A zero-dimensional model which includes 56 species of reactants and 427 reactions is used to study the behavior of charged particles in atmospheric plasmas with different ionization degrees at low altitude （near 0 km...A zero-dimensional model which includes 56 species of reactants and 427 reactions is used to study the behavior of charged particles in atmospheric plasmas with different ionization degrees at low altitude （near 0 km）. The constant coefficient nonlinear equations are solved by using the Quasi-steady-state approximation method. The electron lifetimes are obtained for afterglow plasma with different initial values, and the temporal evolutions of the main charged species are presented, which are dominant in reaction processes. The results show that the electron number density decays quickly. The lifetimes of electrons are shortened by about two orders with increasing ionization degree. Electrons then attach to neutral particles and produce negative ions. When the initial electron densities are in the range of 10l~ ~ 1014 cm-3, the negative ions have sufficiently high densities and long lifetimes for air purification, disinfection and sterilization. Electrons, O（2,-）, O（4,-） CO（4,-） and CO（3,-） are the dominant negative species when the initial electron density neo ≤ 1013 cm^（-3）, and only electrons and CO3 are left when neo 〉 1015 cm^（-3）. N（＋,2）, N＋ and O（＋,2） are dominant in the positive charges for any ionization degree. Other positive species, such as 0（＋,4）, N（＋,3）, NO（＋,2）, NO（＋,2）, Ar（＋,2） and H3O＋. H2O, are dominant only for a certain ionization degree and in a certain period.展开更多
A zero-dimensional model is used to study the processes of physical and chemical reactions in atmospheric plasma with different ionization degrees near the ground （0 km）. The temporal evolutions of CO, C02 and other...A zero-dimensional model is used to study the processes of physical and chemical reactions in atmospheric plasma with different ionization degrees near the ground （0 km）. The temporal evolutions of CO, C02 and other main reactants （namely OH and O2）, which affect the conversion of CO and C02, are obtained for afterglow plasma with different initial values. The results show that the consumption rate of CO is largest when the initiM electron number density neo=1012 cm-3, i.e. the ionization degree is 0.000004%. The number density of CO2 is relatively small when neo=1016 cm-3, i.e. the ionization degree is 0.04%, whereas they are very close under the condition of other ionization degrees. Considering the total number densities of CO and C02 and the consumption rate of CO comprehensively, the best condition is neo=1013 cm-3, i.e. the ionization degree is 0.00004% for reducing the densities of CO and CO2 in the atmospheric plasma. The temporal evolutions of N＋, Ar＋, CO＋ and CO＋ are also shown, and the influences on the temporal evolutions of CO and C02 are analyzed with increasing ionization degree.展开更多
BACKGROUND Major depressive disorder(MDD)with comorbid anxiety is an intricate psychiatric condition,but limited research is available on the degree centrality(DC)between anxious MDD and nonanxious MDD patients.AIM To...BACKGROUND Major depressive disorder(MDD)with comorbid anxiety is an intricate psychiatric condition,but limited research is available on the degree centrality(DC)between anxious MDD and nonanxious MDD patients.AIM To examine changes in DC values and their use as neuroimaging biomarkers in anxious and non-anxious MDD patients.METHODS We examined 23 anxious MDD patients,30 nonanxious MDD patients,and 28 healthy controls(HCs)using the DC for data analysis.RESULTS Compared with HCs,the anxious MDD group reported markedly reduced DC values in the right fusiform gyrus(FFG)and inferior occipital gyrus,whereas elevated DC values in the left middle frontal gyrus and left inferior parietal angular gyrus.The nonanxious MDD group exhibited surged DC values in the bilateral cerebellum IX,right precuneus,and opercular part of the inferior frontal gyrus.Unlike the nonanxious MDD group,the anxious MDD group exhibited declined DC values in the right FFG and bilateral calcarine(CAL).Besides,declined DC values in the right FFG and bilateral CAL negatively correlated with anxiety scores in the MDD group.CONCLUSION This study shows that abnormal DC patterns in MDD,especially in the left CAL,can distinguish MDD from its anxiety subtype,indicating a potential neuroimaging biomarker.展开更多
Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction(ORR).Atomic ordered intermetallic compounds(IMC)provide unique electronic and geometri...Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction(ORR).Atomic ordered intermetallic compounds(IMC)provide unique electronic and geometrical effects as well as stronger intermetallic interactions due to the ordered arrangement of metal atoms,thus exhibiting superior electrocata-lytic activity and durability.However,quantitatively analyzing the ordering degree of IMC and exploring the correlation between the ordering degree and ORR activity remains extremely challenging.Herein,a series of ternary Pt_(2)NiCo interme-tallic catalysts(o-Pt_(2)NiCo)with different ordering degree were synthesized by annealing temperature modulation.Among them,the o-Pt_(2)NiCo which annealed at 800℃for two hours exhibits the highest ordering degree and the optimal ORR ac-tivity,which the mass activity of o-Pt_(2)NiCo is 1.8 times and 2.8 times higher than that of disordered Pt_(2)NiCo alloy and Pt/C.Furthermore,the o-Pt_(2)NiCo still maintains 70.8%mass activity after 30,000 potential cycles.Additionally,the ORR activity test results for Pt_(2)NiCo IMC with different ordering degree also provide a positive correlation between the ordering degree and ORR activity.This work provides a prospective design direction for ternary Pt-based electrocatalysts.展开更多
Formic and acetic acids are the most abundant gaseous organic acids and play the key role in the atmospheric chemistry.In iodine-adduct chemical ionizationmass spectrometry(CIMS),the low utilization efficiency of meth...Formic and acetic acids are the most abundant gaseous organic acids and play the key role in the atmospheric chemistry.In iodine-adduct chemical ionizationmass spectrometry(CIMS),the low utilization efficiency of methyl iodide and humidity interference are two major issues of the vacuum ultraviolet(VUV)lamp initiated CIMS for on-line gaseous formic and acetic acids analysis.In this work,we present a new CIMS based on VUV lamp,and the ion-molecular reactor is separated into photoionization and chemical ionization zones by a reducer electrode.Acetone was added to the photoionization zone,and the VUV photoionization acetone provided low-energy electrons for methyl iodide to generate I−,and the addition of acetone reduced the amount of methyl iodide by 2/3.In the chemical ionization zone,a headspace vial containing ultrapure water was added for humidity calibration,and the vial changes the sensitivity as a function of humidity from ambiguity to well linear correlation(R2>0.95).With humidity calibration,the CIMS can quantitatively measure formic and acetic acids in the humidity range of 0%-88%RH.In this mode,limits of detection of 10 and 50 pptv are obtained for formic and acetic acids,respectively.And the relative standard deviation(RSD)of quantitation stability for 6 days were less than 10.5%.This CIMS was successfully used to determine the formic and acetic acids in the underground parking and ambient environment of the Shandong University campus(Qingdao,China).In addition,we developed a simple model based formic acid concentration to assess vehicular emissions.展开更多
Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects o...Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects on the expression level of (advanced glycation end products) AGEs in wound tissue, so as to provide a basis for the application of AGEs expression level in wound tissue in the future clinical treatment of second-degree burns. Methods: Patients with second-degree burns admitted to the Department of Burns and Plastic Surgery of the Second Affiliated Hospital of Shantou University Medical College from July 2023 to July 2024 were selected as the research subjects. This study was a non-double-blind study, and both patients and researchers were aware of the treatment methods. They were randomly divided into Group A (control group) and Group B (study group). According to the order of their visits, the patients were numbered in advance;then the seed number was taken, and 70 random numbers were generated on the computer using SAS, the first 35 corresponding to group A, and the last 35 corresponding to group B;the random numbers were arranged from small to large, and the rank of the random numbers was the patient number;finally, the patient numbers were arranged from small to large, and the corresponding groups were the grouping scheme. 1) Wound healing time: The wound healing was observed every day, and the wound healing time was calculated when the wound was completely epithelialized. 2) Wound healing: The wound healing area was measured 1, 7, and 14 days after treatment, and transparent paper was used to record combined with a computer-assisted imaging system. Wound healing rate = wound healing area (cm2)/total wound area before treatment (cm2) × 100%. The time for complete wound healing was recorded in the two groups of patients. 3) Pain: The pain was evaluated at 1, 7, and 14 days after treatment using the visual analogue scale (VAS). The higher the score, the more severe the pain. 4) Scar condition: Scar formation was evaluated 1, 3, and 6 months after wound healing using the VAS scale, with a total score of 15 points. The higher the score, the more severe the scar. 5) Detect the expression of AGEs in wound tissue. Results: The wound healed 14.03 ± 2.28 days after eschar removal, with a cure rate of 97.8%. No infection occurred in the wound after eschar removal in all patients. The wound healing time ranged from 9 to 23 days, with an average healing time of 28.41 ± 1.45 days. The healing quality was satisfactory. The Vancouver Scar Scale scored the wound healing scar as 0.81 ± 0.73 points. Western blot was used to detect the expression of AGEs, (receptor for advanced glycation end products) RAGE, and protein in the wound tissue. Results After 7, 14, and 28 days of medication, the wounds of diabetic patients healed well. The drug treatment efficacy and hydroxyproline content showed an upward trend, and the expression levels of AGEs, RAGE, and HIF-1a proteins showed a downward trend. Compared with day 0, the hydroxyproline content of the wound granulation tissue on days 7, 14, and 28 was significantly increased (P< 0.01), and the expression levels of AGEs, RAGE, and HIF-1α proteins were significantly downregulated (P< 0.05 or P< 0.01). Conclusion: Monitoring the expression levels of AGEs and RAGE can reflect the wound-healing effect of patients with second-degree burns, and the prognosis of the wound is closely related to the expression levels of AGEs, RAGE, and scab abrasion. In the treatment of second-degree burn wounds, scab abrasion can grasp the level of necrotic scab removal, can achieve “relatively accurate” removal of necrotic tissue, maximally protect the ecological tissue between wounds and retaining normal tissue, and can play a positive role in promoting the healing process of burn wounds;at the same time, nanosilver dressings have good antibacterial properties and high safety, and mussel mucin has anti-inflammatory and antioxidant activities and the characteristics of blocking nerve endings, which can effectively relieve the burning, stinging, and itching of sensitive skin and effectively promote wound healing.展开更多
Strong feld-induced nonsequential double ionization(NSDI)is a signifcant multi-electron phenomenon that provides crucial insights into understanding electron correlation and multiple ionization of atoms and molecules,...Strong feld-induced nonsequential double ionization(NSDI)is a signifcant multi-electron phenomenon that provides crucial insights into understanding electron correlation and multiple ionization of atoms and molecules,but it is typically unattainable in a circularly polarized laser pulse,especially for long-wavelength lasers.We present evidence that NSDI can occur in the presence of a near-infrared or beyond laser pulse by introducing a bowtie-nanotip.The laser-induced local plasmon can alter the local ellipticity of the feld,thereby enabling NSDI through elliptical trajectories that facilitate recollisions with parent atoms.An oval-shaped momentum distribution of recoiled ions provides evidence for the modifcation of trajectories by the aligned nanotips.Our study introduces an innovative control knob to manipulate NSDI and electron dynamics through the utilization of nanostructures.展开更多
This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the atto...This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the attoclock experimental curve for the H atom at lower laser intensities.Here,we develop a semiclassical model that includes the initial conditions related to the quantum properties of tunneling in the KR model at the beginning of the scattering process.This model is able to explain recent attoclock experimental curves over a wider range of laser and atomic parameters.Our results show the importance of system symmetry and quantum effects in attoclock measurements,suggesting the complex role of the Coulomb potential in strong-field ionization.展开更多
The cultivation of innovative talents has become the primary objective of talent development in colleges and universities and is also essential for the personal development of master's degree students.Ethnic medic...The cultivation of innovative talents has become the primary objective of talent development in colleges and universities and is also essential for the personal development of master's degree students.Ethnic medicine,a key discipline at Guangxi University of Chinese Medicine,aims to cultivate high-level master's degree talents who possess comprehensive qualities,strong innovative capabilities,and distinctive characteristics of Zhuang medicine.This program is designed to better serve the local economic development and social needs of Guangxi,thereby promoting the substantive advancement of higher education within traditional medical institutions.展开更多
