The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning space.In this paper,we pro-pose an adaptive space expansion(ASE)approac...The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning space.In this paper,we pro-pose an adaptive space expansion(ASE)approach which belongs to the informed sampling category to improve the sampling effi-ciency for quickly finding a feasible path.The ASE method enlarges the search space gradually and restrains the sampling process in a sequence of small hyper-ellipsoid ring subsets to avoid exploring the unnecessary space.Specifically,for a con-structed small hyper-ellipsoid ring subset,if the algorithm cannot find a feasible path in it,then the subset is expanded.Thus,the ASE method successively does space exploring and space expan-sion until the final path has been found.Besides,we present a particular construction method of the hyper-ellipsoid ring that uniform random samples can be directly generated in it.At last,we present a feasible motion planner BiASE and an asymptoti-cally optimal motion planner BiASE*using the bidirectional exploring method and the ASE strategy.Simulations demon-strate that the computation speed is much faster than that of the state-of-the-art algorithms.The source codes are available at https://github.com/shshlei/ompl.展开更多
Scale factor of a constant rate biased ring laser gyro （RLG） is studied both theoretically and experimentally. By analyzing experimental data, we find that there are three main terms contributing to the scale factor...Scale factor of a constant rate biased ring laser gyro （RLG） is studied both theoretically and experimentally. By analyzing experimental data, we find that there are three main terms contributing to the scale factor deviation. One of them is independent of time, the second varies linearly with time and the third varies exponentially with time. Theoretical analyses show that the first term is caused by experimental setup, the second and the third are caused by un-uniform thermal expension and cavity loss variation of the RLG.展开更多
Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyc...Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyclic polymers characterized by the endless topology have received extensive attention due to their distinct physical properties as compared to the linear counterparts.To understand these differences and unravel the underlying mechanisms,there is a long pursuit to efficiently fabricate macrocyclic polymers.To date,both ring-closing and ring-expansion strategies have been developed,which drastically elevates the accessibility of macrocyclic polymers.The improved availability of macrocyclic polymers enables the further investigation of the biomedical applications and the preliminary results suggest that macrocyclic polymers outperform their linear analogs in terms of improving gene delivery efficiency,elevating blood circulation time,and enhancing colloidal stability of nanoparticles.展开更多
BACKGROUND The retrospective review of I-ring pupil expansion ring use is designed to examine the patient characteristics and associated surgical challenges in a clinical practice.The hypothesis is that I-ring provide...BACKGROUND The retrospective review of I-ring pupil expansion ring use is designed to examine the patient characteristics and associated surgical challenges in a clinical practice.The hypothesis is that I-ring provides a necessary additive tool in dealing with challenging cataract surgeries with small pupils.AIM To document the safety profile and use of I-ring pupil expansion ring in a clinical practice.METHODS A retrospective chart review of 12 consecutive cases within the same year(2016)of cataract surgeries employing I-ring pupil expansion ring(Beaver-Visitec,International)by a single surgeon at the same ambulatory surgical center was conducted.Demographic,pre-op,intra-op,and post-op data were recorded.Total number of cataract cases performed was also recorded.RESULTS 8 of 12 cases were planned I-ring cases.1 case was decided intraoperatively when femtosecond laser caused the pupil to shrink.The other 3 cases were also decided upon intraoperatively when pupil was deemed to be small.7 patients had IFIS from Flomax use.2 patients had pseudoexfoliation syndrome as the cause of small pupil.2 patients had narrow angles with brunescent cataracts.2 patients had pre-op partial zonular dehiscence.1 patient had 360o of posterior synechiae.2 cases had ruptured posterior capsule that required anterior vitrectomy.No complications were attributed to the pupil expansion ring.A total of 296 cataract surgeries were performed that year by the surgeon,making the rate of pupil ring use 4.1%.CONCLUSION Small pupil requiring pupil expansion ring during cataract surgery is often associated with other challenges,such as brunescent cataract,zonular weakness,and posterior synechiae in this series.I-ring helped to reduce at least one challenge in these difficult cases.展开更多
A convenient synthetic pathway to 2-aryl-5,6-dihydro-4H-benzo[f][1,2,4]triazolo[1,5-a]azepine derivatives 7 was developed.The synthesis was based on the cycloaddition of the 1,2,3,4-tetrahydronaphthalene α-acetoxy az...A convenient synthetic pathway to 2-aryl-5,6-dihydro-4H-benzo[f][1,2,4]triazolo[1,5-a]azepine derivatives 7 was developed.The synthesis was based on the cycloaddition of the 1,2,3,4-tetrahydronaphthalene α-acetoxy azo compounds 3 with Ar-CN in the presence of AlCl3 and the consecutive ring enlargement.展开更多
The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca＋ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms o...The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca＋ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms of symmetry energy. It is found that the neutron-rich system has smaller threshold energy of radial flow and this quantity depends on the form of symmetry potential. It is indicated that the threshold energy of radial flow can provide a new method to determine the symmetry energy of asymmetric nuclear matter.展开更多
基金supported in part by the National Natural Science Foun-dation of China(51975236)the National Key Research and Development Program of China(2018YFA0703203)the Innovation Project of Optics Valley Laboratory(OVL2021BG007)。
文摘The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning space.In this paper,we pro-pose an adaptive space expansion(ASE)approach which belongs to the informed sampling category to improve the sampling effi-ciency for quickly finding a feasible path.The ASE method enlarges the search space gradually and restrains the sampling process in a sequence of small hyper-ellipsoid ring subsets to avoid exploring the unnecessary space.Specifically,for a con-structed small hyper-ellipsoid ring subset,if the algorithm cannot find a feasible path in it,then the subset is expanded.Thus,the ASE method successively does space exploring and space expan-sion until the final path has been found.Besides,we present a particular construction method of the hyper-ellipsoid ring that uniform random samples can be directly generated in it.At last,we present a feasible motion planner BiASE and an asymptoti-cally optimal motion planner BiASE*using the bidirectional exploring method and the ASE strategy.Simulations demon-strate that the computation speed is much faster than that of the state-of-the-art algorithms.The source codes are available at https://github.com/shshlei/ompl.
