To meet the demands of higher education reform and innovative talent cultivation,the teaching team of Tarim University,with ability cultivation as the core,has established a new“331”university mathematics teaching s...To meet the demands of higher education reform and innovative talent cultivation,the teaching team of Tarim University,with ability cultivation as the core,has established a new“331”university mathematics teaching system.Through the multi-dimensional linkage of master teachers’guidance,course optimization,stratified teaching,practical reinforcement,and competition-driven,it has significantly improved students’mathematical application ability and innovative quality.展开更多
Rheumatoid arthritis(RA)patients face significant psychological challenges alongside physical symptoms,necessitating a comprehensive understanding of how psychological vulnerability and adaptation patterns evolve thro...Rheumatoid arthritis(RA)patients face significant psychological challenges alongside physical symptoms,necessitating a comprehensive understanding of how psychological vulnerability and adaptation patterns evolve throughout the disease course.This review examined 95 studies(2000-2025)from PubMed,Web of Science,and CNKI databases including longitudinal cohorts,randomized controlled trials,and mixed-methods research,to characterize the complex interplay between biological,psychological,and social factors affecting RA patients’mental health.Findings revealed three distinct vulnerability trajectories(45%persistently low,30%fluctuating improvement,25%persistently high)and four adaptation stages,with critical intervention periods occurring 3-6 months postdiagnosis and during disease flares.Multiple factors significantly influence psychological outcomes,including gender(females showing 1.8-fold increased risk),age(younger patients experiencing 42%higher vulnerability),pain intensity,inflammatory markers,and neuroendocrine dysregulation(48%showing cortisol rhythm disruption).Early psychological intervention(within 3 months of diagnosis)demonstrated robust benefits,reducing depression incidence by 42%with effects persisting 24-36 months,while different modalities showed complementary advantages:Cognitive behavioral therapy for depression(Cohen’s d=0.68),mindfulness for pain acceptance(38%improvement),and peer support for meaning reconstruction(25.6%increase).These findings underscore the importance of integrating routine psychological assessment into standard RA care,developing stage-appropriate interventions,and advancing research toward personalized biopsychosocial approaches that address the dynamic psychological dimensions of the disease.展开更多
The effect of realistic topology configuration of intercellular connections on the response ability in coupled cell system is numerically investigated by using the Hindmarsh-Rose model. For the proper coupling intensi...The effect of realistic topology configuration of intercellular connections on the response ability in coupled cell system is numerically investigated by using the Hindmarsh-Rose model. For the proper coupling intensity, we set the control parameter to be near the critical value, and the external stimulus is introduced to the first cell in coupled system. It is found that, on one hand, when the cells are coupled with some proper topological structures, the external stimulus could transmit through the system, and shows better response ability and higher sensitivity. On the other hand, the influence of topological configuration on the synchronous ability and selection effect of neural system are also discussed. Our results display that the topology of coupled system may play an important role in the process of signal propagation, which could help us to understand the coordinated performance of cells in tissue.展开更多
The aeromechanical st ability for the coupled rotor/fuselage system of helicopters in forward flight i s investigated. The periodic time-varying equations of motion are developed thr ough building a new 24DOF coupled ...The aeromechanical st ability for the coupled rotor/fuselage system of helicopters in forward flight i s investigated. The periodic time-varying equations of motion are developed thr ough building a new 24DOF coupled rigid/elastic blended element based on the fle xible multibody system theory in this paper. It accounts for the effects of prec one, sweep, and the moderately large elastic deflections on the blade and elasti city of shaft and fuselage of the helicopter. The dynamic coupling between the r igid motion of blades about the flap, lag and pitch hinges of articulated rotor and moderately large elastic deflections are included. There is no restriction o n the rotation amplitudes of flap, lag and pitch in the formulation. The stabili ty of periodic solution is studied using the Floquet theory. The transition matr ix is calculated by the Newmark integration method. The aeromechanical stability of a new helicopter is studied. The results show that it is stable in the given forward flight. But the instability arises with the decrease of the bending and torsion stiffness of the shaft.展开更多
This paper assesses the structure and ability of Local Seismological Gravity Monitoring Network (LSGMN) in China main tectonic zone and China Seismological Gravity Monitoring System (CSGMS) which formed after the proj...This paper assesses the structure and ability of Local Seismological Gravity Monitoring Network (LSGMN) in China main tectonic zone and China Seismological Gravity Monitoring System (CSGMS) which formed after the project of 'China Crustal Movement Observation Network (CCMON)' has been performed. The main conclusions drawn are as follows: ①LSGMN has good monitoring and prediction ability for the earthquake of M_s about 5. But it lacks ability to monitor and predict the strong earthquake of M_s>6 because of the little range of the observation network;②CSGMS has good ability to monitor and predict the earthquake of M_s>7, but the resolving power is not enough for the earthquake magnitude from M_s=6 to M_s=7 because the observation stations are too sparse.展开更多
