Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar slid...Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar sliding kinematic analysis is significantly influenced by the value assigned to the lateral limit angleγlim.However,the assignment ofγlim is currently used generally based on an empirical criterion.This study aims to propose an approach for determining the value ofγlim in deterministic and probabilistic kinematic planar sliding analysis.A new perspective is presented to reveal thatγlim essentially influences the probability of forming a potential planar sliding block.The procedure to calculate this probability is introduced using the block theory method.It is found that the probability is correlated with the number of discontinuity sets presented in rock masses.Thus,different values ofγlim for rock masses with different sets of discontinuities are recommended in both probabilistic and deterministic planar sliding kinematic analyses;whereas a fixed value ofγlim is commonly assigned to different types of rock masses in traditional method.Finally,an engineering case was used to compare the proposed and traditional kinematic analysis methods.The error rates of the traditional method vary from 45%to 119%,while that of the proposed method ranges between 1%and 17%.Therefore,it is likely that the proposed method is superior to the traditional one.展开更多
Rock shed is an effective protection measure against rockfall.To investigate the influences of falling rock’s shape and impact angle on the impact effect of the cushioned rock shed,a modeling approach for a rock shed...Rock shed is an effective protection measure against rockfall.To investigate the influences of falling rock’s shape and impact angle on the impact effect of the cushioned rock shed,a modeling approach for a rock shed with a cushion layer using PFC-FLAC.The granular cushion is modeled as an aggregate of discrete non-cohesion particles,while the concrete plate and the beam are modeled as zones.The falling rock with different sphericities and impact angles is modeled as a rigid assembly.The numerical model is validated by comparing the simulation results with experimental and numerical results from previous literature.This model is applied to analyze the effects of rock shape and impact angle on the dynamic interaction effects between falling rock and cushioned rock shed,including the impact force,transmitted bottom force,penetration depth,and plate deflection.The numerical results show that the variation in the falling rock’s shape has different effects on the falling rock with different impact angles.These findings could support rock shed design by revealing the limitations of the assumptions in the past research,which may result in unsafe rock sheds for some rockfall cases.展开更多
This study conducted an in-depth analysis of the current tax preferential policies for small-scale individual businesses and compared them with similar policies both domestically and internationally,aiming to reveal t...This study conducted an in-depth analysis of the current tax preferential policies for small-scale individual businesses and compared them with similar policies both domestically and internationally,aiming to reveal the advantages and disadvantages of the current system.After examining the impact of these tax preferential policies on the economic status of individual business owners and the broader social economy,this article proposes a set of innovative tax preferential strategies based on theoretical foundations.By developing these innovative strategies and clarifying their implementation paths,the aim is to promote the sustainable and healthy development of small-scale individual businesses,thereby fostering comprehensive socio-economic progress.The conclusion of this study not only summarizes policy recommendations with practical significance but also provides theoretical support for the optimization and innovation of future related systems.展开更多
BACKGROUND The femoral neck dynamic intersection system(FNS)is mechanically more stable than other internal fixation techniques.Current studies have confirmed that the structural design of FNS has good biomechanical p...BACKGROUND The femoral neck dynamic intersection system(FNS)is mechanically more stable than other internal fixation techniques.Current studies have confirmed that the structural design of FNS has good biomechanical properties in European and American populations.However,whether the suitability of the FNS's 130°main nail angle design for Asian populations has been thoroughly investigated remains unclear.AIM To compare the biomechanical stability differences among different main nail angles of the FNS in the treatment of femoral neck fractures in Asian populations.METHODS Computed tomography data of the femur of healthy adult male volunteers were imported into Mimics software to create a three-dimensional model of the femur.The model was adapted to the curve using Geomagic software and imported into Solidworks software to construct the Pauwels I femoral neck fracture model and design the FNS internal fixation model using different main nail angles.Afterward,the models were assembled with the FNS fracture model and meshed using the preprocessing Hypermesh software.Subsequently,they were imported into Abaqus software to analyze and evaluate the biomechanical effects of different angles of the FNS main nail on the treatment of femoral neck fractures.RESULTS The peak displacement of the proximal femur under different angles of FNS fixation under stress was 7.446 millimeters in the 120°group and 7.416 millimeters in the 125°group;in the 130°,135°,and 140°FNS fixation groups,the peak displacement was 7.324 millimeters,8.138 millimeters,and 8.246 millimeters,respectively.In the 120°and 125°FNS fixation groups,the maximum stresses were concentrated at the main nail and the anti-rotation screw,which intersected the fracture line of the femur neck,resulting in peak stresses of 200.7 MPa and 138.8 MPa,respectively.Peak stresses of 208.8 MPa,219.8 MPa,and 239.3 MPa were observed on the angular locking plate distal to the locking screw in the 130°,135°,and 140°fixation groups.CONCLUSION FNS has significant stress distribution properties,a minimal proximal femoral displacement,and an optimal stability for treating femoral neck fractures in Asian populations when performed with a 130°main nail angle.展开更多
This paper is a generic study of schematic structures and the use of modal verbs of 50 English Research Article (RA) abstracts. With Bhatia's (1990) model as the framework, three other move patterns were obtained...This paper is a generic study of schematic structures and the use of modal verbs of 50 English Research Article (RA) abstracts. With Bhatia's (1990) model as the framework, three other move patterns were obtained besides the normal move order. The density of modal verbs varies greatly from move to move with significant differences in the frequency of occurrence in different moves. The use of modal verbs is much more move-determined than discipline-determined.展开更多
