Capacity allocation and energy management strategies for energy storage are critical to the safety and economical operation of microgrids.In this paper,an improved energymanagement strategy based on real-time electric...Capacity allocation and energy management strategies for energy storage are critical to the safety and economical operation of microgrids.In this paper,an improved energymanagement strategy based on real-time electricity price combined with state of charge is proposed to optimize the economic operation of wind and solar microgrids,and the optimal allocation of energy storage capacity is carried out by using this strategy.Firstly,the structure and model of microgrid are analyzed,and the outputmodel of wind power,photovoltaic and energy storage is established.Then,considering the interactive power cost between the microgrid and the main grid and the charge-discharge penalty cost of energy storage,an optimization objective function is established,and an improved energy management strategy is proposed on this basis.Finally,a physicalmodel is built inMATLAB/Simulink for simulation verification,and the energy management strategy is compared and analyzed on sunny and rainy days.The initial configuration cost function of energy storage is added to optimize the allocation of energy storage capacity.The simulation results show that the improved energy management strategy can make the battery charge-discharge response to real-time electricity price and state of charge better than the traditional strategy on sunny or rainy days,reduce the interactive power cost between the microgrid system and the power grid.After analyzing the change of energy storage power with cost,we obtain the best energy storage capacity and energy storage power.展开更多
In the present study, eight strains were isolated from 20 cow vagina samples and identified using phenotype, biochemical analysis, sugar fermentation tests, and 16S rRNA sequence analysis. Among eight strains, only SQ...In the present study, eight strains were isolated from 20 cow vagina samples and identified using phenotype, biochemical analysis, sugar fermentation tests, and 16S rRNA sequence analysis. Among eight strains, only SQ0048 was identified as Lactobacillus johnsonii based on a series of biochemical testing (including the adhesion test, catalase test, bacteriocin production test, antibacterial test, and pH value), suggesting that its biological activity was superior to the other seven strains. Furthermore, SQ0048 had the lowest pH value (4.32) and the shortest fermentation time (8 h) compared with the other strains. The adhesion rate of SQ0048 was significantly higher than that of Lactobacillus delbrueckii, with an average adhesion number of 304 ± 2.67. The hydrogen peroxide production testing in SQ0048 was positive;in addition, bacteriocin gene of SQ0048, encoding an approximately 10-kDa product, was successfully cloned, expressed, and detected using the SDS-PAGE method. Meanwhile, SQ0048 had a weak inhibitory effect on Staphylococcus aureus and Escherichia coli. However, the expression products of the bacteriocin gene of SQ0048 had a very strong inhibitory effect on S. aureus and E. coli, with inhibition zone sizes of 18 ± 0.45 mm and 15 ± 0.60 mm, respectively. These data showed that SQ0048 has excellent antibacterial properties compared with other isolated strains and is a potential probiotic candidate to improve the health of the vaginas of cows by inhibiting pathogenic microorganisms.展开更多
At present,solar thermal power generation is in the demonstration stage,and the large-scale production is affected by many factors.In view of the characteristics of different operating modes of photothermal power gene...At present,solar thermal power generation is in the demonstration stage,and the large-scale production is affected by many factors.In view of the characteristics of different operating modes of photothermal power generation,it is analyzed that the turbine needs to be started and stopped frequently due to different operating modes,which will lead to the instability of the output energy and the reduction of power generation efficiency.In this paper,the dynamic equation of energy conversion process is established by using the law of conservation of energy and conservation of mass.Combined with the logic switching criterion of the system,the system model was established by using the extended differential Petri net,and the validity and accuracy of the model were verified.Through the Petri net model of the system,the system’s working mode switching and power generation situation are analyzed due to the difference of direct normal irradiation intensity(DNI).Finally,the accuracy of the model is proved by comparing it with experimental data of the photovoltaic and thermal demonstration projects that have been connected to the grid.展开更多
To improve the atomic utilization of metals and reduce the cost of industrialization,the one-step total monoatomization of macroscopic bulk metals,as opposed to nanoscale metals,is effective.In this study,we used a th...To improve the atomic utilization of metals and reduce the cost of industrialization,the one-step total monoatomization of macroscopic bulk metals,as opposed to nanoscale metals,is effective.In this study,we used a thermal diffusion method to directly convert commercial centimeter-scale Ni foam to porous Ni single-atom-loaded carbon nanotubes(CNTs).As expected,owing to the coating of single-atom on porous,highly conductive CNT carriers,Ni single-atom electrocatalysts(Ni-SACs)exhibit extremely high activity and selectivity in CO_(2)electroreduction(CO_(2)RR),yielding a current density of>350 mA/cm^(2),a selectivity for CO of>91%under a flow cell configuration using a 1 M potassium chloride(KCl)electrolyte.Based on the superior activity of the Ni-SACs electrocatalyst,an integrated gas-phase electrochemical zero-gap reactor was introduced to generate a significant amount of CO current for potential practical applications.The overall current can be increased to 800 mA,while maintaining CO Faradaic efficiencies(FEs)at above 90%per unit cell.Our findings and insights on the active site transformation mechanism for macroscopic bulk Ni foam conversion into single atoms can inform the design of highly active single-atom catalysts used in industrial CO_(2)RR systems.展开更多
