The dynamic modal model analysis of the oil casing connection is done by finite element method (FEM), and the first nature frequency, the second nature frequency, the vibration mode shape and the time domain of the no...The dynamic modal model analysis of the oil casing connection is done by finite element method (FEM), and the first nature frequency, the second nature frequency, the vibration mode shape and the time domain of the node displacement and the element stress variation in the thread connection are gotten. The Von.Mises stresses of the connection in the static and dynamic state are also studied. The results of calculation and analysis show: (1) because the maximum of static stress is at the coupling thread end of connection, the connection begins to thread off at the coupling thread end, which is in accord with the results of the thread off experiment in laboratory; (2) because the first nature frequency is very high, the probability of casing connection to be damaged from vibration is little; (3) the shock dynamic load makes casing connection begin to thread off at the tube thread end.展开更多
BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different tre...BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different treatment options.AIM To analyze the clinical effect and prognosis of mixed hemorrhoids treated with polidocanol injection combined with automatic elastic thread ligation operation(RPH).METHODS A total of 100 patients with mixed hemorrhoids who visited our hospital from October 2022 to September 2023 were selected and randomly divided into the control group(n=50)and the treatment group(n=50)by rolling the dice.The procedure for prolapse and hemorrhoids(PPH)was adopted in the control group,while polidocanol foam injection+RPH was adopted in the treatment group.The therapeutic effects,operation time,wound healing time,hospital stay,pain situation(24 hours post-operative pain score,first defecation pain score),quality of life(QOL),incidence of complications(post-operative hemorrhage,edema,infection),incidence of anal stenosis 3 months post-operatively and recurrence rate 1 year post-operatively of the two groups were compared.RESULTS Compared with the control group,the total effective rate of treatment group was higher,and the difference was significant(P<0.05).The operation time/wound healing time/hospital stay in the treatment group were shorter than those in the control group(P<0.05).The pain scores at 24 hours after operation/first defecation pain score of the treatment group was significantly lower than those in the control group(P<0.05).After surgery,the QOL scores of the two groups decreased,with the treatment group having higher scores than that of the control group(P<0.05).Compared with the control group,the incidence of postoperative complications in the treatment group was lower,and the difference was significant(P<0.05);However,there was no significant difference in the incidence of postoperative bleeding between the two groups(P>0.05);There was no significant difference in the incidence of anal stenosis 3 months after operation and the recurrence rate 1 year after operation between the two groups(P>0.05).CONCLUSION For patients with mixed hemorrhoids,the therapeutic effect achieved by using polidocanol injection combined with RPH was better.The wounds of the patients healed faster,the postoperative pain was milder,QOL improved,and the incidence of complications was lower,and the short-term and long-term prognosis was good.展开更多
BACKGROUND Intraoperative determination of resection margin and adequate residual liver parenchyma are the key points of hepatectomy for the treatment of liver tumors.Intraoperative ultrasound and indocyanine green fl...BACKGROUND Intraoperative determination of resection margin and adequate residual liver parenchyma are the key points of hepatectomy for the treatment of liver tumors.Intraoperative ultrasound and indocyanine green fluorescence navigation are the most commonly used methods at present,but the technical barriers limit their promotion.AIM To evaluate the value of the three-dimensional location approach with silk thread(3D-LAST)in precise resection of liver tumors.METHODS From September 2020 to January 2022,8 patients with liver tumors including hepatocellular carcinoma,intrahepatic cholangiocarcinoma,hilar cholangiocar-cinoma,and gastric cancer liver metastasis were included in this study.All patients underwent 3D-LAST in precise resection of liver tumors.RESULTS All patients(8/8,100%)underwent the operation successfully without any complications.During the mean follow-up of 8.7 months,all patients survived without tumor recurrence.CONCLUSION In conclusion,the 3D-LAST is a safe and effective new method for liver intraop-erative navigation,which is practical and easy to promote.Core Tip:The aim of this study is