A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced duri...A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel construction.To mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio effect.Physical model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor cables.The large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the tunnel.Comparing the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 mm.This study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas.展开更多
To provide the supplier with the minimizum vehicle travel distance in the distribution process of goods in three situations of new customer demand,customer cancellation service,and change of customer delivery address,...To provide the supplier with the minimizum vehicle travel distance in the distribution process of goods in three situations of new customer demand,customer cancellation service,and change of customer delivery address,based on the ideas of pre-optimization and real-time optimization,a two-stage planning model of dynamic demand based vehicle routing problem with time windows was established.At the pre-optimization stage,an improved genetic algorithm was used to obtain the pre-optimized distribution route,a large-scale neighborhood search method was integrated into the mutation operation to improve the local optimization performance of the genetic algorithm,and a variety of operators were introduced to expand the search space of neighborhood solutions;At the real-time optimization stage,a periodic optimization strategy was adopted to transform a complex dynamic problem into several static problems,and four neighborhood search operators were used to quickly adjust the route.Two different scale examples were designed for experiments.It is proved that the algorithm can plan the better route,and adjust the distribution route in time under the real-time constraints.Therefore,the proposed algorithm can provide theoretical guidance for suppliers to solve the dynamic demand based vehicle routing problem.展开更多
Based on four-year field inspection and investigation on deck pavement of mastic asphalt on Jiangyin Bridge, cracking causes of mastic asphalt are studied. Cracks of deck pavement are summarized on crack length and wi...Based on four-year field inspection and investigation on deck pavement of mastic asphalt on Jiangyin Bridge, cracking causes of mastic asphalt are studied. Cracks of deck pavement are summarized on crack length and width to get a clear view of their propagations. Traffic surveys including traffic volume, axle load and vehicle speed were also conducted to assess their influences. Samples taken on-site were tested with pulling-out test and fatigue test to benchmark their properties. According to the inspection and tests results, it is concluded that the cracks are induced by rutting and fatigue. Lack of fatigue resistance, not well bonded to the steel deck and insufficient high temperature stability are supposed to be the main reasons as well as high density of low speed, excessively overloaded trucks.展开更多
The maximal entropy ordered weighted averaging (ME-OWA) operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the...The maximal entropy ordered weighted averaging (ME-OWA) operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the methods for aggregating metasearch engine results are divided into two kinds. One has a unique solution, and the other has multiple solutions. The proposed method not only has crisp weights, but also provides multiple aggregation results for decision makers to choose from. In order to prove the application of the ME-OWA operator method, under the context of aggregating metasearch engine results, an example is given, which shows the results obtained by the ME-OWA operator method and the minimax linear programming ( minimax-LP ) method. Comparison between these two methods are also made. The results show that the ME-OWA operator has nearly the same aggregation results as those of the minimax-LP method.展开更多
The car sequencing problem(CSP)concerns a production sequence of different types of cars in the mixed-model assembly line.A hybrid algorithm is proposed to find an assembly sequence of CSP with minimum violations.Firs...The car sequencing problem(CSP)concerns a production sequence of different types of cars in the mixed-model assembly line.A hybrid algorithm is proposed to find an assembly sequence of CSP with minimum violations.Firstly,the hybrid algorithm is based on the tabu search and large neighborhood search(TLNS),servicing as the framework.Moreover,two components are incorporated into the hybrid algorithm.One is the parallel constructive heuristic(PCH)that is used to construct a set of initial solutions and find some high quality solutions,and the other is the small neighborhood search(SNS)which is designed to improve the new constructed solutions.The computational results show that the proposed hybrid algorithm(PCH+TLNS+SNS)obtains100best known values out of109public instances,among these89instances get their best known values with100%success rate.By comparing with the well-known related algorithms,computational results demonstrate the effectiveness,efficiency and robustness of the proposed algorithm.展开更多
Tipula(Sivatipula)is a small subgenus of Tipula with only fourteen species described in the world,with eight species previously known to occur in China.Here one new species is added to the fauna of China.A key to the ...Tipula(Sivatipula)is a small subgenus of Tipula with only fourteen species described in the world,with eight species previously known to occur in China.Here one new species is added to the fauna of China.A key to the species(males)of Tipula(Sivatipula)from China is presented.展开更多
