BACKGROUND Traditional esophagogastroduodenoscopy(EGD),an invasive examination method,can cause discomfort and pain in patients.In contrast,magnetically controlled capsule endoscopy(MCE),a noninvasive method,is being ...BACKGROUND Traditional esophagogastroduodenoscopy(EGD),an invasive examination method,can cause discomfort and pain in patients.In contrast,magnetically controlled capsule endoscopy(MCE),a noninvasive method,is being applied for the detection of stomach and small intestinal diseases,but its application in treating esophageal diseases is not widespread.AIM To evaluate the safety and efficacy of detachable string MCE(ds-MCE)for the diagnosis of esophageal diseases.METHODS Fifty patients who had been diagnosed with esophageal diseases were pros-pectively recruited for this clinical study and underwent ds-MCE and conven-tional EGD.The primary endpoints included the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for patients with esophageal diseases.The secondary endpoints consisted of visualizing the esophageal and dentate lines,as well as the subjects'tolerance of the procedure.RESULTS Using EGD as the gold standard,the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for esophageal disease detection were 85.71%,86.21%,81.82%,89.29%,and 86%,respectively.ds-MCE was more comfortable and convenient than EGD was,with 80%of patients feeling that ds-MCE examination was very comfortable or comfortable and 50%of patients believing that detachable string v examination was very convenient.CONCLUSION This study revealed that ds-MCE has the same diagnostic effects as traditional EGD for esophageal diseases and is more comfortable and convenient than EGD,providing a novel noninvasive method for treating esophageal diseases.展开更多
Using real fields instead of complex ones, it is suggested here that the fermions are pairs of coupled strings with an internal tension. The interaction between the two coupled strings is due to an exchange mechanism ...Using real fields instead of complex ones, it is suggested here that the fermions are pairs of coupled strings with an internal tension. The interaction between the two coupled strings is due to an exchange mechanism which is proportional to Planck’s constant. This may be the result of two massless bosons (hypergluons) coupled by a preon (prequark) exchange. It also gives a physical explanation to the origin of the Planck constant, and origin of spin.展开更多
A model for particles based on preons in chiral, vector and tensor/graviton supermultiplets of unbroken global supersymmetry is engineered. The framework of the model is little string theory. Phenomenological predicti...A model for particles based on preons in chiral, vector and tensor/graviton supermultiplets of unbroken global supersymmetry is engineered. The framework of the model is little string theory. Phenomenological predictions are discussed.展开更多
We compare, following Pati, global symmetries, our topological supersymmetric preon model with the heterotic E<sub>8</sub> × E<sub>8</sub> string theory. We include Pati’s supergravity ba...We compare, following Pati, global symmetries, our topological supersymmetric preon model with the heterotic E<sub>8</sub> × E<sub>8</sub> string theory. We include Pati’s supergravity based preon model in this work and compare the preon interactions of his model to ours. Based on preon-string symmetry comparison and preon phenomenological results, we conclude that the fundamental particles are likely preons rather than standard model particles. .展开更多
The mechanical behavior,dynamic evolution,and flow-field distribution of a two-degree-of-freedom riserless drill string were simulated numerically by using FLUENT fluid simulation software with the user-defined functi...The mechanical behavior,dynamic evolution,and flow-field distribution of a two-degree-of-freedom riserless drill string were simulated numerically by using FLUENT fluid simulation software with the user-defined function embedded.The rotation angular velocities before and after the critical rotation angular velocity were used as independent variables,and the reduced velocity range was 3-14.Fluid-structure coupling was realized based on the dynamic overset grid and the SST k-ωturbulence model.Results reveal that the dynamic response of the riserless drill string was considerably affected by rotation and flow velocity,which are coupled with each other.The cross-flow average dimensionless displacement increased with the rotation angular velocity,and rotation considerably enhanced the in-line maximum average dimensionless displacement.However,the cross-flow amplitude caused by vortex-induced vibration was suppressed when the rotation angular velocity reached a certain value.The in-line and cross-flow frequencies were the same,thereby causing the trajectory to deviate from the standard'figure-eight'shape and become a closed circle shape.The vortex did not fall behind the cylinder at low reduced velocity with high-rotation angular velocity,and the structure of the near-wake vortex remained U-shaped.The wake of the cylinder was deflected along the cross-flow direction,thereby leading to vibration asymmetry and resulting in increased vibration instability and disordered vibration trajectories,especially at high-rotation angular velocities.展开更多
