In order to compare the impact of thickness of different layers on fatigue lives of different semi-rigid asphalt pavement structures, the mechanical results from finite element models in ABAQUS are incorporated with t...In order to compare the impact of thickness of different layers on fatigue lives of different semi-rigid asphalt pavement structures, the mechanical results from finite element models in ABAQUS are incorporated with the fatigue results from fatigue models in FE-SAFE to calculate the mechanical response and fatigue lives of semi-rigid pavement structures under heavy traffic loads. Then the influences on fatigue lives caused by the changes in the thickness of layers in pavement structures are also evaluated. The numerical simulation results show that the aggregated base and the large stone porous mixture （LSPM） base have better anti-cracking performance than the conventional semi-rigid base. The appropriate thickness range for the aggregated layer in the aggregated base is 15 to 18 cm. The thickness of the LSPM layer in the LSPM base is recommended to be less than 15 cm.展开更多
The stiffness matrix of semi-rigidly connected composite beams considering interface slip was established and the calculation method for elastic seismic response of composite frame was derived.The corresponding calcul...The stiffness matrix of semi-rigidly connected composite beams considering interface slip was established and the calculation method for elastic seismic response of composite frame was derived.The corresponding calculation programs were developed.Introducing the dimensionless quantities that were related to the connector shearing stiffness and the joint rotation stiffness,the influences of interface slip and semi-rigid joint on composite frame were transferred to quantitative parameter analysis,taking account of cross sectional properties,materials and linear stiffness of composite beam synthetically.Based on the calculation programs,free vibration frequencies and seismic responses of semi-rigid joint steel-concrete composite frame considering interface slip were calculated.The influences of interface slip and semi rigid joint on dynamic characteristics and seismic response were analyzed and the seismic design advices were presented.The results show that the interface slip decreases the free vibration frequencies and increase the seismic responses of composite frame.The semi-rigid joint reduces the free vibration frequencies and increases seismic responses of composite frame compared with rigid joint.With the increase of joint rotational stiffness,the elastic seismic responses of composite frame increase firstly and then decrease.The effects are related to the ratio of joint rotation stiffness to linear stiffness of composite beam.展开更多
Objective:To examine differences in outcomes of semi-rigid ureteroscopy(URS)with or without a modified-ureteral-access-sheath(mUAS)to treat large upper ureteral stones.Methods:Patients with single,radio-opaque large u...Objective:To examine differences in outcomes of semi-rigid ureteroscopy(URS)with or without a modified-ureteral-access-sheath(mUAS)to treat large upper ureteral stones.Methods:Patients with single,radio-opaque large upper ureteral stone(≥10 mm)treated using semi-rigid URS between August 2013 and October 2016 were retrospectively evaluated.The stone-free status was determined from Kidney-ureter-bladder(KUB)X-ray films taken on postoperative Day 1 and after 1 month.Results:Of 103 patients meeting inclusion criteria,43(41.75%)and 60(58.25%)were treated with semi-rigid URS with and without mUAS,respectively.The immediate stone-free rate(SFR)for the mUAS group was significantly higher than the non-mUAS group(40[93.0%]vs.46[76.7%];p=0.033).The SFR at 1 month was also high for patients treated using mUAS,but not statistically different from patients not treated with mUAS(41[95.3%]mUAS vs.51[85.0%]non-mUAS;p=0.115).Auxiliary procedure rates were significantly lower for mUAS patients compared to non-mUAS patients(2[4.7%]vs.14[23.3%];p=0.01).There were no significant differences in surgical duration and hospital stays,and the overall complication rates were statistically similar for mUAS patients compared to non-mUAS patients(1[2.3%]vs.3[5.0%];p=0.638).展开更多
Freeze-thaw damage is the most common disease of semi-rigid bases in cold regions, which may greatly affect the dura- bility of roadways. In this study, the compressive strength and frost resistance of four different ...Freeze-thaw damage is the most common disease of semi-rigid bases in cold regions, which may greatly affect the dura- bility of roadways. In this study, the compressive strength and frost resistance of four different types of semi-rigid bases （lime-fly ash-stabilized sand, cement-stabilized sand, lime-fly ash-stabilized gravel, and cement-stabilized gravel） are assessed by varying the materials content. Based on freeze-thaw and compressive strength tests, this paper presents the performance of the different materials, each having different physical properties, and the optimal amounts of materials contents are proposed.展开更多
Based on the nonlinear displacement-strain relationship,the virtual work principle method was used to establish the nonlinear equilibrium equations of steel beams with semi-rigid connections under vertical uniform loa...Based on the nonlinear displacement-strain relationship,the virtual work principle method was used to establish the nonlinear equilibrium equations of steel beams with semi-rigid connections under vertical uniform loads and temperature change.Considering the non-uniform temperature distribution across the thickness of beams,the formulas for stresses and vertical displacements were presented.On the basis of a flowchart for analysis of the numerical example,the effect of temperature change on the elastic behavior of steel beams was investigated.It is found that the maximal stress is mainly influenced by axial temperature change,and the maximal vertical displacement is principally affected by temperature gradients.And the effect of temperature gradients on the maximal vertical displacement decreases with the increase of rotational stiffness of joints.Both the maximal stress and vertical displacement decrease with the increase of rotational stiffness of joints.It can be concluded that the effects of temperature changes and rotational stiffness of joints on the elastic behavior of steel beams are significant.However,the influence of rotational stiffness becomes smaller when the rotational stiffness is larger.展开更多