The original description of male hypopygium of Tipula(Emodotipula) holoteles Alexander, 1924 is expanded with additional morphological characters and detailed illustrations. The additional morphological descriptions o...The original description of male hypopygium of Tipula(Emodotipula) holoteles Alexander, 1924 is expanded with additional morphological characters and detailed illustrations. The additional morphological descriptions of the female ovipositor along with detailed drawings are provided. The male semen pump and the female vaginal apodeme as well as the spermatheca are also described and illustrated for the first time, representing the first report of these structures of Tipula(Emodotipula) holoteles. Additionally, the taxonomic potential of the semen pump in the subgenus Emodotipula is analyzed and discussed. The new specific name Tipula(Emodotipula) yangi nom. nov. is proposed as a replacement name for junior homonym Tipula(Emodotipula) alexanderi Men, 2017. A worldwide checklist and a key to Chinese species of the subgenus Emodotipula are provided.展开更多
To investigate of pediatric ulcerative colitis activity index (PUCAI) in ulcerative colitis correlate with mucosal inflammation and endoscopic assessment of disease activity (Mayo endoscopic score).METHODSWe reviewed ...To investigate of pediatric ulcerative colitis activity index (PUCAI) in ulcerative colitis correlate with mucosal inflammation and endoscopic assessment of disease activity (Mayo endoscopic score).METHODSWe reviewed charts from ulcerative colitis patients who had undergone both colonoscopy over 3 years. Clinical assessment of disease severity within 35 d (either before or after) the colonoscopy were included. Patients were excluded if they had significant therapeutic interventions (such as the start of corticosteroids or immunosuppressive agents) between the colonoscopy and the clinical assessment. Mayo endoscopic score of the rectum and sigmoid were done by two gastroenterologists. Inter-observer variability in Mayo score was assessed.RESULTSWe identified 99 patients (53% female, 74% pancolitis) that met inclusion criteria. The indications for colonoscopy included ongoing disease activity (62%), consideration of medication change (10%), assessment of medication efficacy (14%), and cancer screening (14%). Based on PUCAI scores, 33% of patients were in remission, 39% had mild disease, 23% had moderate disease, and 4% had severe disease. There was “moderate-substantial” agreement between the two reviewers in assessing rectal Mayo scores (kappa = 0.54, 95%CI: 0.41-0.68).CONCLUSIONEndoscopic disease severity (Mayo score) assessed by reviewing photographs of pediatric colonoscopy has moderate inter-rater reliability, and agreement was less robust in assessing patients with mild disease activity. Endoscopic disease severity generally correlates with clinical disease severity as measured by PUCAI score. However, children with inflamed colons can have significant variation in their reported clinical symptoms. Thus, assessment of both clinical symptoms and endoscopic disease severity may be required in future clinical studies.展开更多
We present the design and performance of a home-built scanning tunneling microscope (STM), which is compact (66 mm tall and 25 mm in diameter), yet equipped with a 3D atomic precision piezoelectric motor in which ...We present the design and performance of a home-built scanning tunneling microscope (STM), which is compact (66 mm tall and 25 mm in diameter), yet equipped with a 3D atomic precision piezoelectric motor in which the Z coarse approach relies on a high simplic-ity friction-type walker (of our own invention) driven by an axially cut piezoelectric tube. The walker is vertically inserted in a piezoelectric scanner tube (PST) with its brim laying at on the PST end as the inertial slider (driven by the PST) for the XZ (sample plane) motion. The STM is designed to be capable of searching rare microscopic targets (defects, dopants, boundaries, nano-devices, etc.) in a macroscopic sample area (square millimeters) under extreme conditions (low temperatures, strong magnetic elds, etc.) in which it ts. It gives good atomic resolution images after scanning a highly oriented pyrolytic graphite sample in air at room temperature.展开更多
Taizhou Bridge is a suspension bridge with three pylons and two 1 080 m main spans. The middle pylon is a steel frame with longitudinal herringbone shape and lateral gate shape. The connection between steel pylon and ...Taizhou Bridge is a suspension bridge with three pylons and two 1 080 m main spans. The middle pylon is a steel frame with longitudinal herringbone shape and lateral gate shape. The connection between steel pylon and concrete pile cap is a key part to transfer the huge inner force from the pylon to the foundation. Its construction quality is a critical factor to the overall structural loading of the whole bridge ; therefore the contact ratio between the bearing steel plate of pylon and concrete pile cap is required to be over 75 %. The inclined joint surface in two directions, longitudinally at 39/1 920 and laterally at 1/4, posted a challenge to the construction work. A procedure test was carried out to find an optimal construction method by comparison, and finally the post-injection method was selected as it can meet the requirement of concrete strength and contact ratio at the connection. The successful application of the post-injection method in Taizhou Bridge can nrovide an examnle and reference for similar nroiects in the future.展开更多
The central buckle, which is often used in a suspension bridge, can improve bridges' performance in the actual operation condition. The influence of the central buckle on natural vibration characteristics and brid...The central buckle, which is often used in a suspension bridge, can improve bridges' performance in the actual operation condition. The influence of the central buckle on natural vibration characteristics and bridge-deck driving comfort of a long-span suspension bridge is studied by using a case study of Siduhe Suspension Bridge in China. Based on the finite element software ANSYS and independently complied program, the influence of the central buckle on the structure force-applied characteristics of a long-span suspension bridge has been explored. The results show that the huge increases of natural frequencies can result in the presence of central buckles because of the increases of bending and torsional rigidities. The central buckle basically makes the stiffening girders and cables within the triangular area covered as a relatively approximate rigid area. Hence, the central buckle can reduce the torsional displacement of the main girder. However, the increases of bending and torsional rigidities have little influence on the impact factor, which is obtained by using vehicle-bridge coupled vibration analysis. This means that the central buckle has little effect on the comfort indices. In addition, it is found that the central buckle can enhance the bridge deck's driving stability due to the decrease of the torsional displacements of the main girder.展开更多
