Joint roughness coefficient（JRC） is the key parameter for the empirical estimation of joint shear strength by using the JRC-JCS（joint wall compressive strength） model.Because JRC has such characteristics as nonuni...Joint roughness coefficient（JRC） is the key parameter for the empirical estimation of joint shear strength by using the JRC-JCS（joint wall compressive strength） model.Because JRC has such characteristics as nonuniformity,anisotropy,and unhomogeneity,directional statistical measurement of JRC is the precondition for ensuring the reliability of the empirical estimation method.However,the directional statistical measurement of JRC is time-consuming.In order to present an ideal measurement method of JRC,new profilographs and roughness rulers were developed according to the properties of rock joint undulating shape based on the review of measurement methods of JRC.Operation methods of the profilographs and roughness rulers were also introduced.A case study shows that the instruments and operation methods produce an effective means for the statistical measurement of JRC.展开更多
The gold nanoparticles in diameter of 10-95 nm have been prepared by Frens procedure, all of which exhibit a resonance scattering peak at 580 nm. The mechanism of resonance scattering for gold nanoparticle has been co...The gold nanoparticles in diameter of 10-95 nm have been prepared by Frens procedure, all of which exhibit a resonance scattering peak at 580 nm. The mechanism of resonance scattering for gold nanoparticle has been considered according to the wave motion theory of nanoparticle in liquid. The principle of superamolecular interface energy band(SIEB) has been set up and utilized to explain the relationship between the diameter and colors for gold nanoparticle in liquid. A novel spectrophotometric ruler for the determination of the diameter has been proposed according to the relationship of the maximum absorption wavelength and diameter.展开更多
AIM:To measure in vitro diameter of imitational varices using a self-made endoscopic scale and confirm its accuracy and clinical feasibility.METHODS:A catheter was introduced into the endoscopeaccessory channel and at...AIM:To measure in vitro diameter of imitational varices using a self-made endoscopic scale and confirm its accuracy and clinical feasibility.METHODS:A catheter was introduced into the endoscopeaccessory channel and attached to a zebra wire guide that was used as a stylet.The wire guide was fixed onto the tip of the catheter by a soft and thin string.By gently advancing the stylet into the catheter,the width of the opening loop at the tip of the endoscope approximated the diameter of the imitational varices.Measurements performed in vitro using this self-made endoscopic ruler were compared to measurements of simulative varices.RESULTS:At the handle,the sleeve moving distance ranged from 5 to 14 mm.There was no obvious proportional relationship between the sleeve movement distance and endoscopic measurement ruler.The results indicated that the gap between the endoscopic measurement and actual measurement of the object size tended to close.The in vitro measurement of the diameter of the simulative varices showed that the two kinds of measuring methods were not significantly different with respect to their accuracy(P=0.8499).CONCLUSION:In vitro experiments confirmed that using a self-designed endoscopic ruler to measure the diameter of simulative varices was objective,accurate and feasible.展开更多
A three-dimensional mathematical model was established to investigate the behavior of molten steel flow and steel/slag interface with different processes and electromagnetic parameters under two different static magne...A three-dimensional mathematical model was established to investigate the behavior of molten steel flow and steel/slag interface with different processes and electromagnetic parameters under two different static magnetic field configurations [ruler-type electromagnetic brake （EMBr ruler） and vertical electromagnetic brake （V-EMBr）] in a continuous casting mold. The results showed that the brake effect of EMBr ruler is significantly influenced by its configuration parameters, the distance between the pole and bottom of the submerged entry nozzle （SEN）, and the port angle of the SEN outlet; therefore, it is not helpful to depress the diffusion of jet flow along the thickness direction of mold. For a constant SEN depth and port angle, there is a reasonable pole position （P = 0 mm） where the pole simultaneously covers three key zones, i.e., the jet flow impact zone and the upward and downward backflow zones. For V-EMBr, the magnetic field can simultaneously cover the three key zones and depress the diffusion of jet flow along the casting and thickness directions of the mold. Both the meniscus height and the impact intensity of the jet flow can be obviously depressed by V-EMBr even if the SEN depth and port angle have changed in the continuous casting process.展开更多
BACKGROUND We invented Endoscopic Ruler,a new endoscopic device to measure the size of varices in patients with cirrhosis and portal hypertension.AIM To assess the feasibility and safety of Endoscopic Ruler,and evalua...BACKGROUND We invented Endoscopic Ruler,a new endoscopic device to measure the size of varices in patients with cirrhosis and portal hypertension.AIM To assess the feasibility and safety of Endoscopic Ruler,and evaluate the agreement on identifying large oesophageal varices(OV)between Endoscopic Ruler and the endoscopists,as well as the interobserver agreement on diagnosing large OV using Endoscopic Ruler.METHODS We prospectively and consecutively enrolled patients with cirrhosis from 11 hospitals,all of whom got esophagogastroduodenoscopy(EGD)with Endoscopic Ruler.The primary study outcome was a successful measurement of the size of varices using Endoscopic Ruler.The secondary outcomes included adverse events,operation time,the agreement of identifying large OV between the objective measurement of Endoscopic Ruler and the empirical reading of endoscopists,together with the interobserver agreement on diagnosing large OV by Endoscopic Ruler.RESULTS From November 2020 to April 2022,a total of 120 eligible patients with cirrhosis were recruited and all of them underwent EGD examinations with Endoscopic Ruler successfully without any adverse event.The median operation time of Endoscopic Ruler was 3.00 min[interquartile range(IQR):3.00 min].The kappa value between Endoscopic Ruler and the endoscopists while detecting large OV was 0.52,demonstrating a moderate agreement.The kappa value for diagnosing large OV using Endoscopic Ruler among the six independent observers was 0.77,demonstrating a substantial agreement.CONCLUSION The data demonstrates that Endoscopic Ruler is feasible and safe for measuring the size of varices in patients with cirrhosis and portal hypertension.Endoscopic Ruler is potential to promote the clinical practice of the two-grade classification system of OV.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 40672186, 50809059)the Natural Science Foundation of Zhejiang Province (No.Y505008)
文摘Joint roughness coefficient（JRC） is the key parameter for the empirical estimation of joint shear strength by using the JRC-JCS（joint wall compressive strength） model.Because JRC has such characteristics as nonuniformity,anisotropy,and unhomogeneity,directional statistical measurement of JRC is the precondition for ensuring the reliability of the empirical estimation method.However,the directional statistical measurement of JRC is time-consuming.In order to present an ideal measurement method of JRC,new profilographs and roughness rulers were developed according to the properties of rock joint undulating shape based on the review of measurement methods of JRC.Operation methods of the profilographs and roughness rulers were also introduced.A case study shows that the instruments and operation methods produce an effective means for the statistical measurement of JRC.