Solvents have an essential association with polymer solution behavior.However,few researches have been deeply done on this respect.In recent years,our research group focus on the study on effect of solvent properties ...Solvents have an essential association with polymer solution behavior.However,few researches have been deeply done on this respect.In recent years,our research group focus on the study on effect of solvent properties on solution behavior and film condensed state structure for semi-rigid conjugated polymer up till to apply for optoelectronic device.Herein,influence of solvent properties including solubility of solvent,aromaticity,polarity and hydrogen bonds on semi-rigid polymer chain solution behavior,i.e.,single chain conformation,chain shape,size and chains aggregated density were studied by means of static/dynamic laser light scattering(DLS/SLS)and exponential law etc.Effect of solvent properties on condensed state structure of the semi-rigid conjugated polymer film was studied by UV absorption spectroscopy,PL spectroscopy and electron microscopy etc.The essential reasons for the influence were discovered and the mechanism was revealed.It was found that solution behavior with different solvent properties had an essential physical relationship with chains condensed state structure of the semi-rigid conjugated polymers.More importantly,there was a quantitative structure-activity relationship between solution and film.The key to this relationship depended on the interaction between solvent molecules and the semi-rigid conjugated polymer chains.This interaction could also affect optoelectronic devices performance.This study is of great significance to effectively control the condensed state structure of the semirigid conjugated polymers in the process of dynamic evolution from solutions to films.It not only enriches the knowledge and understanding of both semi-rigid conjugated polymer solution behaviors and film condensed state physics based on polymer physics,but also is meaningful to practical application for conjugated polymer and other traditional polymer systems.展开更多
Objective:To evaluate and compare the effect of semi-rigid ureterorenoscopy on post-procedural sexual function with three different operating room settings.Methods:In this prospective randomized study,consecutive sexu...Objective:To evaluate and compare the effect of semi-rigid ureterorenoscopy on post-procedural sexual function with three different operating room settings.Methods:In this prospective randomized study,consecutive sexually active patients with normal pre-operative sexual function undergoing uncomplicated semi-rigid ureterorenoscopy for distal ureteric stones were randomized into three groups,with three different operating room settings.Procedure-related anxiety and sexual function were assessed pre-operatively using Amsterdam Preoperative Anxiety and Information Scale and Brief Sexual Function Inventory(in males)and Female Sexual Function Index-6(in females),respectively.All the participants were stented following the procedure,and the stent was removed after 3 weeks.Post-procedural sexual function and general discomfort were assessed and compared between three groups at 1 week,3 weeks,and 12 weeks.The effect of surgery-related anxiety,preoperative sexual function,age,and general discomfort(including stent-related discomfort)on post-procedural sexual function were analyzed using multiple regression analysis.A p-value of less than 0.05 was considered statistically significant.Results:Totally,327 eligible patients were randomized into three groups.The group of patients who underwent the procedural with a screen separating the operating area from the patient vision,while the patient could watch the endoscopy through a separate monitor,had better post-procedural sexual function compared to those who had total vision of the operating area as well as to those whose eyes were blocked.This difference was statistically significant.This post-procedural reduction in sexual function could not be attributed to in situ stent alone.Conclusions:Our study showed that semi-rigid ureterorenoscopy can have significant negative effect on sexual function,which can be reduced with proper preoperative counseling and an ideal operating room settings.展开更多
New and high transparent structural element, steel-glass composite beam was developed in respect to fabrication, static-structural and architectural criteria and consists of steel flanges and glass web assembled toget...New and high transparent structural element, steel-glass composite beam was developed in respect to fabrication, static-structural and architectural criteria and consists of steel flanges and glass web assembled together by semi-rigid polymer adhesive, which is the key element of whole composite system. These beams can be used mainly as members of high transparent roof or floor structure as well as stiffening fins for large area glass facades. This paper deals with experimental research performed at CTU （Czech Technical University） Prague, which started by adhesive selection and initial material tests by ISO527, continued via small-scale steel-glass connection tests and graduated by full-scale tests of hybrid beams with the span of 4 m. Generalized results of these experiments, analytical and numerical studies serve as device, how to accurately predict the behavior of the beam, describe the stress distribution along the cross section and safely and economically design such a kind of structure with semi-rigid shear connection, made by polymer adhesive.展开更多