Pressureless melt infiltration is an economic route f or preparation of high-density ceramic/melt composites. In this study, the Fe40 Al iron aluminide intermetallic, a low cost material of excellent oxidation and cor...Pressureless melt infiltration is an economic route f or preparation of high-density ceramic/melt composites. In this study, the Fe40 Al iron aluminide intermetallic, a low cost material of excellent oxidation and corrosion resistance, was used as binder for fabricating Fe40Al/TiC composites b y pressureless melt infiltration. The wetting ability of liquid Fe40Al in porous TiC pre-form was studied by in-situ monitoring the melting and infiltration p rocess. The infiltration ability was investigated by observing the distance of l iquid Fe40Al intrusion in porous TiC pre-forms at different infiltration temper atures and times by using optical microscope. Porous TiC per-forms with density of 60%～88%TD (theoretical density), prepared under pre-defined sintering temp e rature cycles, were used for fabricating Fe40Al/TiC composites in the range of 1 2%～40% metal content by volume. Almost full dense Fe40Al/TiC composites were su c cessfully fabricated by this technique. Liquid Fe40Al exhibited excellent infilt ration ability, the distance of complete intrusion of liquid Fe40Al in the TiC s intered pre-form with density of 88%TD was over 7 mm after 5 min at the inf iltration temperature of 1 450 ℃. Microstructural observation by SEM and TEM also showed that liquid Fe40Al filled the very narrow gaps among TiC particles, the interfaces of TiC particles and F e40Al plastic ligaments being metallurgical bonded. TEM revealed that high densi ty of dislocations formed in Fe40Al ligaments during solidification, which favor the mechanical properties. Ti decomposed from TiC particles and dissolved into Fe40Al during infiltration. According to the compositional analysis of TEM-EDS, the concentration of Ti in Fe40Al ranges at 1at%～4at% depending on composite f a bricating conditions and the distance from the measuring point to the closest Ti C particles. XRD analysis indicated that the composites were composed of two pha ses, the original TiC and Fe 0.4Al 0.6 intermetallic. No new phase formed during infiltration, but the lattice parameter of Fe 0.4Al 0.6 was expended due to the Ti in the solid solution.展开更多
The miombo woodland is one of the most extensive woodlands in Africa, supporting livelihoods based on biomass fuel for millions of rural people. However, there are growing concerns about the sustainability of harvesti...The miombo woodland is one of the most extensive woodlands in Africa, supporting livelihoods based on biomass fuel for millions of rural people. However, there are growing concerns about the sustainability of harvesting for biomass fuel （mainly charcoal）. Thus, the aim of this study was to examine whether regeneration by coppice is a viable option for sustainably managing miombo woodlands for biomass fuel production. We tested the hypotheses that （1） species, stump diameter, stump height and time since cutting significantly affect the number of sprouts per cut stump （coppice density） and mean sprout height （shoot vigour） and （2） higher coppice density reduces shoot vigour due to competition among coppice shoots in a given stump. In an inventory in areas that were harvested for charcoal production by the local people, 369 stumps of 11 species were recorded with mean coppice stumps ranged from 6 to 84. The mean coppice density ranged from 5 to 8 shoots per stump while the mean height of coppice shoots ranged from 46 to 118 cm with marked interspecific variations. Stump size was signifi- cantly and positively correlated with coppice density for some of the species, but not with shoot vigour for the majority of the species. However, shoot vigour was significantly positively correlated to time since cutting of trees for nearly half of the species. Coppice density had a significant negative correlation with shoot vigour for two species, and a positive correlation for one species. In conclusion, the results provide evidence about the importance of coppice management as a win-win strategy for sustaining charcoal-based rural livelihoods and recovering the miombo woodland ecosystem.展开更多
This paper describes the development of a knowledgebased system (KBS) for determining whether or not, and under what conditions, a bank Ioan officer should grant a business loan to a company. The prototype system deve...This paper describes the development of a knowledgebased system (KBS) for determining whether or not, and under what conditions, a bank Ioan officer should grant a business loan to a company. The prototype system developed focuses on what is bank loans risks management, how to prevent risk by the analysis of the ability of paying back loans. The paper makes the structural analysis involved in the system's decision situation, the structured situation diagram or model, dependency diagram and the document needed by the KBS prototype system thus are developed. Through testing the samples from loan business, the quality for the analysis of the ability of paying back loans can be effectively evaluated by the KBS prototype system.展开更多
The thermodynamic model of multicomponent chemical short range order (MCSRO) was established in order to evaluate the glass forming ability (GFA) of ternary alloys. Comprehensive numerical calculations using MSCRO sof...The thermodynamic model of multicomponent chemical short range order (MCSRO) was established in order to evaluate the glass forming ability (GFA) of ternary alloys. Comprehensive numerical calculations using MSCRO software were conducted to obtain the composition dependence of the MCSRO undercooling in Zr Ni Cu, Zr Si Cu and Pd Si Cu ternary systems. By the MCSRO undercooling principle, the composition range of Zr Ni Cu system with optimum GFA is determined to be 62.5 ～ 75 Zr, 5～ 20 Cu, 12.5 ～ 25 Ni ( n (Ni)/ n (Cu)=1～5). The TTT curves of Zr Ni Cu system were also calculated based on the MCSRO model. The critical cooling rates for Zr based alloy with deep MSCRO undercooling are estimated to be as low as 100?K/s, which is consistent with the practical cooling rate in the preparation of Zr based bulk metallic glass (BMG). The calculation also illustrates that the easy glass forming systems such as Pd based alloys exhibit an extraordinary deep MCSRO undercooling. It is shown that the thermodynamic model of MCSRO provides an effective method for the alloy designing of BMG.展开更多
To meet society’s needs for undergraduate students to have engineering skills and to develop students’ability to operate Linux and engage in network software development,this paper proposes the construction of a new...To meet society’s needs for undergraduate students to have engineering skills and to develop students’ability to operate Linux and engage in network software development,this paper proposes the construction of a new specialized course for network engineering major--Linux system and network programming.This paper analyzes the course’s advantages,presents the contents of this course,designs a series of teaching methods aimed at improving students’engineering ability,proposes a course assessment method that will encourage students to practice,lists the development requirements for an examination software designed for this course,and finally,presents the results of our practice in teaching this course.展开更多