Data centers are being distributed worldwide by cloud service providers(CSPs)to save energy costs through efficient workload alloca-tion strategies.Many CSPs are challenged by the significant rise in user demands due ...Data centers are being distributed worldwide by cloud service providers(CSPs)to save energy costs through efficient workload alloca-tion strategies.Many CSPs are challenged by the significant rise in user demands due to their extensive energy consumption during workload pro-cessing.Numerous research studies have examined distinct operating cost mitigation techniques for geo-distributed data centers(DCs).However,oper-ating cost savings during workload processing,which also considers string-matching techniques in geo-distributed DCs,remains unexplored.In this research,we propose a novel string matching-based geographical load balanc-ing(SMGLB)technique to mitigate the operating cost of the geo-distributed DC.The primary goal of this study is to use a string-matching algorithm(i.e.,Boyer Moore)to compare the contents of incoming workloads to those of documents that have already been processed in a data center.A successful match prevents the global load balancer from sending the user’s request to a data center for processing and displaying the results of the previously processed workload to the user to save energy.On the contrary,if no match can be discovered,the global load balancer will allocate the incoming workload to a specific DC for processing considering variable energy prices,the number of active servers,on-site green energy,and traces of incoming workload.The results of numerical evaluations show that the SMGLB can minimize the operating expenses of the geo-distributed data centers more than the existing workload distribution techniques.展开更多
The finite element method has been applied to simulate the dynamics of a water plugging string in a complex horizontal well of a low-permeability oilfield.The force associated with the pipe string and the packer has b...The finite element method has been applied to simulate the dynamics of a water plugging string in a complex horizontal well of a low-permeability oilfield.The force associated with the pipe string and the packer has been determined under the sucking action of the oil well pump.Such analysis has been conducted for a real drilling well,taking into account the process of lifting,lowering,unblocking and water plugging.Comparison between field measured data and simulation data indicates that the model is reliable and accurate.The packer creep effect under different pressure differences has also been investigated in the framework of the same model.展开更多
The mechanical behavior of the test string in deep wells is generally relatively complex as a result of the high temperature and high pressure,severe dogleg and buckling effects,which in some circumstances can even le...The mechanical behavior of the test string in deep wells is generally relatively complex as a result of the high temperature and high pressure,severe dogleg and buckling effects,which in some circumstances can even lead to string failure.Traditional computational methods for the analysis of these behaviors are often inaccurate.For this reason,here a more accurate mechanical model of the test string is introduced by considering variables such as temperature,pressure,wellbore trajectory,and buckling,as well as combining them with the deformation and string constraint conditions brought in by changes in temperature and pressure during the tripping,setting,and test operations.The model is validated by applying it to a specific high-pressure gas well(located in Northeast Sichuan).展开更多
To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells...To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells were selected to carry out the running test of sand control string with pre-packed screen.Meanwhile,the running simulation was performed by using the Landmark software.The results show that the sand control packer and screen can be run smoothly in the wellbore with a dogleg angle of more than 20°/30 m and keep the structure stable.Additionally,the comprehensive friction coefficient is 0.4,under which and the simulation shows that the sand control string for hydrate exploitation can be run smoothly.These findings have important guiding significance for running the completion sand control string in natural gas hydrate exploitation.展开更多
