Under the impetus of environmental protection policies,the discharge requirements for leachate are becoming more and more stringent.Therefore,the treatment technology of landfill leachate has become a hot research top...Under the impetus of environmental protection policies,the discharge requirements for leachate are becoming more and more stringent.Therefore,the treatment technology of landfill leachate has become a hot research topic at present.In this paper,the chemical composition and water quality characteristics of landfill leachate were briefly introduced,and the characteristics and performance of nanofiltration technology were summarized at first.Afterwards,the recent advances in the application of nanofiltration combination technology in the treatment of landfill leachate at home and abroad were summarized,and the research and application of the combination of membrane separation,chemical coagulation,chemical oxidation and adsorption methods with nanofiltration membrane in the treatment of landfill leachate were mainly introduced.Finally,it is proposed that the combination of nanofiltration technology is feasible and economical,and its reasonable selection and optimization are the directions of future research and have good application prospects.展开更多
The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propaga...The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propagation, spatial diversity equalization is the main technical means. The paper combines the passive phase conjugation and spatial processing to maximize the output array gain. It uses signal-to-noise-plus-interference to evaluate the quality of signals received at different channels. The amplitude of signal is weighted using Sigmoid function. Second order PLL can trace the phase variation caused by channel, so the signal can be accumulated in the same phase. The signals received at different channels need to be normal- ized. It adopts fractional-decision feedback diversity equalizer （FDFDE） and achieves diversity equalization by using different channel weighted coefficients. The simulation and lake trial data processing results show that, the optimized diversity receiving equalization algorithm can im- prove communication system＇s ability in tracking the change of underwater acoustic channel, offset the impact of multipath and noise and improve the performance of communication system. The performance of the communication receiving system is better than that of the equal gain combination. At the same time, the bit error rate （BER） reduces 1.8%.展开更多
Addressing the challenges of passive Radio Frequency Identification(RFID)indoor localization technology in Non-Line-of-Sight(NLoS)and multipath environments,this paper presents an innovative approach by introducing a ...Addressing the challenges of passive Radio Frequency Identification(RFID)indoor localization technology in Non-Line-of-Sight(NLoS)and multipath environments,this paper presents an innovative approach by introducing a combined technology integrating an improved Kalman Filter with Space Domain Phase Difference of Arrival(SD-PDOA)and Received Signal Strength Indicator(RSSI).This methodology utilizes the distinct channel characteristics in multipath and NLoS contexts to effectively filter out interference and accurately extract localization information,thereby facilitating high precision and stability in passive RFID localization.The efficacy of this approach is demonstrated through detailed simulations and empirical tests conducted on a custom-built experimental platform consisting of passive RFID tags and an R420 reader.The findings are significant:in NLoS conditions,the four-antenna localization system achieved a notable localization accuracy of 0.25 m at a distance of 5 m.In complex multipath environments,this system achieved a localization accuracy of approximately 0.5 m at a distance of 5 m.When compared to conventional passive localization methods,our proposed solution exhibits a substantial improvement in indoor localization accuracy under NLoS and multipath conditions.This research provides a robust and effective technical solution for high-precision passive indoor localization in the Internet of Things(IoT)system,marking a significant advancement in the field.展开更多
Our study group has developed a unique combined ters from the industries of dyestuff, pharmaceutical, chemical biological technology to treat high-strength organic wastewaengineering and zymolysis by using the princip...Our study group has developed a unique combined ters from the industries of dyestuff, pharmaceutical, chemical biological technology to treat high-strength organic wastewaengineering and zymolysis by using the principles of anaerobic ecological niche and bio-phase separation. The study obtained five national invention patents and eight patent equipments. This technology contains four kernel processes - two-phase anaerobic-aerobic process, hydrolysis-acidification-oxidation process, UASBAF-oxidation process, and internal cycling-hydrolysis-oxidation process. Fifteen pilot projects were accomplished in the basins of Tai Lake, Huai River, Liao River and Songhua River, and their total capital investment reached 185.214 million Yuan （RMB）. Compared to conventional wastewater treatment technology, the innovative technology is more costeffective for high-strength organic wastewater treatment, can save capital investment by 15% - 30%, lessen land usage by 20% to 40% and decrease the operating cost by 10% to 25%. The operating cost of treatment per cubic meter industrial wastewater could be below 0.6 to 1.4 Yuan （RMB）.展开更多
