Aim: To evaluate the comparative effectiveness of real-time sperm separation technique (Wang's tube method) andother two conventional methods in isolating high-quality sperm preparation, and to compare the spouse ...Aim: To evaluate the comparative effectiveness of real-time sperm separation technique (Wang's tube method) andother two conventional methods in isolating high-quality sperm preparation, and to compare the spouse pregnancy ratein intrauterine insemination (IUI) with sperm preparations isolated by these methods. Methods: The effectivenessof the real-time sperm separation technique, the conventional swim-up and the Percoll discontinuous density gradientmethods in isolating sperm preparations from 60 infertile patients (20 with apparently normal semen and 40, abnormalsemen contaminated with microorganisms and other impurities) was evaluated and compared. The microorganisms to beremoved included bacteria, vires, Chlamydia trachomaticum, Ureaplsama urealyticum, etc. The spouse pregnancyrates in IUI with sperm preparations isolated by these three techniques from 80 oligoasthenoteratospermic patients werealso compared. Results: The quality (including the percentages of normal form, normal-chromatin and motilesperm, and the grade of motility) of sperm obtained by the real-time sperm separation technique was much higher ( P< 0.01) as compared with those by the other two methods. The Wang's tube method was also more effective in remov-ing microorganisms and other impurities. The method provided a higher IUI pregnancy rate than the other two spermseparation techniques ( P < 0.05). Conclusion: The real-time sperm separation technique is the most effectivemethod so far available in isolating high-quality sperm samples to be used in assisted reproduction.展开更多
Membrane separation, a new technology for removing VOCs including pervaporation, vapor permeation, membrane contactor, and membrane bioreactor was presented. Comparing with traditional techniques, these special techni...Membrane separation, a new technology for removing VOCs including pervaporation, vapor permeation, membrane contactor, and membrane bioreactor was presented. Comparing with traditional techniques, these special techniques are an efficient and energy saving technology. Vapor permeation can be applied to recovery of organic solvents from exhaust streams. Membrane contactor could be used for removing or recovering VOCs from air or wastewater. Pervaporation and vapor permeation are viable methods for removing VOCs from wastewater to yield a VOC concentrate which could either be destroyed by conventional means, or be recycled for reuse.展开更多
【正】INTRODUCTION Femtosecond laser technology,introduced clinically for ophthalmic surgery as a technique for creating lamellar flaps in laser in situ keratomileusis(LASIK),has recently been developed into a tool fo...【正】INTRODUCTION Femtosecond laser technology,introduced clinically for ophthalmic surgery as a technique for creating lamellar flaps in laser in situ keratomileusis(LASIK),has recently been developed into a tool for cataract surgery.Preliminary experience for femtosecond laser-assisted cataract surgery show appropriate safety and efficacy,and possible advantage over conventional cataract surgery[1-4].The ability of the femtosecond laser to fragment the lens results in the need for less ultrasound energy to be expended inside the eye.Several studies indicate that less effective phacoemulsification time is needed to emulsify the lens展开更多
We show a method to separate the sound field radiated by a signal source from the sound field radiated by noise sources and to reconstruct the sound field radiated by the signal source. The proposed method is based on...We show a method to separate the sound field radiated by a signal source from the sound field radiated by noise sources and to reconstruct the sound field radiated by the signal source. The proposed method is based on reciprocity theorem and the Fourier transform. Both the sound field and its gradient on a measurement surface are needed in the method. Evanescent waves are considered in the method, which ensures a high resolution reconstruction in the near field region of the signal source when evanescent waves can be measured. A simulation is given to verify the method and the influence of measurement noise on the method is discussed.展开更多
Hydrograph separation is a fundamental catchment descriptor,revealing information about sources of water in runoff generation processes. The water isotopes are ideal tracers in studying hydrological processes since th...Hydrograph separation is a fundamental catchment descriptor,revealing information about sources of water in runoff generation processes. The water isotopes are ideal tracers in studying hydrological processes since the isotope fractionation produces a natural labeling effect within the hydrologic cycle. The water isotope technique has become one of effective means for investigating complex hydrologic system on a catchment scale. This paper reviews the progress on the use of stable water isotope techniques in catchment hydrograph separation in last decades. Also,the isotope mixing model for hydrograph separation and its uncertainties are explained in detail. In future research,there are three hot issues in the use of isotopic hydrograph separation（ IHS） ： integrating new approaches into IHS,calibration and verification of IHS model and IHS application in large river basins.展开更多
BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzy...BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzymatic methods for isolating these cells face challenges such as high costs,lengthy processing time,and regulatory complexities.AIM This systematic review aimed to assess the efficacy and practicality of nonenzymatic,mechanical methods for isolating SVF and ADSCs,comparing these to conventional enzymatic approaches.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across multiple databases.Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue.The risk of bias was assessed,and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.RESULTS Nineteen studies met the inclusion criteria,highlighting various mechanical techniques such as centrifugation,vortexing,and ultrasonic cavitation.The review identified significant variability in cell yield and viability,and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures.Despite some advantages of mechanical methods,including reduced processing time and avoidance of enzymatic reagents,the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.CONCLUSION Non-enzymatic,mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs,potentially simplifying the isolation process and reducing regulatory hurdles.However,further research is necessary to standardize these techniques and ensure consistent,high-quality cell yields for clinical applications.The development of efficient,safe,and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.展开更多
This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristic...This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption （PSA）, chemical absorption （CA）, and membrane absorption （MA）. Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.展开更多
In some oilfields with 3D seismic data, the deeper structure cannot be observed due to poor quality deep seismic data. Layer stripping using both seismic and gravity data is a solution for this problem but it cannot g...In some oilfields with 3D seismic data, the deeper structure cannot be observed due to poor quality deep seismic data. Layer stripping using both seismic and gravity data is a solution for this problem but it cannot get satisfactory results because the horizontal variations in formation density are ignored. We present a variable-density formation separation technique to address this problem. Based on 3D seismic depth data and laterallyvariable density derived from 3D seismic velocity data, the upper formation gravity effect is calculated by forward modeling and removed from the Bouguer gravity. The formation-separated gravity anomaly with variable density is obtained, which mainly reflects the deeper geological structure. In block XX of North Africa, the shallow formations seismic data is excellent but the data at the top of basement is poor. The formation-separated gravity anomaly processed under the control of 3D seismic data fits well with the known seismic interpretation and wells. It makes the geological interpretation more reliable.展开更多
The impacts of emissions from industry,power plant,transportation,residential,and biogenic sources on daily maximum surface ozone （O3DM） over the Beijing-Tianjin-Hebei （BTH） region in North China in the summer of ...The impacts of emissions from industry,power plant,transportation,residential,and biogenic sources on daily maximum surface ozone （O3DM） over the Beijing-Tianjin-Hebei （BTH） region in North China in the summer of 2007 were examined in a modeling study.The modeling system consisted of the Weather Research and Forecasting （WRF） model and the photochemical dispersion model,CAMx.The factor separation technique （FST） was used to quantify the effect of individual emission source types and the synergistic interactions among two or more types.Additionally,the effectiveness of emission reduction scenarios was explored.The industry,power plant,and transportation emission source types were found to be the most important in terms of their individual effects on O3DM.The key contributor to high surface O3 was power plant emissions,with a peak individual effect of 40 ppbv in the southwestern BTH area.The individual effect from the biogenic emission category was quite low.The synergistic effects from the combinations of each pair of anthropogenic emission types suppressed O3 formation,while the synergistic effects for combinations of three were favorable for O3 formation when the industrial and power plant emission source types coexisted.The quadruple synergistic effects were positive only with the combination of power plant,transportation,residential,and biogenic sources,while the quintuple synergistic effect showed only minor impacts on O3DM concentrations.A 30％ reduction in industrial and transportation sources produced the most effective impacts on O3 concentrations,with a maximum decrease of 20 ppbv.These results suggested that the synergistic impacts among emission source types should be considered when formulating emission control strategies for O3 reduction.展开更多