This study systematically investigates the influences of annealing treatment on the energy state,microstructure and macroscopic mechanical behaviors of metallic glasses(MGs).By reducing the energy state,the annealing ...This study systematically investigates the influences of annealing treatment on the energy state,microstructure and macroscopic mechanical behaviors of metallic glasses(MGs).By reducing the energy state,the annealing process significantly enhances the structural ordering degree and uniformity of MGs,thereby improving their overall mechanical reliability.Specifically,annealing promotes the formation of localized icosahedral short-range order,a structural signature that contributes to improved nanohardness and tensile strength.Furthermore,the release and redistribution of internal stress during annealing further optimize the internal stress state,significantly enhancing the fracture resistance and achieving reliable mechanical performance.This study not only elucidates the regulatory mechanisms of annealing on the microstructure of MGs but also provides theoretical support and experimental evidence for exploring MG materials with high strength and high fracture reliability.展开更多
Traditional electrospray ionization tandem mass spectrometry(ESI-MS^(n))has been a powerful tool in diverse research areas,however,it faces great limitations in the study of protein-small molecule interactions.In this...Traditional electrospray ionization tandem mass spectrometry(ESI-MS^(n))has been a powerful tool in diverse research areas,however,it faces great limitations in the study of protein-small molecule interactions.In this article,the state-of-the-art temperature-controlled electrospray ionization tandem mass spectrometry(TC-ESI-MS^(n))is applied to investigate interactions between ubiquitin and two flavonol molecules,respectively.The combination of collision-induced dissociation(CID)and MS solution-melting experiments facilitates the understanding of flavonol-protein interactions in a new dimension across varying temperature ranges.While structural changes of proteins disturbed by small molecules are unseen in ESI-MS^(n),TC-ESI-MS^(n)allows a simultaneous assessment of the stability of the complex in both gas and liquid phases under various temperature conditions,meanwhile investigating the impact on the protein’s structure and tracking changes in thermodynamic data,and the characteristics of structural intermediates.展开更多
We propose a method to characterize the features of a cold strontium cloud in a magneto-optical trap(MOT)through the photoionization of cold Sr atoms in a custom-designed reaction microscope.Sr atoms in the dark state...We propose a method to characterize the features of a cold strontium cloud in a magneto-optical trap(MOT)through the photoionization of cold Sr atoms in a custom-designed reaction microscope.Sr atoms in the dark state of 5s5p3P2 populated via the cascade transition 5s5p^(1)P_(1)→5s4d^(1)D_(2)→5s5p^(3)P_(2)accumulate a significant fraction,giving a long lifetime of 520 s.These atoms in the dark state are subsequently trapped by the gradient magnetic field of the MOT.By scanning the Sr+momentum distributions ionized with an 800 nm infrared femtosecond laser,we are able to outline the size of~0.55 mm in radius and the temperature of~0.40 mK for the dark-state atoms,which is significantly cooler than the MOT temperature of 3.3 mK trapped in the 461 nm.The size of MOT exhibits an oblate spheroidal distribution with a radius of approximately 0.35 mm and 0.55 mm,extracted with momenta of photoion and absorption imaging,respectively.The results using the photoion momenta are consistent with the expected results from absorption imaging,which confirms the method's reliability.The advantage of this method is the ability to simultaneously characterize the distribution information of atoms in different initial states within the cold atomic cloud.展开更多
In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. U...In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. Unlike most previous studies about the X-pattern observed under the severely disturbed background ionosphere, this event is observed under geomagnetically quiet and low solar activity conditions. GOLD's continuous observations reveal that the X-pattern intensity evolves with local time, while its center's longitude remains constant. The total electron content(TEC) data derived from the ground-based Global Navigation Satellite System(GNSS) network aligns well with GOLD observations in capturing the formation of the X-pattern, extending coverage to areas beyond GOLD's observational reach. Additionally, the ESA's Swarm mission show that both sides of the X-pattern can coincide with the occurrence of small-scale equatorial plasma bubbles(EPBs). To further analyze the possible drivers of the X-pattern, observations from the Ionospheric Connection Explorer(ICON) satellite were used. It shows that the latitudinal expansion(or width) between the EIA crests in two hemispheres is proportional(or inversely proportional) to the upward(or downward) plasma drift velocity, which suggests that the zonal electric field should have a notable influence on the formation of EIA X-pattern. Further simulations using the SAMI2 model support this mechanism, as the X-pattern of EIA is successfully reproduced by setting the vertical plasma drift to different values at different longitudes.展开更多
The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^...The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^(2+),O_(2)^(2+)O^(+),O^(2+),and their total)and two Coulomb explosion channels(O^(+)+O^(+)and O^(2+)+O^(+))are obtained by putting the data of O^(2+)on the scale of Ar+from O_(2)and Ar gases mixed with a fixed relative flow ratio of 1:1.The experimental errors are assessed by taking uncertainties of various factors into account.The present absolute cross sections are well consistent with the previous data in the overlapped energy range below 1000 eV.展开更多
In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we pr...In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we propose the Software Engineering Degree Granting Program Construction Practice Project at Harbin Institute of Technology(HIT).This project aims to explore new models for software talent cultivation,establish a superior SE degree granting program,and ultimately cultivate outstanding internationalized composite SE professionals to support the high-quality development of the national software industry.To this end,we design a distinctive overall construction idea and plan for the SE degree granting program,which are characterized by“3I3S:three highlights for specialized cultivation and strictness in three aspects to ensure quality control”.After years of practice and validation of the project at the School of Software at HIT,this project has proven effective in optimizing talent cultivation models,enhancing students’practical abilities,promoting international exchange and cooperation,advancing industry-education integration,and meeting industrial needs.展开更多