This research focuses on identifying the damping ratio of bridges using nonstationary ambient vibration data. The damping ratios of bridges in service have generally been identified using operational modal analysis (...This research focuses on identifying the damping ratio of bridges using nonstationary ambient vibration data. The damping ratios of bridges in service have generally been identified using operational modal analysis (OMA) based on a stationary white noise assumption for input signals. However, most bridges are generally subjected to nonstationary excitations while in service, and this violation of the basic assumption can lead to uncertainties in damping identification. To deal with nonstationarity, an amplitude-modulating function was calculated from measured responses to eliminate global trends caused by nonstationary input. A natural excitation technique (NExT)-eigensystem realization algorithm (ERA) was applied to estimate the damping ratio for a stationarized process. To improve the accuracy of OMA-based damping estimates, a comparative analysis was performed between an extracted stationary process and nonstationary data to assess the effect of eliminating nonstationarity. The mean value and standard deviation of the damping ratio for the first vertical mode decreased after signal stationarization.展开更多
A rigid central buckle is employed in Runyang Suspension Bridge (RSB) to replace commonly used short suspenders in the main span. Based on the seismic waves with 2% probabilities of exceedance, the nonlinear seismic...A rigid central buckle is employed in Runyang Suspension Bridge (RSB) to replace commonly used short suspenders in the main span. Based on the seismic waves with 2% probabilities of exceedance, the nonlinear seismic response time-domain analysis are then conducted and influence of central buckles on seismic response of long-span suspension bridge is specially studied. Analysis resuits show that the central buckle can effectively control the longitudinal floating vibration mode of the deck, and therefore reduce earthquake-excited longitudinal displacement at the end of the deck. However, the central buckle may cause increment of longitudinal displacement at the top of main tower and bending moment at the bottom of the main tower, which should be paid special attention to. Results provide references for anti-earthquake analysis and design of long-span suspension bridges using rigid central buckles.展开更多
AIM To investigate the changes in microbiota in feces of patients with ulcerative colitis(UC) and pouchitis using genomic technology.METHODS Fecal samples were obtained from UC patients with or without an ileal pouch-...AIM To investigate the changes in microbiota in feces of patients with ulcerative colitis(UC) and pouchitis using genomic technology.METHODS Fecal samples were obtained from UC patients with or without an ileal pouch-anal anastomosis(IPAA) procedure, as well as healthy controls. The touchdown polymerase chain reaction technique was used to amplify the whole V3 region of the 16 S r RNA gene, which was transcribed from DNA extracted from fecal samples. Denaturing gradient gel electrophoresis was used to separate the amplicons. The band profiles and similarity indices were analyzed digitally. The predominant microbiota in different groups was confirmed by sequencing the 16 S rR NA gene. RESULTS Microbial biodiversity in the healthy controls was significantly higher compared with the UC groups(P < 0.001) and IPAA groups(P < 0.001). Compared with healthy controls, the UC patients in remission and those in the mildly active stage, the predominant species in patients with moderately and severely active UC changed obviously. In addition, the proportion of the dominant microbiota, which was negatively correlated with the disease activity of UC(r =-6.591, P < 0.01),was decreased in pouchitis patients. The numbers of two types of bacteria, Faecalibacterium prausnitzii and Eubacterium rectale, were reduced in UC. Patients with pouchitis had an altered microbiota composition compared with UC patients. The microbiota from pouchitis patients was less diverse than that from severely active UC patients. Sequencing results showed that similar microbiota, such as Clostridium perfringens, were shared in both UC and pouchitis.CONCLUSION Less diverse fecal microbiota was present in patients with UC and pouchitis. Increased C. perfringens in feces suggest its role in the exacerbation of UC and pouchitis.展开更多
In view of the structure and action behavior of mechatronic systems,a method of searching fault propagation paths called maximum-probability path search(MPPS)is proposed,aiming to determine all possible failure propag...In view of the structure and action behavior of mechatronic systems,a method of searching fault propagation paths called maximum-probability path search(MPPS)is proposed,aiming to determine all possible failure propagation paths with their lengths if faults occur.First,the physical structure system,function behavior,and complex network theory are integrated to define a system structural-action network(SSAN).Second,based on the concept of SSAN,two properties of nodes and edges,i.e.,the topological property and reliability property,are combined to define the failure propagation property.Third,the proposed MPPS model provides all fault propagation paths and possible failure rates of nodes on these paths.Finally,numerical experiments have been implemented to show the accuracy and advancement compared with the methods of Function Space Iteration(FSI)and the algorithm of Ant Colony Optimization(ACO).展开更多