AIM: To compare the efficacy and safety of phacoemulsification(Phaco) against combined phacotrabeculectomy(Phacotrabe) in primary angle-closure glaucoma(PACG) with coexisting cataract.·METHODS: By searchi...AIM: To compare the efficacy and safety of phacoemulsification(Phaco) against combined phacotrabeculectomy(Phacotrabe) in primary angle-closure glaucoma(PACG) with coexisting cataract.·METHODS: By searching electronically the Pub Med,EMBASE, Scientific Citation Index and Cochrane Library published up from inception to January 2014, all randomized controlled trials that matched the predefined criteria were included. The quality of included trials was evaluated according to the guidelines developed by the cochrane collaboration. And the outcomes estimating efficacy and safety of two different surgical treatments were measured and synthesised by Rev Man 5.0.· RESULTS: Five randomized controlled trials were selected and included in Meta-analysis with a total of468 patients(468 eyes) with both PACG and cataract. We found that Phacotrabe had a greater intraocular pressure(IOP) lowing effect [preoperative IOP: weighted mean difference(WMD)=0.58, 95% confidence intervals(95% CI,-0.53 to 1.69), P =0.31; postoperative IOP: WMD =1.37,95% CI(0.45 to 2.28), P =0.003], a lower number of antiglaucoma medications [risk ratio(RR)=0.05, 95% CI(0.02 to 0.18), P 〈0.00001] needed postoperatively and less serious damage of optic nerve [RR =0.48, 95% CI(0.21 to 1.07), P =0.07], but a higher risk of complications[odds ratio(OR)=0.04, 95% CI(0.01 to 0.16), P 〈0.00001]compared with Phaco. The rest studies indicated that there had no significantly difference between the two surgical methods for postoperative best-corrected visual acuity(BCVA) [WMD =-0.05, 95% CI(-0.14 to 0.05), P =0.32] and loss of visual field [RR=1.06, 95% CI(0.61 to1.83), P =0.83].·CONCLUSION: Phaco alone compared with Phacotrabe had a better effect in IOP reduction, whereas the securitydecline. Considering the number of sample size, our results remains to be further studied.展开更多
AIM:To assess the effects of the fixed combination of0.005% latanoprost and 0.5% timolol(FCLT) vs their individual components for primary open angle glaucoma(POAG) and ocular hypertension(OHT).· METHODS:After sea...AIM:To assess the effects of the fixed combination of0.005% latanoprost and 0.5% timolol(FCLT) vs their individual components for primary open angle glaucoma(POAG) and ocular hypertension(OHT).· METHODS:After searched PubMed, EMBASE, the Cochrane Library and SCI, all randomized controlled clinical trials(RCTs) and cross-over studies were included. The control groups were the monotherapy or the concomitant therapy of latanoprost and timolol. The outcomes were visual field defect, optic atrophy, mean intraocular pressure(IOP) and IOP fluctuation. The analysis was carried out in RevMan version 5.1 software.RESULTS:Thepost-interventionmeanIOPofFCLTwas significantly lower compared to timolol [mean difference(MD)-2.92, 95%CI-3.28 to-2.55, P 【0.00001] and latanoprost(MD-1.11, 95%CI-1.51 to-0.72, P 【0.00001). The postintervention IOP fluctuation was also significantly lower compared to timolol(MD-0.88, 95%CI-1.23 to-0.53, P 【0. 00001) and latanoprost( MD- 0. 63, 95 % CI- 1. 04to-0.22, P =0.002). The mean IOP was higher in FCLT morning dose group than the one in unfixed combination of 0.005% latanoprost and 0.5% timolol(UFCLT)(MD1.10, 95% CI 0.81 to 1.39, P 【0.00001). Otherwise, there was no difference between FCLT evening dose group and UFCLT(MD 0.34, 95% CI-0.01 to 0.69, P =0.06).There was no statistical difference for the incidence ofvisual field defect and optic atrophy between FCLT and the monotherapy of components.CONCLUSION:A better IOP lowering effect has been demonstrated for FCLT compared to the monotherapy of components. The IOP lowering effect was worse for FCLT morning dose and almost same for FCLT evening dose compared to the UFCLT. We need more long-term high quality RCTs to demonstrate the outcomes of visual field defect and optic atrophy.visual field defect and optic atrophy between FCLT and the monotherapy of components.CONCLUSION:A better IOP lowering effect has been demonstrated for FCLT compared to the monotherapy of components. The IOP lowering effect was worse for FCLT morning dose and almost same for FCLT evening dose compared to the UFCLT. We need more long-term high quality RCTs to demonstrate the outcomes of visual field defect and optic atrophy.展开更多
Based on the exploration of the engineering geology and the rock mechan-ics testing, limit equilibrium analysis method was adopted to calculate the stability of the Huogeqi Copper Mine slope, the results show that the...Based on the exploration of the engineering geology and the rock mechan-ics testing, limit equilibrium analysis method was adopted to calculate the stability of the Huogeqi Copper Mine slope, the results show that the original slope angle is too con-servative and the slope have the potential of more preferable slope angle. In order to discuss the possibility of slope angle enhancement, sensitivity analysis of parameters related to limit state slope was made. Quantitatively determined angle value of the add-ing and the optimal slope angle was obtained. The study having performed showed that it is not only useful for the safety control of open-pit mine slope but also for the open-pit mine design for the similar geological condition.展开更多
This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW ph...This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW photovoltaic solar panels, a converter, and storage batteries as the proposed sources. The main objective of this study is to conduct a detailed analysis and optimization of a hybrid diesel and renewable energy system to meet the electricity demand of a remote area village of 800 to 1500 inhabitants located in the north of Ngazidja Island in Comoros. The study uses the Hybrid Optimization Model for Electric Renewable (HOMER) Pro to conduct simulations and optimize the analysis using meteorological data from Comoros. The results show that hybrid combination is more profitable in terms of margin on economic cost with a less expensive investment. With a diesel cost of $1/L, an average wind speed of 5.09 m/s and a solar irradiation value of 6.14 kWh/m<sup>2</sup>/day, the system works well with a proportion of renewable energy production of 99.44% with an emission quantity of 1311.407 kg/year. 99.2% of the production comes from renewable sources with an estimated energy surplus of 2,125,344 kWh/year with the cost of electricity (COE) estimated at $0.18/kWh, presenting a cost-effective alternative compared to current market rates. These results present better optimization of the used hybrid energy system, satisfying energy demand and reducing the environmental impact.展开更多
