Environmental pollution has seriously damaged the health of mankind and the development of future generations. Because pollution damages are irreversible, taking effective measures to prevent contamination accidents i...Environmental pollution has seriously damaged the health of mankind and the development of future generations. Because pollution damages are irreversible, taking effective measures to prevent contamination accidents is the primary task for administrative penalty on environmental pollution. However, the specific amount of such penalty is a little bit on the low side, and the standard for fixing the penalty is not rational somewhat. As a result, the original functions and purpose of administrative penalty on environmental pollution cannot be fully achieved. By comparing and using for reference related systems at home and abroad, this paper advances the drawbacks and suggestions for the amount fixing of China’s administrative penalty on environmental pollution in the hope of supplying theoretical basis for the improvement of China’s administrative penalty mechanism on environmental pollution.展开更多
Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero ...Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero energy buildings.Thus,in this work,an adaptive fresh air pre-handling system is designed to reduce the cool-ing and heating loads of HVAC system.The sky-facing surface of the system uses electrochromic mechanism to manipulate the optical properties and thus make full use of solar energy(solar heating)and deep space cold source(radiative cooling)by switching between heating and cooling modes.In the cooling mode,the sky-facing surface shows a transmittance of down to zero,while the reflectance is high at 0.89 on average.In the heating mode,the electrochromic glass is highly transparent,allowing the sunlight to reach the solar heat absorber.To obtain the energy-saving potential under different climates,six cities were selected from various climate regions in China.Results show that the adaptive fresh air pre-handling system can be effective in up to 55.4%time of a year.The maximum energy-saving ratios for medium office,warehouse,and single-family house can reach up to 11.52%,26.62%,and 18.29%,respectively.In addition,the system shows multi-climate adaptability and broad application scenarios,making it a potential solution to building energy saving.展开更多
We propose that the double barrier effect is expected to enhance the tunneling electroresistance(TER)in the ferroelectric tunnel junctions(FTJs).To demonstrate the feasibility of this mechanism,we design a model struc...We propose that the double barrier effect is expected to enhance the tunneling electroresistance(TER)in the ferroelectric tunnel junctions(FTJs).To demonstrate the feasibility of this mechanism,we design a model structure of Pt/BaTiO_(3)/LaAlO_(3)/Pt/BaTiO_(3)/LaAlO_(3)/Pt double barrier ferroelectric tunnel junction(DB-FTJ),which can be considered as two identical Pt/BaTiO_(3)/LaAlO_(3)/Pt single barrier ferroelectric tunnel junctions(SB-FTJs)connected in series.Based on density functional calculation,we obtain the giant TER ratio of 2.210×10^(8)%in the DB-FTJ,which is at least three orders of magnitude larger than that of the SB-FTJs of Pt/BaTiO_(3)/LaAlO_(3)/Pt,together with an ultra-low resistance area product(0.093 KΩμm^(2))in the high conductance state of the DB-FTJ.Moreover,it is possible to control the direction of polarization of the two single ferroelectric barriers separately and thus four resistance states can be achieved,making DB-FTJs promising as multi-state memory devices.展开更多
Phloem-feeding insects cause massive losses in agriculture and horticulture.Host plant resistance to phloem-feeding insects is often mediated by changes in phloem composition,which deter insect settling and feeding an...Phloem-feeding insects cause massive losses in agriculture and horticulture.Host plant resistance to phloem-feeding insects is often mediated by changes in phloem composition,which deter insect settling and feeding and decrease viability.Here,we report that rice plant resistance to the phloem-feeding brown planthopper(BPH)is associated with fortification of the sclerenchyma tissue,which is located just beneath the epidermis and a cell layer or two away from the vascular bundle in the rice leaf sheath.We found that BPHs prefer to feed on the smooth and soft region on the surface of rice leaf sheaths called the long-cell block.We identified Bph30 as a rice BPH resistance gene that prevents BPH stylets from reaching the phloem due to the fortified sclerenchyma.Bph30 is strongly expressed in sclerenchyma cells and enhances cellulose and hemicellulose synthesis,making the cell walls stiffer and sclerenchyma thicker.The structurally fortified sclerenchyma is a formidable barrier preventing BPH stylets from penetrating the leaf sheath tissues and arriving at the phloem to feed.Bph30 belongs to a novel gene family,encoding a protein with two leucine-rich domains.Another member of the family,Bph40,also conferred resistance to BPH.Collectively,the fortified sclerenchyma-mediated resistance mechanism revealed in this study expands our understanding of plant-insect interactions and opens a new path for controlling planthoppers in rice.展开更多