An combined technology of pressure pretreatment with oxygen on refractory gold ores is pointed out and discussed on this paper, according to the experiments included the test in 1 kg grade batch pressure pretreatment ...An combined technology of pressure pretreatment with oxygen on refractory gold ores is pointed out and discussed on this paper, according to the experiments included the test in 1 kg grade batch pressure pretreatment with oxygen of the concentrate from the refractory gold ores of Dongbeizhai in Sichuan province, which is called the most refractory gold ores in China. It is shown that gold recovery reach 91.73% in the combined process which is described as follows: The flotation of the sulphide gold ores is under controlled conditions, producing the concentrate for pressure pretreatment with oxygen in acidic medium and the middling for the pressure pretreatment with oxygen in alkaline medium. The thickening and washing process substitute the pressure filtration process of the pulp after pressure pretreatment. The thick slimes of the two kinds of pressure pretreatment were mixed and then enter the CIL process for simplifying the flowsheet. The possible superabundance of acid of pressure pretreatment with oxygen in acidic medium was neutralized by the tailings of flotation and the cost of neutralization will be lower. The combined technology of pressure pretreatment with oxygen has the same advantages as the normal technology of pressure pretreatment and both is helpful for environment protection.展开更多
There are two sets of thermal reservoirs with different rock types in the Gucheng geothermalfield of Hebei Province,namely the Ordovician fractured carbonate thermal reservoir and the Neogene Guantao sandstone thermal...There are two sets of thermal reservoirs with different rock types in the Gucheng geothermalfield of Hebei Province,namely the Ordovician fractured carbonate thermal reservoir and the Neogene Guantao sandstone thermal reservoir,each developed using independent well networks.The energy demand per unit area in the region is high,and the existing geothermal development methods cannot meet the regional energy demand.For this type of block,combined with the development characteristics of different types of thermal reservoirs,numerical simulation methods were used to study the geothermal development trends of Ordovician fractured carbonate reservoirs and Neogene Guantao Formation sandstone reservoirs.When simulating sandstone thermal storage,priority should be given to demonstrating the optimal rechargeflow rate,while in simulating carbonate thermal storage,the focus should be on considering the influence of fracture development direction on development trends.Through numerical simulation of thermal storage development and combined with well network design,the optimal well spacing,production reinjectionflow rate,and reinjection temperature for two sets of thermal reservoirs developed using the same well network were determined.It is predicted that the average heatflow in the study can increase by 47.8%.This study presents reasonable development technical countermeasures to maximize the heating capacity of the geothermal development zone and provides an effective reference for the efficient development of similar geothermal resources in the Bohai Bay Basin.展开更多
Shijiuyang Constructed Wetland（110 hm^2） is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water ...Shijiuyang Constructed Wetland（110 hm^2） is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water in the Xincheng River every day and supplies raw water for Shijiuyang Drinking Water Plant. Daily data for 28 months indicated that the major water quality indexes of source water had been improved by one grade. The percentage increase for dissolved oxygen and the removal rates of ammonia nitrogen, iron and manganese were 73.63%, 38.86%, 35.64%, and 22.14% respectively. The treatment performance weight of ponds and plant-bed/ditch systems was roughly equal but they treated different pollutants preferentially. Most water quality indexes had better treatment efficacy with increasing temperature and inlet concentrations. These results revealed that the pond–wetland complexes exhibited strong buffering capacity for source water quality improvement. The treatment cost of Shijiuyang Drinking Water Plant was reduced by about 30.3%. Regional rainfall significantly determined the external river water levels and adversely deteriorated the inlet water quality, thus suggesting that the ＂hidden＂ diffuse pollution in the multitudinous stream branches as well as their catchments should be the controlling emphases for river source water protection in the future. The combination of pond and plant-bed/ditch systems provides a successful paradigm for drinking water source pretreatment. Three other drinking water source treatment wetlands with ponds and plant-bed/ditch systems are in operation or construction in the stream networks of the Yangtze River Delta and more people will be benefited.展开更多