to evaluate the value of the three-dimensional location approach with silk thread(3D-LAST)in precise resection of liver tumors.Eight patients with liver tumors including hepatocellular carcinoma,intrahepatic cholangiocarcinoma,hilar cholangiocarcinoma,and gastric cancer liver metastasis underwent the operation successfully without any complications.During the mean follow-up of 8.7 months,all patients survived without tumor recurrence.In conclusion,the 3D-LAST is a safe and effective new method for liver intraoperative navigation,which is practical and easy to promote.INTRODUCTION Hepatectomy is widely used for the treatment of liver tumors.In recent decades,the concept and practice of hepatectomy have developed from irregular,regular and anatomical to the current precise resection.Necessary assistive technologies have enabled these advances.Intraoperative ultrasound(IOUS)localization and indocyanine green(ICG)fluorescence imaging guidance are two frequently-used approaches for laparoscopic hepatectomy[1,2].IOUS is an invaluable auxiliary means widely accepted in surgery for real-time diagnostic information to determine resection range and navigate the surgical path[3].However,the major limitation of IOUS is the time cost during the procedure for paging the sono-graphers and the difficulty of deciphering two dimensional images[4].ICG is a non-toxic water-soluble fluorophore that reveals fluorescence under the near-infrared spectrum[5].Since liver tissue penetration is limited to 5 to 10 mm,that restricted the visualization of deeper tumors by ICG excitation,thereby interfering with its application in laparoscopic hepatectomy[6].IOUS and ICG navigation require specific technical equipment,making implementation difficult in many centers.And these techniques will significantly increase the operation time.Three-dimensional(3D)visualization involves extracting features and producing volumetric images based on computed tomography(CT)through a computer postprocessing technique.This tool offers a reasonable approach to the clinical decision for the potential to display the complex internal anatomy in an intuitive and stereoscopic manner[7].In the past few decades,applying 3D simulation software for liver volume calculation,virtual simulation surgery,portal hypertension monitor,and surgical navigation has proven to be safe and effective[8].Therefore,we propose a new method to find obvious anatomical markers and calculate the resection range according to 3D positioning before operation.During the operation,the scope of resection was delineated with silk thread,and resection was performed.This is a new practical approach,which we named as 3D location approach with silk thread(3D-LAST).RESULTS During the study period from September 2020 to January 2022,5 patients with hepatocellular carcinoma,1 patient with intrahepatic cholangiocarcinoma,1 patient with hilar cholangiocarcinoma,and 1 patient with gastric cancer liver metastasis were assessed for liver resection.There were 5 males and 3 females.The mean age of these patients was 54.3±10.2 years(34-66 years).Preoperative 3D positioning was conducted and the scope of resection was delineated with a surgical suture successfully performed in all 8 patients without complications.The treatment results of these 8 patients are shown in Table 1.The 90-day operative mortality was zero.Complications worse than Dindo-Clavien IIIa was not observed at a mean follow-up time of 8.7 months(4-16 months),there was no evidence of tumor recurrence or extrahepatic metastasis.At the time of reporting,the patients are all alive and lead normal lives.We take one patient as an example,58-year-old male,who found a liver lesion 10 months after gastric cancer surgery.Enhanced CT showed that the lesion was located in the liver S5,about 1.5 cm in diameter,and considered metastatic lesions.We performed 3D-LAST guided hepatectomy on this patient(Figure 1).Other representative 3D-LAST surgical procedures are shown in Figure 2.展开更多
When one steps inside Caoxian’s Youai Cloud Warehouse,a livestreaming base dedicated to hanfu,it feels less like a clothing warehouse and more like a time capsule.Thousands of intricately embroidered garments line th...When one steps inside Caoxian’s Youai Cloud Warehouse,a livestreaming base dedicated to hanfu,it feels less like a clothing warehouse and more like a time capsule.Thousands of intricately embroidered garments line the racks-from elegant horse-face skirts to modernised editions of traditional Chinese clothing.展开更多
