corrosion,scaling and the formation of the water quality proprietary technology under the conditions of high heat load production as well.The use of water ecological conservation and biological treatment technology:the implementation of the reservoir to the ecological technology is characterized by food chain and wetland environmental technology characterized by plants chain.Reservoir ecological management techniques in the use of natural conditions,wind direction,temperature,light and fish biomass in the reservoir water level regulation of balance and combination of organic,control and resolve the reservoirs in spring and summer algae problems and water quality changes rot of the'fresh'operating problems.The artificial wetland technology develops a new way for metallurgical plants'wastewater treatment.All the measures by the implementation of water to create the conditions for the system to achieve the water target of constant innovation,reaching the advanced level of iron and steel enterprises.展开更多
Relaxed Stable Stability （RSS） in an important part of the active control technology. It is a new way to raise the flying speed, distance and maneuverability of missile. Depth study of RSS technology plays an import...Relaxed Stable Stability （RSS） in an important part of the active control technology. It is a new way to raise the flying speed, distance and maneuverability of missile. Depth study of RSS technology plays an important role for the new concept missile design. This paper describes the detailed definition of RSS and its advantages, pres- ents the research status and prospects for its application in the design of new missiles.展开更多
BZ Oilfield is a medium-sized oilfield with shallow delta facies deposits in Bohai Bay of China,compared with fluvial and delta facies oilfields,there is no mature experience for reference of reservoir configuration,w...BZ Oilfield is a medium-sized oilfield with shallow delta facies deposits in Bohai Bay of China,compared with fluvial and delta facies oilfields,there is no mature experience for reference of reservoir configuration,well pattern arrangement and development model in offshore oilfields in China.In view of the difficulty in describing the reservoir configuration of shallow water delta,the single distributary sand dam in shallow water delta is characterized by well-seismic combination and multi-attribute constraints.The mathematical mechanism model of pinch-out position of sand body is established,fine characterization of BZ shallow water delta reservoir is put forward.The horizontal well pattern arrangement type for shallow water delta reservoir is proposed and the method of well pattern optimization based on vertical displacement theory is put forward.A method of inversion of reservoir connectivity using production dynamic data by numerical well testing is proposed and a new method for optimizing water injection rate in water injection wells is proposed aiming at the difficulty of recognizing injection-production connectivity of shallow water delta reservoirs.The fine configuration of BZ shallow water delta reservoir based on distributary sand dam is proposed,which guides the recognition of remaining oil distribution law.By deploying adjustment wells,the water flooding coincidence degree of actual drilling is 86% compared with that of pre-drilling prediction,which indicates that the research results of reservoir configuration can effectively guide the understanding of oilfield geology.Through the theoretical well arrangement type of vertical displacement of single sand body in horizontal wells of shallow water delta reservoir,a high water flooding recovery rate of 35% is achieved in primary well pattern.The connectivity coefficients of injection-production boundary of shallow water delta reservoir configuration are calculated,and the water injection distribution coefficients are obtained by normalizing the directional coefficients.This paper presents a configuration method based on multi-attribute fusion under the constraints of sedimentary process.In this paper,a shallow water delta reservoir configuration method based on multi-attribute fusion constrained by sedimentary process is proposed,and the injection-production connectivity coefficient and injection well distribution coefficient of the configuration boundary are calculated.展开更多
The purpose of given article-consideration of the basic features of modern manufacturing of nuclear fuel which would confirm fact, that the manufacturer does everything that its production would respond not only to re...The purpose of given article-consideration of the basic features of modern manufacturing of nuclear fuel which would confirm fact, that the manufacturer does everything that its production would respond not only to requirements of the consumer, but also to its expected inquiries, and would correspond to intended purposes of fuel. It was defined main tendencies and features of modern technology, especially in nuclear fuel production, on base of meeting discussions, themes of journal articles on nuclear subject. They are correspond with practice of JSC NCCP （Novosibirsk Chemical Concentrates Plant） and listed in the paper. In result of it number of base features of any advanced technology, not only nuclear, described here with examples from NCCP＇s practice. Of course, there is no certain list of all attributes of modern manufacturing as there is no limit to its perfection. These categories are forming by current needs of the market, but listed ones must be.展开更多
