In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selec...In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst.This catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)configuration.Compared to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the reaction.Within the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis acids.This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene selectivity.Through this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.展开更多
Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herei...Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.展开更多
K-struvite was prepared by precipitation method,and the stability of K-struvite in high temperature and acid-base environment were investigated by X-ray diffraction(XRD),thermogravimetric analysis(TG/DSC),and infrared...K-struvite was prepared by precipitation method,and the stability of K-struvite in high temperature and acid-base environment were investigated by X-ray diffraction(XRD),thermogravimetric analysis(TG/DSC),and infrared spectroscopy(FT-IR).The results show that K-struvite decomposes from 50 to 110℃,and the mass loss begins at 50℃before being completely destroyed at 110℃,then further heating at temperature above 500℃leading to complete loss of the binding water in K-struvite.Moreover,K-struvite is more stable in alkaline environments than acidic environment.展开更多
Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot ...Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot and cold ethanol for the extraction. The extract was filtered and part of it was concentrated to yield a reasonable quantity of turmeric indicator. On standardization of acid with a base, 0.05 M base respectively of Sodium hydroxide (NaOH), sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) and Disodium borate (B<sub>4</sub>Na<sub>2</sub>O<sub>7</sub>) were used. Hot and cold extracts of turmeric were used as indicators and were compared with methyl orange and phenolphthalein. On the preliminary test carried out, hot and cold turmeric indicator showed yellow colour in acid medium and orange colour in the base. Methyl orange showed red colour in acid but yellow in the base, phenolphthalein was colourless in acid but pink in the base. During titration there were colour changes at the end points in the entire test carried out. The average volumes at ends points were calculated, the molar concentrations and mass concentrations of the acids used were also determined. The results showed that there was no difference between the natural indicators used and the existing synthetic indicators which are toxic to our environment.展开更多
A recently discovered family of kagome lattice materials,AV_(3)Sb_(5)(A=K,Rb,Cs),has attracted great interest,especiallyin the debate over their dominant superconducting pairing symmetry.To explore this issue,we study...A recently discovered family of kagome lattice materials,AV_(3)Sb_(5)(A=K,Rb,Cs),has attracted great interest,especiallyin the debate over their dominant superconducting pairing symmetry.To explore this issue,we study the superconductingpairing behavior within the kagome-lattice Hubbard model through the constrained path Monte Carlo method.It isfound that doping around the Dirac point generates a dominant next-nearest-neighbor-d pairing symmetry driven by on-siteCoulomb interaction U.However,when considering the nearest-neighbor interaction V,it may induce nearest-neighbor-ppairing to become the preferred pairing symmetry.Our results provide useful information to identify the dominant superconductingpairing symmetry in the AV_(3)Sb_(5)family.展开更多
By utilizing the fluctuation exchange approximation method,we perform a study on the superconducting pairing symmetry in a t_(2g) three-orbital model on the square lattice.Although the tight-binding parameters of the ...By utilizing the fluctuation exchange approximation method,we perform a study on the superconducting pairing symmetry in a t_(2g) three-orbital model on the square lattice.Although the tight-binding parameters of the model are based on Sr_(2)RuO_(4),we have systematically studied the evolution of superconducting pairing symmetry with the carrier density and interactions,making our findings relevant to a broader range of material systems.Under a moderate Hund’s coupling,we find that spin fluctuations dominate the superconducting pairing,leading to a prevalent spin-singlet pairing with a d_(x^(2)-y^(2))-wave symmetry for the carrier density within the range of n=1.5-4 per site.By reducing the Hund’s coupling,the charge fluctuations are enhanced and play a crucial role in determining the pairing symmetry,leading to a transition of the pairing symmetry from the spin-singlet d_(x^(2)-y^(2))-wave to the spin-triplet p-wave.Furthermore,we find that the superconducting pairings are orbital dependent.As the carrier density changes from n=4 to n=1.5,the active orbitals for superconducting pairing shift from the quasi-two-dimensional orbital dxy to the quasi-one-dimensional orbitals d_(xz) and d_(yz).展开更多
Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we r...Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we report a multiple redox-mediated linear paired electrolysis system,combining the hydrogen peroxide mediated cathode process with the I2 mediated anode process,and realize the conversion of furfural to furoic acid in both side of the dividedflow cell simultaneously.By reasonably controlling the cathode potential,the undesired water splitting reaction and furfural reduction side reactions are avoided.Under the galvanostatic electrolysis,the two-mediated electrode processes have good compatibility,which reduce the energy consumption by about 22%while improving the electronic efficiency by about 125%.This system provides a green electrochemical synthesis route with commercial prospects.展开更多