Semi-rigid liquid crystal polymer is a class of liquid crystal polymers different from long rigid rod liquid crystal polymer to which the well-known Onsager and Flory theories are applied. In this paper, three statist...Semi-rigid liquid crystal polymer is a class of liquid crystal polymers different from long rigid rod liquid crystal polymer to which the well-known Onsager and Flory theories are applied. In this paper, three statistical models for the semi-rigid nematic polymer were addressed. They are the elastically jointed rod model, worm-like chain model, and non-homogeneous chain model. The nematic-isotropic transition temperature was examined. The pseudo-second transition temperature is expressed analytically. Comparisons with the experiments were made and the agreements were found.展开更多
A 9-story concrete-filled steel tubular frame model is used to analyze the response of joints due to sudden column loss. Three different models are developed and compared to study the efficiency and feasibility of sim...A 9-story concrete-filled steel tubular frame model is used to analyze the response of joints due to sudden column loss. Three different models are developed and compared to study the efficiency and feasibility of simulation, which include substructure model, beam element model and solid element model. The comparison results show that the substructure model has a satisfying capability, calculation efficiency and accuracy to predict the concerned joints as well as the overall framework. Based on the substructure model and a kind of semi-rigid connection for concretefilled square hollow section steel column proposed in this paper, the nonlinear dynamic analyses are conducted by the alternate path method. It is found that the removal of the ground inner column brings high-level joint moments and comparatively low-level axial tension forces. The initial stiffness and transmitted ultimate moment of the semi-rigid connection are the main factors that influence the frame behavior, and their lower limit should be guaranteed to resist collapse. Reduced ultimate moment results in drastic displacement and axial force development, which may bring progressive collapse. The higher initial stiffness ensures that the structure has a stronger capacity to resist progressive collapse.展开更多
A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic ...A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic loading were tested to study the static behavior of this new type of joint.The main variable parameters for the five joint specimens were the longitudinal reinforcement ratio and the joint type.The experimental results designated that the magnitude of extension of the longitudinal reinforcement is the most important factor that influenced the moment-rotation characteristic of the new type of joint.The concrete slabs could resist 3.8%-19.1% of the total shear load applied to the cross-sections near the beam-to-column connection.The edge stiffened elements,such as the flange of the lipped I-section thin-walled steel beam,were capable of having considerable inelastic deformation capacity although they had comparatively large width-to-thickness ratios.The shear failure of the concrete cantilever edge strip must be taken into account in practical design because it has significant influence on the anchorage of the longitudinal reinforcement in the new type of external joints.展开更多
Background: Modification of surgical techniques to minimize wound infections in penile implant surgery using malleable prosthesis which is easy to use, of very low risk of mechanical failure and is financially suitabl...Background: Modification of surgical techniques to minimize wound infections in penile implant surgery using malleable prosthesis which is easy to use, of very low risk of mechanical failure and is financially suitable to improve outcome and ensures less complications. The aim of the study is to compare infrapubic approach and Penoscrotal approach in penile semi-rigid prosthesis implantation surgery. Patients and methods: Fifty patients were randomly divided into two groups and each group underwent one approach. Results: No statically significant differences were found between both groups in terms of operative time. Corporeal cross over was the most common intraoperative complications, 3 cases in IP approach and 6 cases in PS but not statistically significant. Peyronie’s disease patients underwent penile implant through infrapubic approach in 3 cases and PS in 4 cases with one recorded complication of keloid formations with IP. Urethral false passage reported only in one case with PS approach without affecting the procedure. Only minor complications including superficial wound infection which was significantly more with PS, 6/25 (24%) and IP 1/25 (4%), p value = 0.041. Penile and scrotal edema was common with IP approach (92%) in comparison with PS approach (60%). The urethral catheter can be abandoned with IP to avoid the risk of catheterizations. No significant relation between diabetes and infections and no erosions were encountered. Conclusion: Through this research work, infrapubic approach is better than Penoscrotal approach even if it is not commonly used by surgeon.展开更多
Compressive strength and compressive resilience modulus are two important parameters to measure the mechanical properties of semi-rigid base.The test methods of semi-rigid base cores are different from those of the la...Compressive strength and compressive resilience modulus are two important parameters to measure the mechanical properties of semi-rigid base.The test methods of semi-rigid base cores are different from those of the laboratory samples in terms of sample acquisition,sample selection and humidity requirements.Core-drilling location,size of core sample,smoothness and humidity conditions were analyzed.The test methods of compressive strength and compressive resilience modulus were proposed.The research results show that compressive strength of lime fly-ash stabilized gravels base has a tendency of increasing during a long period.The compressive resilience modulus increases significantly with compressive strength of semi-rigid base.The compressive resilience modulus generally is 3-4 times than the recommended range of asphalt pavement design specifications.The fluctuation range of compressive resilience modulus is obviously higher than the compressive strength.The compressive resilience modulus is more sensitive to the construction variability.The overall trend between the compressive resilience modulus and the back-calculation modulus is consistent.FWD(falling weight deflectometer)back-calculation modulus can reflect the stiffness and bearing capacity of asphalt pavement.展开更多