The application of small shore station technology to automatic water quality monitoring can not only ensure the stability of the work, but also ensure the reliability of the monitored data. In this paper, the stabilit...The application of small shore station technology to automatic water quality monitoring can not only ensure the stability of the work, but also ensure the reliability of the monitored data. In this paper, the stability and reliability of small shore technology are tested through experiments. The results show that the data monitoring of shore station is stable, and the data obtained are consistent with the actual water temperature, ph and other content, which is reliable.展开更多
Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction indu...Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction industry.However,the construction of high-rise steel frame structures requires advanced technology.If the construction technology is effectively implemented and the welding techniques of the construction personnel align with the requirements for high-rise steel frame structures,it can help mitigate deformations in the steel structure,thus preserving the overall construction quality of high-rise steel frame structures.To enhance the applicability of steel frame structures in high-rise buildings,this paper focuses on analyzing the optimization path for the construction process of high-rise steel frame structures.It introduces a tailored approach to control welding-induced deformations in steel frame structures,aiming to make a valuable contribution to the advancement of China’s construction industry.展开更多
Two different technologies,electro-brush plating and arc spraying,were employed to deposit copper film and brass coating on the surface of nonmetal artworks,respectively. The principles of the oxidizing corrosion and ...Two different technologies,electro-brush plating and arc spraying,were employed to deposit copper film and brass coating on the surface of nonmetal artworks,respectively. The principles of the oxidizing corrosion and coloring were researched. The nonmetal artworks attain vivid and ancient bronze effect by the surface deposition and surface coloring processing. By using this technology,the problems of difficulty-to-plating copper and difficulty-to-archaizing for the large outdoor sculptures and other artworks can be solved,and it has prospective application due to low investment.展开更多
The number of hazardous waste in our country increased dramatically in recent years,stabilization/solidification technology begins to attract a wide spread attention by domestic scholars.Based on the domestic related ...The number of hazardous waste in our country increased dramatically in recent years,stabilization/solidification technology begins to attract a wide spread attention by domestic scholars.Based on the domestic related literature,this paper discussed the present situation about the treatment of the solid waste using stabilization/solidification technology;meanwhile we have a variety of outlooks on the future of the stabilization/solidification technology.展开更多
Hydrate-based carbon dioxide(CO_(2))sequestration(HBCS)technology utilizes naturally occurring high-pressure and low-temperature marine conditions to convert CO_(2) into solid hydrates within marine sediments,offering...Hydrate-based carbon dioxide(CO_(2))sequestration(HBCS)technology utilizes naturally occurring high-pressure and low-temperature marine conditions to convert CO_(2) into solid hydrates within marine sediments,offering a promising complementary pathway for carbon emission reduction and large-scale marine sequestration.This review examines the current developments and challenges of HBCS from both scientific and engineering perspectives.First,we present the fundamental principles of HBCS,with particular emphasis on key mechanisms such as phase transition and pore sequestration.Then,we explore the mechanisms of hydrate nucleation and growth that influence core processes,as well as multi-scale stability characteristics from the microscopic to the macroscopic level.Furthermore,we systematically assess thermodynamic and kinetic factors affecting sequestration efficiency,including but not limited to marine reservoir types,injection strategies,and environmentally friendly additives.Subsequently,based on an integrated evaluation of environmental,social,and economic dimensions,we assess the development potential of HBCS technology.Finally,the primary challenges currently faced are identified,and future research directions are proposed.Overall,this review provides a comprehensive overview of the progress and challenges associated with HBCS,emphasizes its potential role in global carbon reduction efforts,and offers theoretical guidance for future industrial applications.展开更多
基金supported by the National Natural Science Foundation of China(U23A20676)Key Research&Development Plan of Shanxi Province(202202040201011)+3 种基金Shanxi Scholarship Council of China(2023-128)Small and medium-sized oriented scientific and technological enterprises innovation ability improvement project of Shandong Province(2023TSGC0004)the Graduate Student Innovation Project of Shanxi Province(2023SJ205)Local Funds for Science and Technology Development Guided by the Central Finance(YDZJSX20231A030).