With a long history, the South Silk Road has been and will continue to be an important corridor of economic, political, cultural and religious exchange between Southwest China and Southeast Asia, South Asia, the Middl...With a long history, the South Silk Road has been and will continue to be an important corridor of economic, political, cultural and religious exchange between Southwest China and Southeast Asia, South Asia, the Middle East, West Asia and Europe. The transportation corridor established by the South Silk Road has both important strategic significance and value for China's transportation safety, and the potential to bring huge political and economic benefits to our country. However, all kinds of challenges and threats need to be dealt with in order for it to achieve strategic value and play the role of a transportation corridor, thereby ensuring China's strategic security.展开更多
In this paper, we conduct research on the infl uence of macroeconomic management of the enterprise from the perspective of general analysis of inertial. Enterprise economic management and economic development is the r...In this paper, we conduct research on the infl uence of macroeconomic management of the enterprise from the perspective of general analysis of inertial. Enterprise economic management and economic development is the relationship between the local and global, between enterprises is global economic development, guide and lead the enterprise smooth and orderly economic management; Enterprise economic management is local while the collaboration and auxiliary enterprise economic development. Only under the guidance of holistic view of the enterprise economic development, the enterprise economic management was able to fi nd right direction. Actively explore peopleoriented human resources management system, new measures. People-oriented human resources management of new system, new initiatives, and throughout its intrinsic nature factors to respect, understanding, and give full play to the role of the basic guiding ideology. Our research provides the new paradigm.展开更多
The origin of arcuate islands and deep-sea trenches has been studied for a long time and various interpretations have been proposed. In this paper, some analytical models are put forward from a geometrical viewpoint a...The origin of arcuate islands and deep-sea trenches has been studied for a long time and various interpretations have been proposed. In this paper, some analytical models are put forward from a geometrical viewpoint and then the theoretical dip angles of the underthrusting slabs of circum-Pacific island arcs are computed and compared with those of the Benioff zone. As a result, it is found that the dip angle of the underthrusting slab is one of the main factors determining the curvature of the arcuate structure. The authors consider that this result may contribute to the plate theory.展开更多
The starting point of the social development and the ultimate goal is to improve the quality of people' s life, the sports form, content, structure and function are put forward new demands, the trend of leisure sport...The starting point of the social development and the ultimate goal is to improve the quality of people' s life, the sports form, content, structure and function are put forward new demands, the trend of leisure sports activities become a new research object. This paper adopts the method of literature and logical analysis from the new era of domestic and foreign leisure sports development present situation and tendency of, analyzes current situation and problems of leisure sports China development, put forward the corresponding countermeasures for the healthy development of leisure sports. Chinese sports in the new period is to improve the quality of life and social development goals.展开更多
The move identification of the present study followed the four-move model of V.K.Bhatia who is the representative personage of ESP.It is composed of four moves(1993):Introducing purpose,Describing methodology,Summariz...The move identification of the present study followed the four-move model of V.K.Bhatia who is the representative personage of ESP.It is composed of four moves(1993):Introducing purpose,Describing methodology,Summarizing results and Presenting conclusions.According to the above theory,Principles of the scientific method of sampling suggested by Nwogu(1997:121)as to the selection of journal were adopted in the study—representativity,reputation,accessibility.The focus is the analysis of move structures of abstract sections of them and contrastive studies between Economics and Humanities&Social Sciences of Lanzhou Jiaotong University in different moves of abstract sections.We find there are some similarities and differences between them.In general,the abstracts of Humanities&Social Sciences are more standard than Economics,which suggested English abstract sections of some Economics bachelor’s degree thesis need to be improved.展开更多
Angle-domain common-image gathers(ADCIGs) are the basic data in migration velocity analysis(MVA) and amplitude variation with angle(AVA) analysis. We propose a common-angle gather-generating scheme using Kirchho...Angle-domain common-image gathers(ADCIGs) are the basic data in migration velocity analysis(MVA) and amplitude variation with angle(AVA) analysis. We propose a common-angle gather-generating scheme using Kirchhoff PSDM based on the traveltime gradient field. The scheme includes three major operations:(1) to calculate the traveltime field of the source and the receiver based on the dynamic programming approach;(2) to obtain the refl ection angle according to the traveltime gradient field in the image space; and(3) to generate the ADCIGs during the migration process. Because of the computation approach, the method for generating ADCIGs is superior to conventional ray-based methods. We use the proposed ADCIGs generation method in 3D large-scale seismic data. The key points of the method are the following.(1) We use common-shot datasets for migration,(2) we load traveltimes based on the shot aperture, and(3) we use the MPI and Open Mp memory sharing to decrease the amount of input and output(I/O). Numerical examples using synthetic data suggest that the ADCIGs improve the quality of the velocity and the effectiveness of the 3D angle-gather generation scheme.展开更多
