BACKGROUND Non variceal upper gastrointestinal bleeding(NVUGIB)is a life-threatening condition requiring prompt and effective hemostasis.Various endoscopic inter-ventions,including novel hemostatic powders(HP),over-th...BACKGROUND Non variceal upper gastrointestinal bleeding(NVUGIB)is a life-threatening condition requiring prompt and effective hemostasis.Various endoscopic inter-ventions,including novel hemostatic powders(HP),over-the-scope clips(OTSC),and traditional approaches,have been employed to manage upper gastroin-testinal bleeding(UGIB).Despite advancements,comparative efficacy and safety of these modalities remain uncertain.AIM To evaluate the efficacy and safety of novel hemostatic interventions compared to conventional endoscopic techniques for managing UGIB.METHODS Cochrane,MEDLINE,PubMed and Scopus libraries were searched for rando-mized controlled trials(RCTs)published up to October 2024.Only RCTs compa-ring novel interventions,such as HP or OTSC,with conventional endoscopic treatments computed tomography(CT)were included.The primary outcome was the 30-day rebleeding rate.Secondary outcomes included initial hemostasis,short-term rebleeding rates,need for salvage therapy(surgical/angiographic),30-day all-cause mortality,and bleeding-related mortality.We performed pairwise and network meta-analyses for all treatments.RESULTS Seventeen studies were included in this analysis.Regarding the 30-day rebleeding rate,OTSC and HP showed superior efficacy compared with CT[OTSC vs CT:Relative risk(RR):0.47,95%confidence interval(CI):0.33-0.65;HP vs CT:RR:0.73,95%CI:0.45-1.13],while OTSC and HP had comparable efficacy(RR:0.56,95%CI:0.30-1.05).OTSC ranked the highest in the network ranking estimate for this outcome.For the secondary outcomes,OTSC demonstrated superior efficacy for the short-term rebleeding rate(OTSC vs CT:RR:0.35,95%CI:0.14-0.74;HP vs CT:RR:0.62,95%CI:0.28-1.35;OTSC vs HP:RR:0.59,95%CI:0.17-1.67).Regarding the initial hemostasis rate,OTSC was slightly more effective than CT(OTSC vs CT:RR:1.20,95%CI:1.06-1.57)and comparable to HP(OTSC vs HP:RR:1.08,95%CI:0.89-1.40).There were no significant differences among treatments for all-cause mortality,bleeding-related mortality,or the necessity of surgical or angiographic salvage therapy.OTSC consistently ranked highest across most outcomes in the network ranking estimate.展开更多
AIM: To compare the functional outcomes of patients who underwent open surgery vs Ponseti method for the management of idiopathic clubfoot and to determine whether correlations exist between functional outcome and rad...AIM: To compare the functional outcomes of patients who underwent open surgery vs Ponseti method for the management of idiopathic clubfoot and to determine whether correlations exist between functional outcome and radiographic measurements.METHODS: A meta-analysis of the literature was conducted for studies concerning primary treatment of patients with idiopathic clubfoot. We searched PubM ed Medline, EMBASE, and the Cochrane Library databases from January 1950 to October 2011. Meta-analyses were performed on outcomes from 12 studies. Pooled means, SDs, and sample sizes were either identified in the results or calculated based on the results of each study.RESULTS: Overall, 835 treated idiopathic clubfeet in 516 patients were reviewed. The average follow-up was 15.7 years. Patients managed with Ponseti method did have a higher rate of excellent or good outcome than patients treated with open surgery(0.76 and 0.62, respectively), but not quite to the point of statistical significance(Q = 3.73, P = 0.053). Age at surgery wasnot correlated with the functional outcome for the surgically treated patients(r =-0.32, P = 0.68). A larger anteroposterior talocalcaneal angle was correlated with a higher rate of excellent or good outcomes(r = 0.80, P = 0.006). There were no other significant correlations between the functional and radiographic outcomes.CONCLUSION: The Ponseti method should be considered the initial treatment of idiopathic clubfeet, and open surgery should be reserved for clubfeet that cannot be completely corrected.展开更多
Natural gas hydrate(NGH),considered as a type of premium energy alternative to conventional hydrocarbons,has been broadly studied.The estimate of the total NGH resources in the world has decreased by more than 90%sinc...Natural gas hydrate(NGH),considered as a type of premium energy alternative to conventional hydrocarbons,has been broadly studied.The estimate of the total NGH resources in the world has decreased by more than 90%since the first evaluation in 1973.Geographic and geophysical conditions of the South China Sea(SCS)are favorable for the formation of NGH,which has been proved by drilling results up to date.The recoverability of the NGH in the SCS has been confirmed by the production tests using both vertical and horizontal wells.Since 2001,35 estimates of NGH resources in the SCS have been made,with relatively stable results varying between 600 and 900×109 ton oil equivalent.In these estimations,the volumetric method was commonly adopted,but the geological conditions,the migration-accumulation mechanisms of NGH,and the practical recoverability were not considered.These estimates cannot be regarded as evaluated resources according to the international resource evaluation standards,but are at most about prospective gas content of NGH,thus inefficient for guiding explorations and developments.To solve these problems,this study divides the past NGH surveys in the SCS into seven stages,acquires key geological parameters of every stage based on previous studies and analogy with other areas,evaluates the NGH resources of these seven stages by using the volumetric method,then adopts a new trend-analysis method to simulate the downward trend of these estimates,and finally predicts the NGH resources in the SCS at 2025 and 2030.The downward trend is because of the continuous improvement of NGH understanding over time,which is consistent with the trend of global NGH estimates.At the present stage(from 2019 to 2021),the average technically recoverable resource(ATRR)is 7.0×10^(12)m^(3),and the estimates of 2025 and 2030 ATRR are 6.46×10^(12)m^(3) and 4.01×10^(12)m^(3)respectively,with a difference of less than 40%.Therefore,it can be inferred that the ATRR of NGH in the SCS is between 4.0 and 6.5×10^(12)m^(3),with an average of 5.25×10^(12)m^(3).展开更多