First-principles calculations are applied for investigating influence of electron donating ability of donor groups in eight thermally activated delayed fluorescence（TADF） molecules on their geometrical structures an...First-principles calculations are applied for investigating influence of electron donating ability of donor groups in eight thermally activated delayed fluorescence（TADF） molecules on their geometrical structures and transition properties as well as reverse intersystem crossing（RISC） processes. Results show that the diphenylamine substitution in the donor part can slightly change the bond angle but decrease bond length between donor and acceptor unit except for the lowest triplet state（Ti） of carbazole-xanthone molecule. As the electron donating ability of donor groups is increased, the overlap between the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO） is decreased. As the diphenylamine groups are added in donor part, the delocalization of HOMO is enlarged,which brings a decreased energy gap(△ES1-T1) between the lowest singlet excited state（S1）and T1 state. Furthermore, with the calculated spin-orbit coupling coefficient(HSO), one finds that the larger value of ■ is, the faster the RISC is. The results show that all investigated molecules are promising candidates as TADF molecules. Overall, a wise molecular design strategy for TADF molecules,in which a small △ES1-T1 can be achieved by enlarging the delocalization of frontier molecular orbitals with large separation between HOMO and LUMO, is proposed.展开更多
It has been confirmed that glass-forming ability （GFA） of supercooled liquids is related to not only liquid phase stability but also the crystallization resistance. In this paper, it is found that the liquid region ...It has been confirmed that glass-forming ability （GFA） of supercooled liquids is related to not only liquid phase stability but also the crystallization resistance. In this paper, it is found that the liquid region interval （T1 - Tg） characterized by the normalized parameter of Tg/T1 could reflect the stability of glass-forming liquids at the equilibrium state, whilst the normalization of supercooled liquid region △Tx=（Tx - Tg）, i.e. △Tx/Tx （wherein T1 is the liquidus temperature, Tg the glass transition temperature, and Tx the onset crystallization temperature） could indicate the crystallization resistance during glass formation. Thus, a new parameter, defined as ζ = Tg/T1＋△Tx/Tx is established to predict the GFA of supercooled liquids. In comparison with other commonly used criteria, this parameter demonstrates a better statistical correlation with the GFA for various glass-forming systems including metallic glasses, oxide glasses and cryoprotectants.展开更多
The glass formation was investigated in the melt-spun Al-rich Al-Co-Y alloys by the microstructure evolution. The best glass former Al88Co5Y7 with the thickness of 230μm was found, and its glass forming ability （GFA...The glass formation was investigated in the melt-spun Al-rich Al-Co-Y alloys by the microstructure evolution. The best glass former Al88Co5Y7 with the thickness of 230μm was found, and its glass forming ability （GFA） was higher than that of previously reported Al88Co4Y8 alloy. This result indicates that GFA is strongly sensitive to the alloy composition in the system. The phase selection method is an effective way to locate the optimum glass formation composition rather than Trg and △Tx parameters.展开更多
It is a rather challenging project to seek the amount of funds raised by funds-raising companies. This paper is focused on China private equity funds that have succeeded in raising their funds. The grey systemic model...It is a rather challenging project to seek the amount of funds raised by funds-raising companies. This paper is focused on China private equity funds that have succeeded in raising their funds. The grey systemic model is applied in the research and a formula is established for the law of fund-raising of the private equity funds in order to sum up the capacity of China private equity investment funds and to establish a model accordingly.展开更多
Despite its significance in both fundamental science and industrial applications,the glass-forming transition in the Al_(2)O_(3)-Y_(2)O_(3)(AY)refractory system is not yet fully understood due to the elusive structure...Despite its significance in both fundamental science and industrial applications,the glass-forming transition in the Al_(2)O_(3)-Y_(2)O_(3)(AY)refractory system is not yet fully understood due to the elusive structure evolution upon cooling.Here,atomic-scale structural changes in AY-bearing melts with different compositions and temperatures are tracked by employing in situ high-energy synchrotron X-ray diffraction and empirical potential structure refinement simulation.We find that the glass-forming abilities(GFA)of AY-bearing melts are intriguingly correlated with the dependence of melt structure on temperature.In the case of the Al_(2)O_(3)and Y_(3)A_(l5)O_(12)(YAG),the observed large structural changes from superheating to under-cooling melt(i.e.,higher temperature susceptibility)correspond to a low GFA.Conversely,the 74Al_(2)O_(3)-26Y_(2)O_(3)(AY26)melt,with the smallest temperature susceptibility,exhibits the highest GFA.Simulation models illustrate that the temperature susceptibility of melt is associated with its atomic arrangement,especially the stability of cation-cation pairs.A balanced network(in AY26 melt),where the unsteady OAl3 tri-clusters are minimized and steady apex-to-apex connections between adjacent network units are abundant,contributes to stabilizing cationic interactions.This,in turn,fosters the formation of largesized Al-O-Al rings,which topologically facilitates the subsequent glass-forming transition.Our findings provide new structural insight into the GFA of AY-bearing melts and may expand to other unconventional glass-forming systems to accelerate glassy materials design.展开更多