From the mixed variational principle, by the selection of the state variables and its dual variables, the Hamiltonian canonical equation for the dynamic analysis of shear deformable antisymmetric angle-ply laminated p...From the mixed variational principle, by the selection of the state variables and its dual variables, the Hamiltonian canonical equation for the dynamic analysis of shear deformable antisymmetric angle-ply laminated plates is derived, leading to the mathematical frame of symplectic geometry and algorithms, and the exact solution for the arbitrary boundary conditions is also derived by the adjoint orthonormalized symplectic expansion method. Numerical results are presented with the emphasis on the effects of length/thickness ratio, arbitrary boundary conditions, degrees of anisotropy, number of layers, ply-angles and the corrected coefficients of transverse shear.展开更多
The aim of this study was investigate the effects of heat treatment on the contact angle of Chinese fir, and the indicators affecting the change of contact an-gle change. It was determined that the duration of treatme...The aim of this study was investigate the effects of heat treatment on the contact angle of Chinese fir, and the indicators affecting the change of contact an-gle change. It was determined that the duration of treatment had significant effect on the change curves of contact angle of Chinese fir wood due to the change curves of contact angle became more centralized and orderly after the specimens heat treated at 180 ℃. Compared with the untreated wood, the contact angle in-creased from 51&#176; to 124&#176; after 4 h treatment, and hydroxyl absorbance of hy-drophilic functional groups decreased from 2.08 to 1.63, while carbonyl absorbance from 0.92 to 0.62. The surface roughness has not significant influence on the con-tact angle. Heat treatment of the Chinese fir caused surface morphological change, which produced hol owed-out phenomenon. The increased surface contact angle caused by heat treatment can be used for outdoor and sauna facilities.展开更多
AIM: To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma.METHODS: We performed a systematic sear...AIM: To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma.METHODS: We performed a systematic search of the related literature in the Cochrane Library, PubM ed, EMBASE, Web of Science databases, CNKI, CBM and Wan Fang databases, with no limitations on language or publication date. The primary efficacy estimate was identified by weighted mean difference of the percentage of intraocular pressure reduction(IOPR%) from baseline to end-point, the percentage of number of glaucoma medications reduction from pre-to post-operation, and the secondary efficacy evaluations were performed by odds ratio(OR) and 95% confidence interval(CI) for complete and qualified success rate. Besides, ORs were applied to assess the tolerability of adverse incidents. Meta-analyses of fixed or random effect models were performed using Rev Man software 5.2 to gather the consequences. Heterogeneity was evaluated by Chi^2 test and the I^2 measure.RESULTS: Ten studies enrolling 3108 patients were included. The combined consequences indicated that both glaucoma and combined cataract and glaucoma surgery significantly decreased IOP. For deep sclerectomy vs deep sclerectomy plus phacoemulsification and canaloplasty vs phaco-canaloplasty, the differences in IOPR% were not all statistically significant while trabeculotomy was detected to gain a quantitatively greater IOPR% compared with trabeculotomy plus phacoemulsification. Furthermore, there was no statistical significance in the complete and qualified success rate, and the rates of adverse incidents for trabeculotomy vs trabeculotomy plus phacoemulsification.CONCLUSION: Compared with trabeculotomy plus phacoemulsification, trabeculectomy alone is more effective in lowering IOP and the number of glaucoma medications, while the two surgeries can not demonstrate statistical differences in the complete success rate, qualified success rate, or incidence of adverse incidents.展开更多
AIM To determine whether contrast-enhanced ultrasonography(CEUS) as the first-line method is more costeffective in evaluating incidentally discovered focal liver lesions(FLLs) than is computed tomography(CT) and magne...AIM To determine whether contrast-enhanced ultrasonography(CEUS) as the first-line method is more costeffective in evaluating incidentally discovered focal liver lesions(FLLs) than is computed tomography(CT) and magnetic resonance imaging(MRI). METHODS Between 2010 and 2015, our prospective study enrolled 459 patients with incidentally found FLLs. The biological nature of FLLs was assessed by CEUS in all patients. CT or MRI examinations were added in unclear cases. The sensitivity and specificity of CEUS were calculated. The total costs of CEUS examinations and of the added examinations performed in inconclusive cases were calculated. Afterwards, the theoretical expenses for evaluating incidentally discovered FLLs using CT or MRI as the first-line method were calculated. The resultswere compared. RESULTS The total cost of the diagnostic process using CEUS for all enrolled patients with FLLs was 75884 USD. When the expenses for additional CT and MRI examinations performed in inconclusive cases were added, the total cost was 90540 US dollar(USD). If all patients had been examined by CT or MR as the first-line method, the costs would have been 78897 USD or 384235 USD, respectively. The difference between the cost of CT and CEUS was 3013 USD(4%) and that between MRI and CEUS was 308352 USD(406.3%). We correctly described 97.06% of benign or malignant lesions, with 96.99% sensitivity and 97.09% specificity. Positive predictive value was 94.16% and negative predictive value was 98.52%. In cases with 4 and more lesions, malignancy is significantly more frequent and inconclusive findings significantly less frequent(P < 0.001).CONCLUSION While the costs of CEUS and CT in evaluating FLLs are comparable, CEUS examination is far more costeffective in comparison to MRI.展开更多
Seismic data structure characteristics means the waveform character arranged in the time sequence at discrete data points in each 2-D or 3-D seismic trace. Hydrocarbon prediction using seismic data structure character...Seismic data structure characteristics means the waveform character arranged in the time sequence at discrete data points in each 2-D or 3-D seismic trace. Hydrocarbon prediction using seismic data structure characteristics is a new reservoir prediction technique. When the main pay interval is in carbonate fracture and fissure-cavern type reservoirs with very strong inhomogeneity, there are some difficulties with hydrocarbon prediction. Because of the special geological conditions of the eighth zone in the Tahe oil field, we apply seismic data structure characteristics to hydrocarbon prediction for the Ordovician reservoir in this zone. We divide the area oil zone into favorable and unfavorable blocks. Eighteen well locations were proposed in the favorable oil block, drilled, and recovered higher output of oil and gas.展开更多
基金funded by National Natural Science Foundation,China(Grant Nos.41972264 and 42207214)Zhejiang Provincial Natural Science Foundation,China(Grant No.LR22E080002).