[Objective] The research aimed to establish a rapid detection method for Shigella. [Method] Combining immunomagnetic separation technology with ATP bioluminescence technology, a new kind of fast and accurate ATP biolu...[Objective] The research aimed to establish a rapid detection method for Shigella. [Method] Combining immunomagnetic separation technology with ATP bioluminescence technology, a new kind of fast and accurate ATP bioluminescence magnetic enzyme immunoassay technique for Shigella was established. [Result] Using ATP bioluminescence magnetic enzyme immunoassay technique to detect standard solution for Shigella （ATCC 25931 ）, result showed that correlation coefficient between relative light intensity detected by instrument and bacteria concentration detec- ted by culture counting method was 0.981 1. Moreover, relation curve between relative light intensity and Shigella concentration was drawn. [ Conclusion] The method had a high detection speed and accuracy, and could be used for the rapid detection of pathogen in food and environment.展开更多
Worldwide construction and demolition waste (CDW) is currently dumped. To close the building cycle and the building materials cycle by recycling CDW in high technical applications, the technical quality of stony mater...Worldwide construction and demolition waste (CDW) is currently dumped. To close the building cycle and the building materials cycle by recycling CDW in high technical applications, the technical quality of stony materials must be improved. For this purpose, concrete rubbles and brick rubbles, the two major stony constituents of CDW, should be separated from each other. Based on the differences in density and content of Fe-2O-3 between the two materials, a wet method of jigging and a dry method of magnetic separation are effective,tested.展开更多
An accurate evaluation of strongly singular domain integral appearing in the stress representation formula is a crucial problem in the stress analysis of functionally graded materials using boundary element method.To ...An accurate evaluation of strongly singular domain integral appearing in the stress representation formula is a crucial problem in the stress analysis of functionally graded materials using boundary element method.To solve this problem,a singularity separation technique is presented in the paper to split the singular integral into regular and singular parts by subtracting and adding a singular term.The singular domain integral is transformed into a boundary integral using the radial integration method.Analytical expressions of the radial integrals are obtained for two commonly used shear moduli varying with spatial coordinates.The regular domain integral,after expressing the displacements in terms of the radial basis functions,is also transformed to the boundary using the radial integration method.Finally,a boundary element method without internal cells is established for computing the stresses at internal nodes of the functionally graded materials with varying shear modulus.展开更多
Granular wastes have negative effects on the environment due to contamination. On the other hand, stony components in granular wastes have a potential good perspectives for utilization in civil engineering works as se...Granular wastes have negative effects on the environment due to contamination. On the other hand, stony components in granular wastes have a potential good perspectives for utilization in civil engineering works as secondary raw building materials. To reuse such materials without environmental risks, all contaminants must be removed or reduced to an acceptable level. Therefore liberation of materials is an important step in waste treatment. For this purpose, separation and cleansing techniques are suitable. Based on the analysis of contaminants in wastes, it is discussed how to select suitable techniques. The rules for technique selection and processes for quality improvement are set up. To evaluate the environmental quality and technical quality of output products, it is necessary to check leaching behaviours and physical properties.展开更多
PIMs(Polymer Inclusion Membranes)are popular in molecular transport in different solutions.Most often they are used in the transport and removal of ionic compounds,for example metal ions or organic ionic compounds.In ...PIMs(Polymer Inclusion Membranes)are popular in molecular transport in different solutions.Most often they are used in the transport and removal of ionic compounds,for example metal ions or organic ionic compounds.In this work,membranes were used as extraction devices for isolation of pharmaceuticals from water samples.PIMs were composed of CTA(Cellulose Triacetate)as polymeric matrix,2-NPOE(2-Nitrophenylo Octyl Ether)as plasticizer,and alkyl quaternary ammonium salt(Aliquat 336)was used as the carrier.The influence of the carrier and plasticizer presence on PIM’s extraction efficiency was described.This extraction deice was used for isolation of ibuprofen,ascorbic acid and paracetamol form water samples.The best retention percentage on polymer membranes was achieved between 80%-100%for three components membranes.The extraction ability of polymeric membranes was described and confirmed using HSP(Hansen Solubility Parameter)determined for each analyte and membrane components.Determination of these parameters allows describing the interaction between the analytes and membrane and concludes which membrane composition gives the best properties.All qualitative and quantitative analysis was done using HPLC(High Performance Liquid Chromatography).展开更多