In chemical science,the vertical ionization potential(VIP)is a crucial metric for understanding the electronegativity,hardness and softness of chemical material systems as well as the electronic structure and stabilit...In chemical science,the vertical ionization potential(VIP)is a crucial metric for understanding the electronegativity,hardness and softness of chemical material systems as well as the electronic structure and stability of molecules.Ever since the last century,the model chemistry composite methods have witnessed tremendous developments in computing the thermodynamic properties as well as the barrier heights.However,their performance in realm of the vertical electron processes of molecular systems has been rarely explored.In this study,we for the first time benchmarked the model chemistry composite methods(e.g.,CBS-QB3,G4 and W1BD)in comparison with the commonly used Koopmans's theorem(KT),electron propagator theory(e.g.,OVGF,D2,P3 and P3+)and CCSD(T)methods in calculating the VIP for up to 613 molecular systems with available experimental measurements.The large-scale test calculations strongly showed that the CBS-QB3 model chemistry composite technique can be well recommended to calculate VIP from the perspectives of accuracy,economy and applicability.Notably,the VIP values of up to 7 molecules were identified to have the absolute errors of larger than 0.3 e V at all calculation levels,which have strong hints that their VIP experimental values should be re-investigated.展开更多
Accurate determination of lung cancer margins at the molecular level is of great significance to determine the optimal extent of resection during surgical operation and reduce the risk of postoperative recurrence.In t...Accurate determination of lung cancer margins at the molecular level is of great significance to determine the optimal extent of resection during surgical operation and reduce the risk of postoperative recurrence.In this study,internal extractive electrospray ionization mass spectrometry(i EESI-MS)was used to trace potential molecular tumor margins in lung cancer tissue.Molecular differential model for the determination of lung cancer tumor margin was established via partial least-squares discriminant analysis(PLS-DA)of iEESI-MS data collected from lung tissue pieces within cancer tumor area and iEESI-MS data collected from lung tissue pieces outside cancer tumor area.Proof-of-concept data demonstrate that the developed molecular differential model yields ca.1-2 mm wider potential molecular tumor margin of a lung cancer compared to the conventional histological analysis,showing promising potential of iEESI-MS to increase the accuracy of tumor margins determination and lower risk of lung cancer postoperative recurrence.Furthermore,our results revealed that creatine and taurine showed positive correlations with lung cancer.展开更多
As a major fault in the northeastern Qinghai-Xizang Plateau,the Haiyuan fault zone is important for understanding the regional deformation.Aiming at the differences in the slip rate and locking degree obtained from di...As a major fault in the northeastern Qinghai-Xizang Plateau,the Haiyuan fault zone is important for understanding the regional deformation.Aiming at the differences in the slip rate and locking degree obtained from different studies,this study constructs a refined block model(including Qilian,Alxa,Ordos,Xining,Haiyuan,and Lanzhou blocks)and uses the grid search and simulated annealing methods to invert GPS data for slip rate and locking degree of the Haiyuan fault zone.The results are as follows:(1)The sinistral slip rates in the western,middle,and eastern segments are 4.93-5.22 mm/a,1.52-4.94 mm/a,and 0.43-1.18 mm/a,decreasing eastward on the whole,while the compression rates are 0.45-1.26 mm/a,0.58-2.62 mm/a,and3.52-4.48 mm/a,increasing eastward on the whole.(2)The locking depth of the western segment increases from about 5 km to about 20 km eastward;the middle segment decreases and then increases eastward;the eastern segment concentrates at about 20 km(PHI is about 0.86).(3)The slip deficit is relatively higher in the Lenglongling,Jinqianghe,Maomaoshan,and Liupanshan faults(averaging about 3.42 mm/a,4.16 mm/a,4.23 mm/a,and 3.43 mm/a within 20 km).(4)The Qilian,Alxa,Xining,Lanzhou,and Haiyuan blocks rotate clockwise,while the Ordos block rotates counterclockwise.Additionally,by comparing different block models,the Haiyuan block should be considered independently.The Haiyuan fault zone adjusts surrounding block movements and uplifts Liupanshan mountain tectonically.The results can provide important references for understanding the regional earthquake risk and deformation mechanism.展开更多
Ionization and dissociation are fundamental processes that molecules undergo in intense femtosecond laser fields.Professor Fanao Kong is a pioneering researcher in this field within China.He has developed an orbital-b...Ionization and dissociation are fundamental processes that molecules undergo in intense femtosecond laser fields.Professor Fanao Kong is a pioneering researcher in this field within China.He has developed an orbital-based molecular ionization model and a laser field-assisted molecular dissociation model to elucidate experimental observations and predict potential applications.The predictions of these models have been corroborated by subsequent theoretical and experimental studies.This review highlights Professor Kong’s significant contributions to the study of molecular ionization and dissociation in intense femtosecond laser fields,emphasizing key advancements and outlining future directions in the field of strong-field laser chemistry.展开更多
基金supported by the Research Foundation of Education Bureau of Hebei Province,China(No.2009308)National Natural Science Foundation of China(No.10805013)the Natural Science Foundation of Hebei Province(Nos.A2011201132,A2009000149)
文摘A zero-dimensional model which includes 56 species of reactants and 427 reactions is used to study the behavior of charged particles in atmospheric plasmas with different ionization degrees at low altitude （near 0 km）. The constant coefficient nonlinear equations are solved by using the Quasi-steady-state approximation method. The electron lifetimes are obtained for afterglow plasma with different initial values, and the temporal evolutions of the main charged species are presented, which are dominant in reaction processes. The results show that the electron number density decays quickly. The lifetimes of electrons are shortened by about two orders with increasing ionization degree. Electrons then attach to neutral particles and produce negative ions. When the initial electron densities are in the range of 10l~ ~ 1014 cm-3, the negative ions have sufficiently high densities and long lifetimes for air purification, disinfection and sterilization. Electrons, O（2,-）, O（4,-） CO（4,-） and CO（3,-） are the dominant negative species when the initial electron density neo ≤ 1013 cm^（-3）, and only electrons and CO3 are left when neo 〉 1015 cm^（-3）. N（＋,2）, N＋ and O（＋,2） are dominant in the positive charges for any ionization degree. Other positive species, such as 0（＋,4）, N（＋,3）, NO（＋,2）, NO（＋,2）, Ar（＋,2） and H3O＋. H2O, are dominant only for a certain ionization degree and in a certain period.