In petroleum extraction,the sealing surfaces of bolted joints are susceptible to damage due to the high-temperature and high-pressure conditions in wellbores.This damage adversely affects sealing performance,consequen...In petroleum extraction,the sealing surfaces of bolted joints are susceptible to damage due to the high-temperature and high-pressure conditions in wellbores.This damage adversely affects sealing performance,consequently leading to the failure and damage of threaded connections.In severe cases,it can result in considerable economic losses and trigger safety accidents.The sealing performance of special bolted joints holds crucial importance for production efficiency,output,equipment lifespan,and cost control.Enhancing the sealing perfor-mance of threaded connections can have a positive impact on industrial production and environmental protection.The existing research on American Petroleum Institute threaded joints has been thorough and has obtained a series of excellent results.However,the research on the sealing damage mechanism of threaded connections under complex well conditions lacks sufficient depth and that on new sealing technology is scarce.This study proposes a half-size evaluation test to address the abovementioned problem.Based on this test,an investigation into the sealing performance of threaded connections under high-temperature,cyclic loading,and high-temperature creep conditions is conducted.This study uses a combined approach of finite element methods and experiments to investigate the impact of different makeup torques on the sealing performance of premium threaded connections(PTCs).The results of the half-size evaluation test indicate that temperature notably influences the sealing performance of threaded connections.The continuous action of high temperatures causes contact pressure and sealing performance to decrease,and sealing contact pressure increases after cooling.Finite element and test results show that for a certain joint A,the greater the torque,the higher the critical sealing pressure of the thread,and the better the sealing performance.The research on the sealing damage mechanism of PTCs provides a scientific basis and theoretical guidance for the further optimization and development of PTCs.展开更多
As the global textile market continues to expand, demand for sewing threads-a critical auxiliary material-is rising. In recent years, automotive interiors, smart outdoor equipment, and medical and ecofriendly products...As the global textile market continues to expand, demand for sewing threads-a critical auxiliary material-is rising. In recent years, automotive interiors, smart outdoor equipment, and medical and ecofriendly products have emerged as new growth engines for the textile industry. This has propelled specialized niche markets for sewing threads designed for these applications, revealing significant and undeniable potential.展开更多
Threaded fasteners are one of the most commonly used connection methods for mechanical structures.Its primary function is to generate appropriate clamping forces and fasten the connected parts.An inappropriate preload...Threaded fasteners are one of the most commonly used connection methods for mechanical structures.Its primary function is to generate appropriate clamping forces and fasten the connected parts.An inappropriate preload can cause loosening,fatigue fracture,and other problems.This will affect the safety and reliability of mechanical equipment.The precise control of the preload has become a critical issue in mechanical assembly processes.Over the past few decades,various tightening measures and methods have been proposed to address this issue.However,many problems continue to exist with practical applications that have not been reviewed comprehensively and systematically.First,various control methods were summarized systematically,and their advantages and disadvantages in engineering applications were analyzed.Torque control is the most widely used tightening method owing to its simple operation and low cost.Therefore,the research on the torque control method was summarized systematically from three aspects:the torque-preload correlation formula,effective friction radius,and friction characteristics during tightening.In addition,the special circumstances that may increase preload uncertainty were discussed.Finally,based on a summary of the current research status,the prospects for future research were discussed.This study would aid researchers in extensively understanding the problems in preload control.展开更多