In this study,we derived atmospheric profiles of temperature,moisture,and ozone,along with surface emissivity,skin temperature,and surface pressure,from infrared-sounder radiances under clear sky (cloudless) condition...In this study,we derived atmospheric profiles of temperature,moisture,and ozone,along with surface emissivity,skin temperature,and surface pressure,from infrared-sounder radiances under clear sky (cloudless) condition.Clouds were detected objectively using the Atmospheric Infrared Sounder under a relatively low spatial resolution and cloud-mask information from the Moderate Resolution Imaging Spectroradiometer under a high horizontal resolution;this detection was conducted using space matching.Newton’s nonlinear physical iterative solution technique is applied to the radiative transfer equation (RTE) to retrieve temperature profiles,relative humidity profiles,and surface variables simultaneously.This technique is carried out by using the results of an eigenvector regression retrieval as the background profile and using corresponding iterative forms for the weighting functions of temperature and water-vapor mixing ratio.The iterative forms are obtained by applying the variational principle to the RTE.We also compared the retrievals obtained with different types of observations.The results show that the retrieved atmospheric sounding profile has great superiority over other observations by accuracy and resolution.Retrieved profiles can be used to improve the initial conditions of numerical models and used in areas where conventional observations are sparse,such as plateaus,deserts,and seas.展开更多
Taizhou Yangtze River Highway Bridge is a large span suspension bridge with three pylons. The elastic cables are installed to connect the steel tower and the steel box girder. The constraints can increase the safety c...Taizhou Yangtze River Highway Bridge is a large span suspension bridge with three pylons. The elastic cables are installed to connect the steel tower and the steel box girder. The constraints can increase the safety coefficient of the middle saddle, and improve the stress conditions of the middle pylon and decrease the deflection in the middle of the main girder, as well as the longitudinal displacement of the main girder caused by live loads. The anchorage boxes of the elastic cable are installed in the wind fairing outside the vertical web plate of the box girder. Two anchor boxes form a pair and are arranged parallelly. Eight anchor boxes are installed in the bridge. In this paper, the design scheme and the technical difficulties in manufacturing are briefly discussed with the precision control techniques.展开更多
Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.Firs...Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.First,the effects of temperature on the main girder spatial position coordinates were analyzed from the transverse,longitudinal and vertical directions of bridge,and the correlation regression models were built between temperature and the position coordinates of main girder in the longitudinal and vertical directions;then the alarming indices of coordinate residuals were conducted,and the mean-value control chart was applied to making statistical pattern identification for abnormal changes of girder dynamic coordinates;and finally,the structural damage alarming method of main girder was established.Analysis results show that temperature has remarkable correlation with position coordinates in the longitudinal and vertical directions of bridge,and has weak correlation with the transverse coordinates.The 3%abnormal change of the longitudinal coordinates and 5%abnormal change of the vertical ones caused by structural damage are respectively identified by the mean-value control chart method based on GPS dynamic monitoring data and hence the structural abnormalities state identification and damage alarming for main girder of long-span suspension bridge can be realized in multiple directions.展开更多
This paper focuses on introducing the manufacture technology of 1 770 MPa galvanized steel wires for stay cables applied to domestic bridges.During the development practices of high strength galvanized wire for stay c...This paper focuses on introducing the manufacture technology of 1 770 MPa galvanized steel wires for stay cables applied to domestic bridges.During the development practices of high strength galvanized wire for stay cables used in Sutong Bridge,Baosteel has established three key technologies based on research of manufacture technology and technical innovation.The three key technologies are:"Double Tensioning + limiter die" process,"dominant process + fine adjustment" in integrated optimization technology and "three-level control" in hot dip galvanization.With these key technologies,Baosteel has produced 1 770 MPa galvanized wires for stay cable,which has high tensile strength,low relaxation and good torsion performances.展开更多
基金Project(41941018)supported by the National Natural Science Foundation of China for the Special Project FundingProject(22-JKCF-08)supported by the Study on in-situ Stress Database and 3D in-situ Stress Inversion Technology of Highway Tunnel in Shanxi Province,China+1 种基金Project(2022-JKKJ-6)supported by the Study on Disaster Mechanism and NPR Anchor Cable Prevention and Control of Coal Mining Caving Subsidence in Operating Tunnel in Mountainous Area,ChinaProject(BBJ2024032)supported by the Fundamental Research Funds for the Central Universities(PhD Top Innovative Talents Fund of CUMTB),China。
文摘A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel construction.To mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio effect.Physical model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor cables.The large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the tunnel.Comparing the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 mm.This study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas.