基金supported by the Research Foundation of Education Bureau of Hebei Province,China(No.Q2012084)National Natural Science Foundation of China(No.10805013)Natural Science Foundation of Hebei Province,China(No.A2011201132)
文摘A zero-dimensional model is used to study the processes of physical and chemical reactions in atmospheric plasma with different ionization degrees near the ground （0 km）. The temporal evolutions of CO, C02 and other main reactants （namely OH and O2）, which affect the conversion of CO and C02, are obtained for afterglow plasma with different initial values. The results show that the consumption rate of CO is largest when the initiM electron number density neo=1012 cm-3, i.e. the ionization degree is 0.000004%. The number density of CO2 is relatively small when neo=1016 cm-3, i.e. the ionization degree is 0.04%, whereas they are very close under the condition of other ionization degrees. Considering the total number densities of CO and C02 and the consumption rate of CO comprehensively, the best condition is neo=1013 cm-3, i.e. the ionization degree is 0.00004% for reducing the densities of CO and CO2 in the atmospheric plasma. The temporal evolutions of N＋, Ar＋, CO＋ and CO＋ are also shown, and the influences on the temporal evolutions of CO and C02 are analyzed with increasing ionization degree.
基金Supported by Hubei Provincial Department of Science and Technology Natural Fund,No.2024AFC056the Open Fund of the Mental Health Research Institute at Three Gorges University,No.YCXL-23-11.
文摘BACKGROUND Major depressive disorder(MDD)with comorbid anxiety is an intricate psychiatric condition,but limited research is available on the degree centrality(DC)between anxious MDD and nonanxious MDD patients.AIM To examine changes in DC values and their use as neuroimaging biomarkers in anxious and non-anxious MDD patients.METHODS We examined 23 anxious MDD patients,30 nonanxious MDD patients,and 28 healthy controls(HCs)using the DC for data analysis.RESULTS Compared with HCs,the anxious MDD group reported markedly reduced DC values in the right fusiform gyrus(FFG)and inferior occipital gyrus,whereas elevated DC values in the left middle frontal gyrus and left inferior parietal angular gyrus.The nonanxious MDD group exhibited surged DC values in the bilateral cerebellum IX,right precuneus,and opercular part of the inferior frontal gyrus.Unlike the nonanxious MDD group,the anxious MDD group exhibited declined DC values in the right FFG and bilateral calcarine(CAL).Besides,declined DC values in the right FFG and bilateral CAL negatively correlated with anxiety scores in the MDD group.CONCLUSION This study shows that abnormal DC patterns in MDD,especially in the left CAL,can distinguish MDD from its anxiety subtype,indicating a potential neuroimaging biomarker.
基金supported by the National Natural Science Foundation(22279036)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003).
文摘Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction(ORR).Atomic ordered intermetallic compounds(IMC)provide unique electronic and geometrical effects as well as stronger intermetallic interactions due to the ordered arrangement of metal atoms,thus exhibiting superior electrocata-lytic activity and durability.However,quantitatively analyzing the ordering degree of IMC and exploring the correlation between the ordering degree and ORR activity remains extremely challenging.Herein,a series of ternary Pt_(2)NiCo interme-tallic catalysts(o-Pt_(2)NiCo)with different ordering degree were synthesized by annealing temperature modulation.Among them,the o-Pt_(2)NiCo which annealed at 800℃for two hours exhibits the highest ordering degree and the optimal ORR ac-tivity,which the mass activity of o-Pt_(2)NiCo is 1.8 times and 2.8 times higher than that of disordered Pt_(2)NiCo alloy and Pt/C.Furthermore,the o-Pt_(2)NiCo still maintains 70.8%mass activity after 30,000 potential cycles.Additionally,the ORR activity test results for Pt_(2)NiCo IMC with different ordering degree also provide a positive correlation between the ordering degree and ORR activity.This work provides a prospective design direction for ternary Pt-based electrocatalysts.
基金supported by the National Special Fund for the Development of Major Research Equipment and Instrument(No.2020YFF01014503)the Young Taishan Scholars(No.tsqn201909039)the College 20 Project fromJi Nan Science&Technology Bureau(No.2021GXRC058).
文摘Formic and acetic acids are the most abundant gaseous organic acids and play the key role in the atmospheric chemistry.In iodine-adduct chemical ionizationmass spectrometry(CIMS),the low utilization efficiency of methyl iodide and humidity interference are two major issues of the vacuum ultraviolet(VUV)lamp initiated CIMS for on-line gaseous formic and acetic acids analysis.In this work,we present a new CIMS based on VUV lamp,and the ion-molecular reactor is separated into photoionization and chemical ionization zones by a reducer electrode.Acetone was added to the photoionization zone,and the VUV photoionization acetone provided low-energy electrons for methyl iodide to generate I−,and the addition of acetone reduced the amount of methyl iodide by 2/3.In the chemical ionization zone,a headspace vial containing ultrapure water was added for humidity calibration,and the vial changes the sensitivity as a function of humidity from ambiguity to well linear correlation(R2>0.95).With humidity calibration,the CIMS can quantitatively measure formic and acetic acids in the humidity range of 0%-88%RH.In this mode,limits of detection of 10 and 50 pptv are obtained for formic and acetic acids,respectively.And the relative standard deviation(RSD)of quantitation stability for 6 days were less than 10.5%.This CIMS was successfully used to determine the formic and acetic acids in the underground parking and ambient environment of the Shandong University campus(Qingdao,China).In addition,we developed a simple model based formic acid concentration to assess vehicular emissions.