The application of amino acid-based surfactant in dishwasher detergent was studied in this paper. The foam and oil-removing performance of amino acid surfactants in alkaline condition were test to discuss feasibility ...The application of amino acid-based surfactant in dishwasher detergent was studied in this paper. The foam and oil-removing performance of amino acid surfactants in alkaline condition were test to discuss feasibility of amino acid-based surfactant from natural origin as the alternative to traditional nonionic surfactants from petroleum origin in dishwasher detergent. Comparative study was conducted through using various amino acid-based surfactants and nonionic surfactants respectively, together with enzymes and peroxide to formulate dishwasher detergents, and their application properties such as foam performance and detergency were also evaluated when washing different tableware in automatic dishwasher. The results showed that among all tested amino acid surfactants, glutamate surfactants showed low foaming and high oil-removing ability in alkaline condition, and excellent decontamination ability in dishwashing tests.展开更多
Recent experimental findings have demonstrated the occurrence of superconductivity in Bernal bilayer graphene when induced by a magnetic field.In this study,we conduct a theoretical investigation of the potential pair...Recent experimental findings have demonstrated the occurrence of superconductivity in Bernal bilayer graphene when induced by a magnetic field.In this study,we conduct a theoretical investigation of the potential pairing symmetry within this superconducting system.By developing a theoretical model,we primarily calculate the free energy of the system with p+ip-wave parallel spin pairing,p+ip-wave anti-parallel spin pairing and d+i d-wave pairing symmetry.Our results confirm that the magnetic field is indeed essential for generating the superconductivity.We discover that the p+ip-wave parallel spin pairing leads to a lower free energy for the system.The numerical calculations of the energy band structure,zero-energy spectral function and density of states for each of the three pairing symmetries under consideration show a strong consistency with the free energy results.展开更多
Electrochemical co-reduction of nitrate(NO_(3)^(-))and carbon dioxide(CO_(2))has been widely regarded as a promising route to produce urea under ambient conditions,however the yield rate of urea has remained limited.H...Electrochemical co-reduction of nitrate(NO_(3)^(-))and carbon dioxide(CO_(2))has been widely regarded as a promising route to produce urea under ambient conditions,however the yield rate of urea has remained limited.Here,we report an atomically ordered intermetallic pallium-zinc(PdZn)electrocatalyst comprising a high density of PdZn pairs for boosting urea electrosynthesis.It is found that Pd and Zn are responsible for the adsorption and activation of NO_(3)^(-)and CO_(2),respectively,and thus the co-adsorption and co-activation NO_(3)^(-)and CO_(2) are achieved in ordered PdZn pairs.More importantly,the ordered and well-defined PdZn pairs provide a dual-site geometric structure conducive to the key C-N coupling with a low kinetical barrier,as demonstrated on both operando measurements and theoretical calculations.Consequently,the PdZn electrocatalyst displays excellent performance for the co-reduction to generate urea with a maximum urea Faradaic efficiency of 62.78%and a urea yield rate of 1274.42μg mg^(-1) h^(-1),and the latter is 1.5-fold larger than disordered pairs in PdZn alloys.This work paves new pathways to boost urea electrosynthesis via constructing ordered dual-metal pairs.展开更多
The prevalence of smartphones is deeply embedded in modern society,impacting various aspects of our lives.Their versatility and functionalities have fundamentally changed how we communicate,work,seek entertainment,and...The prevalence of smartphones is deeply embedded in modern society,impacting various aspects of our lives.Their versatility and functionalities have fundamentally changed how we communicate,work,seek entertainment,and access information.Among the many smartphones available,those operating on the Android platform dominate,being the most widely used type.This widespread adoption of the Android OS has significantly contributed to increased malware attacks targeting the Android ecosystem in recent years.Therefore,there is an urgent need to develop new methods for detecting Android malware.The literature contains numerous works related to Android malware detection.As far as our understanding extends,we are the first ones to identify dangerous combinations of permissions and system calls to uncover malicious behavior in Android applications.We introduce a novel methodology that pairs permissions and system calls to distinguish between benign and malicious samples.This approach combines the advantages of static and dynamic analysis,offering a more comprehensive understanding of an application’s behavior.We establish covalent bonds between permissions and system calls to assess their combined impact.We introduce a novel technique to determine these pairs’Covalent Bond Strength Score.Each pair is assigned two scores,one for malicious behavior and another for benign behavior.These scores serve as the basis for classifying applications as benign or malicious.By correlating permissions with system calls,the study enables a detailed examination of how an app utilizes its requested permissions,aiding in differentiating legitimate and potentially harmful actions.This comprehensive analysis provides a robust framework for Android malware detection,marking a significant contribution to the field.The results of our experiments demonstrate a remarkable overall accuracy of 97.5%,surpassing various state-of-the-art detection techniques proposed in the current literature.展开更多
Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pair...Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pairing forces,as well as a combination of these two forces,were used for the Hartree–Fock–Bogoliubov approximation.Variations in the least-energy fission path,fission barrier,pairing energy,total kinetic energy,scission line,and mass distribution of the fission fragments based on the different forms of the pairing forces were analyzed and discussed.The fission dynamics were studied based on the timedependent generator coordinate method plus the Gaussian overlap approximation.The results demonstrated a sensitivity of the mass and charge distributions of the fission fragments on the form of the pairing force.Based on the investigation of the neutron-induced fission of^(239)Pu,among the volume,mixed,and surface pairing forces,the mixed pairing force presented a good reproduction of the experimental data.展开更多
In this editorial,we commented on the article by Akers et al published in the recent issue of the World Journal of Clinical Cases.We focused specifically on the role of the transcription factor paired box protein 8(PA...In this editorial,we commented on the article by Akers et al published in the recent issue of the World Journal of Clinical Cases.We focused specifically on the role of the transcription factor paired box protein 8(PAX8)belonging to the family PAX in the carcinogenesis of a gynecologic tumor,endocervical adenocarcinoma,arising from the tissue of mesonephric origin,and the potential diagnostic value for the same type of neoplasms.The global vaccination program of human papillomavirus(HPV)has dramatically reduced the incidence of cervical cancer,including cases of adenocarcinoma.The type of adenoid epithelial origin has a lower frequency of HPV detection but tends to be more aggressive and fatal.Cases of endocervical adenocarcinoma occurring in females of menopause age have been described in the 2023 volume of the World Journal of Clinical Cases and in our study recently published in Oncol Lett.The histopathological findings and immunohistochemical assays showed that the lesions had glandular morphology,and the specimens in these two reports were immunohistochemically positive for the transcription factor PAX8,albeit that they had opposing expression profiles of tumor suppressor p16 and estrogen receptor and the presence of the HPV genome.The presence of a mucin protein,MUC 5AC,as revealed in both studies suggested target molecules for the diagnosis of mucinous adenoid type of uterine tumor and other histological origins.The clinical outcome was unfavorable due to metastasis and recurrence.This prompted the improvement of the antitumor modality,with the introduction of precise targeting therapy.Mucin has now been reported to be the therapeutic target for adenocarcinomas.展开更多
The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orb...The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orbitals,electron localization function(ELF)and partial density of states(PDOS).Birefringence is evaluated by means of a Born effective charge approach based on modern polarization theory.The origin of the different responses of birefringence and second-harmonic generation(SHG)is explored,as well as the effect of spin-orbit coupling(SOC)on the band structure and optical properties is explored.The study of this paper can help to deeply understand the lone pairs and their contribution to optical property.展开更多
Electrochemical carbon dioxide reduction reaction(CO_(2)RR)involves a variety of intermediates with highly correlated reaction and ad-desorption energies,hindering optimization of the catalytic activity.For example,in...Electrochemical carbon dioxide reduction reaction(CO_(2)RR)involves a variety of intermediates with highly correlated reaction and ad-desorption energies,hindering optimization of the catalytic activity.For example,increasing the binding of the*COOH to the active site will generally increase the*CO desorption energy.Breaking this relationship may be expected to dramatically improve the intrinsic activity of CO_(2)RR,but remains an unsolved challenge.Herein,we addressed this conundrum by constructing a unique atomic dispersed hetero-pair consisting of Mo-Fe di-atoms anchored on N-doped carbon carrier.This system shows an unprecedented CO_(2)RR intrinsic activity with TOF of 3336 h−1,high selectivity toward CO production,Faradaic efficiency of 95.96%at−0.60 V and excellent stability.Theoretical calculations show that the Mo-Fe diatomic sites increased the*COOH intermediate adsorption energy by bridging adsorption of*COOH intermediates.At the same time,d-d orbital coupling in the Mo-Fe di-atom results in electron delocalization and facilitates desorption of*CO intermediates.Thus,the undesirable correlation between these steps is broken.This work provides a promising approach,specifically the use of di-atoms,for breaking unfavorable relationships based on understanding of the catalytic mechanisms at the atomic scale.展开更多
The utilization of sequence stratigraphic concepts in identifying sands and their spatial continuity in distinct gross depositional settings is key,especially in frontier settings where data paucity is a common challe...The utilization of sequence stratigraphic concepts in identifying sands and their spatial continuity in distinct gross depositional settings is key,especially in frontier settings where data paucity is a common challenge.In the Baka field,onshore Niger Delta,detailed reservoir correlation guided by sequence stratigraphic framework analysis showed the distribution of sand and shale units constituting reservoirseal pairs(RSP)correlatable across the field.Within the 3rd-order packages,it is observed that the lowstand systems tract(LST)and highstand systems tract(HST)contain more RSPs and thicker 4th-and 5th-order sands than the transgressive systems tract(TST).In terms of bathymetry,it is noted that irrespective of systems tracts,the RSP Index(RI)decreases from the proximal shallow/inner shelf settings to the more distal outer shelf