Diffuse large B-cell lymphoma(DLBCL)is a prevalent human malignancy,and understanding its biology will help identify problems in refractory patients and customize alternative therapies for them.We found that DLBCL can...Diffuse large B-cell lymphoma(DLBCL)is a prevalent human malignancy,and understanding its biology will help identify problems in refractory patients and customize alternative therapies for them.We found that DLBCL can be stratified into two independent subtypes with different clinical characteristics and outcomes by consensus clustering of expression of ferroptosis regulatory genes,which proves that ferroptosis is effective in treating refractory cases.In this work,we constructed a novel ferroptosis nanocarrier(PBPMn@PEG)by coating Prussian blue nanoparticles with manganese ions and encapsulating them with poly(ethyleneglycol).The low efficiency of the Fenton reaction of Prussian blue nanoparticles can be improved greatly by manganese coating,and can effectively generate hydroxyl radicals,and induce ferroptosis of lymphoma cells(SU-DHL-10 cells)by down-regulating ferroptosis suppressor genes and up-regulating ferroptosis driver genes.It also induces effective cell apoptosis,which is synergistic with ferroptosis for DLBCL therapy.In vivo experiments also prove that PBPMn@PEG achieved a better anti-tumor effect by up-regulating COX2,HO-1/hemeoxygenase-1(HMOX1),and NADPH oxidase-4(NOX4),and downregulating FSP1 and GPX4,with lower biotoxicity.As a novel and potential DLBCL drug carrier,our discovery served as a foundation for the treatment of the refractory DLBCL by inducing ferroptosis for DLBCL treatment in addition to the therapeutic effect of drugs.展开更多
Activity hijacking is one of the most powerful attacks in Android. Though promising, all the prior activity hijacking attacks suffer from some limitations and have limited attack capabilities. They no longer pose secu...Activity hijacking is one of the most powerful attacks in Android. Though promising, all the prior activity hijacking attacks suffer from some limitations and have limited attack capabilities. They no longer pose security threats in recent Android due to the presence of effective defense mechanisms. In this work, we propose the first automated and adaptive activity hijacking attack, named VenomAttack, enabling a spectrum of customized attacks (e.g., phishing, spoofing, and DoS) on a large scale in recent Android, even the state-of-the-art defense mechanisms are deployed. Specifically, we propose to use hotpatch techniques to identify vulnerable devices and update attack payload without re-installation and re-distribution, hence bypassing offline detection. We present a newly-discovered flaw in Android and a bug in derivatives of Android, each of which allows us to check if a target app is running in the background or not, by which we can determine the right attack timing via a designed transparent activity. We also propose an automated fake activity generation approach, allowing large-scale attacks. Requiring only the common permission INTERNET, we can hijack activities at the right timing without destroying the GUI integrity of the foreground app. We conduct proof-of-concept attacks, showing that VenomAttack poses severe security risks on recent Android versions. The user study demonstrates the effectiveness of VenomAttack in real-world scenarios, achieving a high success rate (95%) without users’ awareness. That would call more attention to the stakeholders like Google.展开更多
Oral squamous cell carcinoma(OSCC)is a prevalent malignant tumor affecting the head and neck region(Leemans et al.,2018).It is often diagnosed at a later stage,leading to a poor prognosis(Muzaffar et al.,2021;Li et al...Oral squamous cell carcinoma(OSCC)is a prevalent malignant tumor affecting the head and neck region(Leemans et al.,2018).It is often diagnosed at a later stage,leading to a poor prognosis(Muzaffar et al.,2021;Li et al.,2023).Despite advances in OSCC treatment,the overall 5-year survival rate of OSCC patients remains alarmingly low,falling below 50%(Jehn et al.,2019;Johnson et al.,2020).According to statistics,only 50%of patients with oral cancer can be treated with surgery.Once discovered,it is more frequently at an advanced stage.In addition,owing to the aggressively invasive and metastatic characteristics of OSCC,most patients die within one year of diagnosis.Hence,the pursuit of novel therapeutic drugs and treatments to improve the response of oral cancer to medication,along with a deeper understanding of their effects.展开更多
Extendible hashing is an effective way to manage increasingly large file system metadata,but it suffers from low concurrency and lack of optimization for non-volatile memory(NVM).In this paper,a multilevel hash direct...Extendible hashing is an effective way to manage increasingly large file system metadata,but it suffers from low concurrency and lack of optimization for non-volatile memory(NVM).In this paper,a multilevel hash directory based on lazy expansion is designed to improve the concurrency and efficiency of extendible hashing,and a hash bucket management algorithm based on groups is presented to improve the efficiency of hash key management by reducing the size of the hash bucket,thereby improving the performance of extendible hashing.Meanwhile,a hierarchical storage strategy of extendible hashing for NVM is given to take advantage of dynamic random access memory(DRAM)and NVM.Furthermore,on the basis of the device driver for Intel Optane DC Persistent Memory,the prototype of high-concurrency extendible hashing named NEHASH is implemented.Yahoo cloud serving benchmark(YCSB)is used to test and compare with CCEH,level hashing,and cuckoo hashing.The results show that NEHASH can improve read throughput by up to 16.5%and write throughput by 19.3%.展开更多
Titanium alloys have been widely used in many industrial clusters such as automotive, aerospace and biomedical industries due to their excellent comprehensive properties. In order to obtain fine microstructures and fa...Titanium alloys have been widely used in many industrial clusters such as automotive, aerospace and biomedical industries due to their excellent comprehensive properties. In order to obtain fine microstructures and favorable properties, a well-designed multi-step thermomechanical processing(TMP) is critically needed in manufacturing of titanium components. In making of titanium components,subtransus processing is a critical step to breakdown lamellar microstructure to fine-structure in hot working process and thus plays a key role in tailoring the final microstructure and properties. To realize this goal, huge efforts have been made to investigate the mechanisms of microstructure evolution and flow behavior during the subtransus processing. This paper reviews the recent experimental and modelling progresses, which aim to provide some guidelines for the process design and microstructure tailoring for titanium alloy research community. The characteristics of the initial lamellar microstructure are presented, followed by the discussion on microstructure evolution during subtransus processing. The globularization of lamellar α is analyzed in detail from three aspects, i.e., globularization mechanism, heterogeneity and kinetics. The typical features of flow behaviors and the explanations of significant flow softening are then summarized. The recent advances in modelling of microstructure evolution and flow behaviors in the subtransus processing are also articulated. The current tantalized issues and challenges in understanding of the microstructure evolution and flow behaviors of the titanium alloys with lamellar microstructure are presented and specified in future exploration of them.展开更多