文摘Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar sliding kinematic analysis is significantly influenced by the value assigned to the lateral limit angleγlim.However,the assignment ofγlim is currently used generally based on an empirical criterion.This study aims to propose an approach for determining the value ofγlim in deterministic and probabilistic kinematic planar sliding analysis.A new perspective is presented to reveal thatγlim essentially influences the probability of forming a potential planar sliding block.The procedure to calculate this probability is introduced using the block theory method.It is found that the probability is correlated with the number of discontinuity sets presented in rock masses.Thus,different values ofγlim for rock masses with different sets of discontinuities are recommended in both probabilistic and deterministic planar sliding kinematic analyses;whereas a fixed value ofγlim is commonly assigned to different types of rock masses in traditional method.Finally,an engineering case was used to compare the proposed and traditional kinematic analysis methods.The error rates of the traditional method vary from 45%to 119%,while that of the proposed method ranges between 1%and 17%.Therefore,it is likely that the proposed method is superior to the traditional one.
基金supported by the National Natural Science Foundation of China(Grant Nos.41941017 and U1702241).
文摘Rock shed is an effective protection measure against rockfall.To investigate the influences of falling rock’s shape and impact angle on the impact effect of the cushioned rock shed,a modeling approach for a rock shed with a cushion layer using PFC-FLAC.The granular cushion is modeled as an aggregate of discrete non-cohesion particles,while the concrete plate and the beam are modeled as zones.The falling rock with different sphericities and impact angles is modeled as a rigid assembly.The numerical model is validated by comparing the simulation results with experimental and numerical results from previous literature.This model is applied to analyze the effects of rock shape and impact angle on the dynamic interaction effects between falling rock and cushioned rock shed,including the impact force,transmitted bottom force,penetration depth,and plate deflection.The numerical results show that the variation in the falling rock’s shape has different effects on the falling rock with different impact angles.These findings could support rock shed design by revealing the limitations of the assumptions in the past research,which may result in unsafe rock sheds for some rockfall cases.
文摘This study conducted an in-depth analysis of the current tax preferential policies for small-scale individual businesses and compared them with similar policies both domestically and internationally,aiming to reveal the advantages and disadvantages of the current system.After examining the impact of these tax preferential policies on the economic status of individual business owners and the broader social economy,this article proposes a set of innovative tax preferential strategies based on theoretical foundations.By developing these innovative strategies and clarifying their implementation paths,the aim is to promote the sustainable and healthy development of small-scale individual businesses,thereby fostering comprehensive socio-economic progress.The conclusion of this study not only summarizes policy recommendations with practical significance but also provides theoretical support for the optimization and innovation of future related systems.
基金Supported by Tianjin Science and Technology planning Project,No.21JCQNJC01060Key Project of Tianjin Natural Science Foundation,No.22JCZDJC00340National Key Research and Development Project of China,No.2022YFC3601904.
文摘BACKGROUND The femoral neck dynamic intersection system(FNS)is mechanically more stable than other internal fixation techniques.Current studies have confirmed that the structural design of FNS has good biomechanical properties in European and American populations.However,whether the suitability of the FNS's 130°main nail angle design for Asian populations has been thoroughly investigated remains unclear.AIM To compare the biomechanical stability differences among different main nail angles of the FNS in the treatment of femoral neck fractures in Asian populations.METHODS Computed tomography data of the femur of healthy adult male volunteers were imported into Mimics software to create a three-dimensional model of the femur.The model was adapted to the curve using Geomagic software and imported into Solidworks software to construct the Pauwels I femoral neck fracture model and design the FNS internal fixation model using different main nail angles.Afterward,the models were assembled with the FNS fracture model and meshed using the preprocessing Hypermesh software.Subsequently,they were imported into Abaqus software to analyze and evaluate the biomechanical effects of different angles of the FNS main nail on the treatment of femoral neck fractures.RESULTS The peak displacement of the proximal femur under different angles of FNS fixation under stress was 7.446 millimeters in the 120°group and 7.416 millimeters in the 125°group;in the 130°,135°,and 140°FNS fixation groups,the peak displacement was 7.324 millimeters,8.138 millimeters,and 8.246 millimeters,respectively.In the 120°and 125°FNS fixation groups,the maximum stresses were concentrated at the main nail and the anti-rotation screw,which intersected the fracture line of the femur neck,resulting in peak stresses of 200.7 MPa and 138.8 MPa,respectively.Peak stresses of 208.8 MPa,219.8 MPa,and 239.3 MPa were observed on the angular locking plate distal to the locking screw in the 130°,135°,and 140°fixation groups.CONCLUSION FNS has significant stress distribution properties,a minimal proximal femoral displacement,and an optimal stability for treating femoral neck fractures in Asian populations when performed with a 130°main nail angle.