OBJECTIVE： To evaluate the effectiveness and safety of the Xingnao Kaiqiao needling method for treating acute ischemic stroke.DATA SOURCES： We retrieved relevant randomized controlled trials involving Xingnao Kaiqia...OBJECTIVE： To evaluate the effectiveness and safety of the Xingnao Kaiqiao needling method for treating acute ischemic stroke.DATA SOURCES： We retrieved relevant randomized controlled trials involving Xingnao Kaiqiao acupuncture for treatment of acute ischemic stroke. The China National Knowledge Infrastructure, Weipu Information Resources System, Wanfang Medical Data System, Chinese Biomedical Literature Database, Cochrane Library, and Pub Med were searched from June 2006 to March 2016.DATA SELECTION： We analyzed randomized and semi-randomized clinical controlled trials that compared Xingnao Kaiqiao acupuncture with various control treatments, such as conventional drugs or other acupuncture therapies, for treatment of acute ischemic stroke. The quality of articles was evaluated according to the Cochrane Handbook for Systematic Reviews of Interventions（Version 5.1）, and the study was carried out using Cochrane system assessment methods. Rev Man 5.2 was used for the meta-analysis of the included studies.OUTCOME MEASURES： The mortality rate, disability rate, activities of daily living（Barthel Index）, and clinical efficacy were observed.RESULTS： Twelve studies met the inclusion criteria for this review. The meta-analysis showed that between Xingnao Kaiqiao acupuncture and the control treatment, Xingnao Kaiqiao acupuncture reduced the disability rate [risk ratio（RR） = 0.51, 95% confidence interval（CI） = 0.27-0.98, z = 2.03, P 〈 0.05], elevated the activities of daily living（weighted mean difference = 12.23, 95% CI： 3.66-20.08, z = 2.80, P 〈 0.005）, and had greater clinical efficacy（RR = 1.61, 95% CI： 1.23-2.09, z = 3.53, P 〈 0.0004）. However, there was no significant difference in mortality rate（RR = 0.61, 95% CI： 0.15-2.45, z = 0.70, P 〉 0.05）. CONCLUSION： The Xingnao Kaiqiao needling method is effective and safe for acute ischemic stroke. However, there was selective bias in this study, and the likelihood of measurement bias is high. Thus, more high-quality randomized controlled trials are needed to provide reliable evidence of the efficacy and safety of Xingnao Kaiqiao acupuncture in the treatment of acute ischemic stroke.展开更多
Line profile analysis of X-ray and neutron diffraction patterns is a powerful tool for determining the microstructure of crystalline materials. The Convolutional-Multiple-Whole-Profile (CMWP) procedure is based on phy...Line profile analysis of X-ray and neutron diffraction patterns is a powerful tool for determining the microstructure of crystalline materials. The Convolutional-Multiple-Whole-Profile (CMWP) procedure is based on physical profile functions for dislocations, domain size, stacking faults and twin boundaries. Order dependence, strain anisotropy, hkl dependent broadening of planar defects and peak shape are used to separate the effect of different lattice defect types. The Marquardt-Levenberg (ML) numerical optimiza-tion procedure has been used successfully to determine crystal defect types and densities. However, in more complex cases like hexagonal materials or multiple phases the ML procedure alone reveals uncer-tainties. In a new approach the ML and a Monte-Carlo statistical method are combined in an alternative manner. The new CMWP procedure eliminates uncertainties and provides globally optimized parameters.展开更多
To analyze the differences in the transport and distribution of different types of proppants and to address issues such as the short effective support of proppant and poor placement in hydraulically intersecting fract...To analyze the differences in the transport and distribution of different types of proppants and to address issues such as the short effective support of proppant and poor placement in hydraulically intersecting fractures,this study considered the combined impact of geological-engineering factors on conductivity.Using reservoir production parameters and the discrete elementmethod,multispherical proppants were constructed.Additionally,a 3D fracture model,based on the specified conditions of the L block,employed coupled(Computational Fluid Dynamics)CFD-DEM(Discrete ElementMethod)for joint simulations to quantitatively analyze the transport and placement patterns of multispherical proppants in intersecting fractures.Results indicate that turbulent kinetic energy is an intrinsic factor affecting proppant transport.Moreover,the efficiency of placement and migration distance of low-sphericity quartz sand constructed by the DEM in the main fracture are significantly reduced compared to spherical ceramic proppants,with a 27.7%decrease in the volume fraction of the fracture surface,subsequently affecting the placement concentration and damaging fracture conductivity.Compared to small-angle fractures,controlling artificial and natural fractures to expand at angles of 45°to 60°increases the effective support length by approximately 20.6%.During hydraulic fracturing of gas wells,ensuring the fracture support area and post-closure conductivity can be achieved by controlling the sphericity of proppants and adjusting the perforation direction to control the direction of artificial fractures.展开更多
Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters accordi...Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.展开更多
This study investigated the physicochemical properties,enzyme activities,volatile flavor components,microbial communities,and sensory evaluation of high-temperature Daqu(HTD)during the maturation process,and a standar...This study investigated the physicochemical properties,enzyme activities,volatile flavor components,microbial communities,and sensory evaluation of high-temperature Daqu(HTD)during the maturation process,and a standard system was established for comprehensive quality evaluation of HTD.There were obvious changes in the physicochemical properties,enzyme activities,and volatile flavor components at different storage periods,which affected the sensory evaluation of HTD to a certain extent.The results of high-throughput sequencing revealed significant microbial diversity,and showed that the bacterial community changed significantly more than did the fungal community.During the storage process,the dominant bacterial genera were Kroppenstedtia and Thermoascus.The correlation between dominant microorganisms and quality indicators highlighted their role in HTD quality.Lactococcus,Candida,Pichia,Paecilomyces,and protease activity played a crucial role in the formation of isovaleraldehyde.Acidic protease activity had the greatest impact on the microbial community.Moisture promoted isobutyric acid generation.Furthermore,the comprehensive quality evaluation standard system was established by the entropy weight method combined with multi-factor fuzzy mathematics.Consequently,this study provides innovative insights for comprehensive quality evaluation of HTD during storage and establishes a groundwork for scientific and rational storage of HTD and quality control of sauce-flavor Baijiu.展开更多