基金supported by Natural Science Foundation Project of Gansu Provincial Science and Technology Department(No.1506RJZA084)Gansu Provincial Education Department Scientific Research Fund Grant Project(No.1204-13).
文摘To provide the supplier with the minimizum vehicle travel distance in the distribution process of goods in three situations of new customer demand,customer cancellation service,and change of customer delivery address,based on the ideas of pre-optimization and real-time optimization,a two-stage planning model of dynamic demand based vehicle routing problem with time windows was established.At the pre-optimization stage,an improved genetic algorithm was used to obtain the pre-optimized distribution route,a large-scale neighborhood search method was integrated into the mutation operation to improve the local optimization performance of the genetic algorithm,and a variety of operators were introduced to expand the search space of neighborhood solutions;At the real-time optimization stage,a periodic optimization strategy was adopted to transform a complex dynamic problem into several static problems,and four neighborhood search operators were used to quickly adjust the route.Two different scale examples were designed for experiments.It is proved that the algorithm can plan the better route,and adjust the distribution route in time under the real-time constraints.Therefore,the proposed algorithm can provide theoretical guidance for suppliers to solve the dynamic demand based vehicle routing problem.
文摘Based on four-year field inspection and investigation on deck pavement of mastic asphalt on Jiangyin Bridge, cracking causes of mastic asphalt are studied. Cracks of deck pavement are summarized on crack length and width to get a clear view of their propagations. Traffic surveys including traffic volume, axle load and vehicle speed were also conducted to assess their influences. Samples taken on-site were tested with pulling-out test and fatigue test to benchmark their properties. According to the inspection and tests results, it is concluded that the cracks are induced by rutting and fatigue. Lack of fatigue resistance, not well bonded to the steel deck and insufficient high temperature stability are supposed to be the main reasons as well as high density of low speed, excessively overloaded trucks.
基金The National Natural Science Foundation of China(No.71171048)
文摘The maximal entropy ordered weighted averaging (ME-OWA) operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the methods for aggregating metasearch engine results are divided into two kinds. One has a unique solution, and the other has multiple solutions. The proposed method not only has crisp weights, but also provides multiple aggregation results for decision makers to choose from. In order to prove the application of the ME-OWA operator method, under the context of aggregating metasearch engine results, an example is given, which shows the results obtained by the ME-OWA operator method and the minimax linear programming ( minimax-LP ) method. Comparison between these two methods are also made. The results show that the ME-OWA operator has nearly the same aggregation results as those of the minimax-LP method.
基金Project(51435009) supported by the National Natural Science Foundation of ChinaProject(LQ14E080002) supported by the Zhejiang Provincial Natural Science Foundation of ChinaProject supported by the K.C.Wong Magna Fund in Ningbo University,China
文摘The car sequencing problem(CSP)concerns a production sequence of different types of cars in the mixed-model assembly line.A hybrid algorithm is proposed to find an assembly sequence of CSP with minimum violations.Firstly,the hybrid algorithm is based on the tabu search and large neighborhood search(TLNS),servicing as the framework.Moreover,two components are incorporated into the hybrid algorithm.One is the parallel constructive heuristic(PCH)that is used to construct a set of initial solutions and find some high quality solutions,and the other is the small neighborhood search(SNS)which is designed to improve the new constructed solutions.The computational results show that the proposed hybrid algorithm(PCH+TLNS+SNS)obtains100best known values out of109public instances,among these89instances get their best known values with100%success rate.By comparing with the well-known related algorithms,computational results demonstrate the effectiveness,efficiency and robustness of the proposed algorithm.
基金supported by the Key Project of Science-Technology Basic Condition Platform of the Ministry of Science and Technology of China(2005DKA21402)the Collaborative Innovation Center of Research and Development on Tibetan Characteristic Agricultural and Animal Husbandry Resources(the Plateau Ecology Research Platform)+1 种基金the Special Project Fund for the Development of Local Colleges and Universities supported by the Central Finance in 2016(the Investigation of Insect Resources in Southeast Xizang)the Survey of Forestry Harmful Biology in Tibet
文摘Tipula(Sivatipula)is a small subgenus of Tipula with only fourteen species described in the world,with eight species previously known to occur in China.Here one new species is added to the fauna of China.A key to the species(males)of Tipula(Sivatipula)from China is presented.