文摘This paper is a generic study of schematic structures and the use of modal verbs of 50 English Research Article (RA) abstracts. With Bhatia's (1990) model as the framework, three other move patterns were obtained besides the normal move order. The density of modal verbs varies greatly from move to move with significant differences in the frequency of occurrence in different moves. The use of modal verbs is much more move-determined than discipline-determined.
文摘AIM: To compare the efficacy and safety of phacoemulsification(Phaco) against combined phacotrabeculectomy(Phacotrabe) in primary angle-closure glaucoma(PACG) with coexisting cataract.·METHODS: By searching electronically the Pub Med,EMBASE, Scientific Citation Index and Cochrane Library published up from inception to January 2014, all randomized controlled trials that matched the predefined criteria were included. The quality of included trials was evaluated according to the guidelines developed by the cochrane collaboration. And the outcomes estimating efficacy and safety of two different surgical treatments were measured and synthesised by Rev Man 5.0.· RESULTS: Five randomized controlled trials were selected and included in Meta-analysis with a total of468 patients(468 eyes) with both PACG and cataract. We found that Phacotrabe had a greater intraocular pressure(IOP) lowing effect [preoperative IOP: weighted mean difference(WMD)=0.58, 95% confidence intervals(95% CI,-0.53 to 1.69), P =0.31; postoperative IOP: WMD =1.37,95% CI(0.45 to 2.28), P =0.003], a lower number of antiglaucoma medications [risk ratio(RR)=0.05, 95% CI(0.02 to 0.18), P 〈0.00001] needed postoperatively and less serious damage of optic nerve [RR =0.48, 95% CI(0.21 to 1.07), P =0.07], but a higher risk of complications[odds ratio(OR)=0.04, 95% CI(0.01 to 0.16), P 〈0.00001]compared with Phaco. The rest studies indicated that there had no significantly difference between the two surgical methods for postoperative best-corrected visual acuity(BCVA) [WMD =-0.05, 95% CI(-0.14 to 0.05), P =0.32] and loss of visual field [RR=1.06, 95% CI(0.61 to1.83), P =0.83].·CONCLUSION: Phaco alone compared with Phacotrabe had a better effect in IOP reduction, whereas the securitydecline. Considering the number of sample size, our results remains to be further studied.
文摘AIM:To assess the effects of the fixed combination of0.005% latanoprost and 0.5% timolol(FCLT) vs their individual components for primary open angle glaucoma(POAG) and ocular hypertension(OHT).· METHODS:After searched PubMed, EMBASE, the Cochrane Library and SCI, all randomized controlled clinical trials(RCTs) and cross-over studies were included. The control groups were the monotherapy or the concomitant therapy of latanoprost and timolol. The outcomes were visual field defect, optic atrophy, mean intraocular pressure(IOP) and IOP fluctuation. The analysis was carried out in RevMan version 5.1 software.RESULTS:Thepost-interventionmeanIOPofFCLTwas significantly lower compared to timolol [mean difference(MD)-2.92, 95%CI-3.28 to-2.55, P 【0.00001] and latanoprost(MD-1.11, 95%CI-1.51 to-0.72, P 【0.00001). The postintervention IOP fluctuation was also significantly lower compared to timolol(MD-0.88, 95%CI-1.23 to-0.53, P 【0. 00001) and latanoprost( MD- 0. 63, 95 % CI- 1. 04to-0.22, P =0.002). The mean IOP was higher in FCLT morning dose group than the one in unfixed combination of 0.005% latanoprost and 0.5% timolol(UFCLT)(MD1.10, 95% CI 0.81 to 1.39, P 【0.00001). Otherwise, there was no difference between FCLT evening dose group and UFCLT(MD 0.34, 95% CI-0.01 to 0.69, P =0.06).There was no statistical difference for the incidence ofvisual field defect and optic atrophy between FCLT and the monotherapy of components.CONCLUSION:A better IOP lowering effect has been demonstrated for FCLT compared to the monotherapy of components. The IOP lowering effect was worse for FCLT morning dose and almost same for FCLT evening dose compared to the UFCLT. We need more long-term high quality RCTs to demonstrate the outcomes of visual field defect and optic atrophy.visual field defect and optic atrophy between FCLT and the monotherapy of components.CONCLUSION:A better IOP lowering effect has been demonstrated for FCLT compared to the monotherapy of components. The IOP lowering effect was worse for FCLT morning dose and almost same for FCLT evening dose compared to the UFCLT. We need more long-term high quality RCTs to demonstrate the outcomes of visual field defect and optic atrophy.
基金Supported by the National Nature Science Foundation of China(50074002)
文摘Based on the exploration of the engineering geology and the rock mechan-ics testing, limit equilibrium analysis method was adopted to calculate the stability of the Huogeqi Copper Mine slope, the results show that the original slope angle is too con-servative and the slope have the potential of more preferable slope angle. In order to discuss the possibility of slope angle enhancement, sensitivity analysis of parameters related to limit state slope was made. Quantitatively determined angle value of the add-ing and the optimal slope angle was obtained. The study having performed showed that it is not only useful for the safety control of open-pit mine slope but also for the open-pit mine design for the similar geological condition.