Interactions and co-evolution between plants and herbivorous insects are critically important in agriculture.Brown planthopper(BPH)is the most severe insect of rice,and the biotypes adapt to feed on different rice gen...Interactions and co-evolution between plants and herbivorous insects are critically important in agriculture.Brown planthopper(BPH)is the most severe insect of rice,and the biotypes adapt to feed on different rice genotypes.Here,we present genomics analyses on 1,520 global rice germplasms for resistance to three BPH biotypes.Genome-wide association studies identified 3,502 single nucleotide polymorphisms(SNPs)and 59 loci associated with BPH resistance in rice.We cloned a previously unidentified gene Bph37 that confers resistance to BPH.The associated loci showed high nucleotide diversity.Genome-wide scans for trans-species polymorphisms revealed ancient balancing selection at the loci.The secondarily evolved insect biotypes II and III exhibited significantly higher virulence and overcame more rice varieties than the primary biotype I.In response,more SNPs and loci evolved in rice for resistance to biotypes II and III.Notably,three exceptional large regions with high SNP density and resistance-associated loci on chromosomes 4 and 6 appear distinct between the resistant and susceptible rice varieties.Surprisingly,these regions in resistant rice might have been retained from wild species Oryza nivara.Our findings expand the understanding of long-term interactions between rice and BPH and provide resistance genes and germplasm resources for breeding durable BPH-resistant rice varieties.展开更多
Air curtains is promising in reducing the short-range infection risk in hospitals.To quantitatively evaluate its performance,this paper explores air curtains equipped on normal consulting desk to avoid doctor’s direc...Air curtains is promising in reducing the short-range infection risk in hospitals.To quantitatively evaluate its performance,this paper explores air curtains equipped on normal consulting desk to avoid doctor’s direct exposure to the patient exhaled pollutants.A numerical investigation is conducted to evaluate the effects of supply air velocity and angle on cutting off performance.Simulation results show that the average mass fraction of exhaled pollutants decreases significantly(70%–90%)in the consulting ward,indicating satisfying performance of air curtains.Increasing supply air velocity is demonstrated to be conducive in forming full air curtains,whereas an excessively high supply air velocity may be of adverse effects by entraining exhaled flow.Besides,the supply air angle is also critical due to its coupling with supply air velocity.It is found that larger angle(0°–40°)is better where velocity is less than 3 m/s,otherwise a small angle(20°)is preferable where velocity is larger than 3 m/s.Exhaled flow could be well suppressed at the supply air angle 20°but moves over air curtains at 40°.This study can provide effective and intuitive guidance in applying air curtains in consulting wards.展开更多
Sulfosalicylic acid(SSA) was used as an intercalation agent and an excellent antenna to synthesize layered rare-earth hydroxide(LRH) materials and directly obtain SSA-modified terbium-doped ytterbium hydroxide nanoshe...Sulfosalicylic acid(SSA) was used as an intercalation agent and an excellent antenna to synthesize layered rare-earth hydroxide(LRH) materials and directly obtain SSA-modified terbium-doped ytterbium hydroxide nanosheets by mechanical exfoliation. The crystal structure and morphologies of the LRHs and nanosheets were determined by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The particle size and zeta potential of the prepared nanosheets were also analyzed. The as-prepared nanosheets exhibited excellent luminescent properties. The positively charged nanosheets were electrophoretically deposited on a conductive glass to form a thin film. The luminescence of this thin film can be quenched by chromate(CrO_4^(2–)) and bilirubin(BR), which shows good sensing properties. The quenching mechanism of the sensing film by CrO_4^(2–) and BR was discussed based on the spectra and structure of the film.展开更多
Dear Editor,Nowadays,medulloblastoma accounts for approximately 25% of all pediatric brain tumors.1 Even with the successful treatment of primary tumors,there are still serious side effects.Honokiol(HNK)is defined as ...Dear Editor,Nowadays,medulloblastoma accounts for approximately 25% of all pediatric brain tumors.1 Even with the successful treatment of primary tumors,there are still serious side effects.Honokiol(HNK)is defined as small bisphenol lignin extracted from the bark and seed cones of several species of Magnolia.展开更多