基金supported by the National Natural Science Foundation of China (31300551)the Anhui Outstanding Young Talent Support Program (gxfx2017059)
文摘The original description of male hypopygium of Tipula(Emodotipula) holoteles Alexander, 1924 is expanded with additional morphological characters and detailed illustrations. The additional morphological descriptions of the female ovipositor along with detailed drawings are provided. The male semen pump and the female vaginal apodeme as well as the spermatheca are also described and illustrated for the first time, representing the first report of these structures of Tipula(Emodotipula) holoteles. Additionally, the taxonomic potential of the semen pump in the subgenus Emodotipula is analyzed and discussed. The new specific name Tipula(Emodotipula) yangi nom. nov. is proposed as a replacement name for junior homonym Tipula(Emodotipula) alexanderi Men, 2017. A worldwide checklist and a key to Chinese species of the subgenus Emodotipula are provided.
文摘To investigate of pediatric ulcerative colitis activity index (PUCAI) in ulcerative colitis correlate with mucosal inflammation and endoscopic assessment of disease activity (Mayo endoscopic score).METHODSWe reviewed charts from ulcerative colitis patients who had undergone both colonoscopy over 3 years. Clinical assessment of disease severity within 35 d (either before or after) the colonoscopy were included. Patients were excluded if they had significant therapeutic interventions (such as the start of corticosteroids or immunosuppressive agents) between the colonoscopy and the clinical assessment. Mayo endoscopic score of the rectum and sigmoid were done by two gastroenterologists. Inter-observer variability in Mayo score was assessed.RESULTSWe identified 99 patients (53% female, 74% pancolitis) that met inclusion criteria. The indications for colonoscopy included ongoing disease activity (62%), consideration of medication change (10%), assessment of medication efficacy (14%), and cancer screening (14%). Based on PUCAI scores, 33% of patients were in remission, 39% had mild disease, 23% had moderate disease, and 4% had severe disease. There was “moderate-substantial” agreement between the two reviewers in assessing rectal Mayo scores (kappa = 0.54, 95%CI: 0.41-0.68).CONCLUSIONEndoscopic disease severity (Mayo score) assessed by reviewing photographs of pediatric colonoscopy has moderate inter-rater reliability, and agreement was less robust in assessing patients with mild disease activity. Endoscopic disease severity generally correlates with clinical disease severity as measured by PUCAI score. However, children with inflamed colons can have significant variation in their reported clinical symptoms. Thus, assessment of both clinical symptoms and endoscopic disease severity may be required in future clinical studies.
文摘We present the design and performance of a home-built scanning tunneling microscope (STM), which is compact (66 mm tall and 25 mm in diameter), yet equipped with a 3D atomic precision piezoelectric motor in which the Z coarse approach relies on a high simplic-ity friction-type walker (of our own invention) driven by an axially cut piezoelectric tube. The walker is vertically inserted in a piezoelectric scanner tube (PST) with its brim laying at on the PST end as the inertial slider (driven by the PST) for the XZ (sample plane) motion. The STM is designed to be capable of searching rare microscopic targets (defects, dopants, boundaries, nano-devices, etc.) in a macroscopic sample area (square millimeters) under extreme conditions (low temperatures, strong magnetic elds, etc.) in which it ts. It gives good atomic resolution images after scanning a highly oriented pyrolytic graphite sample in air at room temperature.
基金National Science and Technology Support Program of China(No.2009BAG15B02)Key Programs for Science and Technology Development of Chinese Transportation Industry(No.2008-353-332-180)
文摘Taizhou Bridge is a suspension bridge with three pylons and two 1 080 m main spans. The middle pylon is a steel frame with longitudinal herringbone shape and lateral gate shape. The connection between steel pylon and concrete pile cap is a key part to transfer the huge inner force from the pylon to the foundation. Its construction quality is a critical factor to the overall structural loading of the whole bridge ; therefore the contact ratio between the bearing steel plate of pylon and concrete pile cap is required to be over 75 %. The inclined joint surface in two directions, longitudinally at 39/1 920 and laterally at 1/4, posted a challenge to the construction work. A procedure test was carried out to find an optimal construction method by comparison, and finally the post-injection method was selected as it can meet the requirement of concrete strength and contact ratio at the connection. The successful application of the post-injection method in Taizhou Bridge can nrovide an examnle and reference for similar nroiects in the future.