文摘This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW photovoltaic solar panels, a converter, and storage batteries as the proposed sources. The main objective of this study is to conduct a detailed analysis and optimization of a hybrid diesel and renewable energy system to meet the electricity demand of a remote area village of 800 to 1500 inhabitants located in the north of Ngazidja Island in Comoros. The study uses the Hybrid Optimization Model for Electric Renewable (HOMER) Pro to conduct simulations and optimize the analysis using meteorological data from Comoros. The results show that hybrid combination is more profitable in terms of margin on economic cost with a less expensive investment. With a diesel cost of $1/L, an average wind speed of 5.09 m/s and a solar irradiation value of 6.14 kWh/m<sup>2</sup>/day, the system works well with a proportion of renewable energy production of 99.44% with an emission quantity of 1311.407 kg/year. 99.2% of the production comes from renewable sources with an estimated energy surplus of 2,125,344 kWh/year with the cost of electricity (COE) estimated at $0.18/kWh, presenting a cost-effective alternative compared to current market rates. These results present better optimization of the used hybrid energy system, satisfying energy demand and reducing the environmental impact.
基金The National Social Science Fund,West Project(12XGL013)Sichuan Science and Technology Department,Soft Science Project(20136RW0120)+1 种基金Sichuan Development Research Center of Oil and Gas Project(Sichuan Oil and Gas Science SKB15-02)Southwest Petroleum University,Youth Teacher Academic Project(201499010101)
文摘With a long history, the South Silk Road has been and will continue to be an important corridor of economic, political, cultural and religious exchange between Southwest China and Southeast Asia, South Asia, the Middle East, West Asia and Europe. The transportation corridor established by the South Silk Road has both important strategic significance and value for China's transportation safety, and the potential to bring huge political and economic benefits to our country. However, all kinds of challenges and threats need to be dealt with in order for it to achieve strategic value and play the role of a transportation corridor, thereby ensuring China's strategic security.
文摘In this paper, we conduct research on the infl uence of macroeconomic management of the enterprise from the perspective of general analysis of inertial. Enterprise economic management and economic development is the relationship between the local and global, between enterprises is global economic development, guide and lead the enterprise smooth and orderly economic management; Enterprise economic management is local while the collaboration and auxiliary enterprise economic development. Only under the guidance of holistic view of the enterprise economic development, the enterprise economic management was able to fi nd right direction. Actively explore peopleoriented human resources management system, new measures. People-oriented human resources management of new system, new initiatives, and throughout its intrinsic nature factors to respect, understanding, and give full play to the role of the basic guiding ideology. Our research provides the new paradigm.
文摘The origin of arcuate islands and deep-sea trenches has been studied for a long time and various interpretations have been proposed. In this paper, some analytical models are put forward from a geometrical viewpoint and then the theoretical dip angles of the underthrusting slabs of circum-Pacific island arcs are computed and compared with those of the Benioff zone. As a result, it is found that the dip angle of the underthrusting slab is one of the main factors determining the curvature of the arcuate structure. The authors consider that this result may contribute to the plate theory.
文摘The starting point of the social development and the ultimate goal is to improve the quality of people' s life, the sports form, content, structure and function are put forward new demands, the trend of leisure sports activities become a new research object. This paper adopts the method of literature and logical analysis from the new era of domestic and foreign leisure sports development present situation and tendency of, analyzes current situation and problems of leisure sports China development, put forward the corresponding countermeasures for the healthy development of leisure sports. Chinese sports in the new period is to improve the quality of life and social development goals.
文摘The move identification of the present study followed the four-move model of V.K.Bhatia who is the representative personage of ESP.It is composed of four moves(1993):Introducing purpose,Describing methodology,Summarizing results and Presenting conclusions.According to the above theory,Principles of the scientific method of sampling suggested by Nwogu(1997:121)as to the selection of journal were adopted in the study—representativity,reputation,accessibility.The focus is the analysis of move structures of abstract sections of them and contrastive studies between Economics and Humanities&Social Sciences of Lanzhou Jiaotong University in different moves of abstract sections.We find there are some similarities and differences between them.In general,the abstracts of Humanities&Social Sciences are more standard than Economics,which suggested English abstract sections of some Economics bachelor’s degree thesis need to be improved.
基金funded by the National Basic Research Program of China(973 Program)(No.2011 CB201002)the National Natural Science Foundation of China(No.41374117)the great and special projects(No.2011ZX05003-003,2011ZX05005-005-008 HZ,and 2011ZX05006-002)
文摘Angle-domain common-image gathers(ADCIGs) are the basic data in migration velocity analysis(MVA) and amplitude variation with angle(AVA) analysis. We propose a common-angle gather-generating scheme using Kirchhoff PSDM based on the traveltime gradient field. The scheme includes three major operations:(1) to calculate the traveltime field of the source and the receiver based on the dynamic programming approach;(2) to obtain the refl ection angle according to the traveltime gradient field in the image space; and(3) to generate the ADCIGs during the migration process. Because of the computation approach, the method for generating ADCIGs is superior to conventional ray-based methods. We use the proposed ADCIGs generation method in 3D large-scale seismic data. The key points of the method are the following.(1) We use common-shot datasets for migration,(2) we load traveltimes based on the shot aperture, and(3) we use the MPI and Open Mp memory sharing to decrease the amount of input and output(I/O). Numerical examples using synthetic data suggest that the ADCIGs improve the quality of the velocity and the effectiveness of the 3D angle-gather generation scheme.