In this paper, we proposed a method for semi-rigid changed 3D point clouds registration. We first segment the point clouds into individual segments and then the alignment energy costs of each segment are calculated. T...In this paper, we proposed a method for semi-rigid changed 3D point clouds registration. We first segment the point clouds into individual segments and then the alignment energy costs of each segment are calculated. The rough initial transformation is estimated by minimizing the energy cost using integer programming. The final registration results are obtained by rigid alignments of separated corresponded segments. Experimental result with simulated point clouds demonstrate that the concept of semi-rigid registration works well.展开更多
Performance-based design for a constructional steel frame in nonlinear-plastic region requires an improvement in order to achieve a reliable structural analysis.The need to explicitly consider the nonlinear behaviour ...Performance-based design for a constructional steel frame in nonlinear-plastic region requires an improvement in order to achieve a reliable structural analysis.The need to explicitly consider the nonlinear behaviour of structures makes the numerical modelling approach much more favourable than expensive and potentially dangerous experimental work.The parameters considered in the analysis are not limited to the linear change of geometry and material yielding,but also include the effect of large deformations,geometrical imperfections,load eccentricities,residual stresses,strain-unloading,and the nonlinear boundary conditions.Such analysis requires the use of accurate mathematical modelling and effective numerical procedures for solving equations of equilibrium.With that in mind,this paper presents the mathematical formulations and finite element procedures of nonlinear inelastic steel frame analysis with quasi-static semi-rigid connections.Verification and validation of the developed analytical procedures are conducted and good agreements are obtained.It is an approach that enables the structural behaviour of constructional steel frames to be traced throughout the entire range of loading until failure.It also provides information on the derivation of the structural analysis by using finite element method.展开更多
Purpose:The purpose of this study was to examine effects of a sport version of a semi-rigid ankle brace (ElementTM) and a soft ankle brace (ASO) on ankle biomechanics and ground reaction forces (GRFs) during a drop la...Purpose:The purpose of this study was to examine effects of a sport version of a semi-rigid ankle brace (ElementTM) and a soft ankle brace (ASO) on ankle biomechanics and ground reaction forces (GRFs) during a drop landing activity in subjects with chronic ankle instability (CAI)compared to healthy subjects with no history of CAI.Methods:Ten healthy subjects and 10 subjects who had multiple ankle sprains participated in the study as the control and unstable subjects,respectively.The CAI subjects were age,body mass index and gender matched with the control subjects.The arch index and ankle functions of the subjects were measured in a subject screening session.During the biomechanical test session,participants performed five trials of drop landing from 0.6 m,wearing no brace ( NB),ElementTM brace and ASO brace.Simultaneous recording of three-dimensional kinematic (240 Hz)and GRF (1200 Hz) data were performed.Results:The CAI subjects had lower ankle functional survey scores.The arch index and deformity results showed greater arch deformity of ElementTM against a static load than in NB and ASO due to greater initial arch position held by the brace.CAI participants had greater eversion velocity than healthy coutrols.The ASO brace reduced the first peak vertical GRF whereas ElementTM increased 2nd peak vertical GRF.ElementTM brace reduced eversion range of motion (ROM) and peak eversion velocity compared to NB and ASO.In addition,ElementTM reduced dorsiflexion ROM and increased peak plantarflexion moment compared to NB and ASO.Conclusion:Results of static arch measurements and dynamic ankle motion suggest that the restrictions offered by both braces are in part due to more dorsiflexed ankle positions at contact,and higher initial arch position and stiffer ankle for ElementTM.展开更多
Tenon-mortise joint is widely used in traditional timber structures around the world.This paper summarizes the results of an experimental study of the structural behavior of tenon-mortise joints made with glulam and C...Tenon-mortise joint is widely used in traditional timber structures around the world.This paper summarizes the results of an experimental study of the structural behavior of tenon-mortise joints made with glulam and CNC technology instead of traditional material and manual work.30 full-scale tenonmortise joints were manufactured and tested under monotonic loading,and the effects of dimension,shape,processing error and adhesive were evaluated.It was found that the round rectangular shaped tenon-mortise joints were comparable with traditional joints in terms of structural performance,but were time and labor saving.The variability of the proposed tenon-mortise joints was lower,which would benefit the design value.Applying adhesive between tenon and mortise increased the average stiffness by 4.3 times and average moment capacity by 27.4%,respectively.The gaps between wood members had little effect on the capacity and stiffness in monotonic bending but may influence the energy dissipation ability in cyclic bending.This study showed the feasibility of combining the traditional joinery method with modern wood products and manufacturing technology,which may promote the application of tenon-mortise joints in modern timber structures.展开更多