文摘The impregnation method for preparing catalysts often faces challenges such as prolonged preparation times and poor dispersion of active components due to the limited mobility of the impregnation liquid.The rotating packed bed(RPB)can break the precursor solution into fine droplets,enabling dynamic impregnation of active components onto the surface of activated carbon.This approach facilitates the uniform distribution of active components on the carrier and enhances the stability and performance of the catalyst.In this study,activated carbon catalysts were prepared using high-gravity technology.It was found that the preparation time for Co-MnO_(x)/GAC using the RPB method was reduced by 98%,the catalytic activity increased by 6.62%,and the loadings of active components increased by 13%and 17%,the catalytic activity remained stable after five cycles,with a significantly lower rate of metal dissolution.A suite of complementary analytical techniques demonstrates that Co-MnO_(x)/GAC(RPB)has higher homogeneity and dispersion.X-ray photoelectron spectroscopy(XPS)results indicate that Co(II)and Mn(IV)/Mn(III)are the primary active sites during the catalytic decomposition of ozone,elucidating the mechanism of synergistic catalytic ozonation by dual-active components.Finally,electron paramagnetic resonance(EPR)confirmed that hydroxyl radicals($OH)were the predominant reactive species in the reaction.
基金The National Key Technology R&D Program of China during the 12th Five Year Plan Period(No.2011BAD31B05)the National Natural Science Foundation of China(No.41371276)+1 种基金the National Science and Technology Major Project of China(No.2009ZX07212-002-003-02)the Knowledge Innovation Project of theInstitute of Soil and Water Conservation,CAS&MWR(No.A315021304)
文摘A plastic mixture construction technology using MBER （material becoming earth into rock） soil stabilizer is introduced and the water quality of a solidified soil cistern using the technology is analyzed. Rainwater was harvested in July, 2012. Water quality of runoff and cistern water after storage was measured, including turbidity, chemical oxygen demand （COD）, total nitrogen, nitrate, and ammonia. Results show that pollutant concentrations in runoff decreased with time, indicating that runoff in the early time should be removed. Nitrate concentrations in cistern water increased after storage, while the remaining parameters decreased. Measured pollutant concentrations did not exceed the limit according to the standard for drinking water in China. It can be concluded that the solidified soil cistern with plastic mixture construction technology can provide available water for domestic use.
文摘A multi-functional micro-arc plasma spraying system was developed according to aerodynamics and plasma spray theory. The soft switch IGBT （Insulated Gate Bipolar Transistor） invert technique, micro-computer control technique, convergent-divergent nozzle structure and axial powder feeding techniques have been adopted in the design of the micro-arc plasma spraying system. It is not only characterized by a small volume, a light weight, highly accurate control, high deposition efficiency and high reliability, but also has multi-functions in plasma spraying, welding and quenching. The experimental results showed that the system can produce a supersonic flame at a low power, spray Al2O3 particles at an average speed up to 430 m/s, and make nanostructured AT13 coatings with an average bonding strength of 42.7 MPa. Compared to conventional 9M plasma spraying with a higher power, the coatings with almost the same properties as those by conventional plasma spray can be deposited by multi-functional micro-arc plasma spraying with a lower power plasma arc due to an improved power supply design, spray gun structure and powder feeding method. Moreover, this system is suitable for working with thin parts and undertaking on site repairs, and as a result, the application of plasma spraying will be greatly extended.
基金supported by the National Natural Science Foundation of China (Grant No. U1934211)the Open Foundation of National Engineering Research Center of High-speed Railway Construction Technology (Grant No. HSR202005)Scientific Research Project of Hunan Education Department (Grant No.20B596)。
文摘In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure(EWP). By means of a threedimensional(3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system(TDS) widely used in China and its optimized drainage system(ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice,including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 k Pa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.
