This work established a quantitative method to access the shear stability of aerobic granular sludge(AGS)and validated its feasibility by using the mature AGS from a pilot-scale(50 tons/day)membrane bioreactor(MBR)for...This work established a quantitative method to access the shear stability of aerobic granular sludge(AGS)and validated its feasibility by using the mature AGS from a pilot-scale(50 tons/day)membrane bioreactor(MBR)for treating real municipal wastewater.The results showed that the changing rate( S)of the peak area(S)of granule size distribution(GSD)exhibited an exponential relationship(R^(2)≥0.76)with the shear time(y=a−b·c^(x)),which was a suitable indicative index to reflect the shear stability of different AGS samples.The limiting granule size(LGS)was defined and proposed to characterize the equilibrium size for AGS after being sheared for a period of time,whose value in terms of Dv50 showed high correlation(R^(2)=0.92)with the parameter a.The free Ca^(2+)(28.44-34.21 mg/L)in the influent specifically interacted with polysaccharides(PS)in the granule’s extracellular polymeric substance(EPS)as a nucleation site,thereby inducing the formation of Ca precipitation to enhance its Young’s modulus,while Ca^(2+) primarily interacted with PS in soluble metabolic product(SMP)during the initial granulation process.Furthermore,the Young’s modulus significantly affected the parameter a related to shear stability(R^(2)=0.99).Since the parameter a was more closely related(R^(2)=1.00)to S than that of the parameter b or c,the excellent correlation(R^(2)=0.99)between the parameter a and the wet density further verified the feasibility of this method.展开更多
To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and...To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and decrease the energy cost further,we report a new carbon capture approach using a 2-methylimidazole(mIm)aqueous solution.The properties and sorption behaviors of this approach have been experimentally investigated.The results show that the mIm solution has higher CO_(2) absorption capacity under relatively higher equilibrium pressure(>130 kPa)and lower desorption heat than the methyldiethanolamine solution.91.6%sorption capacity of mIm solution can be recovered at 353.15 K and 80 kPa.The selectivity for CO_(2)/N_(2) and CO_(2)/CH_(4) can reach an exceptional 7609 and 4324,respectively.Furthermore,the pilot-scale tests were also performed,and the results demonstrate that more than 98%of CO_(2) in the feed gas could be removed and cyclic absorption capacity can reach 1 mol·L^(-1).This work indicates that mIm is an excellent alternative to alkanolamines for carbon capture in the industry.展开更多
The widespread use of pesticides has caused serious harm to ecosystems,necessitating effective and environmentally friendly treatment methods.Bioremediation stands out as a promising approach for pollutant treatment,w...The widespread use of pesticides has caused serious harm to ecosystems,necessitating effective and environmentally friendly treatment methods.Bioremediation stands out as a promising approach for pollutant treatment,wherein the metabolic activities of microorganisms can transform toxic pesticides into compounds with lower or no toxicity.In this study,we obtained eight pesticide-degrading strains from pesticide-contaminated sites through continuous enrichment and screening.Four highly efficient pesticide-degrading strains(degradation ratios exceeding 80%)were identified.Among them,Pseudomonas sp.BL5 exhibited the strongest growth(exceeding 10^(9) CFU·ml^(-1))and outstanding degradation of benzene derivatives and chlorinated hydrocarbons at both laboratory and pilot scales,with degradation ratios exceeding 98%and 99.6%,respectively.This research provides new tools and insights for the bioremediation of pesticide-related pollutants.展开更多
Under the guidance of strain tolerance, a new combination method for crude oil-degrading bacterial consortium was studied. Firstly, more than 50 efficient crude oil-degrading and biosurfactant producing bacteria were ...Under the guidance of strain tolerance, a new combination method for crude oil-degrading bacterial consortium was studied. Firstly, more than 50 efficient crude oil-degrading and biosurfactant producing bacteria were isolated from petroleum-contaminated soil and water in Tianjin Binhai New Area Oil field, China. Twenty-four of them were selected for further study. These strains were identified as belonging Pseudornonas aeruginosa, Bacillus subtilis, Brevibacillus brevis, Achrornobacter sp., Acinetobacter venetianus, Lysinibacillus rnacroides, Klebsiella oxytoca, Stenotrophornonas rhizophila, Rhodococcus sp. and Bacillus thuringiensis. A shake-flask degradation test revealed that 12 of these strains could degrade over 50% of 1% crude oil concentration in 7 d. Of these, 8 strains were able to produce biosurfactants. Furthermore, environmental tolerance experiments indicated that the majority of the strains had the ability to adapt to extreme environments including high temperatures, alkaline en- vironments and high salinity environments. A mixed bacterial agent comprising the strains WB2, W2, W3 and HA was developed based on the environmental tolerance tests and subjected to the pilot-scale degradation test indicating that this bacterial agent could degrade 85.2% of 0.8% crude oil concentration in 60 d. Our results suggest that the application of this mixed agent could remediate crude oil polluted soils in saline and alkaline environments.展开更多