Thin-film beam combining technology is an effective approach to improve output power while maintaining beam quality However,the lack of comprehensive research into the key factors affecting the beam quality in systems...Thin-film beam combining technology is an effective approach to improve output power while maintaining beam quality However,the lack of comprehensive research into the key factors affecting the beam quality in systems makes it challenging to achieve a practical combined beam source with high brightness.This paper clearly established that the temperature rise of dichroic mirrors (DMs) and sub-beam overlapping precision are the main factors affecting the beam quality of the system,with quantified effects.Based on this understanding,a combined light source of four channels of3 kW fiber lasers was achieved,and an output power of 11.4 kW with a beam quality of M_(x)^(2)=1.601 and M_(y)^(2)=1.558using three high-steepness low-absorption DMs and the active control technique.To the best of our knowledge,this is the best beam quality for a 10 kW light source.This study offers a solution for practical high-power laser sources in the tens of kilowatts range.展开更多
Augmented reality(AR)displays are emerging as the next generation of interactive platform,providing deeper humandigital interactions and immersive experiences beyond traditional flat-panel displays.Diffractive wavegui...Augmented reality(AR)displays are emerging as the next generation of interactive platform,providing deeper humandigital interactions and immersive experiences beyond traditional flat-panel displays.Diffractive waveguide is a promising optical combiner technology for AR owing to its potential for the slimmest geometry and lightest weight.However,severe chromatic aberration of diffractive coupler has constrained widespread adoption of diffractive waveguide.Wavelength-dependent light deflection,caused by dispersion in both in-coupling and out-coupling processes,results in limited full-color field of view(FOV)and nonuniform optical responses in color and angular domains.Here we introduce an innovative full-color AR system that overcomes this long-standing challenge of chromatic aberration using a combination of inverse-designed metasurface couplers and a high refractive index waveguide.The optimized metasurface couplers demonstrate true achromatic behavior across the maximum FOV supported by the waveguide(exceeding 45°).Our AR prototype based on the designed metasurface waveguide,exhibits superior color accuracy and uniformity.This unique achromatic metasurface waveguide technology is expected to advance the development of visually compelling experience in compact AR display systems.展开更多
We represent a design of a 20 W, fiber-coupled diode laser module based on 26 single emitters at 520 nm. The module can produce more than 20 W output power from a standard fiber with core diameter of 400 Hm and numeri...We represent a design of a 20 W, fiber-coupled diode laser module based on 26 single emitters at 520 nm. The module can produce more than 20 W output power from a standard fiber with core diameter of 400 Hm and numerical aperture （NA） of 0.22. To achieve a 20 W laser beam, the spatial beam combination and polarization beam combination by polarization beam splitter are used to combine output of 26 single emitters into a single beam, and then an aspheric lens is used to couple the combined beam into an optical fiber. The simulation shows that the total coupling efficiency is more than 95%.展开更多
基金Supported by Science and Technology Project of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.(YCSY2020kyA-14).
文摘Under the impetus of environmental protection policies,the discharge requirements for leachate are becoming more and more stringent.Therefore,the treatment technology of landfill leachate has become a hot research topic at present.In this paper,the chemical composition and water quality characteristics of landfill leachate were briefly introduced,and the characteristics and performance of nanofiltration technology were summarized at first.Afterwards,the recent advances in the application of nanofiltration combination technology in the treatment of landfill leachate at home and abroad were summarized,and the research and application of the combination of membrane separation,chemical coagulation,chemical oxidation and adsorption methods with nanofiltration membrane in the treatment of landfill leachate were mainly introduced.Finally,it is proposed that the combination of nanofiltration technology is feasible and economical,and its reasonable selection and optimization are the directions of future research and have good application prospects.