Greenhouse gas monitoring on a broader scale is necessary to ensure that a cap-and-trade system is effective, reduces measurement uncertainty, and detects fraudulent or illegal activities. The recent strict air qualit...Greenhouse gas monitoring on a broader scale is necessary to ensure that a cap-and-trade system is effective, reduces measurement uncertainty, and detects fraudulent or illegal activities. The recent strict air quality regulation in livestock production facilities has accelerated the need for accurate on-farm determination of greenhouse gas (GHG) emission rates (ERs) from livestock operations in the United States under a wide range of production, management, and climate conditions. The estimation of GHG emissions from different ground-level sources or at a property line is a very complicated process, and such measurements require multidirectional expertise including engineering, micrometeorology, agronomy, applied physics, and chemistry. Accurate measurement of gaseous concentration from an emitting source is a prerequisite and of paramount importance for estimating emissions rates (ERs) using any micro-meteorological and sampling device-based method. This paper provides an overview of the state-of-the-art sensors and analyzers used to measure GHG concentrations. Sensor and analyzer selection and their performance in the laboratory and field were discussed. In addition, protocols for data quality control (QC) and quality assurance (QA) when deploying sensors in the area for long-term use were also discussed. In addition, the preparation of measurement systems, coupling of air samplers with sensing systems for measuring gaseous concentrations, and uncertainties inherent to such measurement methods as a whole to estimate ERs were discussed in this paper.展开更多
A factor separation technique and an improved regional air quality model （RAQM） were applied to calculate synergistic contributions of anthropogenic volatile organic compounds （AVOCs）,biogenic volatile organic com...A factor separation technique and an improved regional air quality model （RAQM） were applied to calculate synergistic contributions of anthropogenic volatile organic compounds （AVOCs）,biogenic volatile organic compounds （BVOCs） and nitrogen oxides （NOx） to daily maximum surface O3（O3DM） concentrations in East Asia in summer （June to August 2000）.The summer averaged synergistic impacts of AVOCs and NOx are dominant in most areas of North China,with a maximum of 60 ppbv,while those of BVOCs and NOx are notable only in some limited areas with high BVOC emissions in South China,with a maximum of 25 ppbv.This result implies that BVOCs contribute much less to summer averaged O3DM concentrations than AVOCs in most areas of East Asia at a coarse spatial resolution （1×1） although global emissions of BVOCs are much greater than those of AVOCs.Daily maximum total contributions of BVOCs can approach 20 ppbv in North China,but they can reach 40 ppbv in South China,approaching or exceeding those in some developed countries in Europe and North America.BVOC emissions in such special areas should be considered when O3 control measures are taken.Synergistic contributions among AVOCs,BVOCs and NOx significantly enhance O3 concentrations in the Beijing-Tianjin-Tangshan region and decrease them in some areas in South China.Thus,the total contributions of BVOCs to O3DM vary significantly from day to day and from location to location.This result suggests that O3 control measures obtained from episodic studies could be limited for long-term applications.展开更多
The mechanism for the maintenance of Tropical Cyclone Bill （1988） after landfall is investigated through a numerical simulation. The role of the large-scale environmental flow is examined using a scale separation te...The mechanism for the maintenance of Tropical Cyclone Bill （1988） after landfall is investigated through a numerical simulation. The role of the large-scale environmental flow is examined using a scale separation technique, which isolates the tropical cyclone from the environmental flow. The results show that Bill was embedded in a deep easterly-southeasterly environmental flow to the north-northeast of a large-scale depression and to the southwest of the western Pacific subtropical high. The depression had a quasi-barotropic structure in the mid-lower troposphere and propagated northwestward with a speed similar to the northwestward movement of Bill. The moisture budgets associated with both the large-scale and the tropical cyclone scale motions indicate that persistent low-level easterly-southeasterly flow transported moisture into the inner core of the tropical cyclone. The low-level circulation of the tropical cyclone transported moisture into the eyewall to support eyewall convection, providing sufficient latent heating to counteract energy loss due to surface friction and causing the storm to weaken relatively slowly after landfall. Warming and a westward extension of the upper-level easterly flow led to westward propagation of the environmental flow in the mid-lower troposphere. As a result, Bill was persistently embedded in an environment of deep easterly flow with high humidity, weak vertical wind shear, convergence in the lower troposphere, and divergence in the upper troposphere. These conditions are favorable for both significant intensification prior to landfall and maintenance of the tropical cyclone after landfall.展开更多