In order to clarify the effect of spherical light-weight aggregates addition on properties of A12 07 - Si02 system castables, adopting ATO mullite traditional light-weight aggregates and ATO mullite spherical light-we...In order to clarify the effect of spherical light-weight aggregates addition on properties of A12 07 - Si02 system castables, adopting ATO mullite traditional light-weight aggregates and ATO mullite spherical light-weight aggre- gates, bauxite homogenization powder, microsilica , cal- cium aluminate cement as main raw materials, light- weight Al2 03 - SiO2 system castables were prepared by replacing conventional light-weight aggregate with spherical light-weight aggregates. The effects of spheri- cal light-weight aggregates addition on workability, me- chanical properties of castables after heated at different temperatures were researched; the microstructure of the aggregates was analyzed by SEM. The result shows that the introduction of spherical light-weight aggregates can significantly improve the flowability and reduce the water addition of the castables. Water demand of the castable is reduced from 18% with the conventional light-weight aggregates to 14% with spherical light-weight aggre- gates. In addition, light-weight castables prepared by spherical aggregates can keep the same workability with- in a wider range of water addition. Therefore, spherical aggregates are user-friendly. The introduction of spheri- cal light-weight aggregates is favorable to packing densi- ty and mechanical properties of castables, such as cold crushing strength, cold modulus of rupture, hot modulus of rupture at 1 200℃.展开更多
BACKGROUND Postoperative complications remain a paramount concern for surgeons and healthcare practitioners.AIM To present a comprehensive analysis of the Estimation of Physiologic Ability and Surgical Stress(E-PASS)s...BACKGROUND Postoperative complications remain a paramount concern for surgeons and healthcare practitioners.AIM To present a comprehensive analysis of the Estimation of Physiologic Ability and Surgical Stress(E-PASS)scoring system’s efficacy in predicting postoperative complications following abdominal surgery.METHODS A systematic search of published studies was conducted,yielding 17 studies with pertinent data.Parameters such as preoperative risk score(PRS),surgical stress score(SSS),comprehensive risk score(CRS),postoperative complications,post-operative mortality,and other clinical data were collected for meta-analysis.Forest plots were employed for continuous and binary variables,withχ2 tests assessing heterogeneity(P value).RESULTS Patients experiencing complications after abdominal surgery exhibited significantly higher E-PASS scores compared to those without complications[mean difference and 95%confidence interval(CI)of PRS:0.10(0.05-0.15);SSS:0.04(0.001-0.08);CRS:0.19(0.07-0.31)].Following the exclusion of low-quality studies,results remained valid with no discernible heterogeneity.Subgroup analysis indicated that variations in sample size and age may contribute to hetero-geneity in CRS analysis.Binary variable meta-analysis demonstrated a correlation between high CRS and increased postoperative complication rates[odds ratio(OR)(95%CI):3.01(1.83-4.95)],with a significant association observed between high CRS and postoperative mortality[OR(95%CI):15.49(3.75-64.01)].CONCLUSION In summary,postoperative complications in abdominal surgery,as assessed by the E-PASS scoring system,are consistently linked to elevated PRS,SSS,and CRS scores.High CRS scores emerge as risk factors for heightened morbidity and mortality.This study establishes the accuracy of the E-PASS scoring system in predicting postoperative morbidity and mortality in abdominal surgery,underscoring its potential for widespread adoption in effective risk assessment.展开更多
Cognitive ability is important component of competitive ability of athletes,an important content of winning elements in sports,and an important topic of modern sports training and scientific research.These problems wi...Cognitive ability is important component of competitive ability of athletes,an important content of winning elements in sports,and an important topic of modern sports training and scientific research.These problems will restrict the improvement of athletes’cognitive ability and mental level.Based on the theory of psychology,use multiple hierarchical thinking,research cognitive theory of sports and the characteristics of cognitive ability of elite athletes,research the structure element system of cognitive ability,construct a two-level structure model of the cognitive ability of excellent athletes,summarize specific characteristics of the first level elements,and apply psychological cognitive theory to the training of modern Olympic Games mobilization,so as to provide valuable cognitive training,psychological training,and intelligence training for athletes theoretical guidance.展开更多
Success in the excavation of geological formations is commonly known as being very important in asserting stability. Furthermore, when the subjected geological formation is rocky and the use of explosives is required,...Success in the excavation of geological formations is commonly known as being very important in asserting stability. Furthermore, when the subjected geological formation is rocky and the use of explosives is required, the demands of successful blasting are multiplied. The present paper proposes a classification system, named： BQS （Blastability Quality System）, for rock masses with closely spaced discontinuities （spacing lower than 0.1 m）. It is obvious that rock quality is one of the main characteristics which define the blast ability of a rock. The BQS can be an easy and widely-used tool as it is a quick evaluator for blastability and rock mass quality at one time. Taking into consideration the research calculations and the parameters of BQS, what has been at question in this paper is the effect of blast ability in a geological formation with closely spaced discontinuities.展开更多
基金Advanced Mathematics A1 First-Class Course of Tarim University(TDYLKC202428)Educational Reform Project of Xinjiang Production and Construction Corps(BTBKXM-2024-Y41)。
文摘To meet the demands of higher education reform and innovative talent cultivation,the teaching team of Tarim University,with ability cultivation as the core,has established a new“331”university mathematics teaching system.Through the multi-dimensional linkage of master teachers’guidance,course optimization,stratified teaching,practical reinforcement,and competition-driven,it has significantly improved students’mathematical application ability and innovative quality.