基金supported by National Natural Science Foundation of China(61531018)
文摘The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propagation, spatial diversity equalization is the main technical means. The paper combines the passive phase conjugation and spatial processing to maximize the output array gain. It uses signal-to-noise-plus-interference to evaluate the quality of signals received at different channels. The amplitude of signal is weighted using Sigmoid function. Second order PLL can trace the phase variation caused by channel, so the signal can be accumulated in the same phase. The signals received at different channels need to be normal- ized. It adopts fractional-decision feedback diversity equalizer （FDFDE） and achieves diversity equalization by using different channel weighted coefficients. The simulation and lake trial data processing results show that, the optimized diversity receiving equalization algorithm can im- prove communication system＇s ability in tracking the change of underwater acoustic channel, offset the impact of multipath and noise and improve the performance of communication system. The performance of the communication receiving system is better than that of the equal gain combination. At the same time, the bit error rate （BER） reduces 1.8%.
基金supported in part by the Joint Project of National Natural Science Foundation of China(U22B2004,62371106)in part by China Mobile Research Institute&X-NET(Project Number:2022H002)+6 种基金in part by the Pre-Research Project(31513070501)in part by National Key R&D Program(2018AAA0103203)in part by Guangdong Provincial Research and Development Plan in Key Areas(2019B010141001)in part by Sichuan Provincial Science and Technology Planning Program of China(2022YFG0230,2023YFG0040)in part by the Fundamental Enhancement Program Technology Area Fund(2021-JCJQ-JJ-0667)in part by the Joint Fund of ZF and Ministry of Education(8091B022126)in part by Innovation Ability Construction Project for Sichuan Provincial Engineering Research Center of Communication Technology for Intelligent IoT(2303-510109-04-03-318020).
文摘Addressing the challenges of passive Radio Frequency Identification(RFID)indoor localization technology in Non-Line-of-Sight(NLoS)and multipath environments,this paper presents an innovative approach by introducing a combined technology integrating an improved Kalman Filter with Space Domain Phase Difference of Arrival(SD-PDOA)and Received Signal Strength Indicator(RSSI).This methodology utilizes the distinct channel characteristics in multipath and NLoS contexts to effectively filter out interference and accurately extract localization information,thereby facilitating high precision and stability in passive RFID localization.The efficacy of this approach is demonstrated through detailed simulations and empirical tests conducted on a custom-built experimental platform consisting of passive RFID tags and an R420 reader.The findings are significant:in NLoS conditions,the four-antenna localization system achieved a notable localization accuracy of 0.25 m at a distance of 5 m.In complex multipath environments,this system achieved a localization accuracy of approximately 0.5 m at a distance of 5 m.When compared to conventional passive localization methods,our proposed solution exhibits a substantial improvement in indoor localization accuracy under NLoS and multipath conditions.This research provides a robust and effective technical solution for high-precision passive indoor localization in the Internet of Things(IoT)system,marking a significant advancement in the field.
文摘Our study group has developed a unique combined ters from the industries of dyestuff, pharmaceutical, chemical biological technology to treat high-strength organic wastewaengineering and zymolysis by using the principles of anaerobic ecological niche and bio-phase separation. The study obtained five national invention patents and eight patent equipments. This technology contains four kernel processes - two-phase anaerobic-aerobic process, hydrolysis-acidification-oxidation process, UASBAF-oxidation process, and internal cycling-hydrolysis-oxidation process. Fifteen pilot projects were accomplished in the basins of Tai Lake, Huai River, Liao River and Songhua River, and their total capital investment reached 185.214 million Yuan （RMB）. Compared to conventional wastewater treatment technology, the innovative technology is more costeffective for high-strength organic wastewater treatment, can save capital investment by 15% - 30%, lessen land usage by 20% to 40% and decrease the operating cost by 10% to 25%. The operating cost of treatment per cubic meter industrial wastewater could be below 0.6 to 1.4 Yuan （RMB）.