String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that...String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that is created and kept by modern computational devices influences researchers to obtain even more powerful methods for coping with this problem. In this research, the Quick Search string matching algorithm are adopted to be implemented under the multi-core environment using OpenMP directive which can be employed to reduce the overall execution time of the program. English text, Proteins and DNA data types are utilized to examine the effect of parallelization and implementation of Quick Search string matching algorithm on multi-core based environment. Experimental outcomes reveal that the overall performance of the mentioned string matching algorithm has been improved, and the improvement in the execution time which has been obtained is considerable enough to recommend the multi-core environment as the suitable platform for parallelizing the Quick Search string matching algorithm.展开更多
提出通过String Kernel方法把负实例语法数据库中的负实例转化成核矩阵,再用Kernel Principal Component Analysis(KPCA)对转换的核矩阵进行特征提取,进而可将原始负实例数据库按照这些特征分成多个容量较小的特征表。通过构造负实例特...提出通过String Kernel方法把负实例语法数据库中的负实例转化成核矩阵,再用Kernel Principal Component Analysis(KPCA)对转换的核矩阵进行特征提取,进而可将原始负实例数据库按照这些特征分成多个容量较小的特征表。通过构造负实例特征索引表设计了一个分类器,待检查的句子通过此分类器被分配到某个负实例特征表里进行匹配搜索,而此特征表的特征属性数和记录数要远远小于原始负实例数据库中的相应数目,从而大大提高了检查的速度,同时不影响语法检查的精度。通过比较测试,可看出提出的方法在保证语法检查精确度的同时有更快的速度。展开更多
Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Jap...Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits(Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk(Accipiter nisus) and Common Cuckoo(Cuculus canorus).Methods: Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls(C–D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C–D calls, and they showed a significantly stronger response to both C and C–D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls.Conclusions: Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.展开更多
Persimmon(Diospyros kaki)is an oriental perennial woody fruit tree whose popular fruit is produced and consumed worldwide.The persimmon fruit is unique because of the hyperaccumulation of proanthocyanidins during frui...Persimmon(Diospyros kaki)is an oriental perennial woody fruit tree whose popular fruit is produced and consumed worldwide.The persimmon fruit is unique because of the hyperaccumulation of proanthocyanidins during fruit development,causing the mature fruit of most cultivars to have an astringent taste.In this study,we obtained a chromosome-scale genome assembly for‘Youshi’(Diospyros oleifera,2n=2x=30),the diploid species of persimmon,by integrating Illumina sequencing,single-molecule real-time sequencing,and high-throughput chromosome conformation capture techniques.The assembled D.oleifera genome consisted of 849.53 Mb,94.14%(799.71 Mb)of which was assigned to 15 pseudochromosomes,and is the first assembled genome for any member of the Ebenaceae.Comparative genomic analysis revealed that the D.oleifera genome underwent an ancientγwhole-genome duplication event.We studied the potential genetic basis for astringency development(proanthocyanidin biosynthesis)and removal(proanthocyanidin insolublization).Proanthocyanidin biosynthesis genes were mainly distributed on chromosome 1,and the clustering of these genes is responsible for the genetic stability of astringency heredity.Genome-based RNA-seq identified deastringency genes,and promoter analysis showed that most of their promoters contained large numbers of low oxygen-responsive motifs,which is consistent with the efficient industrial application of high CO2 treatment to remove astringency.Using the D.oleifera genome as the reference,SLAF-seq indicated that‘Youshi’is one of the ancestors of the cultivated persimmon(2n=6x=90).Our study provides significant insights into the genetic basis of persimmon evolution and the development and removal astringency,and it will facilitate the improvement of the breeding of persimmon fruit.展开更多
Applying pre-stress in glulam beam can reduce its deformation and make full use of the compressive strength of wood.However,when the glulam with low strength and the pre-stressed steel with high strength form combined...Applying pre-stress in glulam beam can reduce its deformation and make full use of the compressive strength of wood.However,when the glulam with low strength and the pre-stressed steel with high strength form combined members,materials of high strength can’t be fully utilized.Therefore,this study puts forward the idea of regulating and controlling string beam of pre-stressed glulam.By regulating and controlling the pre-stress,a part of the load borne by the wood is allocated to the pre-stressed tendon,which is equivalent to completing a redistribution of internal force,thus realizing the repeated utilization of