Avoiding the folding defect and improving the die filling capability in the transitional region are desired in isothermal local loading forming of a large-scale Ti-alloy rib-web component(LTRC). To achieve a high-pr...Avoiding the folding defect and improving the die filling capability in the transitional region are desired in isothermal local loading forming of a large-scale Ti-alloy rib-web component(LTRC). To achieve a high-precision LTRC, the folding evolution and die filling process in the transitional region were investigated by 3 D finite element simulation and experiment using an equal-thickness billet(ETB). It is found that the initial volume distribution in the second-loading region can greatly affect the amount of material transferred into the first-loading region during the second-loading step, and thus lead to the folding defect. Besides, an improper initial volume distribution results in non-concurrent die filling in the cavities of ribs after the second-loading step, and then causes die underfilling. To this end, an unequal-thickness billet(UTB) was employed with the initial volume distribution optimized by the response surface method(RSM). For a certain eigenstructure, the critical value of the percentage of transferred material determined by the ETB was taken as a constraint condition for avoiding the folding defect in the UTB optimization process,and the die underfilling rate was considered as the optimization objective. Then, based on the RSM models of the percentage of transferred material and the die underfilling rate, non-folding parameter combinations and optimum die filling were achieved. Lastly, an optimized UTB was obtained and verified by the simulation and experiment.展开更多
Poultry and eggs are nutritious and healthy foods that contain high-quality proteins and low levels of fat compared with other meats. Recent studies have shown that poultry performance is closely associated with colon...Poultry and eggs are nutritious and healthy foods that contain high-quality proteins and low levels of fat compared with other meats. Recent studies have shown that poultry performance is closely associated with colonic health. Antibiotics are commonly used in the poultry industry to control diseases and enhance survival rates. However, antibiotic use can also result in host gut dysbiosis and immune dysregulation. Such imbalances compromise poultry health and growth performance. Thus, our study investigated the effect of Lactobacillus(L.) plantarum P-8 on the gut microbiome of chickens co-inoculated with the antibiotic lincomycin. Principal coordinate analysis showed that L. plantarum P-8 treatment shifted the faecal bacterial population structure. At the metagenomic level, the Clusters of Orthologous Groups(COGs) functional categories of P, C, N and A were overrepresented in the probiotic group. Additionally, the relative gene abundances of metabolic pathways involved in flagellar assembly,bacterial chemotaxis, nitrogen metabolism, sulfur metabolism, cofactor and vitamin biosynthesis were also higher in the probiotic group than the control; in contrast genes related to galactose degradation,carbon fixation, multiple sugar transport systems and ribosomes were underrepresented in the probiotic group. Our data suggest that feeding L. plantarum P-8 has the potential to improve metabolic activity and nutrient utilization of poultry. Furthermore, the faecal antibiotic resistomes of the two groups could be separated using principal components analysis, indicating that the probiotic treatment may modulate the intestinal antibiotic resistance gene pool by changing the population structure of the gut microbiota.This study has provided interesting insights into the application of probiotics in the poultry industry.展开更多
Revealing the mesoscale deformation mechanisms of titanium alloy with tri-modal microstructure is of great significance to improve its mechanical properties. In this work, the collective behavior and mechanisms of sli...Revealing the mesoscale deformation mechanisms of titanium alloy with tri-modal microstructure is of great significance to improve its mechanical properties. In this work, the collective behavior and mechanisms of slip activities, slip transfer, and grain boundary sliding of tri-modal microstructure were investigated by the combination of quasi-in-situ tensile test, SEM, EBSD and quantitative slip trace analyses. It is found that the slip behavior presents different characteristics in the equiaxed α(α_(p)) and lamellar α(α_(l))grains. Under a low level of deformation, almost all the slip deformation is governed by single basal and prismatic slips for both of α_(p)and α_(l),despite small amount of < a >-pyramidal slip exists in α_(l)grains. As deformation proceeds, < a >-pyramidal and < c + a >-pyramidal slip systems with high Schmid factors were activated in quantities. Specially, certain coarse prismatic slip bands were produced across both of single and colony α_(l)grains whose major axes tilting about 40 °–70 ° from the tensile axis. Slip transfer occurs at the boundaries of α_(p)/α_(p)and α_(l)/β under the condition that there exists perfect alignment between two slip systems and high Schmid factors of outgoing slip system. The slip transfer across α_(l)/β boundary can be divided into two types: straight slip transfer and deflect slip transfer with a deviation angle of 5 °–12 °, depending on the alignment of slip planes of two slip systems. The grain boundary sliding along boundaries of α_(l)/β and α_(p)/β was captured by covering micro-grid on tensile sample. It is found that the crystallographic orientation and the geometrical orientation related to loading axis play great roles in the occurrence of grain boundary sliding.展开更多