Based on the 2006 Chinese asphalt pavement deflection value design index, we used KENLAYER Pavement Analysis and Design software and lstOpt statistical analysis software to can-y on the nonlinear regression, this pape...Based on the 2006 Chinese asphalt pavement deflection value design index, we used KENLAYER Pavement Analysis and Design software and lstOpt statistical analysis software to can-y on the nonlinear regression, this paper establish high-grade highway design equations for the compressive slrain of soil sub-base top （CSSBT） and the radial compressive stress of semi-rigid base top （RCSRBT）. The correlation coefficients inspection standard to get precise proof, which means that our granular base design equations have high credibility and can be used in the Chinese design index of asphalt pavement with granular base （APGB）.展开更多
基金The National Natural Science Foundation of China(No.51378121)
文摘In order to compare the impact of thickness of different layers on fatigue lives of different semi-rigid asphalt pavement structures, the mechanical results from finite element models in ABAQUS are incorporated with the fatigue results from fatigue models in FE-SAFE to calculate the mechanical response and fatigue lives of semi-rigid pavement structures under heavy traffic loads. Then the influences on fatigue lives caused by the changes in the thickness of layers in pavement structures are also evaluated. The numerical simulation results show that the aggregated base and the large stone porous mixture （LSPM） base have better anti-cracking performance than the conventional semi-rigid base. The appropriate thickness range for the aggregated layer in the aggregated base is 15 to 18 cm. The thickness of the LSPM layer in the LSPM base is recommended to be less than 15 cm.
基金Project(50778177) supported by the National Natural Science Foundation of ChinaProject(07JJ1009) supported by the Outstanding Younger Fund of Hunan Province,China
文摘The stiffness matrix of semi-rigidly connected composite beams considering interface slip was established and the calculation method for elastic seismic response of composite frame was derived.The corresponding calculation programs were developed.Introducing the dimensionless quantities that were related to the connector shearing stiffness and the joint rotation stiffness,the influences of interface slip and semi-rigid joint on composite frame were transferred to quantitative parameter analysis,taking account of cross sectional properties,materials and linear stiffness of composite beam synthetically.Based on the calculation programs,free vibration frequencies and seismic responses of semi-rigid joint steel-concrete composite frame considering interface slip were calculated.The influences of interface slip and semi rigid joint on dynamic characteristics and seismic response were analyzed and the seismic design advices were presented.The results show that the interface slip decreases the free vibration frequencies and increase the seismic responses of composite frame.The semi-rigid joint reduces the free vibration frequencies and increases seismic responses of composite frame compared with rigid joint.With the increase of joint rotational stiffness,the elastic seismic responses of composite frame increase firstly and then decrease.The effects are related to the ratio of joint rotation stiffness to linear stiffness of composite beam.
基金This work was financed by grants from the National Natural Science Foundation of China(No.81370804 and No.81670643)Guangzhou Science,Technology and Innovation Commission(No.201604020001,No.201607010162 and No.201704020193).
文摘Objective:To examine differences in outcomes of semi-rigid ureteroscopy(URS)with or without a modified-ureteral-access-sheath(mUAS)to treat large upper ureteral stones.Methods:Patients with single,radio-opaque large upper ureteral stone(≥10 mm)treated using semi-rigid URS between August 2013 and October 2016 were retrospectively evaluated.The stone-free status was determined from Kidney-ureter-bladder(KUB)X-ray films taken on postoperative Day 1 and after 1 month.Results:Of 103 patients meeting inclusion criteria,43(41.75%)and 60(58.25%)were treated with semi-rigid URS with and without mUAS,respectively.The immediate stone-free rate(SFR)for the mUAS group was significantly higher than the non-mUAS group(40[93.0%]vs.46[76.7%];p=0.033).The SFR at 1 month was also high for patients treated using mUAS,but not statistically different from patients not treated with mUAS(41[95.3%]mUAS vs.51[85.0%]non-mUAS;p=0.115).Auxiliary procedure rates were significantly lower for mUAS patients compared to non-mUAS patients(2[4.7%]vs.14[23.3%];p=0.01).There were no significant differences in surgical duration and hospital stays,and the overall complication rates were statistically similar for mUAS patients compared to non-mUAS patients(1[2.3%]vs.3[5.0%];p=0.638).
基金supported by the National Natural Science Foundation of China (Nos. 51378057 and 41371081)
文摘Freeze-thaw damage is the most common disease of semi-rigid bases in cold regions, which may greatly affect the dura- bility of roadways. In this study, the compressive strength and frost resistance of four different types of semi-rigid bases （lime-fly ash-stabilized sand, cement-stabilized sand, lime-fly ash-stabilized gravel, and cement-stabilized gravel） are assessed by varying the materials content. Based on freeze-thaw and compressive strength tests, this paper presents the performance of the different materials, each having different physical properties, and the optimal amounts of materials contents are proposed.