areas.Amongst all three systems tracts,intervals interpreted as lowstand prograding complexes contain the best developed sands and highest RSP.Sand development within the LSTs has been controlled by a pronounced growth fault regime accompanied by high subsidence and sedimentation rates.This is linked to the basinward migration of the sands during prolonged sea-level fall,creating significant accommodation space for sand deposition.On the other hand,the TSTs known to mark periods of progressive sea-level rise and landward migration of sandy facies,show thinner sands enclosed in much thicker,laterally extensive,and better-preserved deeper marine shales.Interpreted seismic sections indicate intense growth faulting and channelization that influenced the syn-and postdepositional development of the sand packages across the field.The initial timing of deformation of subregional faults in this area coincides with periods of abrupt falls in sea level.This approach could be useful for predicting sand-prone areas in frontier fields as well as possible reservoir-seal parameters required for some aspects of petroleum system analysis and quick-look volume estimation.展开更多
We study theoretically the electrical shot noise properties of tunnel junctions between a normal metal and a superconductor with the mixture of singlet s-wave and chiral triplet p-wave pairing due to broken inversion ...We study theoretically the electrical shot noise properties of tunnel junctions between a normal metal and a superconductor with the mixture of singlet s-wave and chiral triplet p-wave pairing due to broken inversion symmetry. We investigate how the shot noise properties vary as the relative amplitude between the two parity components in the pairing potential is changed. It is demonstrated that some characteristics of the electrical shot noise properties of such tunnel junctions may depend sensitively on the relative amplitude between the two parity components in the pairing potential, and some significant changes may occur in the electrical shot noise properties when the relative amplitude between the two parity components is varied from the singlet s-wave pairing dominated regime to the chiral triplet p-wave pairing dominated regime. In the chiral triplet p-wave pairing dominated regime, the ratio of noise power to electric current is close to 2e both in the in-gap and in the out-gap region. In the singlet s-wave pairing dominated regime, the value of this ratio is close to 4e in the inner gap region but may reduce to about 2e in the outer gap region as the relative amplitude of the chiral triplet pairing component is increased. The variations of the differential shot noise with the bias voltage also exhibit some significantly different features in different regimes. Such different features can serve as useful diagnostic tools for the determination of the relative magnitude of the two parity components in the pairing potential.展开更多
In the new era,there is an urgent need to further promote pairing assistance to Tibet,promote the simultaneous construction of a strong agriculture in Tibet and the China's Mainland,and compose a Chinese-style mod...In the new era,there is an urgent need to further promote pairing assistance to Tibet,promote the simultaneous construction of a strong agriculture in Tibet and the China's Mainland,and compose a Chinese-style modernization.Southern Tibet,located in the southeastern part of the Tibet Autonomous Region,includes Shannan City and Nyingchi City,is a region assisted by four provincial partners including Hubei Province.This paper introduces the agricultural environment in southern Tibet,studies its agricultural characteristics,and analyzes the main issues of its pairing assistance.Taking forging the strong consciousness of the Chinese national community as the main line,the paper explores strategies for promoting agricultural high-quality development in southern Tibet through pairing assistance to Tibet from the perspective of agricultural power,and proposes some strategies,such as inheriting agricultural cultural heritage,promoting the upgrading of modern seed industry,enhancing the characteristic advantages of highland barley(naked barley)and animal husbandry industries,and developing edible fungi and cold water fish industries.展开更多
This study highlights the changing priorities of China’s paired assistance throughout the past decades,as well as its theoretical implications and economic growth effects for recipient regions.Using panel data from 3...This study highlights the changing priorities of China’s paired assistance throughout the past decades,as well as its theoretical implications and economic growth effects for recipient regions.Using panel data from 32 prefecture-level cities from 1990 to 2020,this study uses the multiperiod difference-in-differences approach to examine how paired assistance has contributed to economic growth in Xizang Autonomous Region and Xinjiang Uygur Autonomous Region.The findings indicate that,first,the implementation of the paired assistance policy has boosted economic growth in Xizang and Xinjiang.Second,paired assistance has stimulated economic growth in recipient communities by improving infrastructure.Third,paired assistance has contributed to economic growth in recipient communities by providing improved public services such as education and healthcare.Improvements to public services have a relatively smaller indirect effect in short term than infrastructure development on economic growth.Yet both education and healthcare are crucial to people’s quality of life in recipient communities.This paper has refined and broadened research on the effects of paired assistance,providing preference for future policymaking.展开更多
基金the funding support from the National Natural Science Foundation of China(Nos.22202036 and 22302001)the Jilin Province Scientific,the Technological Planning Project of China(No.20230101292JC).