The present study aimed to evaluate the effects of daily feeding pattern on growth performance, blood biochemistry, and antioxidant indexes in pigs. One hundred and eighty female Duroc x Landrace x Yorkshire(DLY) pigs...The present study aimed to evaluate the effects of daily feeding pattern on growth performance, blood biochemistry, and antioxidant indexes in pigs. One hundred and eighty female Duroc x Landrace x Yorkshire(DLY) pigs with similar body weight(11.00 ± 0.12 kg) were randomly assigned to 3 groups: the control group(fed 17.01% CP diet, twice daily); high-low group(H-L group, fed18.33% CP diet in the morning, followed by 15.70% CP diet in the afternoon); and low-high group(L-H group, fed 15.70% CP diet in the morning, followed by 18.33% CP diet in the afternoon)(n = 6). Comparable amounts of their respective diets were given at 05:30 and 15:00 throughout the experimental periods to make all the treatments consumed the same type of food and the same amount of calories on a daily basis. On day 30, one pig was randomly selected per litter for blood samples. Compared with the control group, ADG in the H-L and L-H groups increased by 8.11% and 16.23%, but not significant(P > 0.05); and blood urea nitrogen(BUN) in the H-L and L-H groups decreased by 26.76% and 41.04%(P < 0.05), respectively. The H-L group feeding pattern could significantly improve levels of serum superoxide dismutase(SOD), when compared with the control group. These findings suggest that the twomeal daily feeding pattern with varied levels of CP affects serum levels of BUN and SOD. These changes could effectively silightly improve growth performance and antioxidant capacity in pigs without incurring increased feeding costs.展开更多
Understanding the mechanism of high temperature deformation is important for controlling the forming quality of the titanium alloy forgings.In the present work,the flow softening mechanism in subtransus deformation of...Understanding the mechanism of high temperature deformation is important for controlling the forming quality of the titanium alloy forgings.In the present work,the flow softening mechanism in subtransus deformation of titanium alloys with equiaxed structure was investigated by interrupted isothermal compression tests.The results show that limited strain hardening followed by continuous flow softening occurs in high temperature deformation of a twophase TA15 titanium alloy.The flow softening can not be rationalized by dynamic recrystallization.Instead,the increase of mobile dislocations during deformation is an important reason for flow softening.The grain boundaries(including the a-b interfaces)act as an important source for the generation of mobile dislocations.The continuous flow softening results from the significant deformation heterogeneity in subtransus working.展开更多
Precise control of the size and morphology of metal-organic frameworks(MOFs) presents an important direction for extending these inorganic-organic materials to many more advanced applications. However, because of the ...Precise control of the size and morphology of metal-organic frameworks(MOFs) presents an important direction for extending these inorganic-organic materials to many more advanced applications. However, because of the limit of the crystal-growth rule and mechanism, good-control of the size and morphology of MOFs remains challenging. In this contribution, an iron-terephthalic acid metal-organic framework with different shapes(octahedron, spindle and bipyramidal hexagonal) was easily and reproducibly synthesized via a solvothermal method. Sodium acetate and glycerol were used as modulators. Mechanism studies showed that the crystal nucleation rate and orientational growth both play important roles in determining the final shape of the MOFs. Further investigations showed that the as prepared MOFs exhibit shape-dependent catalytic activities, which means that MOFs can be designed to perform different catalytic functions. This investigation not only provides an effective guideline for the precise control of the size and morphology of metal-organic frameworks, but also extends MOFs to much more advanced applications in terms of catalyst chemistry.展开更多
Anisotropy of mechanical property is an important feature influencing the service performance of titanium(Ti)alloy tube component.In this work,it is found that the hot flow formed Ti alloy tube exhibits higher yield s...Anisotropy of mechanical property is an important feature influencing the service performance of titanium(Ti)alloy tube component.In this work,it is found that the hot flow formed Ti alloy tube exhibits higher yield strength along circumferential direction(CD),and larger elongation along rolling direction(RD),presenting significant anisotropy.Subsequently,the quantitative characteristics and underlying mechanism of the property anisotropy were revealed by analyzing the slip,damage and fracture behavior under the combined effects of the spun{0002}basal texture and fibrous microstructure for different loading directions.The results showed that the prismatic slip in primaryαgrain is the dominant deformation mechanism for both loading directions at the yielding stage.The prismatic slip is harder under CD loading,which makes CD loading present higher yield strength than RD loading.Additionally,the yield anisotropy can be quantified through the inverse ratio of the averaged Schmid Factor of the activated prismatic slip under different loading directions.As for the plasticity anisotropy,the harder and slower slip development under CD loading causes that the CD loading presents larger external force and normal stress on slip plane,thus leading to more significant cleavage fracture than RD loading.Moreover,the micro-crack path under RD loading is more tortuous than CD loading because the fibrous microstructure is elongated along RD,which may suppress the macro fracture under RD loading.These results suggest that weakening the texture and fibrous morphology of microstructure is critical to reduce the differences in slip,damage and fracture behavior along different directions,alleviate the property anisotropy and optimize the service performance of Ti alloy tube formed by hot flow forming.展开更多
基金a phased achievement of Gansu Province’s Major Science and Technology Project(W22KJ2722005)“Research on Optimal Configuration and Operation Strategy of Energy Storage under“New Energy+Energy Storage”Mode”.