基金Project(50478075) supported by the National Natural Science Foundation of ChinaProject(YBJJ0817) supported by Scientific Research Foundation of Graduate School of Southeast University
文摘Based on the nonlinear displacement-strain relationship,the virtual work principle method was used to establish the nonlinear equilibrium equations of steel beams with semi-rigid connections under vertical uniform loads and temperature change.Considering the non-uniform temperature distribution across the thickness of beams,the formulas for stresses and vertical displacements were presented.On the basis of a flowchart for analysis of the numerical example,the effect of temperature change on the elastic behavior of steel beams was investigated.It is found that the maximal stress is mainly influenced by axial temperature change,and the maximal vertical displacement is principally affected by temperature gradients.And the effect of temperature gradients on the maximal vertical displacement decreases with the increase of rotational stiffness of joints.Both the maximal stress and vertical displacement decrease with the increase of rotational stiffness of joints.It can be concluded that the effects of temperature changes and rotational stiffness of joints on the elastic behavior of steel beams are significant.However,the influence of rotational stiffness becomes smaller when the rotational stiffness is larger.
基金the National Natural Science Foundation of China(Nos.91333103 and 21574053).
文摘Solvents have an essential association with polymer solution behavior.However,few researches have been deeply done on this respect.In recent years,our research group focus on the study on effect of solvent properties on solution behavior and film condensed state structure for semi-rigid conjugated polymer up till to apply for optoelectronic device.Herein,influence of solvent properties including solubility of solvent,aromaticity,polarity and hydrogen bonds on semi-rigid polymer chain solution behavior,i.e.,single chain conformation,chain shape,size and chains aggregated density were studied by means of static/dynamic laser light scattering(DLS/SLS)and exponential law etc.Effect of solvent properties on condensed state structure of the semi-rigid conjugated polymer film was studied by UV absorption spectroscopy,PL spectroscopy and electron microscopy etc.The essential reasons for the influence were discovered and the mechanism was revealed.It was found that solution behavior with different solvent properties had an essential physical relationship with chains condensed state structure of the semi-rigid conjugated polymers.More importantly,there was a quantitative structure-activity relationship between solution and film.The key to this relationship depended on the interaction between solvent molecules and the semi-rigid conjugated polymer chains.This interaction could also affect optoelectronic devices performance.This study is of great significance to effectively control the condensed state structure of the semirigid conjugated polymers in the process of dynamic evolution from solutions to films.It not only enriches the knowledge and understanding of both semi-rigid conjugated polymer solution behaviors and film condensed state physics based on polymer physics,but also is meaningful to practical application for conjugated polymer and other traditional polymer systems.
文摘Objective:To evaluate and compare the effect of semi-rigid ureterorenoscopy on post-procedural sexual function with three different operating room settings.Methods:In this prospective randomized study,consecutive sexually active patients with normal pre-operative sexual function undergoing uncomplicated semi-rigid ureterorenoscopy for distal ureteric stones were randomized into three groups,with three different operating room settings.Procedure-related anxiety and sexual function were assessed pre-operatively using Amsterdam Preoperative Anxiety and Information Scale and Brief Sexual Function Inventory(in males)and Female Sexual Function Index-6(in females),respectively.All the participants were stented following the procedure,and the stent was removed after 3 weeks.Post-procedural sexual function and general discomfort were assessed and compared between three groups at 1 week,3 weeks,and 12 weeks.The effect of surgery-related anxiety,preoperative sexual function,age,and general discomfort(including stent-related discomfort)on post-procedural sexual function were analyzed using multiple regression analysis.A p-value of less than 0.05 was considered statistically significant.Results:Totally,327 eligible patients were randomized into three groups.The group of patients who underwent the procedural with a screen separating the operating area from the patient vision,while the patient could watch the endoscopy through a separate monitor,had better post-procedural sexual function compared to those who had total vision of the operating area as well as to those whose eyes were blocked.This difference was statistically significant.This post-procedural reduction in sexual function could not be attributed to in situ stent alone.Conclusions:Our study showed that semi-rigid ureterorenoscopy can have significant negative effect on sexual function,which can be reduced with proper preoperative counseling and an ideal operating room settings.
文摘New and high transparent structural element, steel-glass composite beam was developed in respect to fabrication, static-structural and architectural criteria and consists of steel flanges and glass web assembled together by semi-rigid polymer adhesive, which is the key element of whole composite system. These beams can be used mainly as members of high transparent roof or floor structure as well as stiffening fins for large area glass facades. This paper deals with experimental research performed at CTU （Czech Technical University） Prague, which started by adhesive selection and initial material tests by ISO527, continued via small-scale steel-glass connection tests and graduated by full-scale tests of hybrid beams with the span of 4 m. Generalized results of these experiments, analytical and numerical studies serve as device, how to accurately predict the behavior of the beam, describe the stress distribution along the cross section and safely and economically design such a kind of structure with semi-rigid shear connection, made by polymer adhesive.