With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist i...With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist in the field testing methodologies for wave energy converters(WECs).In this paper,a numerical wave field of the Dawanshan Island Sea Area in Zhuhai City is constructed based on the MIKE21 SW wave model and by using an NCEP wind field driving model.In conjunction with the IEC-62600-100 standard,by taking site testing of the“Wanshan”wave energy converter on which a sea trial has been conducted in Dawanshan Island of Zhuhai city as an example,research on-site testing method for a wave energy converter has been carried out.The wave measurement position for the“Wanshan”converter was determined by combining statistically analyzed field data with a validated numerical wave model.By comparing a valid wave height at the position where a wave rider is located with a valid wave height at the position where the“Wanshan”wave energy converter is situated,the correlation coefficient between simulation and observed data reached 0.90,with a root-mean-square error of 0.19.The representativeness of wave measurement data during site testing is verified and can be used as a basis for calculating the input energy of the“Wanshan”wave energy converter.展开更多
Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the su...Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the substantial pressures exerted by vehicles,trains,and other forms of transportation,but also efficiently transfer these loads to the underlying foundation,ensuring the stability and longevity of the roadway.In recent years,advancements in subgrade engineering technology have propelled the industry towards smarter,greener,and more sustainable practices,particularly in the areas of intelligent monitoring,disaster management,and innovative construction methods.This paper reviews the application and methodologies of intelligent testing equipment,including cone penetration testing(CPT)devices,soil resistivity testers,and intelligent rebound testers,in subgrade engineering.It examines the operating principles,advantages,limitations,and application ranges of these tools in subgrade testing.Additionally,the paper evaluates the practical use of advanced equipment from both domestic and international perspectives,addressing the challenges encountered by various instruments in realworld applications.These devices enable precise,comprehensive testing and evaluation of subgrade conditions at different stages,providing real-time data analysis and intelligent early warnings.This supports effective subgrade health management and maintenance.As intelligent technologies continue to evolve and integrate,these tools will increasingly enhance the accuracy,efficiency,and sustainability of subgrade monitoring.展开更多
Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the...Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the solidification time of conventional cement paste is long when shotcrete is used to treat cohesionless soil landslide.The idea of reinforcing slope with polyurethane solidified soil(i.e.,mixture of polyurethane and sand)was proposed.Model tests and finite element analysis were carried out to study the effectiveness of the proposed new method on the emergency treatment of cohesionless soil landslide.Surcharge loading on the crest of the slope was applied step by step until landslide was triggered so as to test and compare the stability and bearing capacity of slope models with different conditions.The simulated slope displacements were relatively close to the measured results,and the simulated slope deformation characteristics were in good agreement with the observed phenomena,which verifies the accuracy of the numerical method.Under the condition of surcharge loading on the crest of the slope,the unreinforced slope slid when the surcharge loading exceeded 30 k Pa,which presented a failure mode of local instability and collapse at the shallow layer of slope top.The reinforced slope remained stable even when the surcharge loading reached 48 k Pa.The displacement of the reinforced slope was reduced by more than 95%.Overall,this study verifies the effectiveness of polyurethane in the emergency treatment of cohesionless soil landslide and should have broad application prospects in the field of geological disasters concerning the safety of people's live.展开更多
Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by...Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by using portable diagnostic devices,avoiding sending samples to the medical laboratories.It has been extensively explored for diagnosing and monitoring patients’diseases and health conditions with the assistance of development in biochemistry and microfluidics.Microfluidic paper-based analytical devices(μPADs)have gained dramatic popularity in POCT because of their simplicity,user-friendly,fast and accurate result reading and low cost.SeveralμPADs have been successfully commercialized and received excellent feedback during the past several decades.This review briefly discusses the main types ofμPADs,preparation methods and their detection principles,followed by a few representative examples.The future perspectives of the development inμPADs are also provided.展开更多
The study of the charge conjugation and parity(CP)violation of hyperon is the precision frontier for probing possible new CP violation sources beyond the standard model(SM).With the large number of quantum entangled h...The study of the charge conjugation and parity(CP)violation of hyperon is the precision frontier for probing possible new CP violation sources beyond the standard model(SM).With the large number of quantum entangled hyperonantihyperon pairs to be produced at Super Tau-Charm Facility(STCF),the CP asymmetry of hyperon is expected to be tested with a statistical sensitivity of 10^(−4) or even better.To cope with the statistical precision,the systematic effects from various aspects are critical and need to be studied in detail.In this paper,the sensitivity effects on the CP violation parameters associated with the detector resolution,including those of the position and momentum,are studied and discussed in detail.The results provide valuable guidance for the design of STCF detector.展开更多