The brown planthopper(BPH)(Nilaparvata lugens St?l)is a highly destructive pest that seriously damages rice(Oryza sativa L.)and causes severe yield losses.To better understand the physiological and metabolic mechanism...The brown planthopper(BPH)(Nilaparvata lugens St?l)is a highly destructive pest that seriously damages rice(Oryza sativa L.)and causes severe yield losses.To better understand the physiological and metabolic mechanisms through which BPHs respond to resistant rice,we combined mass-spectrometry-based lipidomics with transcriptomic analysis and gene knockdown techniques to compare the lipidomes of BPHs feeding on either of the two resistant(NIL-Bph6 and NIL-Bph9)plants or a wild-type,BPH susceptible(9311)plant.Insects that were fed on resistant rice transformed triglyceride(TG)to phosphatidylcholine(PC)and digalactosyldiacylglycerol(DGDG),with these lipid classes showing significant alterations in fatty acid composition.Moreover,the insects that were fed on resistant rice were characterized by prominent expression changes in genes involved in lipid metabolism processes.Knockdown of the NlBmm gene,which encodes a lipase that regulates the mobilization of lipid reserves,significantly increased TG content and feeding performance of BPHs on resistant plants relative to dsGFP-injected BPHs.Our study provides the first detailed description of lipid changes in BPHs fed on resistant and susceptible rice genotypes.Results from BPHs fed on resistant rice plants reveal that these insects can accelerate TG mobilization to provide energy for cell proliferation,body maintenance,growth and oviposition.展开更多
As an important component,the bond behavior of carbon fiber-reinforced polymer(CFRP)-concrete interface for a reinforced concrete(RC)beam is very significant.In this study,a theoretical model was established to analyz...As an important component,the bond behavior of carbon fiber-reinforced polymer(CFRP)-concrete interface for a reinforced concrete(RC)beam is very significant.In this study,a theoretical model was established to analyze the flexural behavior of CFRP-strengthened RC beams,and the CFRP-concrete interfacial bond-slip relationship under hygrothermal environment was unified into one model.Two failure criteria corresponding to two types of failure modes,i.e.,concrete crushing and intermediate crack(IC)-induced debonding,were developed.Through the theoretical model,the flexural behavior of deflection,interfacial shear stress distribution and ultimate load of a CFRP-strengthened RC beam under hygrothermal environment were obtained and predicted.Moreover,the theoretical model was verified by test results.The results showed that the hygrothermal environment had a significant impact on the CFRP-concrete interface behavior.Compared with the control beam without hygrothermal environment pretreatment,the deflection and ultimate load of the strengthened RC beam decreased by 51.9%and 20%,respectively.展开更多
Spent lithium-ion battery recycling has attracted significant attention because of its importance in regard to the environment and resource importance.Traditional hydrometallurgical methods usually leach all valuable ...Spent lithium-ion battery recycling has attracted significant attention because of its importance in regard to the environment and resource importance.Traditional hydrometallurgical methods usually leach all valuable metals and subsequently extract target meals to prepare corresponding materials.However,Li recovery in these processes requires lengthy operational procedures,and the recovery efficiency is low.In this research,we demonstrate a method to selectively recover lithium before the leaching of other elements by introducing a hydrothermal treatment.Approximately 90%of Li is leached from high-Ni layered oxide cathode powders,while consuming a nearly stoichiometric amount of hydrogen ions.With this selective recovery of Li,the transition metals remain as solid residue hydroxides or oxides.Furthermore,the extraction of Li is found to be highly dependent on the content of transition metals in the cathode materials.A high leaching selectivity of Li(>98%)and nearly 95%leaching efficiency of Li can be reached with LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2).In this case,both the energy and material consumption during the proposed Li recovery is significantly decreased compared to traditional methods;furthermore,the proposed method makes full use of H+to leach Li+.This research is expected to provide new understanding for selectively recovering metal from secondary resources.展开更多
The main purpose of this study was to evaluate the pharmacokinetics of levosulpiride in humans after single and multiple intramuscular injections.Six males and six females received single dose of either 25 mg or 50 mg...The main purpose of this study was to evaluate the pharmacokinetics of levosulpiride in humans after single and multiple intramuscular injections.Six males and six females received single dose of either 25 mg or 50 mg levosulpiride,or multiple doses of 25 mg every 12 h for 5 consecutive days.In the single 25 mg study,the mean peak plasma concentration(C max)was 441 ng/mL,the mean area under the concentration–time curve from 0 to 36 h(AUC_(0–36))was 1724 ng h/mL,and the mean elimination half-life(t_(1/2))was 7.0 h.In the single 50 mg study,the mean C max was 823 ng/mL,the mean AUC_(0–36) was 3748 ng·h/mL,and the mean t_(1/2) was 6.8 h.After multiple doses of 25 mg levosulpiride,the average plasma concentration(C av)was 136 ng/mL,the fluctuation index(DF)was 3.60,and the accumulation ratio(R)was 1.2.Levosulpiride injections appeared to be well tolerated by the subjects,and can be used for successive administration.展开更多