the wood strength and the full utilization of the strength of the high-strength pre-stressed tendon.The bending experiments of 10 beams under 5 working conditions are carried out.The failure mode,bearing capacity and deformation of the beams are analyzed.The results show that 90%of beams are deformed under compression.The ultimate load of the regulated and controlled beam is obviously larger than that of the unregulated beam,and the ultimate load of the beam increases with the increase of the degree of regulation and control.Compared with that of the unregulated beams,the ultimate load of beams regulated by 7.5%-30%increases by 25.42%-65.08%,and the regulated and controlled effect is obvious.With the increase of the regulation and control amplitude of pre-stress,the stiffness of string beam of pre-stressed glulam increases.In addition,with the increase of the regulation and control amplitude,the compression height of the beam increases before the failure,and it reaches the state of full-section compression at the time of failure,giving full play to the compressive property of the glulam.At the end of the experiment,the constitutive relation which can reflect the anisotropy of the wood is established combined with the experimental data.The finite element analysis of the beam under 7 working conditions is carried out by using ABAQUS finite element program,and the influence of the regulation and control amplitude on the stress distribution and ultimate bearing capacity of the beam is discussed.展开更多
A basic classical example of simple harmonic motion is the simple pendulum, consisting of a small bob and a massless string. In a vacuum with zero air resistance, such a pendulum will continue to oscillate indefinitel...A basic classical example of simple harmonic motion is the simple pendulum, consisting of a small bob and a massless string. In a vacuum with zero air resistance, such a pendulum will continue to oscillate indefinitely with a constant amplitude. However, the amplitude of a simple pendulum oscillating in air continuously decreases as its mechanical energy is gradually lost due to air resistance. To this end, it is generally perceived that the main role in the dissipation of mechanical energy is played by the bob of the pendulum, and that the string’s contribution is negligible. The purpose of this research is to experimentally investigate the merit of this assumption. Thus, we experimentally investigate the damping of a simple pendulum as a function of its string diameter and compare that to the contribution from its bob. We find out that although in some cases the effect of the string might be small or even negligible, in general the string can play a significant role, and in some cases even a greater role on the damping of the pendulum than its bob.展开更多
基金the Science and Technology Commission of Shanghai,No.18DZ1930309.
文摘BACKGROUND Traditional esophagogastroduodenoscopy(EGD),an invasive examination method,can cause discomfort and pain in patients.In contrast,magnetically controlled capsule endoscopy(MCE),a noninvasive method,is being applied for the detection of stomach and small intestinal diseases,but its application in treating esophageal diseases is not widespread.AIM To evaluate the safety and efficacy of detachable string MCE(ds-MCE)for the diagnosis of esophageal diseases.METHODS Fifty patients who had been diagnosed with esophageal diseases were pros-pectively recruited for this clinical study and underwent ds-MCE and conven-tional EGD.The primary endpoints included the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for patients with esophageal diseases.The secondary endpoints consisted of visualizing the esophageal and dentate lines,as well as the subjects'tolerance of the procedure.RESULTS Using EGD as the gold standard,the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for esophageal disease detection were 85.71%,86.21%,81.82%,89.29%,and 86%,respectively.ds-MCE was more comfortable and convenient than EGD was,with 80%of patients feeling that ds-MCE examination was very comfortable or comfortable and 50%of patients believing that detachable string v examination was very convenient.CONCLUSION This study revealed that ds-MCE has the same diagnostic effects as traditional EGD for esophageal diseases and is more comfortable and convenient than EGD,providing a novel noninvasive method for treating esophageal diseases.
文摘Using real fields instead of complex ones, it is suggested here that the fermions are pairs of coupled strings with an internal tension. The interaction between the two coupled strings is due to an exchange mechanism which is proportional to Planck’s constant. This may be the result of two massless bosons (hypergluons) coupled by a preon (prequark) exchange. It also gives a physical explanation to the origin of the Planck constant, and origin of spin.