文摘The gold nanoparticles in diameter of 10-95 nm have been prepared by Frens procedure, all of which exhibit a resonance scattering peak at 580 nm. The mechanism of resonance scattering for gold nanoparticle has been considered according to the wave motion theory of nanoparticle in liquid. The principle of superamolecular interface energy band(SIEB) has been set up and utilized to explain the relationship between the diameter and colors for gold nanoparticle in liquid. A novel spectrophotometric ruler for the determination of the diameter has been proposed according to the relationship of the maximum absorption wavelength and diameter.
基金Supported by Chinese Postdoctoral Science Foundation,Grant 2012T50868
文摘AIM:To measure in vitro diameter of imitational varices using a self-made endoscopic scale and confirm its accuracy and clinical feasibility.METHODS:A catheter was introduced into the endoscopeaccessory channel and attached to a zebra wire guide that was used as a stylet.The wire guide was fixed onto the tip of the catheter by a soft and thin string.By gently advancing the stylet into the catheter,the width of the opening loop at the tip of the endoscope approximated the diameter of the imitational varices.Measurements performed in vitro using this self-made endoscopic ruler were compared to measurements of simulative varices.RESULTS:At the handle,the sleeve moving distance ranged from 5 to 14 mm.There was no obvious proportional relationship between the sleeve movement distance and endoscopic measurement ruler.The results indicated that the gap between the endoscopic measurement and actual measurement of the object size tended to close.The in vitro measurement of the diameter of the simulative varices showed that the two kinds of measuring methods were not significantly different with respect to their accuracy(P=0.8499).CONCLUSION:In vitro experiments confirmed that using a self-designed endoscopic ruler to measure the diameter of simulative varices was objective,accurate and feasible.
基金This work was financially supported by the National Natural Science Foundation of China （No. 51574083） and the Program of Introducing Talents of Discipline to Universities （The 111 Project of China, No. B07015）. The authors would also like to thank the referees for their work which has contributed to this paper.
文摘A three-dimensional mathematical model was established to investigate the behavior of molten steel flow and steel/slag interface with different processes and electromagnetic parameters under two different static magnetic field configurations [ruler-type electromagnetic brake （EMBr ruler） and vertical electromagnetic brake （V-EMBr）] in a continuous casting mold. The results showed that the brake effect of EMBr ruler is significantly influenced by its configuration parameters, the distance between the pole and bottom of the submerged entry nozzle （SEN）, and the port angle of the SEN outlet; therefore, it is not helpful to depress the diffusion of jet flow along the thickness direction of mold. For a constant SEN depth and port angle, there is a reasonable pole position （P = 0 mm） where the pole simultaneously covers three key zones, i.e., the jet flow impact zone and the upward and downward backflow zones. For V-EMBr, the magnetic field can simultaneously cover the three key zones and depress the diffusion of jet flow along the casting and thickness directions of the mold. Both the meniscus height and the impact intensity of the jet flow can be obviously depressed by V-EMBr even if the SEN depth and port angle have changed in the continuous casting process.
基金This study is registered at https://www.clinicaltrials.gov/.The registration identification number is NCT04639323.
文摘BACKGROUND We invented Endoscopic Ruler,a new endoscopic device to measure the size of varices in patients with cirrhosis and portal hypertension.AIM To assess the feasibility and safety of Endoscopic Ruler,and evaluate the agreement on identifying large oesophageal varices(OV)between Endoscopic Ruler and the endoscopists,as well as the interobserver agreement on diagnosing large OV using Endoscopic Ruler.METHODS We prospectively and consecutively enrolled patients with cirrhosis from 11 hospitals,all of whom got esophagogastroduodenoscopy(EGD)with Endoscopic Ruler.The primary study outcome was a successful measurement of the size of varices using Endoscopic Ruler.The secondary outcomes included adverse events,operation time,the agreement of identifying large OV between the objective measurement of Endoscopic Ruler and the empirical reading of endoscopists,together with the interobserver agreement on diagnosing large OV by Endoscopic Ruler.RESULTS From November 2020 to April 2022,a total of 120 eligible patients with cirrhosis were recruited and all of them underwent EGD examinations with Endoscopic Ruler successfully without any adverse event.The median operation time of Endoscopic Ruler was 3.00 min[interquartile range(IQR):3.00 min].The kappa value between Endoscopic Ruler and the endoscopists while detecting large OV was 0.52,demonstrating a moderate agreement.The kappa value for diagnosing large OV using Endoscopic Ruler among the six independent observers was 0.77,demonstrating a substantial agreement.CONCLUSION The data demonstrates that Endoscopic Ruler is feasible and safe for measuring the size of varices in patients with cirrhosis and portal hypertension.Endoscopic Ruler is potential to promote the clinical practice of the two-grade classification system of OV.