Due to the heterogeneity of rock masses and the variability of in situ stress,the traditional linear inversion method is insufficiently accurate to achieve high accuracy of the in situ stress field.To address this cha...Due to the heterogeneity of rock masses and the variability of in situ stress,the traditional linear inversion method is insufficiently accurate to achieve high accuracy of the in situ stress field.To address this challenge,nonlinear stress boundaries for a numerical model are determined through regression analysis of a series of nonlinear coefficient matrices,which are derived from the bubbling method.Considering the randomness and flexibility of the bubbling method,a parametric study is conducted to determine recommended ranges for these parameters,including the standard deviation(σb)of bubble radii,the non-uniform coefficient matrix number(λ)for nonlinear stress boundaries,and the number(m)and positions of in situ stress measurement points.A model case study provides a reference for the selection of these parameters.Additionally,when the nonlinear in situ stress inversion method is employed,stress distortion inevitably occurs near model boundaries,aligning with the Saint Venant's principle.Two strategies are proposed accordingly:employing a systematic reduction of nonlinear coefficients to achieve high inversion accuracy while minimizing significant stress distortion,and excluding regions with severe stress distortion near the model edges while utilizing the central part of the model for subsequent simulations.These two strategies have been successfully implemented in the nonlinear in situ stress inversion of the Xincheng Gold Mine and have achieved higher inversion accuracy than the linear method.Specifically,the linear and nonlinear inversion methods yield root mean square errors(RMSE)of 4.15 and 3.2,and inversion relative errors(δAve)of 22.08%and 17.55%,respectively.Therefore,the nonlinear inversion method outperforms the traditional multiple linear regression method,even in the presence of a systematic reduction in the nonlinear stress boundaries.展开更多
Objective:Skill competence is essential for nursing students and experiential teaching method has become increasingly popular in China’s nursing education.To systematically evaluate the effects of experiential teachi...Objective:Skill competence is essential for nursing students and experiential teaching method has become increasingly popular in China’s nursing education.To systematically evaluate the effects of experiential teaching method on the development of nursing students’skill competence,and to provide evidence for nursing education.Methods:The China National Knowledge Infrastructure,VIP,Wanfang Data,PubMed,and Web of Science databases were searched from their inception until November 28,2019.We screened the studies according to inclusion and exclusion criteria,extracted the data,and assessed the quality.Then,a meta-analysis was conducted.Results:Totally 15 studies were included,and 1,633 nursing students were analyzed by Review Manager5.3 and Stata15.1 software.The results show that the experiential teaching method can significantly improve nursing students’nursing skills such as training(SMD=1.05,95%CI:0.95–1.16,P=0.000),learning interest(ES=0.93,95%CI:0.79–1.06),ability to analyze and solve problems(ES=0.75,95%CI:0.55–0.94),ability to judge and innovative thinking(ES=1.01,95%CI:0.77–1.25),abilities of understanding and perception(ES=0.59,95%CI:0.34–0.83),and teaching satisfaction(ES=1.26,95%CI:1.13–1.4).Conclusions:The results suggest that the experiential teaching method is more effective for the nursing students’skill competence than traditional teaching in China.However,due to the heterogeneity and bias risk,a large sample and high-quality studies are needed in future to confirm its effectiveness.展开更多
The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytica...The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytical solutions for free vibration and eigenbuckling of rectangular plates and circular cylindrical shells.By taking the free vibration of rectangular thin plates as an example,this work presents the theoretical framework of the SOV methods in an instructive way,and the bisection–based solution procedures for a group of nonlinear eigenvalue equations.Besides,the explicit equations of nodal lines of the SOV methods are presented,and the relations of nodal line patterns and frequency orders are investigated.It is concluded that the highly accurate SOV methods have the same accuracy for all frequencies,the mode shapes about repeated frequencies can also be precisely captured,and the SOV methods do not have the problem of missing roots as well.展开更多
Objective:This article uses a meta-analysis system to evaluate the clinical efficacy of the method of spleen-invigorating,kidney-tonifying and blood-activating combined with western medicine in the treatment of diabet...Objective:This article uses a meta-analysis system to evaluate the clinical efficacy of the method of spleen-invigorating,kidney-tonifying and blood-activating combined with western medicine in the treatment of diabetic nephropathy,in order to provide evidence-based medicine for the clinical treatment of this disease.Methods:Computer search(January 2009 to June 2020)published in CNKI,Wanfang database,and Weipu Chinese Science and Technology Journal Database with simple western medicine conventional treatment(control group)and on the basis of control group Randomized Controlled Trial(RCT)of the treatment of diabetic nephropathy with spleen-invigorating,kidney-tonifying and blood-activating(experimental group),and manual retrieval of relevant literature that meets the inclusion criteria.Two researchers independently carried out literature screening,and used the improved Jadad rating scale for quality evaluation,and finally used RevMan5.3 statistical software for meta-analysis.Results:A total of 15 randomized controlled trials were included,with a total of 1218 patients,including 621 in the experimental group and 597 in the control group.Meta-analysis showed that the experimental group was improving clinical efficacy(OR=4.35,95%CI[3.12,6.08],P<0.00001),FPG(MD=-0.49,95%CI[-0.89,-0.09],P=0.02),24h urine protein quantification(MD=-0.54,95%CI[-0.90,-0.18],P=0.003),mALB(MD=-15.95,95%CI[-18.12,-13.79],P<0.0001),BUN(MD=-1.79,95%CI[-2.99,-0.59],P=0.004),SCr(MD=-47.63,95%CI[-83.43,-11.83],P=0.009),TC(MD=-1.02,95%CI[-1.42,-0.62],P<0.00001),etc.may be better than the control group;The test group is improving TG(MD=-1.02,95%CI[-1.42,-0.62],P<0.00001)there is no significant difference compared with the control group.Conclusion:The method of spleen-invigorating,kidney-tonifying and blood-activating combined with conventional western medicine treatment of diabetic nephropathy may be superior to conventional western medicine treatment in terms of improving clinical efficacy,FPG,24h urine protein quantification,mALB,BUN,SCr,TC,etc.However,due to the small number and low quality of the literature included in this study,more in-depth research needs to further expand the sample size and include higher quality RCTs.展开更多
Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vi...Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vironment and intensify carbon emissions.However,the use of microbially induced calcium carbonate pre-cipitation(MICP)to obtain bio-cement is a novel technique with the potential to induce soil stability,providing a low-carbon,environment-friendly,and sustainable integrated solution for some geotechnical engineering pro-blems in the environment.This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy.It systematically summarizes and overviews the mineralization mechanism,influ-encing factors,improved methods,engineering characteristics,and current field application status of the MICP.Additionally,it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement.This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand.Furthermore,we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future.The current review purports to provide insights for engineers and interdisciplinary researchers,and guidance for future engineering applications.展开更多