文摘A model for particles based on preons in chiral, vector and tensor/graviton supermultiplets of unbroken global supersymmetry is engineered. The framework of the model is little string theory. Phenomenological predictions are discussed.
文摘We compare, following Pati, global symmetries, our topological supersymmetric preon model with the heterotic E<sub>8</sub> × E<sub>8</sub> string theory. We include Pati’s supergravity based preon model in this work and compare the preon interactions of his model to ours. Based on preon-string symmetry comparison and preon phenomenological results, we conclude that the fundamental particles are likely preons rather than standard model particles. .
基金supported by the National Natural Science Foundation of China(No.U2006226)the National Key Research and Development Program of China(No.2016YFC0303800)。
文摘The mechanical behavior,dynamic evolution,and flow-field distribution of a two-degree-of-freedom riserless drill string were simulated numerically by using FLUENT fluid simulation software with the user-defined function embedded.The rotation angular velocities before and after the critical rotation angular velocity were used as independent variables,and the reduced velocity range was 3-14.Fluid-structure coupling was realized based on the dynamic overset grid and the SST k-ωturbulence model.Results reveal that the dynamic response of the riserless drill string was considerably affected by rotation and flow velocity,which are coupled with each other.The cross-flow average dimensionless displacement increased with the rotation angular velocity,and rotation considerably enhanced the in-line maximum average dimensionless displacement.However,the cross-flow amplitude caused by vortex-induced vibration was suppressed when the rotation angular velocity reached a certain value.The in-line and cross-flow frequencies were the same,thereby causing the trajectory to deviate from the standard'figure-eight'shape and become a closed circle shape.The vortex did not fall behind the cylinder at low reduced velocity with high-rotation angular velocity,and the structure of the near-wake vortex remained U-shaped.The wake of the cylinder was deflected along the cross-flow direction,thereby leading to vibration asymmetry and resulting in increased vibration instability and disordered vibration trajectories,especially at high-rotation angular velocities.
文摘Data centers are being distributed worldwide by cloud service providers(CSPs)to save energy costs through efficient workload alloca-tion strategies.Many CSPs are challenged by the significant rise in user demands due to their extensive energy consumption during workload pro-cessing.Numerous research studies have examined distinct operating cost mitigation techniques for geo-distributed data centers(DCs).However,oper-ating cost savings during workload processing,which also considers string-matching techniques in geo-distributed DCs,remains unexplored.In this research,we propose a novel string matching-based geographical load balanc-ing(SMGLB)technique to mitigate the operating cost of the geo-distributed DC.The primary goal of this study is to use a string-matching algorithm(i.e.,Boyer Moore)to compare the contents of incoming workloads to those of documents that have already been processed in a data center.A successful match prevents the global load balancer from sending the user’s request to a data center for processing and displaying the results of the previously processed workload to the user to save energy.On the contrary,if no match can be discovered,the global load balancer will allocate the incoming workload to a specific DC for processing considering variable energy prices,the number of active servers,on-site green energy,and traces of incoming workload.The results of numerical evaluations show that the SMGLB can minimize the operating expenses of the geo-distributed data centers more than the existing workload distribution techniques.
文摘The finite element method has been applied to simulate the dynamics of a water plugging string in a complex horizontal well of a low-permeability oilfield.The force associated with the pipe string and the packer has been determined under the sucking action of the oil well pump.Such analysis has been conducted for a real drilling well,taking into account the process of lifting,lowering,unblocking and water plugging.Comparison between field measured data and simulation data indicates that the model is reliable and accurate.The packer creep effect under different pressure differences has also been investigated in the framework of the same model.