文摘Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects on the expression level of (advanced glycation end products) AGEs in wound tissue, so as to provide a basis for the application of AGEs expression level in wound tissue in the future clinical treatment of second-degree burns. Methods: Patients with second-degree burns admitted to the Department of Burns and Plastic Surgery of the Second Affiliated Hospital of Shantou University Medical College from July 2023 to July 2024 were selected as the research subjects. This study was a non-double-blind study, and both patients and researchers were aware of the treatment methods. They were randomly divided into Group A (control group) and Group B (study group). According to the order of their visits, the patients were numbered in advance;then the seed number was taken, and 70 random numbers were generated on the computer using SAS, the first 35 corresponding to group A, and the last 35 corresponding to group B;the random numbers were arranged from small to large, and the rank of the random numbers was the patient number;finally, the patient numbers were arranged from small to large, and the corresponding groups were the grouping scheme. 1) Wound healing time: The wound healing was observed every day, and the wound healing time was calculated when the wound was completely epithelialized. 2) Wound healing: The wound healing area was measured 1, 7, and 14 days after treatment, and transparent paper was used to record combined with a computer-assisted imaging system. Wound healing rate = wound healing area (cm2)/total wound area before treatment (cm2) × 100%. The time for complete wound healing was recorded in the two groups of patients. 3) Pain: The pain was evaluated at 1, 7, and 14 days after treatment using the visual analogue scale (VAS). The higher the score, the more severe the pain. 4) Scar condition: Scar formation was evaluated 1, 3, and 6 months after wound healing using the VAS scale, with a total score of 15 points. The higher the score, the more severe the scar. 5) Detect the expression of AGEs in wound tissue. Results: The wound healed 14.03 ± 2.28 days after eschar removal, with a cure rate of 97.8%. No infection occurred in the wound after eschar removal in all patients. The wound healing time ranged from 9 to 23 days, with an average healing time of 28.41 ± 1.45 days. The healing quality was satisfactory. The Vancouver Scar Scale scored the wound healing scar as 0.81 ± 0.73 points. Western blot was used to detect the expression of AGEs, (receptor for advanced glycation end products) RAGE, and protein in the wound tissue. Results After 7, 14, and 28 days of medication, the wounds of diabetic patients healed well. The drug treatment efficacy and hydroxyproline content showed an upward trend, and the expression levels of AGEs, RAGE, and HIF-1a proteins showed a downward trend. Compared with day 0, the hydroxyproline content of the wound granulation tissue on days 7, 14, and 28 was significantly increased (P< 0.01), and the expression levels of AGEs, RAGE, and HIF-1α proteins were significantly downregulated (P< 0.05 or P< 0.01). Conclusion: Monitoring the expression levels of AGEs and RAGE can reflect the wound-healing effect of patients with second-degree burns, and the prognosis of the wound is closely related to the expression levels of AGEs, RAGE, and scab abrasion. In the treatment of second-degree burn wounds, scab abrasion can grasp the level of necrotic scab removal, can achieve “relatively accurate” removal of necrotic tissue, maximally protect the ecological tissue between wounds and retaining normal tissue, and can play a positive role in promoting the healing process of burn wounds;at the same time, nanosilver dressings have good antibacterial properties and high safety, and mussel mucin has anti-inflammatory and antioxidant activities and the characteristics of blocking nerve endings, which can effectively relieve the burning, stinging, and itching of sensitive skin and effectively promote wound healing.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFE0134200)the National Natural Science Foundation of China(Grant Nos.12474343,12174147,and 12074142)the Natural Science Foundation of Jilin Province,China(Grant No.20220101016JC)。
文摘Strong feld-induced nonsequential double ionization(NSDI)is a signifcant multi-electron phenomenon that provides crucial insights into understanding electron correlation and multiple ionization of atoms and molecules,but it is typically unattainable in a circularly polarized laser pulse,especially for long-wavelength lasers.We present evidence that NSDI can occur in the presence of a near-infrared or beyond laser pulse by introducing a bowtie-nanotip.The laser-induced local plasmon can alter the local ellipticity of the feld,thereby enabling NSDI through elliptical trajectories that facilitate recollisions with parent atoms.An oval-shaped momentum distribution of recoiled ions provides evidence for the modifcation of trajectories by the aligned nanotips.Our study introduces an innovative control knob to manipulate NSDI and electron dynamics through the utilization of nanostructures.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12174239,12347165,and 12404330)Shaanxi Fundamental Science Research Project for Mathematics and Physics(Grant No.23JSY022)+2 种基金Natural Science Basic Research Program of Shaanxi(Grant No.2022JM-015)Hebei Natural Science Foundation(Grant No.A2022205002)Science and Technology Project of Hebei Education Department(Grant No.QN2022143)。
文摘This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the attoclock experimental curve for the H atom at lower laser intensities.Here,we develop a semiclassical model that includes the initial conditions related to the quantum properties of tunneling in the KR model at the beginning of the scattering process.This model is able to explain recent attoclock experimental curves over a wider range of laser and atomic parameters.Our results show the importance of system symmetry and quantum effects in attoclock measurements,suggesting the complex role of the Coulomb potential in strong-field ionization.
基金Supported by Innovation Project of Guangxi Graduate Education of Guangxi University of Chinese Medicine(YJSJG201602)Special Project on Innovation and Entrepreneurship Education in Colleges and Universities under the"14 th Five-Year Plan"of Guangxi Education Science(2022ZJY2965).