The application of prestressed carbon reinforced polymer (prestressed CFRP) in reinforced concrete (RC) members can improve the mechanical properties of strengthened structures and strengthening efficiency. This p...The application of prestressed carbon reinforced polymer (prestressed CFRP) in reinforced concrete (RC) members can improve the mechanical properties of strengthened structures and strengthening efficiency. This paper proposed a semi-empirical prediction fornmla of fatigue lives of the RC beams strengthened with prestressed CFRP under bending loads. The formula is established based on the fatigue life prediction method of RC beams and fatigue experimental data of non-prestressed CFRP reinforced beams done before. Fatigue effect coefficient of the formula was confirmed by the fatigue experiments of the RC beams strengthened with prestressed carbon fiber laminate (prestressed CFL) under cyclic bending loads. Fatigue lives of the strengthened beams predicted using the formula agreed well with the experimental data.展开更多
In the production of lithium-ion batteries(LIBs)and recycling of spent LIBs,a large amount of low-concentration lithium-containing wastewater(LCW)is generated.The recovery of Li from this medium has attracted signific...In the production of lithium-ion batteries(LIBs)and recycling of spent LIBs,a large amount of low-concentration lithium-containing wastewater(LCW)is generated.The recovery of Li from this medium has attracted significant global attention from both the environmental and economic perspectives.To achieve effective Li recycling,the features of impurity removal and the interactions among different ions must be understood.However,it is generally dificult to ensure highly efficient removal of impurity ions while retaining Li in the solution for further recovery.In this study,the removal of typical impurity ions from LCW and the interactions between these species were systematically investigated from the thermodynamic and kinetics aspects.It was found that the main impurities(e.g.,Fe^+,AIP^+,Ca^2+,and Mg^2+)could be efficiently removed with high Li recovery by control-ling the ionic strength of the solution.The mechanisms of Fe^3+,Al^+,Ca^2+,and Mg^2+removal were investigated to identify the controlling steps and reaction kinetics.It was found that the precipitates are formed by a zero-order reaction,and the activation energies tend to be low with a sequence of fast chemical reactions that reach equilibrium very quickly.Moreover,this study focused on Li loss during removal of the impurities,and the corresponding removal rates of Fe^+,Al^+,Ca^2+,and Mg^2+were found to be 99.8%,99.5%,99%,and 99.7%,respectively.Conse-quently,high-purity LisPO4 was obtained via one-step precipitation.Thus,this research demonstrates a potential route for the effective recovery of Li from low-concentra-tion LCW and for the appropriate treatment of acidic LCW.展开更多
Particulate matter emission from rotating wheels, which imparts a force to the contact surface and causes strong air currents, is one of the important pollutant sources on the road. This study investigates the particu...Particulate matter emission from rotating wheels, which imparts a force to the contact surface and causes strong air currents, is one of the important pollutant sources on the road. This study investigates the particulate matter emission by measuring mass and size distributions of particulate matter near an isolated rotating wheel in a deliberately designed setup. Five rotating speeds from 0.7 m/s to 1.5 m/s are conducted to test its impact on the emission of particulate matter. Mass of particulate matter is measured at twenty-six sampling points around the rotating wheel under different experimental conditions. Experimental results show that the farther away from the wheel, the less of particulate matters deposited on the sampling points in general. Moreover, the emission factor increases from 0.12 g/vkt to 0.24 g/vkt when the rotating speed of the wheel increases from 0.7 m/s to 1.5 m/s. The number and proportion of PM2.5 and PM10 on different sampling points are also measured. The results show that the position of the highest number of PM2.5 and PM10 tends to move to a further and higher sampling point with the increasing of the speed. Moreover, the number proportions of PM2.5 and PM10 on the sampling points range from 19% to 97% and 61% to 100% at different speeds, respectively. This study is believed to be helpful to estimate particulate matter emission and make effective control strategies on targeted pollution.展开更多
基金The authors acknowledge financial support on this research from the "1000 talents program" of China (Zhi Sun), and the National Natural Science Foundation of China (51425405). This research was also supported by the National Science-Technology Support Program (2015 BAB02B05).