Penetration testing plays a critical role in ensuring security in an increasingly interconnected world. Despite advancements in technology leading to smaller, more portable devices, penetration testing remains reliant...Penetration testing plays a critical role in ensuring security in an increasingly interconnected world. Despite advancements in technology leading to smaller, more portable devices, penetration testing remains reliant on traditional laptops and computers, which, while portable, lack true ultra-portability. This paper explores the potential impact of developing a dedicated, ultra-portable, low-cost device for on-the-go penetration testing. Such a device could replicate the core functionalities of advanced penetration testing tools, including those found in Kali Linux, within a compact form factor that fits easily into a pocket. By offering the convenience and portability akin to a smartphone, this innovative device could redefine the way penetration testers operate, enabling them to carry essential tools wherever they go and ensuring they are always prepared to conduct security assessments efficiently. This approach aims to revolutionize penetration testing by merging high functionality with unparalleled portability.展开更多
NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a nec...NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.展开更多
This study presents the results of a Monte Carlo simulation to compare the statistical power of Siegel-Tukey and Savage tests.The main purpose of the study is to evaluate the statistical power of both tests in scenari...This study presents the results of a Monte Carlo simulation to compare the statistical power of Siegel-Tukey and Savage tests.The main purpose of the study is to evaluate the statistical power of both tests in scenarios involving Normal,Platykurtic and Skewed distributions over different sample sizes and standard deviation values.In the study,standard deviation ratios were set as 2,3,4,1/2,1/3 and 1/4 and power comparisons were made between small and large sample sizes.For equal sample sizes,small sample sizes of 5,8,10,12,16 and 20 and large sample sizes of 25,50,75 and 100 were used.For different sample sizes,the combinations of(4,16),(8,16),(10,20),(16,4),(16,8)and(20,10)small sample sizes and(10,30),(30,10),(50,75),(50,100),(75,50),(75,100),(100,50)and(100,75)large sample sizes were examined in detail.According to the findings,the power analysis under variance heterogeneity conditions shows that the Siegel-Tukey test has a higher statistical power than the other nonparametric Savage test at small and large sample sizes.In particular,the Siegel-Tukey test was reported to offer higher precision and power under variance heterogeneity,regardless of having equal or different sample sizes.展开更多
Geomechanical properties of rocks vary across different measurement scales,primarily due to heterogeneity.Micro-scale geomechanical tests,including micro-scale“scratch tests”and nano-scale nanoindentation tests,are ...Geomechanical properties of rocks vary across different measurement scales,primarily due to heterogeneity.Micro-scale geomechanical tests,including micro-scale“scratch tests”and nano-scale nanoindentation tests,are attractive at different scales.Each method requires minimal sample volume,is low cost,and includes a relatively rapid measurement turnaround time.However,recent micro-scale test results–including scratch test results and nanoindentation results–exhibit tangible variance and uncertainty,suggesting a need to correlate mineral composition mapping to elastic modulus mapping to isolate the relative impact of specific minerals.Different research labs often utilize different interpretation methods,and it is clear that future micro-mechanical tests may benefit from standardized testing and interpretation procedures.The objectives of this study are to seek options for standardized testing and interpretation procedures,through two specific objectives:(1)Quantify chemical and physical controls on micro-mechanical properties and(2)Quantify the source of uncertainties associated with nanoindentation measurements.To reach these goals,we conducted mechanical tests on three different scales:triaxial compression tests,scratch tests,and nanoindentation tests.We found that mineral phase weight percentage is highly correlated with nanoindentation elastic modulus distribution.Finally,we conclude that nanoindentation testing is a mineralogy and microstructure-based method and generally yields significant uncertainty and overestimation.The uncertainty of the testing method is largely associated with not mapping pore space a priori.Lastly,the uncertainty can be reduced by combining phase mapping and modulus mapping with substantial and random data sampling.展开更多
To investigate the evolution of load-bearing characteristics of pre-stressed beams throughout their service life and to provide a basis for accurately assessing the actual working state of damaged pre-stressed concret...To investigate the evolution of load-bearing characteristics of pre-stressed beams throughout their service life and to provide a basis for accurately assessing the actual working state of damaged pre-stressed concrete T-beams,destructive tests were conducted on full-scale pre-stressed concrete beams.Based on the measurement and ana-lysis of beam deflection,strain,and crack development under various loading levels during the research tests,combined with the verification coefficient indicators specified in the codes,the verification coefficients of bridges at different stages of damage can be examined.The results indicate that the T-beams experience complete,incom-plete linear,and non-linear stages during the destructive test process.In the complete linear elastic stage,both the deflection and bottom strain verification coefficients comply with the specifications,indicating a good structural load-bearing capacity no longer adheres to the code’s requirements.In the non-linear stage,both coefficients exhi-bit a sharp increase,resulting in a further decrease in the structure’s load-bearing capacity.According to the pro-visions of the current code,the beam can be in the incomplete linear stage when both values fall within the code’s specified range.The strain verification coefficient sourced from the compression zone at the bottom of theflange is not recommended for assessing the bridge’s load-bearing capacity.展开更多
Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various f...Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various factors affect roots reinforcement during seismic loading have rarely been studied.The objective is to conduct a series of cyclic direct simple shear tests and DEM numerical simulation to investigate the cyclic behaviour of rooted loess.The effects of initial static shear stress and loading frequency on the cyclic resistance of root-soil composites were first investigated.After that,cyclic direct simple shear simulations at constant volume were carried out based on the discrete element method(PFC^(3D))to investigate the effects of root geome-try,mechanical traits and root-soil bond strength on the cyclic strength of rooted loess.It was discovered that the roots could effectively improve the cyclic resistance of loess.The cyclic resistance of the root-soil composite decreases with the increase of the initial shear stress,then increases,and improves with the increase of the frequency.The simulation result show that increases in root elastic modulus and root-soil interfacial bond strength can all enhance the cyclic resistance of root-soil composites,and the maximum cyclic resistance of the root-soil composite was obtained when the initial inclination angle of the root system was 90°.展开更多
The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSN...The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSNS-II)commenced in 2024.The CSNS-II linac design primarily involves the addition of a radio-frequency ion source and a section of a superconducting linear accelerator composed of two types of superconducting cavities,namely double-spoke and six-cell elliptical cavities,after the drift tube linac(DTL).The development of the double-spoke superconducting cavity began in early 2021,and by January 2023,the welding,post-processing,and vertical tests of two 324 MHz double-spoke cavity prototypes were completed,with vertical test gradients of 11.6 and 15 MV/m,and Q_(0)≥3×10^(10)@E_(acc)≤10 MV/m.The R&D of the cryomodule began in January 2022.In October 2023,the clean assembly of the double-spoke cavity string and cold mass installation of the cryomodule commenced,with the installation of the cryomodule and valve box completing in two months.In January 2024,a horizontal test of the cryomodule was completed,making it the first double-spoke cavity cryomodule in China.The test results showed that the maximum gradients of the two superconducting cavities at a pulse width of 4 ms and repetition frequency of 25 Hz were 12.8 and 15.2 MV/m,respectively.This article provides a detailed introduction to the double-spoke superconducting cavity,tuner,coupler,and cryomodule,elaborates on the clean assembly of the cavity string and cold mass installation of the cryomodule,and provides a detailed analysis of the horizontal test results.展开更多
Objective: Hereditary breast and ovarian cancer syndrome (HBOC) increases the risk of developing breast, ovarian, prostate, and pancreatic cancers. With the insurance coverage for BRCA genetic testing, the number of i...Objective: Hereditary breast and ovarian cancer syndrome (HBOC) increases the risk of developing breast, ovarian, prostate, and pancreatic cancers. With the insurance coverage for BRCA genetic testing, the number of individuals diagnosed with HBOC has increased. To use these test results effectively, cascade genetic testing (CGT) is recommended for at-risk relatives;however, it is not yet widely available. The purpose of this study was to investigate the willingness of the general population to share genetic test results and undergo CGT, as well as to analyze the factors influencing these decisions. Based on these findings, the study aimed to identify the types of support needed to support the sharing of genetic test results and promote the use of CGT. Methods: An online survey was conducted with 500 participants (50 men and women from each of the five generations, ranging from 20 to 69 years). Results: Among the HBOC blood relatives, 51.2% wanted to share the genetic results and 71.9% expressed a willingness to undergo CGT. “Matters to be shared with relatives” and “Helpful for my cancer prevention” were identified as key factors promoting the willingness to share the BRCA genetic test results and undergo CGT. The motivation for “Helpful for my cancer prevention” had a particularly strong influence on the decision to undergo CGT. Conclusion: In the general population, there is an emerging understanding that the genetic information impacts not only the individuals but also their entire families and can be valuable for cancer prevention. To promote the sharing of BRCA genetic test results and CGT uptake, the healthcare providers should offer support tailored to each family’s circumstances and establish cancer prevention measures recommended for HBOC.展开更多
The lack of systematic and scientific top-level arrangement in the field of civil aircraft flight test leads to the problems of long duration and high cost.Based on the flight test activity,mathematical models of flig...The lack of systematic and scientific top-level arrangement in the field of civil aircraft flight test leads to the problems of long duration and high cost.Based on the flight test activity,mathematical models of flight test duration and cost are established to set up the framework of flight test process.The top-level arrangement for flight test is optimized by multi-objective algorithm to reduce the duration and cost of flight test.In order to verify the necessity and validity of the mathematical models and the optimization algorithm of top-level arrangement,real flight test data is used to make an example calculation.Results show that the multi-objective optimization results of the top-level flight arrangement are better than the initial arrangement data,which can shorten the duration,reduce the cost,and improve the efficiency of flight test.展开更多
基金supported by the Key Technologies Research and Development Program of Guangzhou (No.2023B03J1284)Guangdong Yuehai Water Investment Co.,Ltd. (No.CC80-QT01-2020-0010).