文摘The cultivation of innovative talents has become the primary objective of talent development in colleges and universities and is also essential for the personal development of master's degree students.Ethnic medicine,a key discipline at Guangxi University of Chinese Medicine,aims to cultivate high-level master's degree talents who possess comprehensive qualities,strong innovative capabilities,and distinctive characteristics of Zhuang medicine.This program is designed to better serve the local economic development and social needs of Guangxi,thereby promoting the substantive advancement of higher education within traditional medical institutions.
基金financially supported by the National Natural Science Foundation of China(Nos.52071118,52371025,and 52171154)supported by the China Scholarship Council(CSC,No.202206120120)for visiting Ph.D.student program at Seoul National University.
文摘This study systematically investigates the influences of annealing treatment on the energy state,microstructure and macroscopic mechanical behaviors of metallic glasses(MGs).By reducing the energy state,the annealing process significantly enhances the structural ordering degree and uniformity of MGs,thereby improving their overall mechanical reliability.Specifically,annealing promotes the formation of localized icosahedral short-range order,a structural signature that contributes to improved nanohardness and tensile strength.Furthermore,the release and redistribution of internal stress during annealing further optimize the internal stress state,significantly enhancing the fracture resistance and achieving reliable mechanical performance.This study not only elucidates the regulatory mechanisms of annealing on the microstructure of MGs but also provides theoretical support and experimental evidence for exploring MG materials with high strength and high fracture reliability.
基金supports by the National Natural Science Foundation of China(No.22174037)the Joint Funds of the Hunan Provincial Natural Science Foundation of China(No.2023JJ50255)+1 种基金Changsha Science and Technology Project(No.Z202269490128)National Key Research and Development Program of China(No.2023YFF0613400)are appreciated.
文摘Traditional electrospray ionization tandem mass spectrometry(ESI-MS^(n))has been a powerful tool in diverse research areas,however,it faces great limitations in the study of protein-small molecule interactions.In this article,the state-of-the-art temperature-controlled electrospray ionization tandem mass spectrometry(TC-ESI-MS^(n))is applied to investigate interactions between ubiquitin and two flavonol molecules,respectively.The combination of collision-induced dissociation(CID)and MS solution-melting experiments facilitates the understanding of flavonol-protein interactions in a new dimension across varying temperature ranges.While structural changes of proteins disturbed by small molecules are unseen in ESI-MS^(n),TC-ESI-MS^(n)allows a simultaneous assessment of the stability of the complex in both gas and liquid phases under various temperature conditions,meanwhile investigating the impact on the protein’s structure and tracking changes in thermodynamic data,and the characteristics of structural intermediates.
基金Project supported by the Natural Science Foundation of Henan(Grant No.252300421304)the National Natural Science Foundation of China(Grant Nos.12204498,12474259+1 种基金12334011)the National Key Research and Development Program of China(Grant No.2022YFA1604302)。
文摘We propose a method to characterize the features of a cold strontium cloud in a magneto-optical trap(MOT)through the photoionization of cold Sr atoms in a custom-designed reaction microscope.Sr atoms in the dark state of 5s5p3P2 populated via the cascade transition 5s5p^(1)P_(1)→5s4d^(1)D_(2)→5s5p^(3)P_(2)accumulate a significant fraction,giving a long lifetime of 520 s.These atoms in the dark state are subsequently trapped by the gradient magnetic field of the MOT.By scanning the Sr+momentum distributions ionized with an 800 nm infrared femtosecond laser,we are able to outline the size of~0.55 mm in radius and the temperature of~0.40 mK for the dark-state atoms,which is significantly cooler than the MOT temperature of 3.3 mK trapped in the 461 nm.The size of MOT exhibits an oblate spheroidal distribution with a radius of approximately 0.35 mm and 0.55 mm,extracted with momenta of photoion and absorption imaging,respectively.The results using the photoion momenta are consistent with the expected results from absorption imaging,which confirms the method's reliability.The advantage of this method is the ability to simultaneously characterize the distribution information of atoms in different initial states within the cold atomic cloud.
基金supported by the National Key R&D Program of China (Grant No. 2022YFF0503700)the special funds of Hubei Luojia Laboratory (220100011)+1 种基金Chao Xiong is supported by the ISSI-BJ project, “the electromagnetic data validation and scientific application research based on CSES satellite”ISSI/ISSI-BJ project “Multi-Scale Magnetosphere–Ionosphere–Thermosphere Interaction”。
文摘In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. Unlike most previous studies about the X-pattern observed under the severely disturbed background ionosphere, this event is observed under geomagnetically quiet and low solar activity conditions. GOLD's continuous observations reveal that the X-pattern intensity evolves with local time, while its center's longitude remains constant. The total electron content(TEC) data derived from the ground-based Global Navigation Satellite System(GNSS) network aligns well with GOLD observations in capturing the formation of the X-pattern, extending coverage to areas beyond GOLD's observational reach. Additionally, the ESA's Swarm mission show that both sides of the X-pattern can coincide with the occurrence of small-scale equatorial plasma bubbles(EPBs). To further analyze the possible drivers of the X-pattern, observations from the Ionospheric Connection Explorer(ICON) satellite were used. It shows that the latitudinal expansion(or width) between the EIA crests in two hemispheres is proportional(or inversely proportional) to the upward(or downward) plasma drift velocity, which suggests that the zonal electric field should have a notable influence on the formation of EIA X-pattern. Further simulations using the SAMI2 model support this mechanism, as the X-pattern of EIA is successfully reproduced by setting the vertical plasma drift to different values at different longitudes.
基金supported by the National Key Research and Development Program of China(No.2022YFA1602502)the National Natural Science Foundation of China(No.12127804).
文摘The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^(2+),O_(2)^(2+)O^(+),O^(2+),and their total)and two Coulomb explosion channels(O^(+)+O^(+)and O^(2+)+O^(+))are obtained by putting the data of O^(2+)on the scale of Ar+from O_(2)and Ar gases mixed with a fixed relative flow ratio of 1:1.The experimental errors are assessed by taking uncertainties of various factors into account.The present absolute cross sections are well consistent with the previous data in the overlapped energy range below 1000 eV.