文摘Environmental pollution has seriously damaged the health of mankind and the development of future generations. Because pollution damages are irreversible, taking effective measures to prevent contamination accidents is the primary task for administrative penalty on environmental pollution. However, the specific amount of such penalty is a little bit on the low side, and the standard for fixing the penalty is not rational somewhat. As a result, the original functions and purpose of administrative penalty on environmental pollution cannot be fully achieved. By comparing and using for reference related systems at home and abroad, this paper advances the drawbacks and suggestions for the amount fixing of China’s administrative penalty on environmental pollution in the hope of supplying theoretical basis for the improvement of China’s administrative penalty mechanism on environmental pollution.
基金the support from National Natural Sci-ence Foundation of China(52276178)Natural Science Foundation of Jiangsu Province,China(BK20200373).
文摘Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero energy buildings.Thus,in this work,an adaptive fresh air pre-handling system is designed to reduce the cool-ing and heating loads of HVAC system.The sky-facing surface of the system uses electrochromic mechanism to manipulate the optical properties and thus make full use of solar energy(solar heating)and deep space cold source(radiative cooling)by switching between heating and cooling modes.In the cooling mode,the sky-facing surface shows a transmittance of down to zero,while the reflectance is high at 0.89 on average.In the heating mode,the electrochromic glass is highly transparent,allowing the sunlight to reach the solar heat absorber.To obtain the energy-saving potential under different climates,six cities were selected from various climate regions in China.Results show that the adaptive fresh air pre-handling system can be effective in up to 55.4%time of a year.The maximum energy-saving ratios for medium office,warehouse,and single-family house can reach up to 11.52%,26.62%,and 18.29%,respectively.In addition,the system shows multi-climate adaptability and broad application scenarios,making it a potential solution to building energy saving.
基金We gratefully acknowledge the support from the National Natural Science Foundation of China(Grant Nos.11974355 and 12074230)National Key R&D Program of China under Grant No.2017YFA0304203the Fund for Shanxi“1331 Project”and Shanxi Province 100-Plan Talent Program.Calculations were performed in Center for Computational Science of CASHIPS,the ScGrid of Supercomputing Center and Computer Network Information Center of Chinese Academy of Sciences.
文摘We propose that the double barrier effect is expected to enhance the tunneling electroresistance(TER)in the ferroelectric tunnel junctions(FTJs).To demonstrate the feasibility of this mechanism,we design a model structure of Pt/BaTiO_(3)/LaAlO_(3)/Pt/BaTiO_(3)/LaAlO_(3)/Pt double barrier ferroelectric tunnel junction(DB-FTJ),which can be considered as two identical Pt/BaTiO_(3)/LaAlO_(3)/Pt single barrier ferroelectric tunnel junctions(SB-FTJs)connected in series.Based on density functional calculation,we obtain the giant TER ratio of 2.210×10^(8)%in the DB-FTJ,which is at least three orders of magnitude larger than that of the SB-FTJs of Pt/BaTiO_(3)/LaAlO_(3)/Pt,together with an ultra-low resistance area product(0.093 KΩμm^(2))in the high conductance state of the DB-FTJ.Moreover,it is possible to control the direction of polarization of the two single ferroelectric barriers separately and thus four resistance states can be achieved,making DB-FTJs promising as multi-state memory devices.
基金This work was supported by the Major Program of Guangdong Basic andApplied Research,China(2019B030302006)the National Program onResearch and Development of Transgenic Plants of China(2016ZX08009-003)+1 种基金grants from the National Natural Science Foundationof China(31630063)the National Key Research and DevelopmentProgram of China(2016YFD0100600 and 2016YFD0100900).
文摘Phloem-feeding insects cause massive losses in agriculture and horticulture.Host plant resistance to phloem-feeding insects is often mediated by changes in phloem composition,which deter insect settling and feeding and decrease viability.Here,we report that rice plant resistance to the phloem-feeding brown planthopper(BPH)is associated with fortification of the sclerenchyma tissue,which is located just beneath the epidermis and a cell layer or two away from the vascular bundle in the rice leaf sheath.We found that BPHs prefer to feed on the smooth and soft region on the surface of rice leaf sheaths called the long-cell block.We identified Bph30 as a rice BPH resistance gene that prevents BPH stylets from reaching the phloem due to the fortified sclerenchyma.Bph30 is strongly expressed in sclerenchyma cells and enhances cellulose and hemicellulose synthesis,making the cell walls stiffer and sclerenchyma thicker.The structurally fortified sclerenchyma is a formidable barrier preventing BPH stylets from penetrating the leaf sheath tissues and arriving at the phloem to feed.Bph30 belongs to a novel gene family,encoding a protein with two leucine-rich domains.Another member of the family,Bph40,also conferred resistance to BPH.Collectively,the fortified sclerenchyma-mediated resistance mechanism revealed in this study expands our understanding of plant-insect interactions and opens a new path for controlling planthoppers in rice.