基金Project(2015CB057701)supported by the National Basic Research Program of ChinaProjects(51308071,51378081)supported by the National Natural Science Foundation of China+2 种基金Project(3JJ4057)supported by the Natural Science Foundation of Hunan Province,ChinaProject(12K076)supported by the Open Fund of Innovation Platform in Hunan Provincial Universities,ChinaProject(2015319825120)supported by the Traffic Department of Appliced Basic Research,China
文摘The central buckle, which is often used in a suspension bridge, can improve bridges' performance in the actual operation condition. The influence of the central buckle on natural vibration characteristics and bridge-deck driving comfort of a long-span suspension bridge is studied by using a case study of Siduhe Suspension Bridge in China. Based on the finite element software ANSYS and independently complied program, the influence of the central buckle on the structure force-applied characteristics of a long-span suspension bridge has been explored. The results show that the huge increases of natural frequencies can result in the presence of central buckles because of the increases of bending and torsional rigidities. The central buckle basically makes the stiffening girders and cables within the triangular area covered as a relatively approximate rigid area. Hence, the central buckle can reduce the torsional displacement of the main girder. However, the increases of bending and torsional rigidities have little influence on the impact factor, which is obtained by using vehicle-bridge coupled vibration analysis. This means that the central buckle has little effect on the comfort indices. In addition, it is found that the central buckle can enhance the bridge deck's driving stability due to the decrease of the torsional displacements of the main girder.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (2017R1A2B4008973)supported by grants (17SCIPB119960-02) from the Ministry of Land+2 种基金 Infrastructure and Transport of the Korean Governmentpartially supported by the BK21 PLUS research program of the National Research Foundation of Koreathe New Technology Research Center for Bridges through the Institute of Engineering Research at Seoul National University
文摘This research focuses on identifying the damping ratio of bridges using nonstationary ambient vibration data. The damping ratios of bridges in service have generally been identified using operational modal analysis (OMA) based on a stationary white noise assumption for input signals. However, most bridges are generally subjected to nonstationary excitations while in service, and this violation of the basic assumption can lead to uncertainties in damping identification. To deal with nonstationarity, an amplitude-modulating function was calculated from measured responses to eliminate global trends caused by nonstationary input. A natural excitation technique (NExT)-eigensystem realization algorithm (ERA) was applied to estimate the damping ratio for a stationarized process. To improve the accuracy of OMA-based damping estimates, a comparative analysis was performed between an extracted stationary process and nonstationary data to assess the effect of eliminating nonstationarity. The mean value and standard deviation of the damping ratio for the first vertical mode decreased after signal stationarization.
文摘A rigid central buckle is employed in Runyang Suspension Bridge (RSB) to replace commonly used short suspenders in the main span. Based on the seismic waves with 2% probabilities of exceedance, the nonlinear seismic response time-domain analysis are then conducted and influence of central buckles on seismic response of long-span suspension bridge is specially studied. Analysis resuits show that the central buckle can effectively control the longitudinal floating vibration mode of the deck, and therefore reduce earthquake-excited longitudinal displacement at the end of the deck. However, the central buckle may cause increment of longitudinal displacement at the top of main tower and bending moment at the bottom of the main tower, which should be paid special attention to. Results provide references for anti-earthquake analysis and design of long-span suspension bridges using rigid central buckles.
基金Supported by Academician Jie-Shou Li Intestinal Barrier Research Foundation,No.LJS_201008
文摘AIM To investigate the changes in microbiota in feces of patients with ulcerative colitis(UC) and pouchitis using genomic technology.METHODS Fecal samples were obtained from UC patients with or without an ileal pouch-anal anastomosis(IPAA) procedure, as well as healthy controls. The touchdown polymerase chain reaction technique was used to amplify the whole V3 region of the 16 S r RNA gene, which was transcribed from DNA extracted from fecal samples. Denaturing gradient gel electrophoresis was used to separate the amplicons. The band profiles and similarity indices were analyzed digitally. The predominant microbiota in different groups was confirmed by sequencing the 16 S rR NA gene. RESULTS Microbial biodiversity in the healthy controls was significantly higher compared with the UC groups(P < 0.001) and IPAA groups(P < 0.001). Compared with healthy controls, the UC patients in remission and those in the mildly active stage, the predominant species in patients with moderately and severely active UC changed obviously. In addition, the proportion of the dominant microbiota, which was negatively correlated with the disease activity of UC(r =-6.591, P < 0.01),was decreased in pouchitis patients. The numbers of two types of bacteria, Faecalibacterium prausnitzii and Eubacterium rectale, were reduced in UC. Patients with pouchitis had an altered microbiota composition compared with UC patients. The microbiota from pouchitis patients was less diverse than that from severely active UC patients. Sequencing results showed that similar microbiota, such as Clostridium perfringens, were shared in both UC and pouchitis.CONCLUSION Less diverse fecal microbiota was present in patients with UC and pouchitis. Increased C. perfringens in feces suggest its role in the exacerbation of UC and pouchitis.