文摘In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst.This catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)configuration.Compared to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the reaction.Within the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis acids.This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene selectivity.Through this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.
基金supported by the National Natural Science Foundation of China (52161025)the Natural Science Foundation of Gansu Province (20JR10RA241)。
文摘Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.
基金Funded by the National Natural Science Foundation of China(No.51972214)。
文摘K-struvite was prepared by precipitation method,and the stability of K-struvite in high temperature and acid-base environment were investigated by X-ray diffraction(XRD),thermogravimetric analysis(TG/DSC),and infrared spectroscopy(FT-IR).The results show that K-struvite decomposes from 50 to 110℃,and the mass loss begins at 50℃before being completely destroyed at 110℃,then further heating at temperature above 500℃leading to complete loss of the binding water in K-struvite.Moreover,K-struvite is more stable in alkaline environments than acidic environment.
文摘Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot and cold ethanol for the extraction. The extract was filtered and part of it was concentrated to yield a reasonable quantity of turmeric indicator. On standardization of acid with a base, 0.05 M base respectively of Sodium hydroxide (NaOH), sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) and Disodium borate (B<sub>4</sub>Na<sub>2</sub>O<sub>7</sub>) were used. Hot and cold extracts of turmeric were used as indicators and were compared with methyl orange and phenolphthalein. On the preliminary test carried out, hot and cold turmeric indicator showed yellow colour in acid medium and orange colour in the base. Methyl orange showed red colour in acid but yellow in the base, phenolphthalein was colourless in acid but pink in the base. During titration there were colour changes at the end points in the entire test carried out. The average volumes at ends points were calculated, the molar concentrations and mass concentrations of the acids used were also determined. The results showed that there was no difference between the natural indicators used and the existing synthetic indicators which are toxic to our environment.
基金supported by Beijing Natural Science Foundation(Grant No.1242022).The numerical simulations in this work were performed at HSCC of Beijing Normal University.
文摘A recently discovered family of kagome lattice materials,AV_(3)Sb_(5)(A=K,Rb,Cs),has attracted great interest,especiallyin the debate over their dominant superconducting pairing symmetry.To explore this issue,we study the superconductingpairing behavior within the kagome-lattice Hubbard model through the constrained path Monte Carlo method.It isfound that doping around the Dirac point generates a dominant next-nearest-neighbor-d pairing symmetry driven by on-siteCoulomb interaction U.However,when considering the nearest-neighbor interaction V,it may induce nearest-neighbor-ppairing to become the preferred pairing symmetry.Our results provide useful information to identify the dominant superconductingpairing symmetry in the AV_(3)Sb_(5)family.
基金Project supported by the National Key Research and Development Program of China (Grant No.2021YFA1400400)the National Natural Science Foundation of China (Grant Nos.92165205,12074175,and 12374137)。
文摘By utilizing the fluctuation exchange approximation method,we perform a study on the superconducting pairing symmetry in a t_(2g) three-orbital model on the square lattice.Although the tight-binding parameters of the model are based on Sr_(2)RuO_(4),we have systematically studied the evolution of superconducting pairing symmetry with the carrier density and interactions,making our findings relevant to a broader range of material systems.Under a moderate Hund’s coupling,we find that spin fluctuations dominate the superconducting pairing,leading to a prevalent spin-singlet pairing with a d_(x^(2)-y^(2))-wave symmetry for the carrier density within the range of n=1.5-4 per site.By reducing the Hund’s coupling,the charge fluctuations are enhanced and play a crucial role in determining the pairing symmetry,leading to a transition of the pairing symmetry from the spin-singlet d_(x^(2)-y^(2))-wave to the spin-triplet p-wave.Furthermore,we find that the superconducting pairings are orbital dependent.As the carrier density changes from n=4 to n=1.5,the active orbitals for superconducting pairing shift from the quasi-two-dimensional orbital dxy to the quasi-one-dimensional orbitals d_(xz) and d_(yz).
基金This study is supported by the National Key Research and Development Program of China(2017YFB0307500).
文摘Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we report a multiple redox-mediated linear paired electrolysis system,combining the hydrogen peroxide mediated cathode process with the I2 mediated anode process,and realize the conversion of furfural to furoic acid in both side of the dividedflow cell simultaneously.By reasonably controlling the cathode potential,the undesired water splitting reaction and furfural reduction side reactions are avoided.Under the galvanostatic electrolysis,the two-mediated electrode processes have good compatibility,which reduce the energy consumption by about 22%while improving the electronic efficiency by about 125%.This system provides a green electrochemical synthesis route with commercial prospects.