文摘Capacity allocation and energy management strategies for energy storage are critical to the safety and economical operation of microgrids.In this paper,an improved energymanagement strategy based on real-time electricity price combined with state of charge is proposed to optimize the economic operation of wind and solar microgrids,and the optimal allocation of energy storage capacity is carried out by using this strategy.Firstly,the structure and model of microgrid are analyzed,and the outputmodel of wind power,photovoltaic and energy storage is established.Then,considering the interactive power cost between the microgrid and the main grid and the charge-discharge penalty cost of energy storage,an optimization objective function is established,and an improved energy management strategy is proposed on this basis.Finally,a physicalmodel is built inMATLAB/Simulink for simulation verification,and the energy management strategy is compared and analyzed on sunny and rainy days.The initial configuration cost function of energy storage is added to optimize the allocation of energy storage capacity.The simulation results show that the improved energy management strategy can make the battery charge-discharge response to real-time electricity price and state of charge better than the traditional strategy on sunny or rainy days,reduce the interactive power cost between the microgrid system and the power grid.After analyzing the change of energy storage power with cost,we obtain the best energy storage capacity and energy storage power.
文摘In the present study, eight strains were isolated from 20 cow vagina samples and identified using phenotype, biochemical analysis, sugar fermentation tests, and 16S rRNA sequence analysis. Among eight strains, only SQ0048 was identified as Lactobacillus johnsonii based on a series of biochemical testing (including the adhesion test, catalase test, bacteriocin production test, antibacterial test, and pH value), suggesting that its biological activity was superior to the other seven strains. Furthermore, SQ0048 had the lowest pH value (4.32) and the shortest fermentation time (8 h) compared with the other strains. The adhesion rate of SQ0048 was significantly higher than that of Lactobacillus delbrueckii, with an average adhesion number of 304 ± 2.67. The hydrogen peroxide production testing in SQ0048 was positive;in addition, bacteriocin gene of SQ0048, encoding an approximately 10-kDa product, was successfully cloned, expressed, and detected using the SDS-PAGE method. Meanwhile, SQ0048 had a weak inhibitory effect on Staphylococcus aureus and Escherichia coli. However, the expression products of the bacteriocin gene of SQ0048 had a very strong inhibitory effect on S. aureus and E. coli, with inhibition zone sizes of 18 ± 0.45 mm and 15 ± 0.60 mm, respectively. These data showed that SQ0048 has excellent antibacterial properties compared with other isolated strains and is a potential probiotic candidate to improve the health of the vaginas of cows by inhibiting pathogenic microorganisms.
基金supported by the Science Technology Project of State Grid Corporation of China(Grant No.52272219000 V)the Major Science and Technology Project of Gansu Province(Grant No.20ZD7GF011).
文摘At present,solar thermal power generation is in the demonstration stage,and the large-scale production is affected by many factors.In view of the characteristics of different operating modes of photothermal power generation,it is analyzed that the turbine needs to be started and stopped frequently due to different operating modes,which will lead to the instability of the output energy and the reduction of power generation efficiency.In this paper,the dynamic equation of energy conversion process is established by using the law of conservation of energy and conservation of mass.Combined with the logic switching criterion of the system,the system model was established by using the extended differential Petri net,and the validity and accuracy of the model were verified.Through the Petri net model of the system,the system’s working mode switching and power generation situation are analyzed due to the difference of direct normal irradiation intensity(DNI).Finally,the accuracy of the model is proved by comparing it with experimental data of the photovoltaic and thermal demonstration projects that have been connected to the grid.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.22101182)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110499)+2 种基金Shenzhen Science and Technology Program(No.JCYJ20210324095202006),Shenzhen University Young Teacher Research Project(No.000002110713)the Shccig-Qinling Program(No.2021JLM-27)the Jinchuan Group Co.Ltd.Chemical Environmental Protection Industry Joint Laboratory(No.20-0837).
文摘To improve the atomic utilization of metals and reduce the cost of industrialization,the one-step total monoatomization of macroscopic bulk metals,as opposed to nanoscale metals,is effective.In this study,we used a thermal diffusion method to directly convert commercial centimeter-scale Ni foam to porous Ni single-atom-loaded carbon nanotubes(CNTs).As expected,owing to the coating of single-atom on porous,highly conductive CNT carriers,Ni single-atom electrocatalysts(Ni-SACs)exhibit extremely high activity and selectivity in CO_(2)electroreduction(CO_(2)RR),yielding a current density of>350 mA/cm^(2),a selectivity for CO of>91%under a flow cell configuration using a 1 M potassium chloride(KCl)electrolyte.Based on the superior activity of the Ni-SACs electrocatalyst,an integrated gas-phase electrochemical zero-gap reactor was introduced to generate a significant amount of CO current for potential practical applications.The overall current can be increased to 800 mA,while maintaining CO Faradaic efficiencies(FEs)at above 90%per unit cell.Our findings and insights on the active site transformation mechanism for macroscopic bulk Ni foam conversion into single atoms can inform the design of highly active single-atom catalysts used in industrial CO_(2)RR systems.
基金supported by the National Natural Science Foundation of China(Nos.32071334,51825302,and 21734002)Natural Science Foundation of Chongqing(Nos.cstc2021jcyj-cxttX0002 and cstc2019jscx-msxmX0160).