In this paper,we propose a new method,the variable separation technique,for obtaining a breather and rogue wave solution to the nonlinear evolution equation.Integrable systems of the derivative nonlinear Schr?dinger t...In this paper,we propose a new method,the variable separation technique,for obtaining a breather and rogue wave solution to the nonlinear evolution equation.Integrable systems of the derivative nonlinear Schr?dinger type are used as three examples to illustrate the effectiveness of the presented method.We then obtain a family of rational solutions.This family of solutions includes the Akhmediev breather,the Kuznetsov-Ma breather,versatile rogue waves,and various interactions of localized waves.Moreover,the main characteristics of these solutions are discussed and some graphics are presented.More importantly,our results show that more abundant and novel localized waves may exist in the multicomponent coupled equations than in the uncoupled ones.展开更多
基金Project suppocted by the Youth Science Research Foundation of the Department of Public Health,Guangdong Province(No.B199121)
文摘Aim: To evaluate the comparative effectiveness of real-time sperm separation technique (Wang's tube method) andother two conventional methods in isolating high-quality sperm preparation, and to compare the spouse pregnancy ratein intrauterine insemination (IUI) with sperm preparations isolated by these methods. Methods: The effectivenessof the real-time sperm separation technique, the conventional swim-up and the Percoll discontinuous density gradientmethods in isolating sperm preparations from 60 infertile patients (20 with apparently normal semen and 40, abnormalsemen contaminated with microorganisms and other impurities) was evaluated and compared. The microorganisms to beremoved included bacteria, vires, Chlamydia trachomaticum, Ureaplsama urealyticum, etc. The spouse pregnancyrates in IUI with sperm preparations isolated by these three techniques from 80 oligoasthenoteratospermic patients werealso compared. Results: The quality (including the percentages of normal form, normal-chromatin and motilesperm, and the grade of motility) of sperm obtained by the real-time sperm separation technique was much higher ( P< 0.01) as compared with those by the other two methods. The Wang's tube method was also more effective in remov-ing microorganisms and other impurities. The method provided a higher IUI pregnancy rate than the other two spermseparation techniques ( P < 0.05). Conclusion: The real-time sperm separation technique is the most effectivemethod so far available in isolating high-quality sperm samples to be used in assisted reproduction.
基金TheNationalNaturalScienceFoundationofChina (No .2 9836 16 0 )
文摘Membrane separation, a new technology for removing VOCs including pervaporation, vapor permeation, membrane contactor, and membrane bioreactor was presented. Comparing with traditional techniques, these special techniques are an efficient and energy saving technology. Vapor permeation can be applied to recovery of organic solvents from exhaust streams. Membrane contactor could be used for removing or recovering VOCs from air or wastewater. Pervaporation and vapor permeation are viable methods for removing VOCs from wastewater to yield a VOC concentrate which could either be destroyed by conventional means, or be recycled for reuse.
文摘【正】INTRODUCTION Femtosecond laser technology,introduced clinically for ophthalmic surgery as a technique for creating lamellar flaps in laser in situ keratomileusis(LASIK),has recently been developed into a tool for cataract surgery.Preliminary experience for femtosecond laser-assisted cataract surgery show appropriate safety and efficacy,and possible advantage over conventional cataract surgery[1-4].The ability of the femtosecond laser to fragment the lens results in the need for less ultrasound energy to be expended inside the eye.Several studies indicate that less effective phacoemulsification time is needed to emulsify the lens
基金Supported by the National Natural Science Foundation of China under Grant Nos 11374270 and 11674294
文摘We show a method to separate the sound field radiated by a signal source from the sound field radiated by noise sources and to reconstruct the sound field radiated by the signal source. The proposed method is based on reciprocity theorem and the Fourier transform. Both the sound field and its gradient on a measurement surface are needed in the method. Evanescent waves are considered in the method, which ensures a high resolution reconstruction in the near field region of the signal source when evanescent waves can be measured. A simulation is given to verify the method and the influence of measurement noise on the method is discussed.