基金financial support from National Basic Research Program of China (No.2013CB227903)the National Natural Science Foundation of General Program of China (No.51574244)the Joint Funds of the National Natural Science Foundation of China (No.U1361209) are greatly appreciated
文摘The stability control of longwall coalface is the key technology of large-cutting-height mining method.Therefore,a systematic study of the factors that affect coalface stability and its control technology is required in the development of large-cutting-height mining method in China. After the practical field observation and years of study,it was found that the more than 95% of failures in coalface are shear failure. The shear failure analysis model of coalface has been established,that can perform systematic study among factors such as mining height,coal mass strength,roof load,support resistance,and face flipper protecting plate horizontal force. Meanwhile,sensitivity analysis of factors influencing coalface stability showed that improving support capacity,cohesion of coal mass and decreasing roof load of coalface are the key to improve coalface stability. Numerical simulation of the factors affecting coalface stability has been performed using UDEC software and the results are consistent with the theoretical analysis. The coalface reinforcement technology of large-cutting-height mining method using the grouting combined with coir rope is presented. Laboratory tests have been carried out to verify its reinforcement effect and practical application has been implemented in several coal mines with good results.It has now become the main technology to reduce longwall coalface failure of large-cutting-height mining method.
基金supported by the National Natural Science Foundation of China under Grant 62034002 and 62374026.
文摘A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.
基金supported by the National Natural Science Foundation of China(Nos.52074296,52004286)the China Postdoctoral Science Foundation(Nos.2020T130701,2019M650895)the Fundamental Research Funds for the Central Universities(Nos.2022YJSNY18,2022XJNY02)。
文摘To ameliorate the defects of insufcient support resistance of traditional roadside flling bodies for gob-side entry retaining(GER),overcome the inability to adapt to the deformation of surrounding rock,and isolate the goaf efectively,a new type of high-water material as a roadside flling body for GER technology with double roadways was proposed.The instability analysis and control technology of GER with double roadways by flling high-water material into a gently inclined coal seam were studied.The basic mechanical properties of the new high-water material were investigated through laboratory experiments,and their main advantages were identifed.The reasonable width of the roadside flling wall of a high-water material was obtained by combining ground pressure observation and theoretical calculations.The distribution characteristics of the stress and plastic zone of surrounding rock of GER after being stabilized by the disturbance of the working face were studied using numerical simulations,and the failure range of GER by flling with high-water material was revealed.Based on this,a coupling control technology of anchor cables and bolts+single props+metal mesh+anchor bolts is proposed.Through the coupling methods of arranging borehole peeping and observing the convergences of surrounding rock,the results demonstrate that GER with double roadways by flling with a 1.8-m-wide high-water material has a good control efect.The above research will play an active role in promoting the application of high-water materials in GER roadside flling.
文摘Five experimental self-shielded flux cored wires are fabricated withdifferent amount of Fe_2O_3 in the flux. The effect of Fe_2O_3 on welding technology and mechanicalproperties of weld metals deposited by these wires are studied. The results show that with theincrease of Fe_2O_3 in the mix, the melting point of the pretreated mix is increased. LiBaF_3 andBaFe_(12)O_(19), which are very low in inherent moisture, are formed after the pretreatment. Themechanical properties are evaluated to the weld metals. The low temperature notch toughness of theweld metals is increased linearly with the Fe_2O_3 content in the flux due to the balance betweenFe_2O_3 and residual Al in the weld metal. The optimum Fe_2O_3 content in flux is 2.5 percent approx3.5 percent.
文摘The number of hazardous waste in our country increased dramatically in recent years,stabilization/solidification technology begins to attract a wide spread attention by domestic scholars.Based on the domestic related literature,this paper discussed the present situation about the treatment of the solid waste using stabilization/solidification technology;meanwhile we have a variety of outlooks on the future of the stabilization/solidification technology.