文摘An combined technology of pressure pretreatment with oxygen on refractory gold ores is pointed out and discussed on this paper, according to the experiments included the test in 1 kg grade batch pressure pretreatment with oxygen of the concentrate from the refractory gold ores of Dongbeizhai in Sichuan province, which is called the most refractory gold ores in China. It is shown that gold recovery reach 91.73% in the combined process which is described as follows: The flotation of the sulphide gold ores is under controlled conditions, producing the concentrate for pressure pretreatment with oxygen in acidic medium and the middling for the pressure pretreatment with oxygen in alkaline medium. The thickening and washing process substitute the pressure filtration process of the pulp after pressure pretreatment. The thick slimes of the two kinds of pressure pretreatment were mixed and then enter the CIL process for simplifying the flowsheet. The possible superabundance of acid of pressure pretreatment with oxygen in acidic medium was neutralized by the tailings of flotation and the cost of neutralization will be lower. The combined technology of pressure pretreatment with oxygen has the same advantages as the normal technology of pressure pretreatment and both is helpful for environment protection.
基金Science and Technology Project of China Petroleum and Chemical Corporation Limited(No.KLJP23008).
文摘There are two sets of thermal reservoirs with different rock types in the Gucheng geothermalfield of Hebei Province,namely the Ordovician fractured carbonate thermal reservoir and the Neogene Guantao sandstone thermal reservoir,each developed using independent well networks.The energy demand per unit area in the region is high,and the existing geothermal development methods cannot meet the regional energy demand.For this type of block,combined with the development characteristics of different types of thermal reservoirs,numerical simulation methods were used to study the geothermal development trends of Ordovician fractured carbonate reservoirs and Neogene Guantao Formation sandstone reservoirs.When simulating sandstone thermal storage,priority should be given to demonstrating the optimal rechargeflow rate,while in simulating carbonate thermal storage,the focus should be on considering the influence of fracture development direction on development trends.Through numerical simulation of thermal storage development and combined with well network design,the optimal well spacing,production reinjectionflow rate,and reinjection temperature for two sets of thermal reservoirs developed using the same well network were determined.It is predicted that the average heatflow in the study can increase by 47.8%.This study presents reasonable development technical countermeasures to maximize the heating capacity of the geothermal development zone and provides an effective reference for the efficient development of similar geothermal resources in the Bohai Bay Basin.
基金upported by the National Natural Science Foundation of China (No. 51278487)the Major National Water Pollution Control and Management Project of China (Nos. 2012ZX07403-003-03, 2008ZX07421-001)+1 种基金the National Basic Research Program (973) of China (No. 2009CB421103)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX2-EW-410-05)
文摘Shijiuyang Constructed Wetland（110 hm^2） is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water in the Xincheng River every day and supplies raw water for Shijiuyang Drinking Water Plant. Daily data for 28 months indicated that the major water quality indexes of source water had been improved by one grade. The percentage increase for dissolved oxygen and the removal rates of ammonia nitrogen, iron and manganese were 73.63%, 38.86%, 35.64%, and 22.14% respectively. The treatment performance weight of ponds and plant-bed/ditch systems was roughly equal but they treated different pollutants preferentially. Most water quality indexes had better treatment efficacy with increasing temperature and inlet concentrations. These results revealed that the pond–wetland complexes exhibited strong buffering capacity for source water quality improvement. The treatment cost of Shijiuyang Drinking Water Plant was reduced by about 30.3%. Regional rainfall significantly determined the external river water levels and adversely deteriorated the inlet water quality, thus suggesting that the ＂hidden＂ diffuse pollution in the multitudinous stream branches as well as their catchments should be the controlling emphases for river source water protection in the future. The combination of pond and plant-bed/ditch systems provides a successful paradigm for drinking water source pretreatment. Three other drinking water source treatment wetlands with ponds and plant-bed/ditch systems are in operation or construction in the stream networks of the Yangtze River Delta and more people will be benefited.