Bearing is an indispensable key component in mechanical equipment,and its working state is directly related to the stability and safety of the whole equipment.In recent years,with the rapid development of artificial i...Bearing is an indispensable key component in mechanical equipment,and its working state is directly related to the stability and safety of the whole equipment.In recent years,with the rapid development of artificial intelligence technology,especially the breakthrough of deep learning technology,it provides a new idea for bearing fault diagnosis.Deep learning can automatically learn features from a large amount of data,has a strong nonlinear modeling ability,and can effectively solve the problems existing in traditional methods.Aiming at the key problems in bearing fault diagnosis,this paper studies the fault diagnosis method based on deep learning,which not only provides a new solution for bearing fault diagnosis but also provides a reference for the application of deep learning in other mechanical fault diagnosis fields.展开更多
To quantify the seismic resilience of buildings,a method for evaluating functional loss from the component level to the overall building is proposed,and the dual-parameter seismic resilience assessment method based on...To quantify the seismic resilience of buildings,a method for evaluating functional loss from the component level to the overall building is proposed,and the dual-parameter seismic resilience assessment method based on postearthquake loss and recovery time is improved.A threelevel function tree model is established,which can consider the dynamic changes in weight coefficients of different category of components relative to their functional losses.Bayesian networks are utilized to quantify the impact of weather conditions,construction technology levels,and worker skill levels on component repair time.A method for determining the real-time functional recovery curve of buildings based on the component repair process is proposed.Taking a three-story teaching building as an example,the seismic resilience indices under basic earthquakes and rare earthquakes are calculated.The results show that the seismic resilience grade of the teaching building is comprehensively judged as GradeⅢ,and its resilience grade is more significantly affected by postearthquake loss.The proposed method can be used to predict the seismic resilience of buildings prior to earthquakes,identify weak components within buildings,and provide guidance for taking measures to enhance the seismic resilience of buildings.展开更多
Ocean energy has progressively gained considerable interest due to its sufficient potential to meet the world’s energy demand,and the blade is the core component in electricity generation from the ocean current.Howev...Ocean energy has progressively gained considerable interest due to its sufficient potential to meet the world’s energy demand,and the blade is the core component in electricity generation from the ocean current.However,the widened hydraulic excitation frequency may satisfy the blade resonance due to the time variation in the velocity and angle of attack of the ocean current,even resulting in blade fatigue and destructively interfering with grid stability.A key parameter that determines the resonance amplitude of the blade is the hydrodynamic damping ratio(HDR).However,HDR is difficult to obtain due to the complex fluid-structure interaction(FSI).Therefore,a literature review was conducted on the hydrodynamic damping characteristics of blade-like structures.The experimental and simulation methods used to identify and obtain the HDR quantitatively were described,placing emphasis on the experimental processes and simulation setups.Moreover,the accuracy and efficiency of different simulation methods were compared,and the modal work approach was recommended.The effects of key typical parameters,including flow velocity,angle of attack,gap,rotational speed,and cavitation,on the HDR were then summarized,and the suggestions on operating conditions were presented from the perspective of increasing the HDR.Subsequently,considering multiple flow parameters,several theoretical derivations and semi-empirical prediction formulas for HDR were introduced,and the accuracy and application were discussed.Based on the shortcomings of the existing research,the direction of future research was finally determined.The current work offers a clear understanding of the HDR of blade-like structures,which could improve the evaluation accuracy of flow-induced vibration in the design stage.展开更多
The self-assembled nanoparticles(SAN)formed during the decoction process of traditional Chinese medicine(TCM)exhibit non-uniform particle sizes and a tendency for aggregation.Our group found that the p H-driven method...The self-assembled nanoparticles(SAN)formed during the decoction process of traditional Chinese medicine(TCM)exhibit non-uniform particle sizes and a tendency for aggregation.Our group found that the p H-driven method can improve the self-assembly phenomenon of Herpetospermum caudigerum Wall.,and the SAN exhibited uniform particle size and demonstrated good stability.In this paper,we analyzed the interactions between the main active compound,herpetrione(Her),and its main carrier,Herpetospermum caudigerum Wall.polysaccharide(HCWP),along with their self-assembly mechanisms under different p H values.The binding constants of Her and HCWP increase with rising p H,leading to the formation of Her-HCWP SAN with a smaller particle size,higher zeta potential,and improved thermal stability.While the contributions of hydrogen bonding and electrostatic attraction to the formation of Her-HCWP SAN increase with rising p H,the hydrophobic force consistently plays a dominant role.This study enhances our scientific understanding of the self-assembly phenomenon of TCM improved by p H driven method.展开更多
Observatories typically deploy all-sky cameras for monitoring cloud cover and weather conditions.However,many of these cameras lack scientific-grade sensors,r.esulting in limited photometric precision,which makes calc...Observatories typically deploy all-sky cameras for monitoring cloud cover and weather conditions.However,many of these cameras lack scientific-grade sensors,r.esulting in limited photometric precision,which makes calculating the sky area visibility distribution via extinction measurement challenging.To address this issue,we propose the Photometry-Free Sky Area Visibility Estimation(PFSAVE)method.This method uses the standard magnitude of the faintest star observed within a given sky area to estimate visibility.By employing a pertransformation refitting optimization strategy,we achieve a high-precision coordinate transformation model with an accuracy of 0.42 pixels.Using the results of HEALPix segmentation is also introduced to achieve high spatial resolution.Comprehensive analysis based on real allsky images demonstrates that our method exhibits higher accuracy than the extinction-based method.Our method supports both manual and robotic dynamic scheduling,especially under partially cloudy conditions.展开更多