文摘With the development of the production scale and the increasing of the process technologies and facilities,product quality and the requirement of water supply continuously put forward new requirements to water treatment technology.The practice of the water saving technology should ensure the safe of water using and the innovation of technique data.Especially the stabilization of water quality should also meet the production at full capacity,reduce equipment failure rate and maintain the sustainable development under the condition of the minimal resource consumption.This article describes the practice of Baosteel saving technology,water-saving ideas from the system to start,according to Baosteel raw water intake requirements and process water and drainage characteristics,water and salt water tidal according to changes in the Yangtze River and the Yangtze River upstream and downstream trends in water discharge on water quality factors,established the electrical conductivity,chloride ion indicators for the control of the Yangtze River water,the implementation of'avoid salt build light'water at the same time,combined with the actual situation of water pollution in the Yangtze River,the use of force coefficient correlation theory,the implementation of'avoid taking clear pollution'to ensure the quality of raw water intake.System and cascade utilization of water,process water,based on whole plant water balance testing,analysis,technical parameters of the system and processes the user running the pressure balance pipe network,and implemented a stabilization system to adjust water pressure,reducing the water supply network systemwater loss;application of electrochemical principles,the implementation of the protection of underground pipes Baosteel,implemented a water use,steps to use,the operating mode of water supply in series to increase water reuse,reduce wastewater discharge system.Water quality stability and water-saving in the process;carry out water quality stability technology in the different complicated processes of the steel industry;apply the environmental protection and water quality,sterilization,non-phosphorus and low phosphorus technologies which are suitable for high concentration of circulating water.By these technologies,we achieved the water-saving in the process in different seasons and solved the technical problems affecting production such as equipment corrosion,scaling and the formation of the water quality proprietary technology under the conditions of high heat load production as well.The use of water ecological conservation and biological treatment technology:the implementation of the reservoir to the ecological technology is characterized by food chain and wetland environmental technology characterized by plants chain.Reservoir ecological management techniques in the use of natural conditions,wind direction,temperature,light and fish biomass in the reservoir water level regulation of balance and combination of organic,control and resolve the reservoirs in spring and summer algae problems and water quality changes rot of the'fresh'operating problems.The artificial wetland technology develops a new way for metallurgical plants'wastewater treatment.All the measures by the implementation of water to create the conditions for the system to achieve the water target of constant innovation,reaching the advanced level of iron and steel enterprises.
文摘Relaxed Stable Stability （RSS） in an important part of the active control technology. It is a new way to raise the flying speed, distance and maneuverability of missile. Depth study of RSS technology plays an important role for the new concept missile design. This paper describes the detailed definition of RSS and its advantages, pres- ents the research status and prospects for its application in the design of new missiles.
文摘BZ Oilfield is a medium-sized oilfield with shallow delta facies deposits in Bohai Bay of China,compared with fluvial and delta facies oilfields,there is no mature experience for reference of reservoir configuration,well pattern arrangement and development model in offshore oilfields in China.In view of the difficulty in describing the reservoir configuration of shallow water delta,the single distributary sand dam in shallow water delta is characterized by well-seismic combination and multi-attribute constraints.The mathematical mechanism model of pinch-out position of sand body is established,fine characterization of BZ shallow water delta reservoir is put forward.The horizontal well pattern arrangement type for shallow water delta reservoir is proposed and the method of well pattern optimization based on vertical displacement theory is put forward.A method of inversion of reservoir connectivity using production dynamic data by numerical well testing is proposed and a new method for optimizing water injection rate in water injection wells is proposed aiming at the difficulty of recognizing injection-production connectivity of shallow water delta reservoirs.The fine configuration of BZ shallow water delta reservoir based on distributary sand dam is proposed,which guides the recognition of remaining oil distribution law.By deploying adjustment wells,the water flooding coincidence degree of actual drilling is 86% compared with that of pre-drilling prediction,which indicates that the research results of reservoir configuration can effectively guide the understanding of oilfield geology.Through the theoretical well arrangement type of vertical displacement of single sand body in horizontal wells of shallow water delta reservoir,a high water flooding recovery rate of 35% is achieved in primary well pattern.The connectivity coefficients of injection-production boundary of shallow water delta reservoir configuration are calculated,and the water injection distribution coefficients are obtained by normalizing the directional coefficients.This paper presents a configuration method based on multi-attribute fusion under the constraints of sedimentary process.In this paper,a shallow water delta reservoir configuration method based on multi-attribute fusion constrained by sedimentary process is proposed,and the injection-production connectivity coefficient and injection well distribution coefficient of the configuration boundary are calculated.