基金This work was supported by grants from the National Natural Science Foundation of China(31630063)National Key Research and Development Program(2016YFD0100600,2016YFD0100900)the National Program on Research&Development of Transgenic Plants(2016ZX08009-003-001).
文摘Interactions and co-evolution between plants and herbivorous insects are critically important in agriculture.Brown planthopper(BPH)is the most severe insect of rice,and the biotypes adapt to feed on different rice genotypes.Here,we present genomics analyses on 1,520 global rice germplasms for resistance to three BPH biotypes.Genome-wide association studies identified 3,502 single nucleotide polymorphisms(SNPs)and 59 loci associated with BPH resistance in rice.We cloned a previously unidentified gene Bph37 that confers resistance to BPH.The associated loci showed high nucleotide diversity.Genome-wide scans for trans-species polymorphisms revealed ancient balancing selection at the loci.The secondarily evolved insect biotypes II and III exhibited significantly higher virulence and overcame more rice varieties than the primary biotype I.In response,more SNPs and loci evolved in rice for resistance to biotypes II and III.Notably,three exceptional large regions with high SNP density and resistance-associated loci on chromosomes 4 and 6 appear distinct between the resistant and susceptible rice varieties.Surprisingly,these regions in resistant rice might have been retained from wild species Oryza nivara.Our findings expand the understanding of long-term interactions between rice and BPH and provide resistance genes and germplasm resources for breeding durable BPH-resistant rice varieties.
基金This work is jointed supported by the National Natural Science Foundation of China(No.51778128)the National Key Research and Development Program of China(No.2018YFC1200100)+1 种基金the Entrepreneurship Leadership Project in Guangzhou Development Zone of China(No.CY2018-003)the Scientific Research Foundation of Graduate School of Southeast University(No.YBPY1903).
文摘Air curtains is promising in reducing the short-range infection risk in hospitals.To quantitatively evaluate its performance,this paper explores air curtains equipped on normal consulting desk to avoid doctor’s direct exposure to the patient exhaled pollutants.A numerical investigation is conducted to evaluate the effects of supply air velocity and angle on cutting off performance.Simulation results show that the average mass fraction of exhaled pollutants decreases significantly(70%–90%)in the consulting ward,indicating satisfying performance of air curtains.Increasing supply air velocity is demonstrated to be conducive in forming full air curtains,whereas an excessively high supply air velocity may be of adverse effects by entraining exhaled flow.Besides,the supply air angle is also critical due to its coupling with supply air velocity.It is found that larger angle(0°–40°)is better where velocity is less than 3 m/s,otherwise a small angle(20°)is preferable where velocity is larger than 3 m/s.Exhaled flow could be well suppressed at the supply air angle 20°but moves over air curtains at 40°.This study can provide effective and intuitive guidance in applying air curtains in consulting wards.
文摘Sulfosalicylic acid(SSA) was used as an intercalation agent and an excellent antenna to synthesize layered rare-earth hydroxide(LRH) materials and directly obtain SSA-modified terbium-doped ytterbium hydroxide nanosheets by mechanical exfoliation. The crystal structure and morphologies of the LRHs and nanosheets were determined by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The particle size and zeta potential of the prepared nanosheets were also analyzed. The as-prepared nanosheets exhibited excellent luminescent properties. The positively charged nanosheets were electrophoretically deposited on a conductive glass to form a thin film. The luminescence of this thin film can be quenched by chromate(CrO_4^(2–)) and bilirubin(BR), which shows good sensing properties. The quenching mechanism of the sensing film by CrO_4^(2–) and BR was discussed based on the spectra and structure of the film.
基金This study was funded by the National Natural Science Foundation of China(No.81972338)Clinical Major Specialty Projects of Beijing(2-1-2-038).
文摘Dear Editor,Nowadays,medulloblastoma accounts for approximately 25% of all pediatric brain tumors.1 Even with the successful treatment of primary tumors,there are still serious side effects.Honokiol(HNK)is defined as small bisphenol lignin extracted from the bark and seed cones of several species of Magnolia.