基金supported by the National Natural Science Foundation of China (Nos. 62061136008, 62275196, 62192772, 62305251, 61925504, 61975153, 6201101335, 62020106009, 62192770 and 61621001)Science and Technology Commission of Shanghai Municipality (Nos. 17JC1400800, 20JC1414600 and 21JC1406100)+3 种基金Special Development Funds for Major Projects of Shanghai Zhangjiang National Independent Innovation Demonstration Zone (No. ZJ2021-ZD-008)Shanghai Municipal Science and Technology Major Project (No. 2021SHZDZX0100)Fundamental Research Funds for the Central UniversitiesNational Key R&D Program of China (No. 2022YFA1603403)。
文摘Thin-film beam combining technology is an effective approach to improve output power while maintaining beam quality However,the lack of comprehensive research into the key factors affecting the beam quality in systems makes it challenging to achieve a practical combined beam source with high brightness.This paper clearly established that the temperature rise of dichroic mirrors (DMs) and sub-beam overlapping precision are the main factors affecting the beam quality of the system,with quantified effects.Based on this understanding,a combined light source of four channels of3 kW fiber lasers was achieved,and an output power of 11.4 kW with a beam quality of M_(x)^(2)=1.601 and M_(y)^(2)=1.558using three high-steepness low-absorption DMs and the active control technique.To the best of our knowledge,this is the best beam quality for a 10 kW light source.This study offers a solution for practical high-power laser sources in the tens of kilowatts range.
基金supported by the National Key Research and Development Program of China(No.2022YFB3602903)Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting(No.2017KSYS007)+2 种基金Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting(No.ZDSYS201707281632549)Shenzhen Science and Technology Program(No.JCYJ20220818100411025)Shenzhen Development and Reform Commission Project(Grant No.XMHT20220114005).
文摘Augmented reality(AR)displays are emerging as the next generation of interactive platform,providing deeper humandigital interactions and immersive experiences beyond traditional flat-panel displays.Diffractive waveguide is a promising optical combiner technology for AR owing to its potential for the slimmest geometry and lightest weight.However,severe chromatic aberration of diffractive coupler has constrained widespread adoption of diffractive waveguide.Wavelength-dependent light deflection,caused by dispersion in both in-coupling and out-coupling processes,results in limited full-color field of view(FOV)and nonuniform optical responses in color and angular domains.Here we introduce an innovative full-color AR system that overcomes this long-standing challenge of chromatic aberration using a combination of inverse-designed metasurface couplers and a high refractive index waveguide.The optimized metasurface couplers demonstrate true achromatic behavior across the maximum FOV supported by the waveguide(exceeding 45°).Our AR prototype based on the designed metasurface waveguide,exhibits superior color accuracy and uniformity.This unique achromatic metasurface waveguide technology is expected to advance the development of visually compelling experience in compact AR display systems.
基金supported by the National Key R&D Program of China(No.2016YFB0402105)the Key Deployment Program of the Chinese Academy of Sciences(No.KGZD-SW-T01-2)the National Natural Science Foundation of China(No.61404135)
文摘We represent a design of a 20 W, fiber-coupled diode laser module based on 26 single emitters at 520 nm. The module can produce more than 20 W output power from a standard fiber with core diameter of 400 Hm and numerical aperture （NA） of 0.22. To achieve a 20 W laser beam, the spatial beam combination and polarization beam combination by polarization beam splitter are used to combine output of 26 single emitters into a single beam, and then an aspheric lens is used to couple the combined beam into an optical fiber. The simulation shows that the total coupling efficiency is more than 95%.