文摘The purpose of given article-consideration of the basic features of modern manufacturing of nuclear fuel which would confirm fact, that the manufacturer does everything that its production would respond not only to requirements of the consumer, but also to its expected inquiries, and would correspond to intended purposes of fuel. It was defined main tendencies and features of modern technology, especially in nuclear fuel production, on base of meeting discussions, themes of journal articles on nuclear subject. They are correspond with practice of JSC NCCP （Novosibirsk Chemical Concentrates Plant） and listed in the paper. In result of it number of base features of any advanced technology, not only nuclear, described here with examples from NCCP＇s practice. Of course, there is no certain list of all attributes of modern manufacturing as there is no limit to its perfection. These categories are forming by current needs of the market, but listed ones must be.
文摘The application of small shore station technology to automatic water quality monitoring can not only ensure the stability of the work, but also ensure the reliability of the monitored data. In this paper, the stability and reliability of small shore technology are tested through experiments. The results show that the data monitoring of shore station is stable, and the data obtained are consistent with the actual water temperature, ph and other content, which is reliable.
文摘Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction industry.However,the construction of high-rise steel frame structures requires advanced technology.If the construction technology is effectively implemented and the welding techniques of the construction personnel align with the requirements for high-rise steel frame structures,it can help mitigate deformations in the steel structure,thus preserving the overall construction quality of high-rise steel frame structures.To enhance the applicability of steel frame structures in high-rise buildings,this paper focuses on analyzing the optimization path for the construction process of high-rise steel frame structures.It introduces a tailored approach to control welding-induced deformations in steel frame structures,aiming to make a valuable contribution to the advancement of China’s construction industry.
基金Project (50675072) supported by the National Natural Science Foundation of ChinaProject (2006F3084) supported by the Youth Innovation Found of Fujian Province, ChinaProject (06BS104) supported by the Science Research Found of Huaqiao University
文摘Two different technologies,electro-brush plating and arc spraying,were employed to deposit copper film and brass coating on the surface of nonmetal artworks,respectively. The principles of the oxidizing corrosion and coloring were researched. The nonmetal artworks attain vivid and ancient bronze effect by the surface deposition and surface coloring processing. By using this technology,the problems of difficulty-to-plating copper and difficulty-to-archaizing for the large outdoor sculptures and other artworks can be solved,and it has prospective application due to low investment.
文摘The number of hazardous waste in our country increased dramatically in recent years,stabilization/solidification technology begins to attract a wide spread attention by domestic scholars.Based on the domestic related literature,this paper discussed the present situation about the treatment of the solid waste using stabilization/solidification technology;meanwhile we have a variety of outlooks on the future of the stabilization/solidification technology.
基金supported by the National Key Research and Development Program of China for Young Scientists(Grant No.2023YFB4104100)National Natural Science Foundation of China(Grant 52176057 and 52304098)+3 种基金National Key Research and Development Program of China(Grant No.2023YFB4104201)supported by Unveiling and Commanding Foundation of Liaoning Province(Grant 2023JH1/10400003)Shenzhen Science and Technology Program(No.JCYJ20220818095605012)supported by the Young Changjiang Scholars programme of China.
文摘Hydrate-based carbon dioxide(CO_(2))sequestration(HBCS)technology utilizes naturally occurring high-pressure and low-temperature marine conditions to convert CO_(2) into solid hydrates within marine sediments,offering a promising complementary pathway for carbon emission reduction and large-scale marine sequestration.This review examines the current developments and challenges of HBCS from both scientific and engineering perspectives.First,we present the fundamental principles of HBCS,with particular emphasis on key mechanisms such as phase transition and pore sequestration.Then,we explore the mechanisms of hydrate nucleation and growth that influence core processes,as well as multi-scale stability characteristics from the microscopic to the macroscopic level.Furthermore,we systematically assess thermodynamic and kinetic factors affecting sequestration efficiency,including but not limited to marine reservoir types,injection strategies,and environmentally friendly additives.Subsequently,based on an integrated evaluation of environmental,social,and economic dimensions,we assess the development potential of HBCS technology.Finally,the primary challenges currently faced are identified,and future research directions are proposed.Overall,this review provides a comprehensive overview of the progress and challenges associated with HBCS,emphasizes its potential role in global carbon reduction efforts,and offers theoretical guidance for future industrial applications.