文摘The application of amino acid-based surfactant in dishwasher detergent was studied in this paper. The foam and oil-removing performance of amino acid surfactants in alkaline condition were test to discuss feasibility of amino acid-based surfactant from natural origin as the alternative to traditional nonionic surfactants from petroleum origin in dishwasher detergent. Comparative study was conducted through using various amino acid-based surfactants and nonionic surfactants respectively, together with enzymes and peroxide to formulate dishwasher detergents, and their application properties such as foam performance and detergency were also evaluated when washing different tableware in automatic dishwasher. The results showed that among all tested amino acid surfactants, glutamate surfactants showed low foaming and high oil-removing ability in alkaline condition, and excellent decontamination ability in dishwashing tests.
基金Project supported by the National Natural Science Foundation of China (Grant No.12074130)the Natural Science Foundation of Guangdong Province (Grant No.2021A1515012340)。
文摘Recent experimental findings have demonstrated the occurrence of superconductivity in Bernal bilayer graphene when induced by a magnetic field.In this study,we conduct a theoretical investigation of the potential pairing symmetry within this superconducting system.By developing a theoretical model,we primarily calculate the free energy of the system with p+ip-wave parallel spin pairing,p+ip-wave anti-parallel spin pairing and d+i d-wave pairing symmetry.Our results confirm that the magnetic field is indeed essential for generating the superconductivity.We discover that the p+ip-wave parallel spin pairing leads to a lower free energy for the system.The numerical calculations of the energy band structure,zero-energy spectral function and density of states for each of the three pairing symmetries under consideration show a strong consistency with the free energy results.
基金supported by the National Natural Science Foundation of China(22379100,U21A20312)the Shenzhen Science and Technology Program(Grant No.20231121200418001)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2022B1515120084)the Key Project of Department of Education of Guangdong Province(2023ZDZX3020)。
文摘Electrochemical co-reduction of nitrate(NO_(3)^(-))and carbon dioxide(CO_(2))has been widely regarded as a promising route to produce urea under ambient conditions,however the yield rate of urea has remained limited.Here,we report an atomically ordered intermetallic pallium-zinc(PdZn)electrocatalyst comprising a high density of PdZn pairs for boosting urea electrosynthesis.It is found that Pd and Zn are responsible for the adsorption and activation of NO_(3)^(-)and CO_(2),respectively,and thus the co-adsorption and co-activation NO_(3)^(-)and CO_(2) are achieved in ordered PdZn pairs.More importantly,the ordered and well-defined PdZn pairs provide a dual-site geometric structure conducive to the key C-N coupling with a low kinetical barrier,as demonstrated on both operando measurements and theoretical calculations.Consequently,the PdZn electrocatalyst displays excellent performance for the co-reduction to generate urea with a maximum urea Faradaic efficiency of 62.78%and a urea yield rate of 1274.42μg mg^(-1) h^(-1),and the latter is 1.5-fold larger than disordered pairs in PdZn alloys.This work paves new pathways to boost urea electrosynthesis via constructing ordered dual-metal pairs.
文摘The prevalence of smartphones is deeply embedded in modern society,impacting various aspects of our lives.Their versatility and functionalities have fundamentally changed how we communicate,work,seek entertainment,and access information.Among the many smartphones available,those operating on the Android platform dominate,being the most widely used type.This widespread adoption of the Android OS has significantly contributed to increased malware attacks targeting the Android ecosystem in recent years.Therefore,there is an urgent need to develop new methods for detecting Android malware.The literature contains numerous works related to Android malware detection.As far as our understanding extends,we are the first ones to identify dangerous combinations of permissions and system calls to uncover malicious behavior in Android applications.We introduce a novel methodology that pairs permissions and system calls to distinguish between benign and malicious samples.This approach combines the advantages of static and dynamic analysis,offering a more comprehensive understanding of an application’s behavior.We establish covalent bonds between permissions and system calls to assess their combined impact.We introduce a novel technique to determine these pairs’Covalent Bond Strength Score.Each pair is assigned two scores,one for malicious behavior and another for benign behavior.These scores serve as the basis for classifying applications as benign or malicious.By correlating permissions with system calls,the study enables a detailed examination of how an app utilizes its requested permissions,aiding in differentiating legitimate and potentially harmful actions.This comprehensive analysis provides a robust framework for Android malware detection,marking a significant contribution to the field.The results of our experiments demonstrate a remarkable overall accuracy of 97.5%,surpassing various state-of-the-art detection techniques proposed in the current literature.
基金supported by the National Key R&D Program of China(No.2022YFA1602000)National Natural Science Foundation of China(Nos.12275081,U2067205,11790325,and U1732138)the Continuous-support Basic Scientific Research Project。
文摘Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pairing forces,as well as a combination of these two forces,were used for the Hartree–Fock–Bogoliubov approximation.Variations in the least-energy fission path,fission barrier,pairing energy,total kinetic energy,scission line,and mass distribution of the fission fragments based on the different forms of the pairing forces were analyzed and discussed.The fission dynamics were studied based on the timedependent generator coordinate method plus the Gaussian overlap approximation.The results demonstrated a sensitivity of the mass and charge distributions of the fission fragments on the form of the pairing force.Based on the investigation of the neutron-induced fission of^(239)Pu,among the volume,mixed,and surface pairing forces,the mixed pairing force presented a good reproduction of the experimental data.