基金Supported by Chongqing Health Commission and Chongqing Science and Technology Bureau,No.2023MSXM182。
文摘Rheumatoid arthritis(RA)patients face significant psychological challenges alongside physical symptoms,necessitating a comprehensive understanding of how psychological vulnerability and adaptation patterns evolve throughout the disease course.This review examined 95 studies(2000-2025)from PubMed,Web of Science,and CNKI databases including longitudinal cohorts,randomized controlled trials,and mixed-methods research,to characterize the complex interplay between biological,psychological,and social factors affecting RA patients’mental health.Findings revealed three distinct vulnerability trajectories(45%persistently low,30%fluctuating improvement,25%persistently high)and four adaptation stages,with critical intervention periods occurring 3-6 months postdiagnosis and during disease flares.Multiple factors significantly influence psychological outcomes,including gender(females showing 1.8-fold increased risk),age(younger patients experiencing 42%higher vulnerability),pain intensity,inflammatory markers,and neuroendocrine dysregulation(48%showing cortisol rhythm disruption).Early psychological intervention(within 3 months of diagnosis)demonstrated robust benefits,reducing depression incidence by 42%with effects persisting 24-36 months,while different modalities showed complementary advantages:Cognitive behavioral therapy for depression(Cohen’s d=0.68),mindfulness for pain acceptance(38%improvement),and peer support for meaning reconstruction(25.6%increase).These findings underscore the importance of integrating routine psychological assessment into standard RA care,developing stage-appropriate interventions,and advancing research toward personalized biopsychosocial approaches that address the dynamic psychological dimensions of the disease.
文摘The effect of realistic topology configuration of intercellular connections on the response ability in coupled cell system is numerically investigated by using the Hindmarsh-Rose model. For the proper coupling intensity, we set the control parameter to be near the critical value, and the external stimulus is introduced to the first cell in coupled system. It is found that, on one hand, when the cells are coupled with some proper topological structures, the external stimulus could transmit through the system, and shows better response ability and higher sensitivity. On the other hand, the influence of topological configuration on the synchronous ability and selection effect of neural system are also discussed. Our results display that the topology of coupled system may play an important role in the process of signal propagation, which could help us to understand the coordinated performance of cells in tissue.
文摘The aeromechanical st ability for the coupled rotor/fuselage system of helicopters in forward flight i s investigated. The periodic time-varying equations of motion are developed thr ough building a new 24DOF coupled rigid/elastic blended element based on the fle xible multibody system theory in this paper. It accounts for the effects of prec one, sweep, and the moderately large elastic deflections on the blade and elasti city of shaft and fuselage of the helicopter. The dynamic coupling between the r igid motion of blades about the flap, lag and pitch hinges of articulated rotor and moderately large elastic deflections are included. There is no restriction o n the rotation amplitudes of flap, lag and pitch in the formulation. The stabili ty of periodic solution is studied using the Floquet theory. The transition matr ix is calculated by the Newmark integration method. The aeromechanical stability of a new helicopter is studied. The results show that it is stable in the given forward flight. But the instability arises with the decrease of the bending and torsion stiffness of the shaft.
基金The State Natural Science Foundation!(49974019)State Climb Plan
文摘This paper assesses the structure and ability of Local Seismological Gravity Monitoring Network (LSGMN) in China main tectonic zone and China Seismological Gravity Monitoring System (CSGMS) which formed after the project of 'China Crustal Movement Observation Network (CCMON)' has been performed. The main conclusions drawn are as follows: ①LSGMN has good monitoring and prediction ability for the earthquake of M_s about 5. But it lacks ability to monitor and predict the strong earthquake of M_s>6 because of the little range of the observation network;②CSGMS has good ability to monitor and predict the earthquake of M_s>7, but the resolving power is not enough for the earthquake magnitude from M_s=6 to M_s=7 because the observation stations are too sparse.