文摘Diffuse large B-cell lymphoma(DLBCL)is a prevalent human malignancy,and understanding its biology will help identify problems in refractory patients and customize alternative therapies for them.We found that DLBCL can be stratified into two independent subtypes with different clinical characteristics and outcomes by consensus clustering of expression of ferroptosis regulatory genes,which proves that ferroptosis is effective in treating refractory cases.In this work,we constructed a novel ferroptosis nanocarrier(PBPMn@PEG)by coating Prussian blue nanoparticles with manganese ions and encapsulating them with poly(ethyleneglycol).The low efficiency of the Fenton reaction of Prussian blue nanoparticles can be improved greatly by manganese coating,and can effectively generate hydroxyl radicals,and induce ferroptosis of lymphoma cells(SU-DHL-10 cells)by down-regulating ferroptosis suppressor genes and up-regulating ferroptosis driver genes.It also induces effective cell apoptosis,which is synergistic with ferroptosis for DLBCL therapy.In vivo experiments also prove that PBPMn@PEG achieved a better anti-tumor effect by up-regulating COX2,HO-1/hemeoxygenase-1(HMOX1),and NADPH oxidase-4(NOX4),and downregulating FSP1 and GPX4,with lower biotoxicity.As a novel and potential DLBCL drug carrier,our discovery served as a foundation for the treatment of the refractory DLBCL by inducing ferroptosis for DLBCL treatment in addition to the therapeutic effect of drugs.
基金supported by the National Natural Science Foundation of China (Grant Nos. 62072309 and 6171101225).
文摘Activity hijacking is one of the most powerful attacks in Android. Though promising, all the prior activity hijacking attacks suffer from some limitations and have limited attack capabilities. They no longer pose security threats in recent Android due to the presence of effective defense mechanisms. In this work, we propose the first automated and adaptive activity hijacking attack, named VenomAttack, enabling a spectrum of customized attacks (e.g., phishing, spoofing, and DoS) on a large scale in recent Android, even the state-of-the-art defense mechanisms are deployed. Specifically, we propose to use hotpatch techniques to identify vulnerable devices and update attack payload without re-installation and re-distribution, hence bypassing offline detection. We present a newly-discovered flaw in Android and a bug in derivatives of Android, each of which allows us to check if a target app is running in the background or not, by which we can determine the right attack timing via a designed transparent activity. We also propose an automated fake activity generation approach, allowing large-scale attacks. Requiring only the common permission INTERNET, we can hijack activities at the right timing without destroying the GUI integrity of the foreground app. We conduct proof-of-concept attacks, showing that VenomAttack poses severe security risks on recent Android versions. The user study demonstrates the effectiveness of VenomAttack in real-world scenarios, achieving a high success rate (95%) without users’ awareness. That would call more attention to the stakeholders like Google.
基金supported by the Zhejiang Provincial Traditional Chinese Medicine Science and Technology Project(Nos.2019ZB015 and 2019ZA014),China.
文摘Oral squamous cell carcinoma(OSCC)is a prevalent malignant tumor affecting the head and neck region(Leemans et al.,2018).It is often diagnosed at a later stage,leading to a poor prognosis(Muzaffar et al.,2021;Li et al.,2023).Despite advances in OSCC treatment,the overall 5-year survival rate of OSCC patients remains alarmingly low,falling below 50%(Jehn et al.,2019;Johnson et al.,2020).According to statistics,only 50%of patients with oral cancer can be treated with surgery.Once discovered,it is more frequently at an advanced stage.In addition,owing to the aggressively invasive and metastatic characteristics of OSCC,most patients die within one year of diagnosis.Hence,the pursuit of novel therapeutic drugs and treatments to improve the response of oral cancer to medication,along with a deeper understanding of their effects.
基金Project supported by the National Natural Science Foundation of China(No.61806086)the National Key R&D Program of China(No.2018YFB0804204)。
文摘Extendible hashing is an effective way to manage increasingly large file system metadata,but it suffers from low concurrency and lack of optimization for non-volatile memory(NVM).In this paper,a multilevel hash directory based on lazy expansion is designed to improve the concurrency and efficiency of extendible hashing,and a hash bucket management algorithm based on groups is presented to improve the efficiency of hash key management by reducing the size of the hash bucket,thereby improving the performance of extendible hashing.Meanwhile,a hierarchical storage strategy of extendible hashing for NVM is given to take advantage of dynamic random access memory(DRAM)and NVM.Furthermore,on the basis of the device driver for Intel Optane DC Persistent Memory,the prototype of high-concurrency extendible hashing named NEHASH is implemented.Yahoo cloud serving benchmark(YCSB)is used to test and compare with CCEH,level hashing,and cuckoo hashing.The results show that NEHASH can improve read throughput by up to 16.5%and write throughput by 19.3%.
基金the support of National Natural Science Foundation of China(Nos.51605388,51875467)the Hong Kong Scholar Program(No.XJ2018010)the Young Elite Scientists Sponsorship Program by CAST(No.2018QNRC001).