文摘In this editorial,we commented on the article by Akers et al published in the recent issue of the World Journal of Clinical Cases.We focused specifically on the role of the transcription factor paired box protein 8(PAX8)belonging to the family PAX in the carcinogenesis of a gynecologic tumor,endocervical adenocarcinoma,arising from the tissue of mesonephric origin,and the potential diagnostic value for the same type of neoplasms.The global vaccination program of human papillomavirus(HPV)has dramatically reduced the incidence of cervical cancer,including cases of adenocarcinoma.The type of adenoid epithelial origin has a lower frequency of HPV detection but tends to be more aggressive and fatal.Cases of endocervical adenocarcinoma occurring in females of menopause age have been described in the 2023 volume of the World Journal of Clinical Cases and in our study recently published in Oncol Lett.The histopathological findings and immunohistochemical assays showed that the lesions had glandular morphology,and the specimens in these two reports were immunohistochemically positive for the transcription factor PAX8,albeit that they had opposing expression profiles of tumor suppressor p16 and estrogen receptor and the presence of the HPV genome.The presence of a mucin protein,MUC 5AC,as revealed in both studies suggested target molecules for the diagnosis of mucinous adenoid type of uterine tumor and other histological origins.The clinical outcome was unfavorable due to metastasis and recurrence.This prompted the improvement of the antitumor modality,with the introduction of precise targeting therapy.Mucin has now been reported to be the therapeutic target for adenocarcinomas.
基金supported by the National Natural Science Foundation of the People's Republic of China“Mechanistic study of the influence of ns^(2) cation intrinsic properties and coordination environment on birefringence and frequency doubling effects”(12264047),“The study of the mechanism of the influence of lead-oxygen polyhedra and their coordination environments on the gain of the frequency doubling effect”(11864040)Tianshan Talent Project of Xinjiang Uygur Autonomous Region of China“Design,synthesis and photofunctional study of novel rare earth phosphate materials”(2022TSYCJU0004)。
文摘The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orbitals,electron localization function(ELF)and partial density of states(PDOS).Birefringence is evaluated by means of a Born effective charge approach based on modern polarization theory.The origin of the different responses of birefringence and second-harmonic generation(SHG)is explored,as well as the effect of spin-orbit coupling(SOC)on the band structure and optical properties is explored.The study of this paper can help to deeply understand the lone pairs and their contribution to optical property.
基金the National Natural Science Foundation of China(22279044,12034002,and 22202080)the Project for Self-Innovation Capability Construction of Jilin Province Development and Reform Commission(2021C026)+1 种基金Jilin Province Science and Technology Development Program(20210301009GX)the Fundamental Research Funds for the Central Universities.
文摘Electrochemical carbon dioxide reduction reaction(CO_(2)RR)involves a variety of intermediates with highly correlated reaction and ad-desorption energies,hindering optimization of the catalytic activity.For example,increasing the binding of the*COOH to the active site will generally increase the*CO desorption energy.Breaking this relationship may be expected to dramatically improve the intrinsic activity of CO_(2)RR,but remains an unsolved challenge.Herein,we addressed this conundrum by constructing a unique atomic dispersed hetero-pair consisting of Mo-Fe di-atoms anchored on N-doped carbon carrier.This system shows an unprecedented CO_(2)RR intrinsic activity with TOF of 3336 h−1,high selectivity toward CO production,Faradaic efficiency of 95.96%at−0.60 V and excellent stability.Theoretical calculations show that the Mo-Fe diatomic sites increased the*COOH intermediate adsorption energy by bridging adsorption of*COOH intermediates.At the same time,d-d orbital coupling in the Mo-Fe di-atom results in electron delocalization and facilitates desorption of*CO intermediates.Thus,the undesirable correlation between these steps is broken.This work provides a promising approach,specifically the use of di-atoms,for breaking unfavorable relationships based on understanding of the catalytic mechanisms at the atomic scale.
基金sponsored by the Shell Petroleum Development Company of Nigeria Limited(SPDC).