文摘Pressureless melt infiltration is an economic route f or preparation of high-density ceramic/melt composites. In this study, the Fe40 Al iron aluminide intermetallic, a low cost material of excellent oxidation and corrosion resistance, was used as binder for fabricating Fe40Al/TiC composites b y pressureless melt infiltration. The wetting ability of liquid Fe40Al in porous TiC pre-form was studied by in-situ monitoring the melting and infiltration p rocess. The infiltration ability was investigated by observing the distance of l iquid Fe40Al intrusion in porous TiC pre-forms at different infiltration temper atures and times by using optical microscope. Porous TiC per-forms with density of 60%～88%TD (theoretical density), prepared under pre-defined sintering temp e rature cycles, were used for fabricating Fe40Al/TiC composites in the range of 1 2%～40% metal content by volume. Almost full dense Fe40Al/TiC composites were su c cessfully fabricated by this technique. Liquid Fe40Al exhibited excellent infilt ration ability, the distance of complete intrusion of liquid Fe40Al in the TiC s intered pre-form with density of 88%TD was over 7 mm after 5 min at the inf iltration temperature of 1 450 ℃. Microstructural observation by SEM and TEM also showed that liquid Fe40Al filled the very narrow gaps among TiC particles, the interfaces of TiC particles and F e40Al plastic ligaments being metallurgical bonded. TEM revealed that high densi ty of dislocations formed in Fe40Al ligaments during solidification, which favor the mechanical properties. Ti decomposed from TiC particles and dissolved into Fe40Al during infiltration. According to the compositional analysis of TEM-EDS, the concentration of Ti in Fe40Al ranges at 1at%～4at% depending on composite f a bricating conditions and the distance from the measuring point to the closest Ti C particles. XRD analysis indicated that the composites were composed of two pha ses, the original TiC and Fe 0.4Al 0.6 intermetallic. No new phase formed during infiltration, but the lattice parameter of Fe 0.4Al 0.6 was expended due to the Ti in the solid solution.
基金financially supported by the Swedish Research Link
文摘The miombo woodland is one of the most extensive woodlands in Africa, supporting livelihoods based on biomass fuel for millions of rural people. However, there are growing concerns about the sustainability of harvesting for biomass fuel （mainly charcoal）. Thus, the aim of this study was to examine whether regeneration by coppice is a viable option for sustainably managing miombo woodlands for biomass fuel production. We tested the hypotheses that （1） species, stump diameter, stump height and time since cutting significantly affect the number of sprouts per cut stump （coppice density） and mean sprout height （shoot vigour） and （2） higher coppice density reduces shoot vigour due to competition among coppice shoots in a given stump. In an inventory in areas that were harvested for charcoal production by the local people, 369 stumps of 11 species were recorded with mean coppice stumps ranged from 6 to 84. The mean coppice density ranged from 5 to 8 shoots per stump while the mean height of coppice shoots ranged from 46 to 118 cm with marked interspecific variations. Stump size was signifi- cantly and positively correlated with coppice density for some of the species, but not with shoot vigour for the majority of the species. However, shoot vigour was significantly positively correlated to time since cutting of trees for nearly half of the species. Coppice density had a significant negative correlation with shoot vigour for two species, and a positive correlation for one species. In conclusion, the results provide evidence about the importance of coppice management as a win-win strategy for sustaining charcoal-based rural livelihoods and recovering the miombo woodland ecosystem.
基金Supported by the National Science Foundation of China(No.7977086)
文摘This paper describes the development of a knowledgebased system (KBS) for determining whether or not, and under what conditions, a bank Ioan officer should grant a business loan to a company. The prototype system developed focuses on what is bank loans risks management, how to prevent risk by the analysis of the ability of paying back loans. The paper makes the structural analysis involved in the system's decision situation, the structured situation diagram or model, dependency diagram and the document needed by the KBS prototype system thus are developed. Through testing the samples from loan business, the quality for the analysis of the ability of paying back loans can be effectively evaluated by the KBS prototype system.
文摘The thermodynamic model of multicomponent chemical short range order (MCSRO) was established in order to evaluate the glass forming ability (GFA) of ternary alloys. Comprehensive numerical calculations using MSCRO software were conducted to obtain the composition dependence of the MCSRO undercooling in Zr Ni Cu, Zr Si Cu and Pd Si Cu ternary systems. By the MCSRO undercooling principle, the composition range of Zr Ni Cu system with optimum GFA is determined to be 62.5 ～ 75 Zr, 5～ 20 Cu, 12.5 ～ 25 Ni ( n (Ni)/ n (Cu)=1～5). The TTT curves of Zr Ni Cu system were also calculated based on the MCSRO model. The critical cooling rates for Zr based alloy with deep MSCRO undercooling are estimated to be as low as 100?K/s, which is consistent with the practical cooling rate in the preparation of Zr based bulk metallic glass (BMG). The calculation also illustrates that the easy glass forming systems such as Pd based alloys exhibit an extraordinary deep MCSRO undercooling. It is shown that the thermodynamic model of MCSRO provides an effective method for the alloy designing of BMG.