基金supported by the National Natural Science Foundation of China(31630063)。
文摘The brown planthopper(BPH)(Nilaparvata lugens St?l)is a highly destructive pest that seriously damages rice(Oryza sativa L.)and causes severe yield losses.To better understand the physiological and metabolic mechanisms through which BPHs respond to resistant rice,we combined mass-spectrometry-based lipidomics with transcriptomic analysis and gene knockdown techniques to compare the lipidomes of BPHs feeding on either of the two resistant(NIL-Bph6 and NIL-Bph9)plants or a wild-type,BPH susceptible(9311)plant.Insects that were fed on resistant rice transformed triglyceride(TG)to phosphatidylcholine(PC)and digalactosyldiacylglycerol(DGDG),with these lipid classes showing significant alterations in fatty acid composition.Moreover,the insects that were fed on resistant rice were characterized by prominent expression changes in genes involved in lipid metabolism processes.Knockdown of the NlBmm gene,which encodes a lipase that regulates the mobilization of lipid reserves,significantly increased TG content and feeding performance of BPHs on resistant plants relative to dsGFP-injected BPHs.Our study provides the first detailed description of lipid changes in BPHs fed on resistant and susceptible rice genotypes.Results from BPHs fed on resistant rice plants reveal that these insects can accelerate TG mobilization to provide energy for cell proliferation,body maintenance,growth and oviposition.
基金The authors would like to acknowledge the financial support from the National Natural Science Foundation of China(Nos.11872185,11627802,51678249,11132004)the Natural Science Foundation of Guangdong Province(No.2019A1515012222).
文摘As an important component,the bond behavior of carbon fiber-reinforced polymer(CFRP)-concrete interface for a reinforced concrete(RC)beam is very significant.In this study,a theoretical model was established to analyze the flexural behavior of CFRP-strengthened RC beams,and the CFRP-concrete interfacial bond-slip relationship under hygrothermal environment was unified into one model.Two failure criteria corresponding to two types of failure modes,i.e.,concrete crushing and intermediate crack(IC)-induced debonding,were developed.Through the theoretical model,the flexural behavior of deflection,interfacial shear stress distribution and ultimate load of a CFRP-strengthened RC beam under hygrothermal environment were obtained and predicted.Moreover,the theoretical model was verified by test results.The results showed that the hygrothermal environment had a significant impact on the CFRP-concrete interface behavior.Compared with the control beam without hygrothermal environment pretreatment,the deflection and ultimate load of the strengthened RC beam decreased by 51.9%and 20%,respectively.
基金the great help on thermodynamics calculation using HSC 6.0 software and the financial support on this research from the National Key Research and Development Program of China(Grant Nos.2017YFB0403300/2017YFB0403305)the National Natural Science Foundation of China under Grant Nos.51874269 and 51934006,and 1000 Talents Program of China(Z.S.)+1 种基金the Innovation Academy for Green Manufacture,Chinese Academy of Sciences(IAGM-2019-A15)the Key Program of Chinese Academy of Sciences(ZDRW_CN_2020-1).
文摘Spent lithium-ion battery recycling has attracted significant attention because of its importance in regard to the environment and resource importance.Traditional hydrometallurgical methods usually leach all valuable metals and subsequently extract target meals to prepare corresponding materials.However,Li recovery in these processes requires lengthy operational procedures,and the recovery efficiency is low.In this research,we demonstrate a method to selectively recover lithium before the leaching of other elements by introducing a hydrothermal treatment.Approximately 90%of Li is leached from high-Ni layered oxide cathode powders,while consuming a nearly stoichiometric amount of hydrogen ions.With this selective recovery of Li,the transition metals remain as solid residue hydroxides or oxides.Furthermore,the extraction of Li is found to be highly dependent on the content of transition metals in the cathode materials.A high leaching selectivity of Li(>98%)and nearly 95%leaching efficiency of Li can be reached with LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2).In this case,both the energy and material consumption during the proposed Li recovery is significantly decreased compared to traditional methods;furthermore,the proposed method makes full use of H+to leach Li+.This research is expected to provide new understanding for selectively recovering metal from secondary resources.
文摘The main purpose of this study was to evaluate the pharmacokinetics of levosulpiride in humans after single and multiple intramuscular injections.Six males and six females received single dose of either 25 mg or 50 mg levosulpiride,or multiple doses of 25 mg every 12 h for 5 consecutive days.In the single 25 mg study,the mean peak plasma concentration(C max)was 441 ng/mL,the mean area under the concentration–time curve from 0 to 36 h(AUC_(0–36))was 1724 ng h/mL,and the mean elimination half-life(t_(1/2))was 7.0 h.In the single 50 mg study,the mean C max was 823 ng/mL,the mean AUC_(0–36) was 3748 ng·h/mL,and the mean t_(1/2) was 6.8 h.After multiple doses of 25 mg levosulpiride,the average plasma concentration(C av)was 136 ng/mL,the fluctuation index(DF)was 3.60,and the accumulation ratio(R)was 1.2.Levosulpiride injections appeared to be well tolerated by the subjects,and can be used for successive administration.