This study aims to develop a chloride diffusion simulation method that considers the hydration microstructure and pore solution properties during the hydration of tricalcium silicate(C3S).The method combines the hydra...This study aims to develop a chloride diffusion simulation method that considers the hydration microstructure and pore solution properties during the hydration of tricalcium silicate(C3S).The method combines the hydration simulation,thermodynamic calculation,and finite element analysis to examine the effects of pore solution,including effect of electrochemical potential,effect of chemical activity,and effect of mechanical interactions between ions,on the chloride effective diffusion coefficient of hydrated C3S paste.The results indicate that the effect of electrochemical potential on chloride diffusion becomes stronger with increasing hydration age due to the increase in the content of hydrated calcium silicate;as the hydration age increases,the effect of chemical activity on chloride diffusion weakens when the number of diffusible elements decreases;the effect of mechanical interactions between ions on chloride diffusion decreases with the increase of hydration age.展开更多
文摘BACKGROUND Non variceal upper gastrointestinal bleeding(NVUGIB)is a life-threatening condition requiring prompt and effective hemostasis.Various endoscopic inter-ventions,including novel hemostatic powders(HP),over-the-scope clips(OTSC),and traditional approaches,have been employed to manage upper gastroin-testinal bleeding(UGIB).Despite advancements,comparative efficacy and safety of these modalities remain uncertain.AIM To evaluate the efficacy and safety of novel hemostatic interventions compared to conventional endoscopic techniques for managing UGIB.METHODS Cochrane,MEDLINE,PubMed and Scopus libraries were searched for rando-mized controlled trials(RCTs)published up to October 2024.Only RCTs compa-ring novel interventions,such as HP or OTSC,with conventional endoscopic treatments computed tomography(CT)were included.The primary outcome was the 30-day rebleeding rate.Secondary outcomes included initial hemostasis,short-term rebleeding rates,need for salvage therapy(surgical/angiographic),30-day all-cause mortality,and bleeding-related mortality.We performed pairwise and network meta-analyses for all treatments.RESULTS Seventeen studies were included in this analysis.Regarding the 30-day rebleeding rate,OTSC and HP showed superior efficacy compared with CT[OTSC vs CT:Relative risk(RR):0.47,95%confidence interval(CI):0.33-0.65;HP vs CT:RR:0.73,95%CI:0.45-1.13],while OTSC and HP had comparable efficacy(RR:0.56,95%CI:0.30-1.05).OTSC ranked the highest in the network ranking estimate for this outcome.For the secondary outcomes,OTSC demonstrated superior efficacy for the short-term rebleeding rate(OTSC vs CT:RR:0.35,95%CI:0.14-0.74;HP vs CT:RR:0.62,95%CI:0.28-1.35;OTSC vs HP:RR:0.59,95%CI:0.17-1.67).Regarding the initial hemostasis rate,OTSC was slightly more effective than CT(OTSC vs CT:RR:1.20,95%CI:1.06-1.57)and comparable to HP(OTSC vs HP:RR:1.08,95%CI:0.89-1.40).There were no significant differences among treatments for all-cause mortality,bleeding-related mortality,or the necessity of surgical or angiographic salvage therapy.OTSC consistently ranked highest across most outcomes in the network ranking estimate.
文摘AIM: To compare the functional outcomes of patients who underwent open surgery vs Ponseti method for the management of idiopathic clubfoot and to determine whether correlations exist between functional outcome and radiographic measurements.METHODS: A meta-analysis of the literature was conducted for studies concerning primary treatment of patients with idiopathic clubfoot. We searched PubM ed Medline, EMBASE, and the Cochrane Library databases from January 1950 to October 2011. Meta-analyses were performed on outcomes from 12 studies. Pooled means, SDs, and sample sizes were either identified in the results or calculated based on the results of each study.RESULTS: Overall, 835 treated idiopathic clubfeet in 516 patients were reviewed. The average follow-up was 15.7 years. Patients managed with Ponseti method did have a higher rate of excellent or good outcome than patients treated with open surgery(0.76 and 0.62, respectively), but not quite to the point of statistical significance(Q = 3.73, P = 0.053). Age at surgery wasnot correlated with the functional outcome for the surgically treated patients(r =-0.32, P = 0.68). A larger anteroposterior talocalcaneal angle was correlated with a higher rate of excellent or good outcomes(r = 0.80, P = 0.006). There were no other significant correlations between the functional and radiographic outcomes.CONCLUSION: The Ponseti method should be considered the initial treatment of idiopathic clubfeet, and open surgery should be reserved for clubfeet that cannot be completely corrected.
基金financially supported by the CAS consultation project“South China Sea Oil and Gas Comprehensive Development Strategy”(2019-ZW11-Z-035)the National Basic Research Program of China(973 Program)(2006CB202300,2011CB201100)the National High-Tech R&D Program of China(863 Program)(2013AA092600)。
文摘Natural gas hydrate(NGH),considered as a type of premium energy alternative to conventional hydrocarbons,has been broadly studied.The estimate of the total NGH resources in the world has decreased by more than 90%since the first evaluation in 1973.Geographic and geophysical conditions of the South China Sea(SCS)are favorable for the formation of NGH,which has been proved by drilling results up to date.The recoverability of the NGH in the SCS has been confirmed by the production tests using both vertical and horizontal wells.Since 2001,35 estimates of NGH resources in the SCS have been made,with relatively stable results varying between 600 and 900×109 ton oil equivalent.In these estimations,the volumetric method was commonly adopted,but the geological conditions,the migration-accumulation mechanisms of NGH,and the practical recoverability were not considered.These estimates cannot be regarded as evaluated resources according to the international resource evaluation standards,but are at most about prospective gas content of NGH,thus inefficient for guiding explorations and developments.To solve these problems,this study divides the past NGH surveys in the SCS into seven stages,acquires key geological parameters of every stage based on previous studies and analogy with other areas,evaluates the NGH resources of these seven stages by using the volumetric method,then adopts a new trend-analysis method to simulate the downward trend of these estimates,and finally predicts the NGH resources in the SCS at 2025 and 2030.The downward trend is because of the continuous improvement of NGH understanding over time,which is consistent with the trend of global NGH estimates.At the present stage(from 2019 to 2021),the average technically recoverable resource(ATRR)is 7.0×10^(12)m^(3),and the estimates of 2025 and 2030 ATRR are 6.46×10^(12)m^(3) and 4.01×10^(12)m^(3)respectively,with a difference of less than 40%.Therefore,it can be inferred that the ATRR of NGH in the SCS is between 4.0 and 6.5×10^(12)m^(3),with an average of 5.25×10^(12)m^(3).