文摘The mechanical behavior of the test string in deep wells is generally relatively complex as a result of the high temperature and high pressure,severe dogleg and buckling effects,which in some circumstances can even lead to string failure.Traditional computational methods for the analysis of these behaviors are often inaccurate.For this reason,here a more accurate mechanical model of the test string is introduced by considering variables such as temperature,pressure,wellbore trajectory,and buckling,as well as combining them with the deformation and string constraint conditions brought in by changes in temperature and pressure during the tripping,setting,and test operations.The model is validated by applying it to a specific high-pressure gas well(located in Northeast Sichuan).
基金supported jointly by one of the major projects of Basic and Applied Basic Research in Guangdong Province“Key Basic Theory Research for Natural Gas Hydrate Trial Production in Shenhu Pilot Test Area”(2020B0301030003)the project from Southern Marine Science&Engineering Guangdong Laboratory Guangzhou City“Research on New Closed Circulation Drilling Technology without Riser”(GML2019ZD0501)the special project for hydrate from China Geological Survey“Trial Production Implementation for Natural Gas Hydrate in Shenhu Pilot Test Area”(DD20190226)。
文摘To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells were selected to carry out the running test of sand control string with pre-packed screen.Meanwhile,the running simulation was performed by using the Landmark software.The results show that the sand control packer and screen can be run smoothly in the wellbore with a dogleg angle of more than 20°/30 m and keep the structure stable.Additionally,the comprehensive friction coefficient is 0.4,under which and the simulation shows that the sand control string for hydrate exploitation can be run smoothly.These findings have important guiding significance for running the completion sand control string in natural gas hydrate exploitation.
文摘String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that is created and kept by modern computational devices influences researchers to obtain even more powerful methods for coping with this problem. In this research, the Quick Search string matching algorithm are adopted to be implemented under the multi-core environment using OpenMP directive which can be employed to reduce the overall execution time of the program. English text, Proteins and DNA data types are utilized to examine the effect of parallelization and implementation of Quick Search string matching algorithm on multi-core based environment. Experimental outcomes reveal that the overall performance of the mentioned string matching algorithm has been improved, and the improvement in the execution time which has been obtained is considerable enough to recommend the multi-core environment as the suitable platform for parallelizing the Quick Search string matching algorithm.
文摘提出通过String Kernel方法把负实例语法数据库中的负实例转化成核矩阵,再用Kernel Principal Component Analysis(KPCA)对转换的核矩阵进行特征提取,进而可将原始负实例数据库按照这些特征分成多个容量较小的特征表。通过构造负实例特征索引表设计了一个分类器,待检查的句子通过此分类器被分配到某个负实例特征表里进行匹配搜索,而此特征表的特征属性数和记录数要远远小于原始负实例数据库中的相应数目,从而大大提高了检查的速度,同时不影响语法检查的精度。通过比较测试,可看出提出的方法在保证语法检查精确度的同时有更快的速度。
基金supported by the National Natural Science Foundation of China(31272331 and 31470458 to HW,31472013 and 31772453 to WL)the Fundamental Research Funds for the Central Universities(2412016KJ043)the Open Project Program of Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization(130028685)
文摘Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits(Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk(Accipiter nisus) and Common Cuckoo(Cuculus canorus).Methods: Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls(C–D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C–D calls, and they showed a significantly stronger response to both C and C–D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls.Conclusions: Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.
基金supported by the National Key Research and Development Program(2016YFD0400102)the National Natural Science Foundation of China(31672204,31722042)+1 种基金the Fok Ying Tung Education Foundation,China(161028),Key Agricultural New Varieties Breeding Projects funded by the Zhejiang Province Science and Technology Department(2016C02052-10)Fundamental Research Funds of CAF(CAFYBB2017SY015).