基金Project supported by the National Natural Science Foundation of China (Nos. 11132004 and 51078145)the Guangdong Province Natural Science Foundation of China (No. 9251064101000016)
文摘The application of prestressed carbon reinforced polymer (prestressed CFRP) in reinforced concrete (RC) members can improve the mechanical properties of strengthened structures and strengthening efficiency. This paper proposed a semi-empirical prediction fornmla of fatigue lives of the RC beams strengthened with prestressed CFRP under bending loads. The formula is established based on the fatigue life prediction method of RC beams and fatigue experimental data of non-prestressed CFRP reinforced beams done before. Fatigue effect coefficient of the formula was confirmed by the fatigue experiments of the RC beams strengthened with prestressed carbon fiber laminate (prestressed CFL) under cyclic bending loads. Fatigue lives of the strengthened beams predicted using the formula agreed well with the experimental data.
基金support for this research from the National Key Research and Development Program ofChina(No.2017YFB0403300 and 2017YFB0403305)the National Natural Science Foundation of China(Grant Nos.51425405,51674022,and L1624051)+1 种基金Key Program of Chinese Acadermy of Sciences KFZD-SW-3151000 Talents Program of China(Z.S),as well as the Shanxi Provincial Science and Technology Major Projects(MC2016-05).
文摘In the production of lithium-ion batteries(LIBs)and recycling of spent LIBs,a large amount of low-concentration lithium-containing wastewater(LCW)is generated.The recovery of Li from this medium has attracted significant global attention from both the environmental and economic perspectives.To achieve effective Li recycling,the features of impurity removal and the interactions among different ions must be understood.However,it is generally dificult to ensure highly efficient removal of impurity ions while retaining Li in the solution for further recovery.In this study,the removal of typical impurity ions from LCW and the interactions between these species were systematically investigated from the thermodynamic and kinetics aspects.It was found that the main impurities(e.g.,Fe^+,AIP^+,Ca^2+,and Mg^2+)could be efficiently removed with high Li recovery by control-ling the ionic strength of the solution.The mechanisms of Fe^3+,Al^+,Ca^2+,and Mg^2+removal were investigated to identify the controlling steps and reaction kinetics.It was found that the precipitates are formed by a zero-order reaction,and the activation energies tend to be low with a sequence of fast chemical reactions that reach equilibrium very quickly.Moreover,this study focused on Li loss during removal of the impurities,and the corresponding removal rates of Fe^+,Al^+,Ca^2+,and Mg^2+were found to be 99.8%,99.5%,99%,and 99.7%,respectively.Conse-quently,high-purity LisPO4 was obtained via one-step precipitation.Thus,this research demonstrates a potential route for the effective recovery of Li from low-concentra-tion LCW and for the appropriate treatment of acidic LCW.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2018YFC0705300)the Fundamental Research Funds for the Central Universities(2242019K41024).
文摘Particulate matter emission from rotating wheels, which imparts a force to the contact surface and causes strong air currents, is one of the important pollutant sources on the road. This study investigates the particulate matter emission by measuring mass and size distributions of particulate matter near an isolated rotating wheel in a deliberately designed setup. Five rotating speeds from 0.7 m/s to 1.5 m/s are conducted to test its impact on the emission of particulate matter. Mass of particulate matter is measured at twenty-six sampling points around the rotating wheel under different experimental conditions. Experimental results show that the farther away from the wheel, the less of particulate matters deposited on the sampling points in general. Moreover, the emission factor increases from 0.12 g/vkt to 0.24 g/vkt when the rotating speed of the wheel increases from 0.7 m/s to 1.5 m/s. The number and proportion of PM2.5 and PM10 on different sampling points are also measured. The results show that the position of the highest number of PM2.5 and PM10 tends to move to a further and higher sampling point with the increasing of the speed. Moreover, the number proportions of PM2.5 and PM10 on the sampling points range from 19% to 97% and 61% to 100% at different speeds, respectively. This study is believed to be helpful to estimate particulate matter emission and make effective control strategies on targeted pollution.