基金supported by the Support Program(Ⅱ)of Hundreds of Universities Outstanding Innovative Talents in Hebei Province of China,No.BR2-104
文摘OBJECTIVE： To evaluate the effectiveness and safety of the Xingnao Kaiqiao needling method for treating acute ischemic stroke.DATA SOURCES： We retrieved relevant randomized controlled trials involving Xingnao Kaiqiao acupuncture for treatment of acute ischemic stroke. The China National Knowledge Infrastructure, Weipu Information Resources System, Wanfang Medical Data System, Chinese Biomedical Literature Database, Cochrane Library, and Pub Med were searched from June 2006 to March 2016.DATA SELECTION： We analyzed randomized and semi-randomized clinical controlled trials that compared Xingnao Kaiqiao acupuncture with various control treatments, such as conventional drugs or other acupuncture therapies, for treatment of acute ischemic stroke. The quality of articles was evaluated according to the Cochrane Handbook for Systematic Reviews of Interventions（Version 5.1）, and the study was carried out using Cochrane system assessment methods. Rev Man 5.2 was used for the meta-analysis of the included studies.OUTCOME MEASURES： The mortality rate, disability rate, activities of daily living（Barthel Index）, and clinical efficacy were observed.RESULTS： Twelve studies met the inclusion criteria for this review. The meta-analysis showed that between Xingnao Kaiqiao acupuncture and the control treatment, Xingnao Kaiqiao acupuncture reduced the disability rate [risk ratio（RR） = 0.51, 95% confidence interval（CI） = 0.27-0.98, z = 2.03, P 〈 0.05], elevated the activities of daily living（weighted mean difference = 12.23, 95% CI： 3.66-20.08, z = 2.80, P 〈 0.005）, and had greater clinical efficacy（RR = 1.61, 95% CI： 1.23-2.09, z = 3.53, P 〈 0.0004）. However, there was no significant difference in mortality rate（RR = 0.61, 95% CI： 0.15-2.45, z = 0.70, P 〉 0.05）. CONCLUSION： The Xingnao Kaiqiao needling method is effective and safe for acute ischemic stroke. However, there was selective bias in this study, and the likelihood of measurement bias is high. Thus, more high-quality randomized controlled trials are needed to provide reliable evidence of the efficacy and safety of Xingnao Kaiqiao acupuncture in the treatment of acute ischemic stroke.
基金support of the János Bolyai Research Fellowship of the Hungarian Academy of Sciences. T.U. is grateful for partial funding of this work by an EPSRC Leadership Fellowship [EP/I005420/1, EP/K039237/1, EP/K034650/1, EP/L018616/1 and EP/K034332/1] for the study of irradiation damage in zirconium alloys
文摘Line profile analysis of X-ray and neutron diffraction patterns is a powerful tool for determining the microstructure of crystalline materials. The Convolutional-Multiple-Whole-Profile (CMWP) procedure is based on physical profile functions for dislocations, domain size, stacking faults and twin boundaries. Order dependence, strain anisotropy, hkl dependent broadening of planar defects and peak shape are used to separate the effect of different lattice defect types. The Marquardt-Levenberg (ML) numerical optimiza-tion procedure has been used successfully to determine crystal defect types and densities. However, in more complex cases like hexagonal materials or multiple phases the ML procedure alone reveals uncer-tainties. In a new approach the ML and a Monte-Carlo statistical method are combined in an alternative manner. The new CMWP procedure eliminates uncertainties and provides globally optimized parameters.
基金funded by the project of the Major Scientific and Technological Projects of CNOOC in the 14th Five-Year Plan(No.KJGG2022-0701)the CNOOC Research Institute(No.2020PFS-03).
文摘To analyze the differences in the transport and distribution of different types of proppants and to address issues such as the short effective support of proppant and poor placement in hydraulically intersecting fractures,this study considered the combined impact of geological-engineering factors on conductivity.Using reservoir production parameters and the discrete elementmethod,multispherical proppants were constructed.Additionally,a 3D fracture model,based on the specified conditions of the L block,employed coupled(Computational Fluid Dynamics)CFD-DEM(Discrete ElementMethod)for joint simulations to quantitatively analyze the transport and placement patterns of multispherical proppants in intersecting fractures.Results indicate that turbulent kinetic energy is an intrinsic factor affecting proppant transport.Moreover,the efficiency of placement and migration distance of low-sphericity quartz sand constructed by the DEM in the main fracture are significantly reduced compared to spherical ceramic proppants,with a 27.7%decrease in the volume fraction of the fracture surface,subsequently affecting the placement concentration and damaging fracture conductivity.Compared to small-angle fractures,controlling artificial and natural fractures to expand at angles of 45°to 60°increases the effective support length by approximately 20.6%.During hydraulic fracturing of gas wells,ensuring the fracture support area and post-closure conductivity can be achieved by controlling the sphericity of proppants and adjusting the perforation direction to control the direction of artificial fractures.
基金supported by the Innovation Foundation of Provincial Education Department of Gansu(2024B-005)the Gansu Province National Science Foundation(22YF7GA182)the Fundamental Research Funds for the Central Universities(No.lzujbky2022-kb01)。
文摘Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.
文摘This study investigated the physicochemical properties,enzyme activities,volatile flavor components,microbial communities,and sensory evaluation of high-temperature Daqu(HTD)during the maturation process,and a standard system was established for comprehensive quality evaluation of HTD.There were obvious changes in the physicochemical properties,enzyme activities,and volatile flavor components at different storage periods,which affected the sensory evaluation of HTD to a certain extent.The results of high-throughput sequencing revealed significant microbial diversity,and showed that the bacterial community changed significantly more than did the fungal community.During the storage process,the dominant bacterial genera were Kroppenstedtia and Thermoascus.The correlation between dominant microorganisms and quality indicators highlighted their role in HTD quality.Lactococcus,Candida,Pichia,Paecilomyces,and protease activity played a crucial role in the formation of isovaleraldehyde.Acidic protease activity had the greatest impact on the microbial community.Moisture promoted isobutyric acid generation.Furthermore,the comprehensive quality evaluation standard system was established by the entropy weight method combined with multi-factor fuzzy mathematics.Consequently,this study provides innovative insights for comprehensive quality evaluation of HTD during storage and establishes a groundwork for scientific and rational storage of HTD and quality control of sauce-flavor Baijiu.
基金funded by the National Key R&D Program of China(Grant No.2022YFC2903904)the National Natural Science Foundation of China(Grant Nos.51904057 and U1906208).