文摘The utilization of sequence stratigraphic concepts in identifying sands and their spatial continuity in distinct gross depositional settings is key,especially in frontier settings where data paucity is a common challenge.In the Baka field,onshore Niger Delta,detailed reservoir correlation guided by sequence stratigraphic framework analysis showed the distribution of sand and shale units constituting reservoirseal pairs(RSP)correlatable across the field.Within the 3rd-order packages,it is observed that the lowstand systems tract(LST)and highstand systems tract(HST)contain more RSPs and thicker 4th-and 5th-order sands than the transgressive systems tract(TST).In terms of bathymetry,it is noted that irrespective of systems tracts,the RSP Index(RI)decreases from the proximal shallow/inner shelf settings to the more distal outer shelf areas.Amongst all three systems tracts,intervals interpreted as lowstand prograding complexes contain the best developed sands and highest RSP.Sand development within the LSTs has been controlled by a pronounced growth fault regime accompanied by high subsidence and sedimentation rates.This is linked to the basinward migration of the sands during prolonged sea-level fall,creating significant accommodation space for sand deposition.On the other hand,the TSTs known to mark periods of progressive sea-level rise and landward migration of sandy facies,show thinner sands enclosed in much thicker,laterally extensive,and better-preserved deeper marine shales.Interpreted seismic sections indicate intense growth faulting and channelization that influenced the syn-and postdepositional development of the sand packages across the field.The initial timing of deformation of subregional faults in this area coincides with periods of abrupt falls in sea level.This approach could be useful for predicting sand-prone areas in frontier fields as well as possible reservoir-seal parameters required for some aspects of petroleum system analysis and quick-look volume estimation.
文摘We study theoretically the electrical shot noise properties of tunnel junctions between a normal metal and a superconductor with the mixture of singlet s-wave and chiral triplet p-wave pairing due to broken inversion symmetry. We investigate how the shot noise properties vary as the relative amplitude between the two parity components in the pairing potential is changed. It is demonstrated that some characteristics of the electrical shot noise properties of such tunnel junctions may depend sensitively on the relative amplitude between the two parity components in the pairing potential, and some significant changes may occur in the electrical shot noise properties when the relative amplitude between the two parity components is varied from the singlet s-wave pairing dominated regime to the chiral triplet p-wave pairing dominated regime. In the chiral triplet p-wave pairing dominated regime, the ratio of noise power to electric current is close to 2e both in the in-gap and in the out-gap region. In the singlet s-wave pairing dominated regime, the value of this ratio is close to 4e in the inner gap region but may reduce to about 2e in the outer gap region as the relative amplitude of the chiral triplet pairing component is increased. The variations of the differential shot noise with the bias voltage also exhibit some significantly different features in different regimes. Such different features can serve as useful diagnostic tools for the determination of the relative magnitude of the two parity components in the pairing potential.
基金Supported by the Project of National Social Science Foundation of China(22CMZ015).
文摘In the new era,there is an urgent need to further promote pairing assistance to Tibet,promote the simultaneous construction of a strong agriculture in Tibet and the China's Mainland,and compose a Chinese-style modernization.Southern Tibet,located in the southeastern part of the Tibet Autonomous Region,includes Shannan City and Nyingchi City,is a region assisted by four provincial partners including Hubei Province.This paper introduces the agricultural environment in southern Tibet,studies its agricultural characteristics,and analyzes the main issues of its pairing assistance.Taking forging the strong consciousness of the Chinese national community as the main line,the paper explores strategies for promoting agricultural high-quality development in southern Tibet through pairing assistance to Tibet from the perspective of agricultural power,and proposes some strategies,such as inheriting agricultural cultural heritage,promoting the upgrading of modern seed industry,enhancing the characteristic advantages of highland barley(naked barley)and animal husbandry industries,and developing edible fungi and cold water fish industries.
基金supported by the Major Project of the National Social Science Fund of China (NSSFC)“Economic Development for Ethnic Minorities under Socialism with Chinese Characteristics and International Comparison”(Grant No. 19ZDA173)the NSSFC Project “Study on the Implementation and Development of Educational Assistance to Xizang and Xinjiang under the Horizon of the Community of the Chinese Nation”(Grant No. CMA220323)the Elite Innovation Team of Pu’er University “Innovation Team for the Prosperity of Border Regions and Common Modernization of Ethnic Minority Regions”(Grant No. 2023PEXYCXTD002)
文摘This study highlights the changing priorities of China’s paired assistance throughout the past decades,as well as its theoretical implications and economic growth effects for recipient regions.Using panel data from 32 prefecture-level cities from 1990 to 2020,this study uses the multiperiod difference-in-differences approach to examine how paired assistance has contributed to economic growth in Xizang Autonomous Region and Xinjiang Uygur Autonomous Region.The findings indicate that,first,the implementation of the paired assistance policy has boosted economic growth in Xizang and Xinjiang.Second,paired assistance has stimulated economic growth in recipient communities by improving infrastructure.Third,paired assistance has contributed to economic growth in recipient communities by providing improved public services such as education and healthcare.Improvements to public services have a relatively smaller indirect effect in short term than infrastructure development on economic growth.Yet both education and healthcare are crucial to people’s quality of life in recipient communities.This paper has refined and broadened research on the effects of paired assistance,providing preference for future policymaking.