In cosmetic surgery, golden threads have been used in thread lift procedures, wherein golden threads are placed under the skin of the neck and chin. These are mainly applied in the maxillofacial region adjacent to the...In cosmetic surgery, golden threads have been used in thread lift procedures, wherein golden threads are placed under the skin of the neck and chin. These are mainly applied in the maxillofacial region adjacent to the sites of dental treatment to achieve cosmetic benefits. However, as dentists typically lack sufficient knowledge about the golden thread lift procedure, it may present a challenge to dental examinations and treatments. It is therefore crucial for dentists to have a comprehensive understanding of the procedure. This case report covers our experience with the dental examination of a patient with golden threads. We emphasize the dental complications and precautions that should be taken for such cases. These golden threads are made of pure gold, nonabsorbable, and can be broken. These can obstruct dental examination, as well as cause metal allergies and foreign body granulomas. Additionally, it is difficult to completely remove these threads when they break apart. In the future, since more patients are expected to undergo this procedure, it is possible to encounter these golden threads as artifacts on imaging. Therefore, it is important to educate dentists about the golden thread lift procedure and its dental implications. It is also imperative to determine whether the patient has undergone the golden thread lift procedure in the medical questionnaire prior to the magnetic resonance imaging examination. Thus, dentists should be able to conduct a detailed interview with the patient, determine the feasibility of examination or treatment, and communicate this assessment to the patient.展开更多
The whole lacrimal passage intubation is widely used in lacrimal surgery.However,one of the most typical complications is the prolapse of the silicone tube from the medial canthus.In case,the bicanalicular silicone tu...The whole lacrimal passage intubation is widely used in lacrimal surgery.However,one of the most typical complications is the prolapse of the silicone tube from the medial canthus.In case,the bicanalicular silicone tube after whole lacrimal duct intubation has completely prolapsed from the medial canthus before extubation,then cannot be found in the opening of the nasolacrimal duct,and it would be a challenge to reposition or removal.A novel approach to employ a modified suture-probe and silk thread traction technique has been developed,and it is not only safe and effective,but also cost-effective.展开更多
We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuratio...We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuration lessens wear, increases load capacity, and improves efficiency. The threaded chain consists of nut-shaped links. This paper presents the results of tests carried out on a prototype with a reduction ratio of 46.展开更多
A young artist reinvents an old sartorial skill from rural ethnic communities into globally recognized high fashion.LACKING a unified writing system,the ancestors of the Miao people,an ethnic group primarily living in...A young artist reinvents an old sartorial skill from rural ethnic communities into globally recognized high fashion.LACKING a unified writing system,the ancestors of the Miao people,an ethnic group primarily living in mountainous areas in central and southwestern China,encoded their history in the exquisite design of traditional clothing,especially embroidery.They express reverence for nature and appreciation of life with needles and threads.展开更多
High-quality AlN epitaxial layers with low dislocation densities and uniform crystal quality are essential for next-gener-ation optoelectronic and power devices.This study reports the epitaxial growth of 6-inch AlN fi...High-quality AlN epitaxial layers with low dislocation densities and uniform crystal quality are essential for next-gener-ation optoelectronic and power devices.This study reports the epitaxial growth of 6-inch AlN films on 17 nm AlN/sapphire tem-plates using metal-organic chemical vapor deposition(MOCVD).Comprehensive characterization reveals significant advance-ments in crystal quality and uniformity.Atomic force microscopy(AFM)shows progressive surface roughness reduction during early growth stages,achieving stabilization at a root mean square(RMS)roughness of 0.216 nm within 3 min,confirming suc-cessful 2D growth mode.X-ray rocking curve(XRC)analysis indicates a marked reduction in the(0002)reflection full width at half maximum(FWHM),from 445 to 96 arcsec,evidencing effective dislocation annihilation.Transmission electron microscopy(TEM)demonstrates the elimination of edge dislocations near the AlN template interface.Stress analysis highlights the role of a highly compressive 17 nm AlN template(5.11 GPa)in facilitating threading dislocation bending and annihilation,yielding a final dislocation density of~1.5×10^(7) cm^(-2).Raman spectroscopy and XRC mapping confirm excellent uniformity of stress and crystal quality across the wafer.These findings demonstrate the feasibility of this method for producing high-quality,large-area,atomically flat AlN films,advancing applications in optoelectronics and power electronics.展开更多