文摘From the mixed variational principle, by the selection of the state variables and its dual variables, the Hamiltonian canonical equation for the dynamic analysis of shear deformable antisymmetric angle-ply laminated plates is derived, leading to the mathematical frame of symplectic geometry and algorithms, and the exact solution for the arbitrary boundary conditions is also derived by the adjoint orthonormalized symplectic expansion method. Numerical results are presented with the emphasis on the effects of length/thickness ratio, arbitrary boundary conditions, degrees of anisotropy, number of layers, ply-angles and the corrected coefficients of transverse shear.
基金Supported by Science and Technology Programs of Liangqing District of Nanning City(201304A)Science and Technology Program of Guangxi University(XJZ120270)~~
文摘The aim of this study was investigate the effects of heat treatment on the contact angle of Chinese fir, and the indicators affecting the change of contact an-gle change. It was determined that the duration of treatment had significant effect on the change curves of contact angle of Chinese fir wood due to the change curves of contact angle became more centralized and orderly after the specimens heat treated at 180 ℃. Compared with the untreated wood, the contact angle in-creased from 51&#176; to 124&#176; after 4 h treatment, and hydroxyl absorbance of hy-drophilic functional groups decreased from 2.08 to 1.63, while carbonyl absorbance from 0.92 to 0.62. The surface roughness has not significant influence on the con-tact angle. Heat treatment of the Chinese fir caused surface morphological change, which produced hol owed-out phenomenon. The increased surface contact angle caused by heat treatment can be used for outdoor and sauna facilities.
基金Supported by National Natural Science Foundation of China(No.8170080No.81470609)the Natural Science Foundation of Shandong Province(No.ZR2017MH008)
文摘AIM: To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma.METHODS: We performed a systematic search of the related literature in the Cochrane Library, PubM ed, EMBASE, Web of Science databases, CNKI, CBM and Wan Fang databases, with no limitations on language or publication date. The primary efficacy estimate was identified by weighted mean difference of the percentage of intraocular pressure reduction(IOPR%) from baseline to end-point, the percentage of number of glaucoma medications reduction from pre-to post-operation, and the secondary efficacy evaluations were performed by odds ratio(OR) and 95% confidence interval(CI) for complete and qualified success rate. Besides, ORs were applied to assess the tolerability of adverse incidents. Meta-analyses of fixed or random effect models were performed using Rev Man software 5.2 to gather the consequences. Heterogeneity was evaluated by Chi^2 test and the I^2 measure.RESULTS: Ten studies enrolling 3108 patients were included. The combined consequences indicated that both glaucoma and combined cataract and glaucoma surgery significantly decreased IOP. For deep sclerectomy vs deep sclerectomy plus phacoemulsification and canaloplasty vs phaco-canaloplasty, the differences in IOPR% were not all statistically significant while trabeculotomy was detected to gain a quantitatively greater IOPR% compared with trabeculotomy plus phacoemulsification. Furthermore, there was no statistical significance in the complete and qualified success rate, and the rates of adverse incidents for trabeculotomy vs trabeculotomy plus phacoemulsification.CONCLUSION: Compared with trabeculotomy plus phacoemulsification, trabeculectomy alone is more effective in lowering IOP and the number of glaucoma medications, while the two surgeries can not demonstrate statistical differences in the complete success rate, qualified success rate, or incidence of adverse incidents.
基金Supported by Masaryk University,No.MUNI/A/1083/2015
文摘AIM To determine whether contrast-enhanced ultrasonography(CEUS) as the first-line method is more costeffective in evaluating incidentally discovered focal liver lesions(FLLs) than is computed tomography(CT) and magnetic resonance imaging(MRI). METHODS Between 2010 and 2015, our prospective study enrolled 459 patients with incidentally found FLLs. The biological nature of FLLs was assessed by CEUS in all patients. CT or MRI examinations were added in unclear cases. The sensitivity and specificity of CEUS were calculated. The total costs of CEUS examinations and of the added examinations performed in inconclusive cases were calculated. Afterwards, the theoretical expenses for evaluating incidentally discovered FLLs using CT or MRI as the first-line method were calculated. The resultswere compared. RESULTS The total cost of the diagnostic process using CEUS for all enrolled patients with FLLs was 75884 USD. When the expenses for additional CT and MRI examinations performed in inconclusive cases were added, the total cost was 90540 US dollar(USD). If all patients had been examined by CT or MR as the first-line method, the costs would have been 78897 USD or 384235 USD, respectively. The difference between the cost of CT and CEUS was 3013 USD(4%) and that between MRI and CEUS was 308352 USD(406.3%). We correctly described 97.06% of benign or malignant lesions, with 96.99% sensitivity and 97.09% specificity. Positive predictive value was 94.16% and negative predictive value was 98.52%. In cases with 4 and more lesions, malignancy is significantly more frequent and inconclusive findings significantly less frequent(P < 0.001).CONCLUSION While the costs of CEUS and CT in evaluating FLLs are comparable, CEUS examination is far more costeffective in comparison to MRI.
基金This reservoir research is sponsored by the National 973 Subject Project (No. 2001CB209).
文摘Seismic data structure characteristics means the waveform character arranged in the time sequence at discrete data points in each 2-D or 3-D seismic trace. Hydrocarbon prediction using seismic data structure characteristics is a new reservoir prediction technique. When the main pay interval is in carbonate fracture and fissure-cavern type reservoirs with very strong inhomogeneity, there are some difficulties with hydrocarbon prediction. Because of the special geological conditions of the eighth zone in the Tahe oil field, we apply seismic data structure characteristics to hydrocarbon prediction for the Ordovician reservoir in this zone. We divide the area oil zone into favorable and unfavorable blocks. Eighteen well locations were proposed in the favorable oil block, drilled, and recovered higher output of oil and gas.