文摘Titanium alloys have been widely used in many industrial clusters such as automotive, aerospace and biomedical industries due to their excellent comprehensive properties. In order to obtain fine microstructures and favorable properties, a well-designed multi-step thermomechanical processing(TMP) is critically needed in manufacturing of titanium components. In making of titanium components,subtransus processing is a critical step to breakdown lamellar microstructure to fine-structure in hot working process and thus plays a key role in tailoring the final microstructure and properties. To realize this goal, huge efforts have been made to investigate the mechanisms of microstructure evolution and flow behavior during the subtransus processing. This paper reviews the recent experimental and modelling progresses, which aim to provide some guidelines for the process design and microstructure tailoring for titanium alloy research community. The characteristics of the initial lamellar microstructure are presented, followed by the discussion on microstructure evolution during subtransus processing. The globularization of lamellar α is analyzed in detail from three aspects, i.e., globularization mechanism, heterogeneity and kinetics. The typical features of flow behaviors and the explanations of significant flow softening are then summarized. The recent advances in modelling of microstructure evolution and flow behaviors in the subtransus processing are also articulated. The current tantalized issues and challenges in understanding of the microstructure evolution and flow behaviors of the titanium alloys with lamellar microstructure are presented and specified in future exploration of them.
基金supports of the National Natural Science Foundation of China (No. 51575449)Research Fund of the State Key Laboratory of Solidification Processing (NWPU) of China (No. 104-QP2014)+1 种基金the 111 Project (No. B08040)the Fundamental Research Funds for the Central Universities (3102015AX004)
文摘Avoiding the folding defect and improving the die filling capability in the transitional region are desired in isothermal local loading forming of a large-scale Ti-alloy rib-web component(LTRC). To achieve a high-precision LTRC, the folding evolution and die filling process in the transitional region were investigated by 3 D finite element simulation and experiment using an equal-thickness billet(ETB). It is found that the initial volume distribution in the second-loading region can greatly affect the amount of material transferred into the first-loading region during the second-loading step, and thus lead to the folding defect. Besides, an improper initial volume distribution results in non-concurrent die filling in the cavities of ribs after the second-loading step, and then causes die underfilling. To this end, an unequal-thickness billet(UTB) was employed with the initial volume distribution optimized by the response surface method(RSM). For a certain eigenstructure, the critical value of the percentage of transferred material determined by the ETB was taken as a constraint condition for avoiding the folding defect in the UTB optimization process,and the die underfilling rate was considered as the optimization objective. Then, based on the RSM models of the percentage of transferred material and the die underfilling rate, non-folding parameter combinations and optimum die filling were achieved. Lastly, an optimized UTB was obtained and verified by the simulation and experiment.
文摘Poultry and eggs are nutritious and healthy foods that contain high-quality proteins and low levels of fat compared with other meats. Recent studies have shown that poultry performance is closely associated with colonic health. Antibiotics are commonly used in the poultry industry to control diseases and enhance survival rates. However, antibiotic use can also result in host gut dysbiosis and immune dysregulation. Such imbalances compromise poultry health and growth performance. Thus, our study investigated the effect of Lactobacillus(L.) plantarum P-8 on the gut microbiome of chickens co-inoculated with the antibiotic lincomycin. Principal coordinate analysis showed that L. plantarum P-8 treatment shifted the faecal bacterial population structure. At the metagenomic level, the Clusters of Orthologous Groups(COGs) functional categories of P, C, N and A were overrepresented in the probiotic group. Additionally, the relative gene abundances of metabolic pathways involved in flagellar assembly,bacterial chemotaxis, nitrogen metabolism, sulfur metabolism, cofactor and vitamin biosynthesis were also higher in the probiotic group than the control; in contrast genes related to galactose degradation,carbon fixation, multiple sugar transport systems and ribosomes were underrepresented in the probiotic group. Our data suggest that feeding L. plantarum P-8 has the potential to improve metabolic activity and nutrient utilization of poultry. Furthermore, the faecal antibiotic resistomes of the two groups could be separated using principal components analysis, indicating that the probiotic treatment may modulate the intestinal antibiotic resistance gene pool by changing the population structure of the gut microbiota.This study has provided interesting insights into the application of probiotics in the poultry industry.
基金the support of the National Natural Science Foundation of China(No.51875467,92060107)the National Science Fund for Distinguished Young Scholars of China(No.51625505)+2 种基金the National Key R&D Program of China(No.2020YFA0711100)Young Elite Scientists Sponsorship Program and the General Program of ScienceTechnology Development Project of Beijing Municipal Education Commission(No.KM202010005008)
文摘Revealing the mesoscale deformation mechanisms of titanium alloy with tri-modal microstructure is of great significance to improve its mechanical properties. In this work, the collective behavior and mechanisms of slip activities, slip transfer, and grain boundary sliding of tri-modal microstructure were investigated by the combination of quasi-in-situ tensile test, SEM, EBSD and quantitative slip trace analyses. It is found that the slip behavior presents different characteristics in the equiaxed α(α_(p)) and lamellar α(α_(l))grains. Under a low level of deformation, almost all the slip deformation is governed by single basal and prismatic slips for both of α_(p)and α_(l),despite small amount of < a >-pyramidal slip exists in α_(l)grains. As deformation proceeds, < a >-pyramidal and < c + a >-pyramidal slip systems with high Schmid factors were activated in quantities. Specially, certain coarse prismatic slip bands were produced across both of single and colony α_(l)grains whose major axes tilting about 40 °–70 ° from the tensile axis. Slip transfer occurs at the boundaries of α_(p)/α_(p)and α_(l)/β under the condition that there exists perfect alignment between two slip systems and high Schmid factors of outgoing slip system. The slip transfer across α_(l)/β boundary can be divided into two types: straight slip transfer and deflect slip transfer with a deviation angle of 5 °–12 °, depending on the alignment of slip planes of two slip systems. The grain boundary sliding along boundaries of α_(l)/β and α_(p)/β was captured by covering micro-grid on tensile sample. It is found that the crystallographic orientation and the geometrical orientation related to loading axis play great roles in the occurrence of grain boundary sliding.