文摘Persimmon(Diospyros kaki)is an oriental perennial woody fruit tree whose popular fruit is produced and consumed worldwide.The persimmon fruit is unique because of the hyperaccumulation of proanthocyanidins during fruit development,causing the mature fruit of most cultivars to have an astringent taste.In this study,we obtained a chromosome-scale genome assembly for‘Youshi’(Diospyros oleifera,2n=2x=30),the diploid species of persimmon,by integrating Illumina sequencing,single-molecule real-time sequencing,and high-throughput chromosome conformation capture techniques.The assembled D.oleifera genome consisted of 849.53 Mb,94.14%(799.71 Mb)of which was assigned to 15 pseudochromosomes,and is the first assembled genome for any member of the Ebenaceae.Comparative genomic analysis revealed that the D.oleifera genome underwent an ancientγwhole-genome duplication event.We studied the potential genetic basis for astringency development(proanthocyanidin biosynthesis)and removal(proanthocyanidin insolublization).Proanthocyanidin biosynthesis genes were mainly distributed on chromosome 1,and the clustering of these genes is responsible for the genetic stability of astringency heredity.Genome-based RNA-seq identified deastringency genes,and promoter analysis showed that most of their promoters contained large numbers of low oxygen-responsive motifs,which is consistent with the efficient industrial application of high CO2 treatment to remove astringency.Using the D.oleifera genome as the reference,SLAF-seq indicated that‘Youshi’is one of the ancestors of the cultivated persimmon(2n=6x=90).Our study provides significant insights into the genetic basis of persimmon evolution and the development and removal astringency,and it will facilitate the improvement of the breeding of persimmon fruit.
基金In the process,this project was supported by the Fundamental Research Funds for the Central Universities(2572017DB02)Natural Science Foundation of Heilongjiang Province(JJ2019LH0696)by Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province in 2016(LBH-Q16011).
文摘Applying pre-stress in glulam beam can reduce its deformation and make full use of the compressive strength of wood.However,when the glulam with low strength and the pre-stressed steel with high strength form combined members,materials of high strength can’t be fully utilized.Therefore,this study puts forward the idea of regulating and controlling string beam of pre-stressed glulam.By regulating and controlling the pre-stress,a part of the load borne by the wood is allocated to the pre-stressed tendon,which is equivalent to completing a redistribution of internal force,thus realizing the repeated utilization of the wood strength and the full utilization of the strength of the high-strength pre-stressed tendon.The bending experiments of 10 beams under 5 working conditions are carried out.The failure mode,bearing capacity and deformation of the beams are analyzed.The results show that 90%of beams are deformed under compression.The ultimate load of the regulated and controlled beam is obviously larger than that of the unregulated beam,and the ultimate load of the beam increases with the increase of the degree of regulation and control.Compared with that of the unregulated beams,the ultimate load of beams regulated by 7.5%-30%increases by 25.42%-65.08%,and the regulated and controlled effect is obvious.With the increase of the regulation and control amplitude of pre-stress,the stiffness of string beam of pre-stressed glulam increases.In addition,with the increase of the regulation and control amplitude,the compression height of the beam increases before the failure,and it reaches the state of full-section compression at the time of failure,giving full play to the compressive property of the glulam.At the end of the experiment,the constitutive relation which can reflect the anisotropy of the wood is established combined with the experimental data.The finite element analysis of the beam under 7 working conditions is carried out by using ABAQUS finite element program,and the influence of the regulation and control amplitude on the stress distribution and ultimate bearing capacity of the beam is discussed.
文摘A basic classical example of simple harmonic motion is the simple pendulum, consisting of a small bob and a massless string. In a vacuum with zero air resistance, such a pendulum will continue to oscillate indefinitely with a constant amplitude. However, the amplitude of a simple pendulum oscillating in air continuously decreases as its mechanical energy is gradually lost due to air resistance. To this end, it is generally perceived that the main role in the dissipation of mechanical energy is played by the bob of the pendulum, and that the string’s contribution is negligible. The purpose of this research is to experimentally investigate the merit of this assumption. Thus, we experimentally investigate the damping of a simple pendulum as a function of its string diameter and compare that to the contribution from its bob. We find out that although in some cases the effect of the string might be small or even negligible, in general the string can play a significant role, and in some cases even a greater role on the damping of the pendulum than its bob.