文摘This work established a quantitative method to access the shear stability of aerobic granular sludge(AGS)and validated its feasibility by using the mature AGS from a pilot-scale(50 tons/day)membrane bioreactor(MBR)for treating real municipal wastewater.The results showed that the changing rate( S)of the peak area(S)of granule size distribution(GSD)exhibited an exponential relationship(R^(2)≥0.76)with the shear time(y=a−b·c^(x)),which was a suitable indicative index to reflect the shear stability of different AGS samples.The limiting granule size(LGS)was defined and proposed to characterize the equilibrium size for AGS after being sheared for a period of time,whose value in terms of Dv50 showed high correlation(R^(2)=0.92)with the parameter a.The free Ca^(2+)(28.44-34.21 mg/L)in the influent specifically interacted with polysaccharides(PS)in the granule’s extracellular polymeric substance(EPS)as a nucleation site,thereby inducing the formation of Ca precipitation to enhance its Young’s modulus,while Ca^(2+) primarily interacted with PS in soluble metabolic product(SMP)during the initial granulation process.Furthermore,the Young’s modulus significantly affected the parameter a related to shear stability(R^(2)=0.99).Since the parameter a was more closely related(R^(2)=1.00)to S than that of the parameter b or c,the excellent correlation(R^(2)=0.99)between the parameter a and the wet density further verified the feasibility of this method.
基金The financial supports received from National Natural Science Foundation of China (U20B6005, 22178378, and 22127812)
文摘To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and decrease the energy cost further,we report a new carbon capture approach using a 2-methylimidazole(mIm)aqueous solution.The properties and sorption behaviors of this approach have been experimentally investigated.The results show that the mIm solution has higher CO_(2) absorption capacity under relatively higher equilibrium pressure(>130 kPa)and lower desorption heat than the methyldiethanolamine solution.91.6%sorption capacity of mIm solution can be recovered at 353.15 K and 80 kPa.The selectivity for CO_(2)/N_(2) and CO_(2)/CH_(4) can reach an exceptional 7609 and 4324,respectively.Furthermore,the pilot-scale tests were also performed,and the results demonstrate that more than 98%of CO_(2) in the feed gas could be removed and cyclic absorption capacity can reach 1 mol·L^(-1).This work indicates that mIm is an excellent alternative to alkanolamines for carbon capture in the industry.
基金supported by the National Key Research and Development Program of China(2018YFA0902100)the National Natural Science Foundation of China(22178262)the Tianjin Key Research and Development Program(23YFZCSN00110).
文摘The widespread use of pesticides has caused serious harm to ecosystems,necessitating effective and environmentally friendly treatment methods.Bioremediation stands out as a promising approach for pollutant treatment,wherein the metabolic activities of microorganisms can transform toxic pesticides into compounds with lower or no toxicity.In this study,we obtained eight pesticide-degrading strains from pesticide-contaminated sites through continuous enrichment and screening.Four highly efficient pesticide-degrading strains(degradation ratios exceeding 80%)were identified.Among them,Pseudomonas sp.BL5 exhibited the strongest growth(exceeding 10^(9) CFU·ml^(-1))and outstanding degradation of benzene derivatives and chlorinated hydrocarbons at both laboratory and pilot scales,with degradation ratios exceeding 98%and 99.6%,respectively.This research provides new tools and insights for the bioremediation of pesticide-related pollutants.
基金Supported by the National Basic Research Program of China(“973”Program:2014CB745100)the National Natural Science Foundation of China(21576197)+2 种基金Tianjin Research Program of Application Foundation and Advanced Technology(14JCQNJC06700)the Major Research Plan of Tianjin(16YFXTSF00460)Tianjin Penglai 19-3 Oil Spill Accident Compensation Project(19-3BC2014-03)
文摘Under the guidance of strain tolerance, a new combination method for crude oil-degrading bacterial consortium was studied. Firstly, more than 50 efficient crude oil-degrading and biosurfactant producing bacteria were isolated from petroleum-contaminated soil and water in Tianjin Binhai New Area Oil field, China. Twenty-four of them were selected for further study. These strains were identified as belonging Pseudornonas aeruginosa, Bacillus subtilis, Brevibacillus brevis, Achrornobacter sp., Acinetobacter venetianus, Lysinibacillus rnacroides, Klebsiella oxytoca, Stenotrophornonas rhizophila, Rhodococcus sp. and Bacillus thuringiensis. A shake-flask degradation test revealed that 12 of these strains could degrade over 50% of 1% crude oil concentration in 7 d. Of these, 8 strains were able to produce biosurfactants. Furthermore, environmental tolerance experiments indicated that the majority of the strains had the ability to adapt to extreme environments including high temperatures, alkaline en- vironments and high salinity environments. A mixed bacterial agent comprising the strains WB2, W2, W3 and HA was developed based on the environmental tolerance tests and subjected to the pilot-scale degradation test indicating that this bacterial agent could degrade 85.2% of 0.8% crude oil concentration in 60 d. Our results suggest that the application of this mixed agent could remediate crude oil polluted soils in saline and alkaline environments.