基金supported by grants from the National key research and development program of China (2016YFD0500504)National Key Technology Research and Development Program of the Ministry of Science and Technology of China (2012BAD39B03)Major Project of Hunan Province (2015NK1002)
文摘The present study aimed to evaluate the effects of daily feeding pattern on growth performance, blood biochemistry, and antioxidant indexes in pigs. One hundred and eighty female Duroc x Landrace x Yorkshire(DLY) pigs with similar body weight(11.00 ± 0.12 kg) were randomly assigned to 3 groups: the control group(fed 17.01% CP diet, twice daily); high-low group(H-L group, fed18.33% CP diet in the morning, followed by 15.70% CP diet in the afternoon); and low-high group(L-H group, fed 15.70% CP diet in the morning, followed by 18.33% CP diet in the afternoon)(n = 6). Comparable amounts of their respective diets were given at 05:30 and 15:00 throughout the experimental periods to make all the treatments consumed the same type of food and the same amount of calories on a daily basis. On day 30, one pig was randomly selected per litter for blood samples. Compared with the control group, ADG in the H-L and L-H groups increased by 8.11% and 16.23%, but not significant(P > 0.05); and blood urea nitrogen(BUN) in the H-L and L-H groups decreased by 26.76% and 41.04%(P < 0.05), respectively. The H-L group feeding pattern could significantly improve levels of serum superoxide dismutase(SOD), when compared with the control group. These findings suggest that the twomeal daily feeding pattern with varied levels of CP affects serum levels of BUN and SOD. These changes could effectively silightly improve growth performance and antioxidant capacity in pigs without incurring increased feeding costs.
基金supported by the National Natural Science Foundation of China (50935007,51205317)the National Basic Research Program of China (2010CB731701)111 Project (B08040)
文摘Understanding the mechanism of high temperature deformation is important for controlling the forming quality of the titanium alloy forgings.In the present work,the flow softening mechanism in subtransus deformation of titanium alloys with equiaxed structure was investigated by interrupted isothermal compression tests.The results show that limited strain hardening followed by continuous flow softening occurs in high temperature deformation of a twophase TA15 titanium alloy.The flow softening can not be rationalized by dynamic recrystallization.Instead,the increase of mobile dislocations during deformation is an important reason for flow softening.The grain boundaries(including the a-b interfaces)act as an important source for the generation of mobile dislocations.The continuous flow softening results from the significant deformation heterogeneity in subtransus working.
基金supported by the National Natural Science Foundation of China(21175109)the Chongqing Key Laboratory Special Fund
文摘Precise control of the size and morphology of metal-organic frameworks(MOFs) presents an important direction for extending these inorganic-organic materials to many more advanced applications. However, because of the limit of the crystal-growth rule and mechanism, good-control of the size and morphology of MOFs remains challenging. In this contribution, an iron-terephthalic acid metal-organic framework with different shapes(octahedron, spindle and bipyramidal hexagonal) was easily and reproducibly synthesized via a solvothermal method. Sodium acetate and glycerol were used as modulators. Mechanism studies showed that the crystal nucleation rate and orientational growth both play important roles in determining the final shape of the MOFs. Further investigations showed that the as prepared MOFs exhibit shape-dependent catalytic activities, which means that MOFs can be designed to perform different catalytic functions. This investigation not only provides an effective guideline for the precise control of the size and morphology of metal-organic frameworks, but also extends MOFs to much more advanced applications in terms of catalyst chemistry.
基金financially supported by the National Natural Science Foundation of China(No.51875467,52005313)the National Science Fund for Distinguished Young Scholars of China(No.51625505)+1 种基金the Young Elite Scientists Sponsorship Program by CAST(No.2018QNRC001)the Research Fund of the State Key Laboratory of Solidification Processing(NPU)of China(No.2019TS-10)。
文摘Anisotropy of mechanical property is an important feature influencing the service performance of titanium(Ti)alloy tube component.In this work,it is found that the hot flow formed Ti alloy tube exhibits higher yield strength along circumferential direction(CD),and larger elongation along rolling direction(RD),presenting significant anisotropy.Subsequently,the quantitative characteristics and underlying mechanism of the property anisotropy were revealed by analyzing the slip,damage and fracture behavior under the combined effects of the spun{0002}basal texture and fibrous microstructure for different loading directions.The results showed that the prismatic slip in primaryαgrain is the dominant deformation mechanism for both loading directions at the yielding stage.The prismatic slip is harder under CD loading,which makes CD loading present higher yield strength than RD loading.Additionally,the yield anisotropy can be quantified through the inverse ratio of the averaged Schmid Factor of the activated prismatic slip under different loading directions.As for the plasticity anisotropy,the harder and slower slip development under CD loading causes that the CD loading presents larger external force and normal stress on slip plane,thus leading to more significant cleavage fracture than RD loading.Moreover,the micro-crack path under RD loading is more tortuous than CD loading because the fibrous microstructure is elongated along RD,which may suppress the macro fracture under RD loading.These results suggest that weakening the texture and fibrous morphology of microstructure is critical to reduce the differences in slip,damage and fracture behavior along different directions,alleviate the property anisotropy and optimize the service performance of Ti alloy tube formed by hot flow forming.