文摘Scale factor of a constant rate biased ring laser gyro （RLG） is studied both theoretically and experimentally. By analyzing experimental data, we find that there are three main terms contributing to the scale factor deviation. One of them is independent of time, the second varies linearly with time and the third varies exponentially with time. Theoretical analyses show that the first term is caused by experimental setup, the second and the third are caused by un-uniform thermal expension and cavity loss variation of the RLG.
基金supported by the National Natural Science Foundation of China(51690150,51690154,21674103,51673179)International S&T Cooperation Program of China of MOST(2016YFE0129700)
文摘Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyclic polymers characterized by the endless topology have received extensive attention due to their distinct physical properties as compared to the linear counterparts.To understand these differences and unravel the underlying mechanisms,there is a long pursuit to efficiently fabricate macrocyclic polymers.To date,both ring-closing and ring-expansion strategies have been developed,which drastically elevates the accessibility of macrocyclic polymers.The improved availability of macrocyclic polymers enables the further investigation of the biomedical applications and the preliminary results suggest that macrocyclic polymers outperform their linear analogs in terms of improving gene delivery efficiency,elevating blood circulation time,and enhancing colloidal stability of nanoparticles.
基金Supported by a research grant from Beaver-Visited International,the manufacturer of the I-ring
文摘BACKGROUND The retrospective review of I-ring pupil expansion ring use is designed to examine the patient characteristics and associated surgical challenges in a clinical practice.The hypothesis is that I-ring provides a necessary additive tool in dealing with challenging cataract surgeries with small pupils.AIM To document the safety profile and use of I-ring pupil expansion ring in a clinical practice.METHODS A retrospective chart review of 12 consecutive cases within the same year(2016)of cataract surgeries employing I-ring pupil expansion ring(Beaver-Visitec,International)by a single surgeon at the same ambulatory surgical center was conducted.Demographic,pre-op,intra-op,and post-op data were recorded.Total number of cataract cases performed was also recorded.RESULTS 8 of 12 cases were planned I-ring cases.1 case was decided intraoperatively when femtosecond laser caused the pupil to shrink.The other 3 cases were also decided upon intraoperatively when pupil was deemed to be small.7 patients had IFIS from Flomax use.2 patients had pseudoexfoliation syndrome as the cause of small pupil.2 patients had narrow angles with brunescent cataracts.2 patients had pre-op partial zonular dehiscence.1 patient had 360o of posterior synechiae.2 cases had ruptured posterior capsule that required anterior vitrectomy.No complications were attributed to the pupil expansion ring.A total of 296 cataract surgeries were performed that year by the surgeon,making the rate of pupil ring use 4.1%.CONCLUSION Small pupil requiring pupil expansion ring during cataract surgery is often associated with other challenges,such as brunescent cataract,zonular weakness,and posterior synechiae in this series.I-ring helped to reduce at least one challenge in these difficult cases.
基金carried out with the financial assistance of the National Natural Science Foundation of China （Project 20372015）.
文摘A convenient synthetic pathway to 2-aryl-5,6-dihydro-4H-benzo[f][1,2,4]triazolo[1,5-a]azepine derivatives 7 was developed.The synthesis was based on the cycloaddition of the 1,2,3,4-tetrahydronaphthalene α-acetoxy azo compounds 3 with Ar-CN in the presence of AlCl3 and the consecutive ring enlargement.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10575012 and 10435020, the Science Foundation of Beljlng, and the Science Foundation of Beijing Normal University.
文摘The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca＋ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms of symmetry energy. It is found that the neutron-rich system has smaller threshold energy of radial flow and this quantity depends on the form of symmetry potential. It is indicated that the threshold energy of radial flow can provide a new method to determine the symmetry energy of asymmetric nuclear matter.