基金Supported by the National Natural Science Foundation of China(41101066)the China Postdoctoral Science Foundation Funded Project(2013M532094)
文摘Hydrograph separation is a fundamental catchment descriptor,revealing information about sources of water in runoff generation processes. The water isotopes are ideal tracers in studying hydrological processes since the isotope fractionation produces a natural labeling effect within the hydrologic cycle. The water isotope technique has become one of effective means for investigating complex hydrologic system on a catchment scale. This paper reviews the progress on the use of stable water isotope techniques in catchment hydrograph separation in last decades. Also,the isotope mixing model for hydrograph separation and its uncertainties are explained in detail. In future research,there are three hot issues in the use of isotopic hydrograph separation（ IHS） ： integrating new approaches into IHS,calibration and verification of IHS model and IHS application in large river basins.
文摘BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzymatic methods for isolating these cells face challenges such as high costs,lengthy processing time,and regulatory complexities.AIM This systematic review aimed to assess the efficacy and practicality of nonenzymatic,mechanical methods for isolating SVF and ADSCs,comparing these to conventional enzymatic approaches.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across multiple databases.Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue.The risk of bias was assessed,and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.RESULTS Nineteen studies met the inclusion criteria,highlighting various mechanical techniques such as centrifugation,vortexing,and ultrasonic cavitation.The review identified significant variability in cell yield and viability,and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures.Despite some advantages of mechanical methods,including reduced processing time and avoidance of enzymatic reagents,the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.CONCLUSION Non-enzymatic,mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs,potentially simplifying the isolation process and reducing regulatory hurdles.However,further research is necessary to standardize these techniques and ensure consistent,high-quality cell yields for clinical applications.The development of efficient,safe,and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.
基金the China University of Petroleum Foundationthe Research Institute of Safety and Environment TechnologyChina National Petroleum Corporation
文摘This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption （PSA）, chemical absorption （CA）, and membrane absorption （MA）. Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.
文摘In some oilfields with 3D seismic data, the deeper structure cannot be observed due to poor quality deep seismic data. Layer stripping using both seismic and gravity data is a solution for this problem but it cannot get satisfactory results because the horizontal variations in formation density are ignored. We present a variable-density formation separation technique to address this problem. Based on 3D seismic depth data and laterallyvariable density derived from 3D seismic velocity data, the upper formation gravity effect is calculated by forward modeling and removed from the Bouguer gravity. The formation-separated gravity anomaly with variable density is obtained, which mainly reflects the deeper geological structure. In block XX of North Africa, the shallow formations seismic data is excellent but the data at the top of basement is poor. The formation-separated gravity anomaly processed under the control of 3D seismic data fits well with the known seismic interpretation and wells. It makes the geological interpretation more reliable.
基金jointly supported by a key project of the Chinese Academy of Sciences (Grant No. XDB05030301)the National Natural Science Foundation of China (Grant Nos. 40905055 and 41175105)the special fund of the State Key Joint Laboratory of Environment Simulation and Pollution Control (Grant No. 13K04ESPCP)
文摘The impacts of emissions from industry,power plant,transportation,residential,and biogenic sources on daily maximum surface ozone （O3DM） over the Beijing-Tianjin-Hebei （BTH） region in North China in the summer of 2007 were examined in a modeling study.The modeling system consisted of the Weather Research and Forecasting （WRF） model and the photochemical dispersion model,CAMx.The factor separation technique （FST） was used to quantify the effect of individual emission source types and the synergistic interactions among two or more types.Additionally,the effectiveness of emission reduction scenarios was explored.The industry,power plant,and transportation emission source types were found to be the most important in terms of their individual effects on O3DM.The key contributor to high surface O3 was power plant emissions,with a peak individual effect of 40 ppbv in the southwestern BTH area.The individual effect from the biogenic emission category was quite low.The synergistic effects from the combinations of each pair of anthropogenic emission types suppressed O3 formation,while the synergistic effects for combinations of three were favorable for O3 formation when the industrial and power plant emission source types coexisted.The quadruple synergistic effects were positive only with the combination of power plant,transportation,residential,and biogenic sources,while the quintuple synergistic effect showed only minor impacts on O3DM concentrations.A 30％ reduction in industrial and transportation sources produced the most effective impacts on O3 concentrations,with a maximum decrease of 20 ppbv.These results suggested that the synergistic impacts among emission source types should be considered when formulating emission control strategies for O3 reduction.