基金supported in part by the Education Reform Key Projects of Heilongjiang Province under Grant Nos.SJGZ20220011,SJGZ20220012,and SJGZY2024008。
文摘In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we propose the Software Engineering Degree Granting Program Construction Practice Project at Harbin Institute of Technology(HIT).This project aims to explore new models for software talent cultivation,establish a superior SE degree granting program,and ultimately cultivate outstanding internationalized composite SE professionals to support the high-quality development of the national software industry.To this end,we design a distinctive overall construction idea and plan for the SE degree granting program,which are characterized by“3I3S:three highlights for specialized cultivation and strictness in three aspects to ensure quality control”.After years of practice and validation of the project at the School of Software at HIT,this project has proven effective in optimizing talent cultivation models,enhancing students’practical abilities,promoting international exchange and cooperation,advancing industry-education integration,and meeting industrial needs.
基金funded by the National Natural Science Foundation of China(Nos.22073069,21773082)Science Research Project of Hebei Education Department(No.QN2024255)。
文摘In chemical science,the vertical ionization potential(VIP)is a crucial metric for understanding the electronegativity,hardness and softness of chemical material systems as well as the electronic structure and stability of molecules.Ever since the last century,the model chemistry composite methods have witnessed tremendous developments in computing the thermodynamic properties as well as the barrier heights.However,their performance in realm of the vertical electron processes of molecular systems has been rarely explored.In this study,we for the first time benchmarked the model chemistry composite methods(e.g.,CBS-QB3,G4 and W1BD)in comparison with the commonly used Koopmans's theorem(KT),electron propagator theory(e.g.,OVGF,D2,P3 and P3+)and CCSD(T)methods in calculating the VIP for up to 613 molecular systems with available experimental measurements.The large-scale test calculations strongly showed that the CBS-QB3 model chemistry composite technique can be well recommended to calculate VIP from the perspectives of accuracy,economy and applicability.Notably,the VIP values of up to 7 molecules were identified to have the absolute errors of larger than 0.3 e V at all calculation levels,which have strong hints that their VIP experimental values should be re-investigated.
基金supported by Jiangxi Provincial International Science and Technology Cooperation Project(Nos.20203BDH80W010 and 20232BBH80012)the National Natural Science Foundation of China(Nos.82160410 and 81860379)+1 种基金Foundation of Jiangxi Provincial Department of Science and Technology(No.20212ACB206018)Key Research and Development Program of Jiangxi Province(No.20223BBG71009)。
文摘Accurate determination of lung cancer margins at the molecular level is of great significance to determine the optimal extent of resection during surgical operation and reduce the risk of postoperative recurrence.In this study,internal extractive electrospray ionization mass spectrometry(i EESI-MS)was used to trace potential molecular tumor margins in lung cancer tissue.Molecular differential model for the determination of lung cancer tumor margin was established via partial least-squares discriminant analysis(PLS-DA)of iEESI-MS data collected from lung tissue pieces within cancer tumor area and iEESI-MS data collected from lung tissue pieces outside cancer tumor area.Proof-of-concept data demonstrate that the developed molecular differential model yields ca.1-2 mm wider potential molecular tumor margin of a lung cancer compared to the conventional histological analysis,showing promising potential of iEESI-MS to increase the accuracy of tumor margins determination and lower risk of lung cancer postoperative recurrence.Furthermore,our results revealed that creatine and taurine showed positive correlations with lung cancer.
基金supported by the National Natural Science Foundation of China(42474003,42074007)the Fundamental Research Funds for the Central Universities(2042023kfyq01)。
文摘As a major fault in the northeastern Qinghai-Xizang Plateau,the Haiyuan fault zone is important for understanding the regional deformation.Aiming at the differences in the slip rate and locking degree obtained from different studies,this study constructs a refined block model(including Qilian,Alxa,Ordos,Xining,Haiyuan,and Lanzhou blocks)and uses the grid search and simulated annealing methods to invert GPS data for slip rate and locking degree of the Haiyuan fault zone.The results are as follows:(1)The sinistral slip rates in the western,middle,and eastern segments are 4.93-5.22 mm/a,1.52-4.94 mm/a,and 0.43-1.18 mm/a,decreasing eastward on the whole,while the compression rates are 0.45-1.26 mm/a,0.58-2.62 mm/a,and3.52-4.48 mm/a,increasing eastward on the whole.(2)The locking depth of the western segment increases from about 5 km to about 20 km eastward;the middle segment decreases and then increases eastward;the eastern segment concentrates at about 20 km(PHI is about 0.86).(3)The slip deficit is relatively higher in the Lenglongling,Jinqianghe,Maomaoshan,and Liupanshan faults(averaging about 3.42 mm/a,4.16 mm/a,4.23 mm/a,and 3.43 mm/a within 20 km).(4)The Qilian,Alxa,Xining,Lanzhou,and Haiyuan blocks rotate clockwise,while the Ordos block rotates counterclockwise.Additionally,by comparing different block models,the Haiyuan block should be considered independently.The Haiyuan fault zone adjusts surrounding block movements and uplifts Liupanshan mountain tectonically.The results can provide important references for understanding the regional earthquake risk and deformation mechanism.
基金supported by the National Key R&D Program of China(No.2023YFA1406801)the National Natural Science Foundation of China(Nos.12174011,12434013).
文摘Ionization and dissociation are fundamental processes that molecules undergo in intense femtosecond laser fields.Professor Fanao Kong is a pioneering researcher in this field within China.He has developed an orbital-based molecular ionization model and a laser field-assisted molecular dissociation model to elucidate experimental observations and predict potential applications.The predictions of these models have been corroborated by subsequent theoretical and experimental studies.This review highlights Professor Kong’s significant contributions to the study of molecular ionization and dissociation in intense femtosecond laser fields,emphasizing key advancements and outlining future directions in the field of strong-field laser chemistry.