基金supported by the Teaching Research and Reform Project of Qingdao University of Technology under Grant 2024-10335040。
文摘To meet society’s needs for undergraduate students to have engineering skills and to develop students’ability to operate Linux and engage in network software development,this paper proposes the construction of a new specialized course for network engineering major--Linux system and network programming.This paper analyzes the course’s advantages,presents the contents of this course,designs a series of teaching methods aimed at improving students’engineering ability,proposes a course assessment method that will encourage students to practice,lists the development requirements for an examination software designed for this course,and finally,presents the results of our practice in teaching this course.
基金This work was supported by the National Natural Science Foundation of China(No.11374195 and No.21403133),the Taishan Scholar Project of Shandong Province,the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province(No.BS2014CL001),and the General Financial Grant from the China Postdoctoral Science Foundation(No.2014M560571).
文摘First-principles calculations are applied for investigating influence of electron donating ability of donor groups in eight thermally activated delayed fluorescence（TADF） molecules on their geometrical structures and transition properties as well as reverse intersystem crossing（RISC） processes. Results show that the diphenylamine substitution in the donor part can slightly change the bond angle but decrease bond length between donor and acceptor unit except for the lowest triplet state（Ti） of carbazole-xanthone molecule. As the electron donating ability of donor groups is increased, the overlap between the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO） is decreased. As the diphenylamine groups are added in donor part, the delocalization of HOMO is enlarged,which brings a decreased energy gap(△ES1-T1) between the lowest singlet excited state（S1）and T1 state. Furthermore, with the calculated spin-orbit coupling coefficient(HSO), one finds that the larger value of ■ is, the faster the RISC is. The results show that all investigated molecules are promising candidates as TADF molecules. Overall, a wise molecular design strategy for TADF molecules,in which a small △ES1-T1 can be achieved by enlarging the delocalization of frontier molecular orbitals with large separation between HOMO and LUMO, is proposed.
基金Project supported by National Science Council, Taiwan, China (Grant No NSC 94-2216-E-110-010)post-doc sponsorship from National Science Council, Taiwan, China (Grant No NSC 95-2816-E-110-001)
文摘It has been confirmed that glass-forming ability （GFA） of supercooled liquids is related to not only liquid phase stability but also the crystallization resistance. In this paper, it is found that the liquid region interval （T1 - Tg） characterized by the normalized parameter of Tg/T1 could reflect the stability of glass-forming liquids at the equilibrium state, whilst the normalization of supercooled liquid region △Tx=（Tx - Tg）, i.e. △Tx/Tx （wherein T1 is the liquidus temperature, Tg the glass transition temperature, and Tx the onset crystallization temperature） could indicate the crystallization resistance during glass formation. Thus, a new parameter, defined as ζ = Tg/T1＋△Tx/Tx is established to predict the GFA of supercooled liquids. In comparison with other commonly used criteria, this parameter demonstrates a better statistical correlation with the GFA for various glass-forming systems including metallic glasses, oxide glasses and cryoprotectants.
基金supported by the National Natural Science Foundation of China(Grant Nos.50471075,50471076).
文摘The glass formation was investigated in the melt-spun Al-rich Al-Co-Y alloys by the microstructure evolution. The best glass former Al88Co5Y7 with the thickness of 230μm was found, and its glass forming ability （GFA） was higher than that of previously reported Al88Co4Y8 alloy. This result indicates that GFA is strongly sensitive to the alloy composition in the system. The phase selection method is an effective way to locate the optimum glass formation composition rather than Trg and △Tx parameters.
文摘It is a rather challenging project to seek the amount of funds raised by funds-raising companies. This paper is focused on China private equity funds that have succeeded in raising their funds. The grey systemic model is applied in the research and a formula is established for the law of fund-raising of the private equity funds in order to sum up the capacity of China private equity investment funds and to establish a model accordingly.
基金supported by the National Natural Science Foundation of China-Key Program(No.52234010)National Natural Science Foundation of China(No.51971138)+2 种基金National Natural Science Foundation of China-Distinguished Young Scholars(No.52325407)National Key Basic Research Program of China(No.2020YFA0406101)the fund of the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202102).
文摘Despite its significance in both fundamental science and industrial applications,the glass-forming transition in the Al_(2)O_(3)-Y_(2)O_(3)(AY)refractory system is not yet fully understood due to the elusive structure evolution upon cooling.Here,atomic-scale structural changes in AY-bearing melts with different compositions and temperatures are tracked by employing in situ high-energy synchrotron X-ray diffraction and empirical potential structure refinement simulation.We find that the glass-forming abilities(GFA)of AY-bearing melts are intriguingly correlated with the dependence of melt structure on temperature.In the case of the Al_(2)O_(3)and Y_(3)A_(l5)O_(12)(YAG),the observed large structural changes from superheating to under-cooling melt(i.e.,higher temperature susceptibility)correspond to a low GFA.Conversely,the 74Al_(2)O_(3)-26Y_(2)O_(3)(AY26)melt,with the smallest temperature susceptibility,exhibits the highest GFA.Simulation models illustrate that the temperature susceptibility of melt is associated with its atomic arrangement,especially the stability of cation-cation pairs.A balanced network(in AY26 melt),where the unsteady OAl3 tri-clusters are minimized and steady apex-to-apex connections between adjacent network units are abundant,contributes to stabilizing cationic interactions.This,in turn,fosters the formation of largesized Al-O-Al rings,which topologically facilitates the subsequent glass-forming transition.Our findings provide new structural insight into the GFA of AY-bearing melts and may expand to other unconventional glass-forming systems to accelerate glassy materials design.