文摘[Objective] The research aimed to establish a rapid detection method for Shigella. [Method] Combining immunomagnetic separation technology with ATP bioluminescence technology, a new kind of fast and accurate ATP bioluminescence magnetic enzyme immunoassay technique for Shigella was established. [Result] Using ATP bioluminescence magnetic enzyme immunoassay technique to detect standard solution for Shigella （ATCC 25931 ）, result showed that correlation coefficient between relative light intensity detected by instrument and bacteria concentration detec- ted by culture counting method was 0.981 1. Moreover, relation curve between relative light intensity and Shigella concentration was drawn. [ Conclusion] The method had a high detection speed and accuracy, and could be used for the rapid detection of pathogen in food and environment.
文摘Worldwide construction and demolition waste (CDW) is currently dumped. To close the building cycle and the building materials cycle by recycling CDW in high technical applications, the technical quality of stony materials must be improved. For this purpose, concrete rubbles and brick rubbles, the two major stony constituents of CDW, should be separated from each other. Based on the differences in density and content of Fe-2O-3 between the two materials, a wet method of jigging and a dry method of magnetic separation are effective,tested.
基金supported by the National Natural Science Foundation of China(11172055 and 11202045)
文摘An accurate evaluation of strongly singular domain integral appearing in the stress representation formula is a crucial problem in the stress analysis of functionally graded materials using boundary element method.To solve this problem,a singularity separation technique is presented in the paper to split the singular integral into regular and singular parts by subtracting and adding a singular term.The singular domain integral is transformed into a boundary integral using the radial integration method.Analytical expressions of the radial integrals are obtained for two commonly used shear moduli varying with spatial coordinates.The regular domain integral,after expressing the displacements in terms of the radial basis functions,is also transformed to the boundary using the radial integration method.Finally,a boundary element method without internal cells is established for computing the stresses at internal nodes of the functionally graded materials with varying shear modulus.
文摘Granular wastes have negative effects on the environment due to contamination. On the other hand, stony components in granular wastes have a potential good perspectives for utilization in civil engineering works as secondary raw building materials. To reuse such materials without environmental risks, all contaminants must be removed or reduced to an acceptable level. Therefore liberation of materials is an important step in waste treatment. For this purpose, separation and cleansing techniques are suitable. Based on the analysis of contaminants in wastes, it is discussed how to select suitable techniques. The rules for technique selection and processes for quality improvement are set up. To evaluate the environmental quality and technical quality of output products, it is necessary to check leaching behaviours and physical properties.
基金supported by Polish Ministry of Science and Education.
文摘PIMs(Polymer Inclusion Membranes)are popular in molecular transport in different solutions.Most often they are used in the transport and removal of ionic compounds,for example metal ions or organic ionic compounds.In this work,membranes were used as extraction devices for isolation of pharmaceuticals from water samples.PIMs were composed of CTA(Cellulose Triacetate)as polymeric matrix,2-NPOE(2-Nitrophenylo Octyl Ether)as plasticizer,and alkyl quaternary ammonium salt(Aliquat 336)was used as the carrier.The influence of the carrier and plasticizer presence on PIM’s extraction efficiency was described.This extraction deice was used for isolation of ibuprofen,ascorbic acid and paracetamol form water samples.The best retention percentage on polymer membranes was achieved between 80%-100%for three components membranes.The extraction ability of polymeric membranes was described and confirmed using HSP(Hansen Solubility Parameter)determined for each analyte and membrane components.Determination of these parameters allows describing the interaction between the analytes and membrane and concludes which membrane composition gives the best properties.All qualitative and quantitative analysis was done using HPLC(High Performance Liquid Chromatography).