基金supported by the“National Ocean Technology Center Innovation Fund”under Project No.N3220Z002,led by Ning Jia.The official website of the National Ocean Technology Center is accessible at:http://www.notcsoa.org.cn/.
文摘With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist in the field testing methodologies for wave energy converters(WECs).In this paper,a numerical wave field of the Dawanshan Island Sea Area in Zhuhai City is constructed based on the MIKE21 SW wave model and by using an NCEP wind field driving model.In conjunction with the IEC-62600-100 standard,by taking site testing of the“Wanshan”wave energy converter on which a sea trial has been conducted in Dawanshan Island of Zhuhai city as an example,research on-site testing method for a wave energy converter has been carried out.The wave measurement position for the“Wanshan”converter was determined by combining statistically analyzed field data with a validated numerical wave model.By comparing a valid wave height at the position where a wave rider is located with a valid wave height at the position where the“Wanshan”wave energy converter is situated,the correlation coefficient between simulation and observed data reached 0.90,with a root-mean-square error of 0.19.The representativeness of wave measurement data during site testing is verified and can be used as a basis for calculating the input energy of the“Wanshan”wave energy converter.
基金supported by the National Natural Science Foundation of China for Distinguished Young Scholars(Grant No.42225206)National Natural Science Foundation of China(42207180,42477209,42302320).
文摘Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the substantial pressures exerted by vehicles,trains,and other forms of transportation,but also efficiently transfer these loads to the underlying foundation,ensuring the stability and longevity of the roadway.In recent years,advancements in subgrade engineering technology have propelled the industry towards smarter,greener,and more sustainable practices,particularly in the areas of intelligent monitoring,disaster management,and innovative construction methods.This paper reviews the application and methodologies of intelligent testing equipment,including cone penetration testing(CPT)devices,soil resistivity testers,and intelligent rebound testers,in subgrade engineering.It examines the operating principles,advantages,limitations,and application ranges of these tools in subgrade testing.Additionally,the paper evaluates the practical use of advanced equipment from both domestic and international perspectives,addressing the challenges encountered by various instruments in realworld applications.These devices enable precise,comprehensive testing and evaluation of subgrade conditions at different stages,providing real-time data analysis and intelligent early warnings.This supports effective subgrade health management and maintenance.As intelligent technologies continue to evolve and integrate,these tools will increasingly enhance the accuracy,efficiency,and sustainability of subgrade monitoring.
基金the financial support from the Fujian Science Foundation for Outstanding Youth(2023J06039)the National Natural Science Foundation of China(Grant No.41977259,U2005205,41972268)the Independent Research Project of Technology Innovation Center for Monitoring and Restoration Engineering of Ecological Fragile Zone in Southeast China(KY-090000-04-2022-019)。
文摘Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the solidification time of conventional cement paste is long when shotcrete is used to treat cohesionless soil landslide.The idea of reinforcing slope with polyurethane solidified soil(i.e.,mixture of polyurethane and sand)was proposed.Model tests and finite element analysis were carried out to study the effectiveness of the proposed new method on the emergency treatment of cohesionless soil landslide.Surcharge loading on the crest of the slope was applied step by step until landslide was triggered so as to test and compare the stability and bearing capacity of slope models with different conditions.The simulated slope displacements were relatively close to the measured results,and the simulated slope deformation characteristics were in good agreement with the observed phenomena,which verifies the accuracy of the numerical method.Under the condition of surcharge loading on the crest of the slope,the unreinforced slope slid when the surcharge loading exceeded 30 k Pa,which presented a failure mode of local instability and collapse at the shallow layer of slope top.The reinforced slope remained stable even when the surcharge loading reached 48 k Pa.The displacement of the reinforced slope was reduced by more than 95%.Overall,this study verifies the effectiveness of polyurethane in the emergency treatment of cohesionless soil landslide and should have broad application prospects in the field of geological disasters concerning the safety of people's live.
文摘Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by using portable diagnostic devices,avoiding sending samples to the medical laboratories.It has been extensively explored for diagnosing and monitoring patients’diseases and health conditions with the assistance of development in biochemistry and microfluidics.Microfluidic paper-based analytical devices(μPADs)have gained dramatic popularity in POCT because of their simplicity,user-friendly,fast and accurate result reading and low cost.SeveralμPADs have been successfully commercialized and received excellent feedback during the past several decades.This review briefly discusses the main types ofμPADs,preparation methods and their detection principles,followed by a few representative examples.The future perspectives of the development inμPADs are also provided.