文摘Due to the heterogeneity of rock masses and the variability of in situ stress,the traditional linear inversion method is insufficiently accurate to achieve high accuracy of the in situ stress field.To address this challenge,nonlinear stress boundaries for a numerical model are determined through regression analysis of a series of nonlinear coefficient matrices,which are derived from the bubbling method.Considering the randomness and flexibility of the bubbling method,a parametric study is conducted to determine recommended ranges for these parameters,including the standard deviation(σb)of bubble radii,the non-uniform coefficient matrix number(λ)for nonlinear stress boundaries,and the number(m)and positions of in situ stress measurement points.A model case study provides a reference for the selection of these parameters.Additionally,when the nonlinear in situ stress inversion method is employed,stress distortion inevitably occurs near model boundaries,aligning with the Saint Venant's principle.Two strategies are proposed accordingly:employing a systematic reduction of nonlinear coefficients to achieve high inversion accuracy while minimizing significant stress distortion,and excluding regions with severe stress distortion near the model edges while utilizing the central part of the model for subsequent simulations.These two strategies have been successfully implemented in the nonlinear in situ stress inversion of the Xincheng Gold Mine and have achieved higher inversion accuracy than the linear method.Specifically,the linear and nonlinear inversion methods yield root mean square errors(RMSE)of 4.15 and 3.2,and inversion relative errors(δAve)of 22.08%and 17.55%,respectively.Therefore,the nonlinear inversion method outperforms the traditional multiple linear regression method,even in the presence of a systematic reduction in the nonlinear stress boundaries.
文摘Objective:Skill competence is essential for nursing students and experiential teaching method has become increasingly popular in China’s nursing education.To systematically evaluate the effects of experiential teaching method on the development of nursing students’skill competence,and to provide evidence for nursing education.Methods:The China National Knowledge Infrastructure,VIP,Wanfang Data,PubMed,and Web of Science databases were searched from their inception until November 28,2019.We screened the studies according to inclusion and exclusion criteria,extracted the data,and assessed the quality.Then,a meta-analysis was conducted.Results:Totally 15 studies were included,and 1,633 nursing students were analyzed by Review Manager5.3 and Stata15.1 software.The results show that the experiential teaching method can significantly improve nursing students’nursing skills such as training(SMD=1.05,95%CI:0.95–1.16,P=0.000),learning interest(ES=0.93,95%CI:0.79–1.06),ability to analyze and solve problems(ES=0.75,95%CI:0.55–0.94),ability to judge and innovative thinking(ES=1.01,95%CI:0.77–1.25),abilities of understanding and perception(ES=0.59,95%CI:0.34–0.83),and teaching satisfaction(ES=1.26,95%CI:1.13–1.4).Conclusions:The results suggest that the experiential teaching method is more effective for the nursing students’skill competence than traditional teaching in China.However,due to the heterogeneity and bias risk,a large sample and high-quality studies are needed in future to confirm its effectiveness.
基金supported by the National Natural Science Foundation of China(12172023).
文摘The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytical solutions for free vibration and eigenbuckling of rectangular plates and circular cylindrical shells.By taking the free vibration of rectangular thin plates as an example,this work presents the theoretical framework of the SOV methods in an instructive way,and the bisection–based solution procedures for a group of nonlinear eigenvalue equations.Besides,the explicit equations of nodal lines of the SOV methods are presented,and the relations of nodal line patterns and frequency orders are investigated.It is concluded that the highly accurate SOV methods have the same accuracy for all frequencies,the mode shapes about repeated frequencies can also be precisely captured,and the SOV methods do not have the problem of missing roots as well.
基金The second round of construction project of the National Traditional Chinese Medicine School Inheritance Studio of the State Administration of Traditional Chinese Medicine(Guo TCM Ren Jiao Han[2019]No.62)Scientific Research Project of the Shaanxi Provincial Administration of Traditional Chinese Medicine(No.2019-ZZ-LC006)Shaanxi The construction project of famous traditional Chinese medicine inheritance studio of Provincial Administration of Traditional Chinese Medicine(No.2019017).
文摘Objective:This article uses a meta-analysis system to evaluate the clinical efficacy of the method of spleen-invigorating,kidney-tonifying and blood-activating combined with western medicine in the treatment of diabetic nephropathy,in order to provide evidence-based medicine for the clinical treatment of this disease.Methods:Computer search(January 2009 to June 2020)published in CNKI,Wanfang database,and Weipu Chinese Science and Technology Journal Database with simple western medicine conventional treatment(control group)and on the basis of control group Randomized Controlled Trial(RCT)of the treatment of diabetic nephropathy with spleen-invigorating,kidney-tonifying and blood-activating(experimental group),and manual retrieval of relevant literature that meets the inclusion criteria.Two researchers independently carried out literature screening,and used the improved Jadad rating scale for quality evaluation,and finally used RevMan5.3 statistical software for meta-analysis.Results:A total of 15 randomized controlled trials were included,with a total of 1218 patients,including 621 in the experimental group and 597 in the control group.Meta-analysis showed that the experimental group was improving clinical efficacy(OR=4.35,95%CI[3.12,6.08],P<0.00001),FPG(MD=-0.49,95%CI[-0.89,-0.09],P=0.02),24h urine protein quantification(MD=-0.54,95%CI[-0.90,-0.18],P=0.003),mALB(MD=-15.95,95%CI[-18.12,-13.79],P<0.0001),BUN(MD=-1.79,95%CI[-2.99,-0.59],P=0.004),SCr(MD=-47.63,95%CI[-83.43,-11.83],P=0.009),TC(MD=-1.02,95%CI[-1.42,-0.62],P<0.00001),etc.may be better than the control group;The test group is improving TG(MD=-1.02,95%CI[-1.42,-0.62],P<0.00001)there is no significant difference compared with the control group.Conclusion:The method of spleen-invigorating,kidney-tonifying and blood-activating combined with conventional western medicine treatment of diabetic nephropathy may be superior to conventional western medicine treatment in terms of improving clinical efficacy,FPG,24h urine protein quantification,mALB,BUN,SCr,TC,etc.However,due to the small number and low quality of the literature included in this study,more in-depth research needs to further expand the sample size and include higher quality RCTs.
基金funded by the National Natural Science Foundation of China(No.41962016)the Natural Science Foundation of NingXia(Nos.2023AAC02023,2023A1218,and 2021AAC02006).
文摘Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vironment and intensify carbon emissions.However,the use of microbially induced calcium carbonate pre-cipitation(MICP)to obtain bio-cement is a novel technique with the potential to induce soil stability,providing a low-carbon,environment-friendly,and sustainable integrated solution for some geotechnical engineering pro-blems in the environment.This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy.It systematically summarizes and overviews the mineralization mechanism,influ-encing factors,improved methods,engineering characteristics,and current field application status of the MICP.Additionally,it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement.This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand.Furthermore,we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future.The current review purports to provide insights for engineers and interdisciplinary researchers,and guidance for future engineering applications.