文摘Greenhouse gas monitoring on a broader scale is necessary to ensure that a cap-and-trade system is effective, reduces measurement uncertainty, and detects fraudulent or illegal activities. The recent strict air quality regulation in livestock production facilities has accelerated the need for accurate on-farm determination of greenhouse gas (GHG) emission rates (ERs) from livestock operations in the United States under a wide range of production, management, and climate conditions. The estimation of GHG emissions from different ground-level sources or at a property line is a very complicated process, and such measurements require multidirectional expertise including engineering, micrometeorology, agronomy, applied physics, and chemistry. Accurate measurement of gaseous concentration from an emitting source is a prerequisite and of paramount importance for estimating emissions rates (ERs) using any micro-meteorological and sampling device-based method. This paper provides an overview of the state-of-the-art sensors and analyzers used to measure GHG concentrations. Sensor and analyzer selection and their performance in the laboratory and field were discussed. In addition, protocols for data quality control (QC) and quality assurance (QA) when deploying sensors in the area for long-term use were also discussed. In addition, the preparation of measurement systems, coupling of air samplers with sensing systems for measuring gaseous concentrations, and uncertainties inherent to such measurement methods as a whole to estimate ERs were discussed in this paper.
基金supported by the National Natural Science Foundation of China(No.40905055,41175105)the Key Project of the Chinese Academy of Sciences(No.KZCX1-YW-06-04)
文摘A factor separation technique and an improved regional air quality model （RAQM） were applied to calculate synergistic contributions of anthropogenic volatile organic compounds （AVOCs）,biogenic volatile organic compounds （BVOCs） and nitrogen oxides （NOx） to daily maximum surface O3（O3DM） concentrations in East Asia in summer （June to August 2000）.The summer averaged synergistic impacts of AVOCs and NOx are dominant in most areas of North China,with a maximum of 60 ppbv,while those of BVOCs and NOx are notable only in some limited areas with high BVOC emissions in South China,with a maximum of 25 ppbv.This result implies that BVOCs contribute much less to summer averaged O3DM concentrations than AVOCs in most areas of East Asia at a coarse spatial resolution （1×1） although global emissions of BVOCs are much greater than those of AVOCs.Daily maximum total contributions of BVOCs can approach 20 ppbv in North China,but they can reach 40 ppbv in South China,approaching or exceeding those in some developed countries in Europe and North America.BVOC emissions in such special areas should be considered when O3 control measures are taken.Synergistic contributions among AVOCs,BVOCs and NOx significantly enhance O3 concentrations in the Beijing-Tianjin-Tangshan region and decrease them in some areas in South China.Thus,the total contributions of BVOCs to O3DM vary significantly from day to day and from location to location.This result suggests that O3 control measures obtained from episodic studies could be limited for long-term applications.
基金Supported by the National Natural Science Foundation of China (40675026)National (Key) Basic Research and Development (973) Program of China (2009CB421504)
文摘The mechanism for the maintenance of Tropical Cyclone Bill （1988） after landfall is investigated through a numerical simulation. The role of the large-scale environmental flow is examined using a scale separation technique, which isolates the tropical cyclone from the environmental flow. The results show that Bill was embedded in a deep easterly-southeasterly environmental flow to the north-northeast of a large-scale depression and to the southwest of the western Pacific subtropical high. The depression had a quasi-barotropic structure in the mid-lower troposphere and propagated northwestward with a speed similar to the northwestward movement of Bill. The moisture budgets associated with both the large-scale and the tropical cyclone scale motions indicate that persistent low-level easterly-southeasterly flow transported moisture into the inner core of the tropical cyclone. The low-level circulation of the tropical cyclone transported moisture into the eyewall to support eyewall convection, providing sufficient latent heating to counteract energy loss due to surface friction and causing the storm to weaken relatively slowly after landfall. Warming and a westward extension of the upper-level easterly flow led to westward propagation of the environmental flow in the mid-lower troposphere. As a result, Bill was persistently embedded in an environment of deep easterly flow with high humidity, weak vertical wind shear, convergence in the lower troposphere, and divergence in the upper troposphere. These conditions are favorable for both significant intensification prior to landfall and maintenance of the tropical cyclone after landfall.
文摘In this paper,we propose a new method,the variable separation technique,for obtaining a breather and rogue wave solution to the nonlinear evolution equation.Integrable systems of the derivative nonlinear Schr?dinger type are used as three examples to illustrate the effectiveness of the presented method.We then obtain a family of rational solutions.This family of solutions includes the Akhmediev breather,the Kuznetsov-Ma breather,versatile rogue waves,and various interactions of localized waves.Moreover,the main characteristics of these solutions are discussed and some graphics are presented.More importantly,our results show that more abundant and novel localized waves may exist in the multicomponent coupled equations than in the uncoupled ones.