基金The National Natural Science Foundation of China(Grant No.51402089)
文摘In order to clarify the effect of spherical light-weight aggregates addition on properties of A12 07 - Si02 system castables, adopting ATO mullite traditional light-weight aggregates and ATO mullite spherical light-weight aggre- gates, bauxite homogenization powder, microsilica , cal- cium aluminate cement as main raw materials, light- weight Al2 03 - SiO2 system castables were prepared by replacing conventional light-weight aggregate with spherical light-weight aggregates. The effects of spheri- cal light-weight aggregates addition on workability, me- chanical properties of castables after heated at different temperatures were researched; the microstructure of the aggregates was analyzed by SEM. The result shows that the introduction of spherical light-weight aggregates can significantly improve the flowability and reduce the water addition of the castables. Water demand of the castable is reduced from 18% with the conventional light-weight aggregates to 14% with spherical light-weight aggre- gates. In addition, light-weight castables prepared by spherical aggregates can keep the same workability with- in a wider range of water addition. Therefore, spherical aggregates are user-friendly. The introduction of spheri- cal light-weight aggregates is favorable to packing densi- ty and mechanical properties of castables, such as cold crushing strength, cold modulus of rupture, hot modulus of rupture at 1 200℃.
基金Supported by Medical Science and Technology Project of Zhejiang Province of China,No.2020PY053.
文摘BACKGROUND Postoperative complications remain a paramount concern for surgeons and healthcare practitioners.AIM To present a comprehensive analysis of the Estimation of Physiologic Ability and Surgical Stress(E-PASS)scoring system’s efficacy in predicting postoperative complications following abdominal surgery.METHODS A systematic search of published studies was conducted,yielding 17 studies with pertinent data.Parameters such as preoperative risk score(PRS),surgical stress score(SSS),comprehensive risk score(CRS),postoperative complications,post-operative mortality,and other clinical data were collected for meta-analysis.Forest plots were employed for continuous and binary variables,withχ2 tests assessing heterogeneity(P value).RESULTS Patients experiencing complications after abdominal surgery exhibited significantly higher E-PASS scores compared to those without complications[mean difference and 95%confidence interval(CI)of PRS:0.10(0.05-0.15);SSS:0.04(0.001-0.08);CRS:0.19(0.07-0.31)].Following the exclusion of low-quality studies,results remained valid with no discernible heterogeneity.Subgroup analysis indicated that variations in sample size and age may contribute to hetero-geneity in CRS analysis.Binary variable meta-analysis demonstrated a correlation between high CRS and increased postoperative complication rates[odds ratio(OR)(95%CI):3.01(1.83-4.95)],with a significant association observed between high CRS and postoperative mortality[OR(95%CI):15.49(3.75-64.01)].CONCLUSION In summary,postoperative complications in abdominal surgery,as assessed by the E-PASS scoring system,are consistently linked to elevated PRS,SSS,and CRS scores.High CRS scores emerge as risk factors for heightened morbidity and mortality.This study establishes the accuracy of the E-PASS scoring system in predicting postoperative morbidity and mortality in abdominal surgery,underscoring its potential for widespread adoption in effective risk assessment.
基金Thanks to Professor Korobeynikov Georgiy of National University of Physical Education and Sports of Ukraine.Thanks to Professor Chen Jinsong of Jiangsu Ocean University of Chinathanks for your support and help.
文摘Cognitive ability is important component of competitive ability of athletes,an important content of winning elements in sports,and an important topic of modern sports training and scientific research.These problems will restrict the improvement of athletes’cognitive ability and mental level.Based on the theory of psychology,use multiple hierarchical thinking,research cognitive theory of sports and the characteristics of cognitive ability of elite athletes,research the structure element system of cognitive ability,construct a two-level structure model of the cognitive ability of excellent athletes,summarize specific characteristics of the first level elements,and apply psychological cognitive theory to the training of modern Olympic Games mobilization,so as to provide valuable cognitive training,psychological training,and intelligence training for athletes theoretical guidance.
文摘Success in the excavation of geological formations is commonly known as being very important in asserting stability. Furthermore, when the subjected geological formation is rocky and the use of explosives is required, the demands of successful blasting are multiplied. The present paper proposes a classification system, named： BQS （Blastability Quality System）, for rock masses with closely spaced discontinuities （spacing lower than 0.1 m）. It is obvious that rock quality is one of the main characteristics which define the blast ability of a rock. The BQS can be an easy and widely-used tool as it is a quick evaluator for blastability and rock mass quality at one time. Taking into consideration the research calculations and the parameters of BQS, what has been at question in this paper is the effect of blast ability in a geological formation with closely spaced discontinuities.