基金The work was supported by the Foundation of State Education Committee of China
文摘Semi-rigid liquid crystal polymer is a class of liquid crystal polymers different from long rigid rod liquid crystal polymer to which the well-known Onsager and Flory theories are applied. In this paper, three statistical models for the semi-rigid nematic polymer were addressed. They are the elastically jointed rod model, worm-like chain model, and non-homogeneous chain model. The nematic-isotropic transition temperature was examined. The pseudo-second transition temperature is expressed analytically. Comparisons with the experiments were made and the agreements were found.
基金Supported by National Natural Science Foundation of China (No.50878066)Natural Science Foundation of Heilongjiang Province (No.ZJG0701)Heilongjiang Postdoctoral Science Foundation
文摘A 9-story concrete-filled steel tubular frame model is used to analyze the response of joints due to sudden column loss. Three different models are developed and compared to study the efficiency and feasibility of simulation, which include substructure model, beam element model and solid element model. The comparison results show that the substructure model has a satisfying capability, calculation efficiency and accuracy to predict the concerned joints as well as the overall framework. Based on the substructure model and a kind of semi-rigid connection for concretefilled square hollow section steel column proposed in this paper, the nonlinear dynamic analyses are conducted by the alternate path method. It is found that the removal of the ground inner column brings high-level joint moments and comparatively low-level axial tension forces. The initial stiffness and transmitted ultimate moment of the semi-rigid connection are the main factors that influence the frame behavior, and their lower limit should be guaranteed to resist collapse. Reduced ultimate moment results in drastic displacement and axial force development, which may bring progressive collapse. The higher initial stiffness ensures that the structure has a stronger capacity to resist progressive collapse.
基金Sponsored by the National Natural Science Foundation of China (Grant No.50478027)
文摘A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic loading were tested to study the static behavior of this new type of joint.The main variable parameters for the five joint specimens were the longitudinal reinforcement ratio and the joint type.The experimental results designated that the magnitude of extension of the longitudinal reinforcement is the most important factor that influenced the moment-rotation characteristic of the new type of joint.The concrete slabs could resist 3.8%-19.1% of the total shear load applied to the cross-sections near the beam-to-column connection.The edge stiffened elements,such as the flange of the lipped I-section thin-walled steel beam,were capable of having considerable inelastic deformation capacity although they had comparatively large width-to-thickness ratios.The shear failure of the concrete cantilever edge strip must be taken into account in practical design because it has significant influence on the anchorage of the longitudinal reinforcement in the new type of external joints.
文摘Background: Modification of surgical techniques to minimize wound infections in penile implant surgery using malleable prosthesis which is easy to use, of very low risk of mechanical failure and is financially suitable to improve outcome and ensures less complications. The aim of the study is to compare infrapubic approach and Penoscrotal approach in penile semi-rigid prosthesis implantation surgery. Patients and methods: Fifty patients were randomly divided into two groups and each group underwent one approach. Results: No statically significant differences were found between both groups in terms of operative time. Corporeal cross over was the most common intraoperative complications, 3 cases in IP approach and 6 cases in PS but not statistically significant. Peyronie’s disease patients underwent penile implant through infrapubic approach in 3 cases and PS in 4 cases with one recorded complication of keloid formations with IP. Urethral false passage reported only in one case with PS approach without affecting the procedure. Only minor complications including superficial wound infection which was significantly more with PS, 6/25 (24%) and IP 1/25 (4%), p value = 0.041. Penile and scrotal edema was common with IP approach (92%) in comparison with PS approach (60%). The urethral catheter can be abandoned with IP to avoid the risk of catheterizations. No significant relation between diabetes and infections and no erosions were encountered. Conclusion: Through this research work, infrapubic approach is better than Penoscrotal approach even if it is not commonly used by surgeon.
文摘Compressive strength and compressive resilience modulus are two important parameters to measure the mechanical properties of semi-rigid base.The test methods of semi-rigid base cores are different from those of the laboratory samples in terms of sample acquisition,sample selection and humidity requirements.Core-drilling location,size of core sample,smoothness and humidity conditions were analyzed.The test methods of compressive strength and compressive resilience modulus were proposed.The research results show that compressive strength of lime fly-ash stabilized gravels base has a tendency of increasing during a long period.The compressive resilience modulus increases significantly with compressive strength of semi-rigid base.The compressive resilience modulus generally is 3-4 times than the recommended range of asphalt pavement design specifications.The fluctuation range of compressive resilience modulus is obviously higher than the compressive strength.The compressive resilience modulus is more sensitive to the construction variability.The overall trend between the compressive resilience modulus and the back-calculation modulus is consistent.FWD(falling weight deflectometer)back-calculation modulus can reflect the stiffness and bearing capacity of asphalt pavement.