文摘Bearing is an indispensable key component in mechanical equipment,and its working state is directly related to the stability and safety of the whole equipment.In recent years,with the rapid development of artificial intelligence technology,especially the breakthrough of deep learning technology,it provides a new idea for bearing fault diagnosis.Deep learning can automatically learn features from a large amount of data,has a strong nonlinear modeling ability,and can effectively solve the problems existing in traditional methods.Aiming at the key problems in bearing fault diagnosis,this paper studies the fault diagnosis method based on deep learning,which not only provides a new solution for bearing fault diagnosis but also provides a reference for the application of deep learning in other mechanical fault diagnosis fields.
基金The National Key Research and Development Program of China(No.2023YFC3805003)。
文摘To quantify the seismic resilience of buildings,a method for evaluating functional loss from the component level to the overall building is proposed,and the dual-parameter seismic resilience assessment method based on postearthquake loss and recovery time is improved.A threelevel function tree model is established,which can consider the dynamic changes in weight coefficients of different category of components relative to their functional losses.Bayesian networks are utilized to quantify the impact of weather conditions,construction technology levels,and worker skill levels on component repair time.A method for determining the real-time functional recovery curve of buildings based on the component repair process is proposed.Taking a three-story teaching building as an example,the seismic resilience indices under basic earthquakes and rare earthquakes are calculated.The results show that the seismic resilience grade of the teaching building is comprehensively judged as GradeⅢ,and its resilience grade is more significantly affected by postearthquake loss.The proposed method can be used to predict the seismic resilience of buildings prior to earthquakes,identify weak components within buildings,and provide guidance for taking measures to enhance the seismic resilience of buildings.
基金Supported by the National Natural Science Foundation of China(Nos.52222904 and 52309117)China Postdoctoral Science Foundation(Nos.2022TQ0168 and 2023M731895).
文摘Ocean energy has progressively gained considerable interest due to its sufficient potential to meet the world’s energy demand,and the blade is the core component in electricity generation from the ocean current.However,the widened hydraulic excitation frequency may satisfy the blade resonance due to the time variation in the velocity and angle of attack of the ocean current,even resulting in blade fatigue and destructively interfering with grid stability.A key parameter that determines the resonance amplitude of the blade is the hydrodynamic damping ratio(HDR).However,HDR is difficult to obtain due to the complex fluid-structure interaction(FSI).Therefore,a literature review was conducted on the hydrodynamic damping characteristics of blade-like structures.The experimental and simulation methods used to identify and obtain the HDR quantitatively were described,placing emphasis on the experimental processes and simulation setups.Moreover,the accuracy and efficiency of different simulation methods were compared,and the modal work approach was recommended.The effects of key typical parameters,including flow velocity,angle of attack,gap,rotational speed,and cavitation,on the HDR were then summarized,and the suggestions on operating conditions were presented from the perspective of increasing the HDR.Subsequently,considering multiple flow parameters,several theoretical derivations and semi-empirical prediction formulas for HDR were introduced,and the accuracy and application were discussed.Based on the shortcomings of the existing research,the direction of future research was finally determined.The current work offers a clear understanding of the HDR of blade-like structures,which could improve the evaluation accuracy of flow-induced vibration in the design stage.
基金supported by the National Natural Science Foundation of China(Nos.81873092,82174074)。
文摘The self-assembled nanoparticles(SAN)formed during the decoction process of traditional Chinese medicine(TCM)exhibit non-uniform particle sizes and a tendency for aggregation.Our group found that the p H-driven method can improve the self-assembly phenomenon of Herpetospermum caudigerum Wall.,and the SAN exhibited uniform particle size and demonstrated good stability.In this paper,we analyzed the interactions between the main active compound,herpetrione(Her),and its main carrier,Herpetospermum caudigerum Wall.polysaccharide(HCWP),along with their self-assembly mechanisms under different p H values.The binding constants of Her and HCWP increase with rising p H,leading to the formation of Her-HCWP SAN with a smaller particle size,higher zeta potential,and improved thermal stability.While the contributions of hydrogen bonding and electrostatic attraction to the formation of Her-HCWP SAN increase with rising p H,the hydrophobic force consistently plays a dominant role.This study enhances our scientific understanding of the self-assembly phenomenon of TCM improved by p H driven method.
基金supported by Natural Science Foundation of Jilin Province(20210101468JC)Chinese Academy of Sciences and Local Government Cooperation Project(2023SYHZ0027,23SH04)National Natural Science Foundation of China(12273063&12203078)。
文摘Observatories typically deploy all-sky cameras for monitoring cloud cover and weather conditions.However,many of these cameras lack scientific-grade sensors,r.esulting in limited photometric precision,which makes calculating the sky area visibility distribution via extinction measurement challenging.To address this issue,we propose the Photometry-Free Sky Area Visibility Estimation(PFSAVE)method.This method uses the standard magnitude of the faintest star observed within a given sky area to estimate visibility.By employing a pertransformation refitting optimization strategy,we achieve a high-precision coordinate transformation model with an accuracy of 0.42 pixels.Using the results of HEALPix segmentation is also introduced to achieve high spatial resolution.Comprehensive analysis based on real allsky images demonstrates that our method exhibits higher accuracy than the extinction-based method.Our method supports both manual and robotic dynamic scheduling,especially under partially cloudy conditions.
基金Funded by the Natural Science Foundation of Jiangsu Province(No.BK20241529)China Postdoctoral Science Foundation(No.2024M750736)。
文摘This study aims to develop a chloride diffusion simulation method that considers the hydration microstructure and pore solution properties during the hydration of tricalcium silicate(C3S).The method combines the hydration simulation,thermodynamic calculation,and finite element analysis to examine the effects of pore solution,including effect of electrochemical potential,effect of chemical activity,and effect of mechanical interactions between ions,on the chloride effective diffusion coefficient of hydrated C3S paste.The results indicate that the effect of electrochemical potential on chloride diffusion becomes stronger with increasing hydration age due to the increase in the content of hydrated calcium silicate;as the hydration age increases,the effect of chemical activity on chloride diffusion weakens when the number of diffusible elements decreases;the effect of mechanical interactions between ions on chloride diffusion decreases with the increase of hydration age.