基金supported by the National Key R&D Program of China(2022YFA1602200)the International Partnership Program of the Chinese Academy of Sciences(211134KYSB20200057).
文摘The study of the charge conjugation and parity(CP)violation of hyperon is the precision frontier for probing possible new CP violation sources beyond the standard model(SM).With the large number of quantum entangled hyperonantihyperon pairs to be produced at Super Tau-Charm Facility(STCF),the CP asymmetry of hyperon is expected to be tested with a statistical sensitivity of 10^(−4) or even better.To cope with the statistical precision,the systematic effects from various aspects are critical and need to be studied in detail.In this paper,the sensitivity effects on the CP violation parameters associated with the detector resolution,including those of the position and momentum,are studied and discussed in detail.The results provide valuable guidance for the design of STCF detector.
文摘Penetration testing plays a critical role in ensuring security in an increasingly interconnected world. Despite advancements in technology leading to smaller, more portable devices, penetration testing remains reliant on traditional laptops and computers, which, while portable, lack true ultra-portability. This paper explores the potential impact of developing a dedicated, ultra-portable, low-cost device for on-the-go penetration testing. Such a device could replicate the core functionalities of advanced penetration testing tools, including those found in Kali Linux, within a compact form factor that fits easily into a pocket. By offering the convenience and portability akin to a smartphone, this innovative device could redefine the way penetration testers operate, enabling them to carry essential tools wherever they go and ensuring they are always prepared to conduct security assessments efficiently. This approach aims to revolutionize penetration testing by merging high functionality with unparalleled portability.
文摘NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.
文摘This study presents the results of a Monte Carlo simulation to compare the statistical power of Siegel-Tukey and Savage tests.The main purpose of the study is to evaluate the statistical power of both tests in scenarios involving Normal,Platykurtic and Skewed distributions over different sample sizes and standard deviation values.In the study,standard deviation ratios were set as 2,3,4,1/2,1/3 and 1/4 and power comparisons were made between small and large sample sizes.For equal sample sizes,small sample sizes of 5,8,10,12,16 and 20 and large sample sizes of 25,50,75 and 100 were used.For different sample sizes,the combinations of(4,16),(8,16),(10,20),(16,4),(16,8)and(20,10)small sample sizes and(10,30),(30,10),(50,75),(50,100),(75,50),(75,100),(100,50)and(100,75)large sample sizes were examined in detail.According to the findings,the power analysis under variance heterogeneity conditions shows that the Siegel-Tukey test has a higher statistical power than the other nonparametric Savage test at small and large sample sizes.In particular,the Siegel-Tukey test was reported to offer higher precision and power under variance heterogeneity,regardless of having equal or different sample sizes.
基金support of this project through the Southwest Regional Partnership on Carbon Sequestration(Grant No.DE-FC26-05NT42591)Improving Production in the Emerging Paradox Oil Play(Grant No.DE-FE0031775).
文摘Geomechanical properties of rocks vary across different measurement scales,primarily due to heterogeneity.Micro-scale geomechanical tests,including micro-scale“scratch tests”and nano-scale nanoindentation tests,are attractive at different scales.Each method requires minimal sample volume,is low cost,and includes a relatively rapid measurement turnaround time.However,recent micro-scale test results–including scratch test results and nanoindentation results–exhibit tangible variance and uncertainty,suggesting a need to correlate mineral composition mapping to elastic modulus mapping to isolate the relative impact of specific minerals.Different research labs often utilize different interpretation methods,and it is clear that future micro-mechanical tests may benefit from standardized testing and interpretation procedures.The objectives of this study are to seek options for standardized testing and interpretation procedures,through two specific objectives:(1)Quantify chemical and physical controls on micro-mechanical properties and(2)Quantify the source of uncertainties associated with nanoindentation measurements.To reach these goals,we conducted mechanical tests on three different scales:triaxial compression tests,scratch tests,and nanoindentation tests.We found that mineral phase weight percentage is highly correlated with nanoindentation elastic modulus distribution.Finally,we conclude that nanoindentation testing is a mineralogy and microstructure-based method and generally yields significant uncertainty and overestimation.The uncertainty of the testing method is largely associated with not mapping pore space a priori.Lastly,the uncertainty can be reduced by combining phase mapping and modulus mapping with substantial and random data sampling.
文摘To investigate the evolution of load-bearing characteristics of pre-stressed beams throughout their service life and to provide a basis for accurately assessing the actual working state of damaged pre-stressed concrete T-beams,destructive tests were conducted on full-scale pre-stressed concrete beams.Based on the measurement and ana-lysis of beam deflection,strain,and crack development under various loading levels during the research tests,combined with the verification coefficient indicators specified in the codes,the verification coefficients of bridges at different stages of damage can be examined.The results indicate that the T-beams experience complete,incom-plete linear,and non-linear stages during the destructive test process.In the complete linear elastic stage,both the deflection and bottom strain verification coefficients comply with the specifications,indicating a good structural load-bearing capacity no longer adheres to the code’s requirements.In the non-linear stage,both coefficients exhi-bit a sharp increase,resulting in a further decrease in the structure’s load-bearing capacity.According to the pro-visions of the current code,the beam can be in the incomplete linear stage when both values fall within the code’s specified range.The strain verification coefficient sourced from the compression zone at the bottom of theflange is not recommended for assessing the bridge’s load-bearing capacity.