文摘In this paper, we proposed a method for semi-rigid changed 3D point clouds registration. We first segment the point clouds into individual segments and then the alignment energy costs of each segment are calculated. The rough initial transformation is estimated by minimizing the energy cost using integer programming. The final registration results are obtained by rigid alignments of separated corresponded segments. Experimental result with simulated point clouds demonstrate that the concept of semi-rigid registration works well.
基金The authors would like to acknowledge the supports from Universiti Teknologi Malaysia(UTM)and Ministry of Higher Education(MOHE).
文摘Performance-based design for a constructional steel frame in nonlinear-plastic region requires an improvement in order to achieve a reliable structural analysis.The need to explicitly consider the nonlinear behaviour of structures makes the numerical modelling approach much more favourable than expensive and potentially dangerous experimental work.The parameters considered in the analysis are not limited to the linear change of geometry and material yielding,but also include the effect of large deformations,geometrical imperfections,load eccentricities,residual stresses,strain-unloading,and the nonlinear boundary conditions.Such analysis requires the use of accurate mathematical modelling and effective numerical procedures for solving equations of equilibrium.With that in mind,this paper presents the mathematical formulations and finite element procedures of nonlinear inelastic steel frame analysis with quasi-static semi-rigid connections.Verification and validation of the developed analytical procedures are conducted and good agreements are obtained.It is an approach that enables the structural behaviour of constructional steel frames to be traced throughout the entire range of loading until failure.It also provides information on the derivation of the structural analysis by using finite element method.
基金supported in part by DeRoyal Industries, Inc.,Powell,TN,USA
文摘Purpose:The purpose of this study was to examine effects of a sport version of a semi-rigid ankle brace (ElementTM) and a soft ankle brace (ASO) on ankle biomechanics and ground reaction forces (GRFs) during a drop landing activity in subjects with chronic ankle instability (CAI)compared to healthy subjects with no history of CAI.Methods:Ten healthy subjects and 10 subjects who had multiple ankle sprains participated in the study as the control and unstable subjects,respectively.The CAI subjects were age,body mass index and gender matched with the control subjects.The arch index and ankle functions of the subjects were measured in a subject screening session.During the biomechanical test session,participants performed five trials of drop landing from 0.6 m,wearing no brace ( NB),ElementTM brace and ASO brace.Simultaneous recording of three-dimensional kinematic (240 Hz)and GRF (1200 Hz) data were performed.Results:The CAI subjects had lower ankle functional survey scores.The arch index and deformity results showed greater arch deformity of ElementTM against a static load than in NB and ASO due to greater initial arch position held by the brace.CAI participants had greater eversion velocity than healthy coutrols.The ASO brace reduced the first peak vertical GRF whereas ElementTM increased 2nd peak vertical GRF.ElementTM brace reduced eversion range of motion (ROM) and peak eversion velocity compared to NB and ASO.In addition,ElementTM reduced dorsiflexion ROM and increased peak plantarflexion moment compared to NB and ASO.Conclusion:Results of static arch measurements and dynamic ankle motion suggest that the restrictions offered by both braces are in part due to more dorsiflexed ankle positions at contact,and higher initial arch position and stiffer ankle for ElementTM.
文摘Tenon-mortise joint is widely used in traditional timber structures around the world.This paper summarizes the results of an experimental study of the structural behavior of tenon-mortise joints made with glulam and CNC technology instead of traditional material and manual work.30 full-scale tenonmortise joints were manufactured and tested under monotonic loading,and the effects of dimension,shape,processing error and adhesive were evaluated.It was found that the round rectangular shaped tenon-mortise joints were comparable with traditional joints in terms of structural performance,but were time and labor saving.The variability of the proposed tenon-mortise joints was lower,which would benefit the design value.Applying adhesive between tenon and mortise increased the average stiffness by 4.3 times and average moment capacity by 27.4%,respectively.The gaps between wood members had little effect on the capacity and stiffness in monotonic bending but may influence the energy dissipation ability in cyclic bending.This study showed the feasibility of combining the traditional joinery method with modern wood products and manufacturing technology,which may promote the application of tenon-mortise joints in modern timber structures.
基金supported by the Singapore Government Foundation Project under the Nan Yang Technological University Transport Research Team Program (No. CTG/09-398)the Chinese Science Technology Foundation Project of Yunnan (No. TST477126A)
文摘Based on the 2006 Chinese asphalt pavement deflection value design index, we used KENLAYER Pavement Analysis and Design software and lstOpt statistical analysis software to can-y on the nonlinear regression, this paper establish high-grade highway design equations for the compressive slrain of soil sub-base top （CSSBT） and the radial compressive stress of semi-rigid base top （RCSRBT）. The correlation coefficients inspection standard to get precise proof, which means that our granular base design equations have high credibility and can be used in the Chinese design index of asphalt pavement with granular base （APGB）.