基金Project(2017JBZ103)supported by the Fundamental Research Funds for the Central Universities,China
文摘In view of the structure and action behavior of mechatronic systems,a method of searching fault propagation paths called maximum-probability path search(MPPS)is proposed,aiming to determine all possible failure propagation paths with their lengths if faults occur.First,the physical structure system,function behavior,and complex network theory are integrated to define a system structural-action network(SSAN).Second,based on the concept of SSAN,two properties of nodes and edges,i.e.,the topological property and reliability property,are combined to define the failure propagation property.Third,the proposed MPPS model provides all fault propagation paths and possible failure rates of nodes on these paths.Finally,numerical experiments have been implemented to show the accuracy and advancement compared with the methods of Function Space Iteration(FSI)and the algorithm of Ant Colony Optimization(ACO).
基金project of the Ministry of Sciences and Technology of the People’s Republic of China (GYHY200706020)projects of National Natural Science Foundation of China ((40975034, 40505009)project of State Key Laboratory of Severe Weather (2008LASW-A01)
文摘In this study,we derived atmospheric profiles of temperature,moisture,and ozone,along with surface emissivity,skin temperature,and surface pressure,from infrared-sounder radiances under clear sky (cloudless) condition.Clouds were detected objectively using the Atmospheric Infrared Sounder under a relatively low spatial resolution and cloud-mask information from the Moderate Resolution Imaging Spectroradiometer under a high horizontal resolution;this detection was conducted using space matching.Newton’s nonlinear physical iterative solution technique is applied to the radiative transfer equation (RTE) to retrieve temperature profiles,relative humidity profiles,and surface variables simultaneously.This technique is carried out by using the results of an eigenvector regression retrieval as the background profile and using corresponding iterative forms for the weighting functions of temperature and water-vapor mixing ratio.The iterative forms are obtained by applying the variational principle to the RTE.We also compared the retrievals obtained with different types of observations.The results show that the retrieved atmospheric sounding profile has great superiority over other observations by accuracy and resolution.Retrieved profiles can be used to improve the initial conditions of numerical models and used in areas where conventional observations are sparse,such as plateaus,deserts,and seas.
基金National Science and Technology Support Program of China ( No. 2009BAG15B02)
文摘Taizhou Yangtze River Highway Bridge is a large span suspension bridge with three pylons. The elastic cables are installed to connect the steel tower and the steel box girder. The constraints can increase the safety coefficient of the middle saddle, and improve the stress conditions of the middle pylon and decrease the deflection in the middle of the main girder, as well as the longitudinal displacement of the main girder caused by live loads. The anchorage boxes of the elastic cable are installed in the wind fairing outside the vertical web plate of the box girder. Two anchor boxes form a pair and are arranged parallelly. Eight anchor boxes are installed in the bridge. In this paper, the design scheme and the technical difficulties in manufacturing are briefly discussed with the precision control techniques.
基金Project(51078080)supported by the National Natural Science Foundation of ChinaProject(20130969010)supported by Aeronautical Science Foundation of China+1 种基金Project(2011Y03-6)supported by Traffic Transportation Technology Project of Jiangsu Province,ChinaProject(BK2012562)supported by the Natural Science Foundation of Jiangsu Province,China
文摘Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.First,the effects of temperature on the main girder spatial position coordinates were analyzed from the transverse,longitudinal and vertical directions of bridge,and the correlation regression models were built between temperature and the position coordinates of main girder in the longitudinal and vertical directions;then the alarming indices of coordinate residuals were conducted,and the mean-value control chart was applied to making statistical pattern identification for abnormal changes of girder dynamic coordinates;and finally,the structural damage alarming method of main girder was established.Analysis results show that temperature has remarkable correlation with position coordinates in the longitudinal and vertical directions of bridge,and has weak correlation with the transverse coordinates.The 3%abnormal change of the longitudinal coordinates and 5%abnormal change of the vertical ones caused by structural damage are respectively identified by the mean-value control chart method based on GPS dynamic monitoring data and hence the structural abnormalities state identification and damage alarming for main girder of long-span suspension bridge can be realized in multiple directions.
基金National Science and Technology Planning Project(No.2006BAG04B02)
文摘This paper focuses on introducing the manufacture technology of 1 770 MPa galvanized steel wires for stay cables applied to domestic bridges.During the development practices of high strength galvanized wire for stay cables used in Sutong Bridge,Baosteel has established three key technologies based on research of manufacture technology and technical innovation.The three key technologies are:"Double Tensioning + limiter die" process,"dominant process + fine adjustment" in integrated optimization technology and "three-level control" in hot dip galvanization.With these key technologies,Baosteel has produced 1 770 MPa galvanized wires for stay cable,which has high tensile strength,low relaxation and good torsion performances.