文摘Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various factors affect roots reinforcement during seismic loading have rarely been studied.The objective is to conduct a series of cyclic direct simple shear tests and DEM numerical simulation to investigate the cyclic behaviour of rooted loess.The effects of initial static shear stress and loading frequency on the cyclic resistance of root-soil composites were first investigated.After that,cyclic direct simple shear simulations at constant volume were carried out based on the discrete element method(PFC^(3D))to investigate the effects of root geome-try,mechanical traits and root-soil bond strength on the cyclic strength of rooted loess.It was discovered that the roots could effectively improve the cyclic resistance of loess.The cyclic resistance of the root-soil composite decreases with the increase of the initial shear stress,then increases,and improves with the increase of the frequency.The simulation result show that increases in root elastic modulus and root-soil interfacial bond strength can all enhance the cyclic resistance of root-soil composites,and the maximum cyclic resistance of the root-soil composite was obtained when the initial inclination angle of the root system was 90°.
文摘The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSNS-II)commenced in 2024.The CSNS-II linac design primarily involves the addition of a radio-frequency ion source and a section of a superconducting linear accelerator composed of two types of superconducting cavities,namely double-spoke and six-cell elliptical cavities,after the drift tube linac(DTL).The development of the double-spoke superconducting cavity began in early 2021,and by January 2023,the welding,post-processing,and vertical tests of two 324 MHz double-spoke cavity prototypes were completed,with vertical test gradients of 11.6 and 15 MV/m,and Q_(0)≥3×10^(10)@E_(acc)≤10 MV/m.The R&D of the cryomodule began in January 2022.In October 2023,the clean assembly of the double-spoke cavity string and cold mass installation of the cryomodule commenced,with the installation of the cryomodule and valve box completing in two months.In January 2024,a horizontal test of the cryomodule was completed,making it the first double-spoke cavity cryomodule in China.The test results showed that the maximum gradients of the two superconducting cavities at a pulse width of 4 ms and repetition frequency of 25 Hz were 12.8 and 15.2 MV/m,respectively.This article provides a detailed introduction to the double-spoke superconducting cavity,tuner,coupler,and cryomodule,elaborates on the clean assembly of the cavity string and cold mass installation of the cryomodule,and provides a detailed analysis of the horizontal test results.
文摘Objective: Hereditary breast and ovarian cancer syndrome (HBOC) increases the risk of developing breast, ovarian, prostate, and pancreatic cancers. With the insurance coverage for BRCA genetic testing, the number of individuals diagnosed with HBOC has increased. To use these test results effectively, cascade genetic testing (CGT) is recommended for at-risk relatives;however, it is not yet widely available. The purpose of this study was to investigate the willingness of the general population to share genetic test results and undergo CGT, as well as to analyze the factors influencing these decisions. Based on these findings, the study aimed to identify the types of support needed to support the sharing of genetic test results and promote the use of CGT. Methods: An online survey was conducted with 500 participants (50 men and women from each of the five generations, ranging from 20 to 69 years). Results: Among the HBOC blood relatives, 51.2% wanted to share the genetic results and 71.9% expressed a willingness to undergo CGT. “Matters to be shared with relatives” and “Helpful for my cancer prevention” were identified as key factors promoting the willingness to share the BRCA genetic test results and undergo CGT. The motivation for “Helpful for my cancer prevention” had a particularly strong influence on the decision to undergo CGT. Conclusion: In the general population, there is an emerging understanding that the genetic information impacts not only the individuals but also their entire families and can be valuable for cancer prevention. To promote the sharing of BRCA genetic test results and CGT uptake, the healthcare providers should offer support tailored to each family’s circumstances and establish cancer prevention measures recommended for HBOC.
基金supported by the National Natural Science Foundation of China(62073267,61903305)the Fundamental Research Funds for the Central Universities(HXGJXM202214).
文摘The lack of systematic and scientific top-level arrangement in the field of civil aircraft flight test leads to the problems of long duration and high cost.Based on the flight test activity,mathematical models of flight test duration and cost are established to set up the framework of flight test process.The top-level arrangement for flight test is optimized by multi-objective algorithm to reduce the duration and cost of flight test.In order to verify the necessity and validity of the mathematical models and the optimization algorithm of top-level arrangement,real flight test data is used to make an example calculation.Results show that the multi-objective optimization results of the top-level flight arrangement are better than the initial arrangement data,which can shorten the duration,reduce the cost,and improve the efficiency of flight test.