This paper focuses on the effect of welding parameters on microstructure and tensile strength of joints welded by friction-stir welding(FSW).The effects of pin profile(threaded conical,non-threaded conical and triangu...This paper focuses on the effect of welding parameters on microstructure and tensile strength of joints welded by friction-stir welding(FSW).The effects of pin profile(threaded conical,non-threaded conical and triangular pin),tool rotational speed(800,1000,1250 and 1600 r·min^(-1))and welding speed(63,80,100 and 125 mm·min^(-1))on the mechanical and microstructural properties of joints welded in 5-mm 7075-T6 were investigated.The results depict that the pin profile has a major role in the shape and grain size of the weld nugget zone(WNZ).In other words,a wider weld nugget and a finer grain size by threaded conical pin are obtained in WNZ.The attained data of tensile tests show that the maximum ultimate tensile strength(UTS)belongs to the threaded conical pin which is attributed to a finer grain size generated in the weld nugget zone.Additionally,it is found that the tensile strength increases with the welding speed increasing,whereas rotational speed has a bilateral effect on the tensile strength.The microhardness tests show that the minimum hardness is obtained in the heat-affected zone(HAZ).展开更多
It is common for the rotating pin largely plunging into lower sheet to break up lap interface of Friction Stir Lap Welding(FSLW)joint,but the unavoidable up-bending morphology of hook outside Nugget Zone(NZ)largely re...It is common for the rotating pin largely plunging into lower sheet to break up lap interface of Friction Stir Lap Welding(FSLW)joint,but the unavoidable up-bending morphology of hook outside Nugget Zone(NZ)largely reduces the joint bearing ability.Based on the novel Opposite-directions Flowing FSLW(OF-FSLW)by the self-developed rotating tool with an Xshaped right-left thread pin,the 2024 aluminum alloys lap joint was successfully welded in this study.The migration law of lap interface during welding was investigated by the experimental and numerical methods,and then how the rotating pin and its rotating velocity affect the formation and strength of OF-FSLW joint was further analyzed.The results show that the Material Concentrated Zone(MCZ)which formed above the original lap interface made the hook bend downward,the NZ greatly enlarged and the beginning part of cold lap compressed and thickened,thereby heightening the joint bearing ability.For the OF-FSLW joint,its maximum tensile strength was403 MPa,and the corresponding joint efficiency of 90.8%was an incredible and superb value for the 2000 series heat-treatment strengthened aluminum alloys friction stir welded joint.The OF-FSLW technology by the rotating tool with an X-shaped right-left thread pin is proven to be a greatly effective approach for manufacturing the aluminum alloys lap joint with superb strength.展开更多
文摘The dynamic modal model analysis of the oil casing connection is done by finite element method (FEM), and the first nature frequency, the second nature frequency, the vibration mode shape and the time domain of the node displacement and the element stress variation in the thread connection are gotten. The Von.Mises stresses of the connection in the static and dynamic state are also studied. The results of calculation and analysis show: (1) because the maximum of static stress is at the coupling thread end of connection, the connection begins to thread off at the coupling thread end, which is in accord with the results of the thread off experiment in laboratory; (2) because the first nature frequency is very high, the probability of casing connection to be damaged from vibration is little; (3) the shock dynamic load makes casing connection begin to thread off at the tube thread end.
文摘BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different treatment options.AIM To analyze the clinical effect and prognosis of mixed hemorrhoids treated with polidocanol injection combined with automatic elastic thread ligation operation(RPH).METHODS A total of 100 patients with mixed hemorrhoids who visited our hospital from October 2022 to September 2023 were selected and randomly divided into the control group(n=50)and the treatment group(n=50)by rolling the dice.The procedure for prolapse and hemorrhoids(PPH)was adopted in the control group,while polidocanol foam injection+RPH was adopted in the treatment group.The therapeutic effects,operation time,wound healing time,hospital stay,pain situation(24 hours post-operative pain score,first defecation pain score),quality of life(QOL),incidence of complications(post-operative hemorrhage,edema,infection),incidence of anal stenosis 3 months post-operatively and recurrence rate 1 year post-operatively of the two groups were compared.RESULTS Compared with the control group,the total effective rate of treatment group was higher,and the difference was significant(P<0.05).The operation time/wound healing time/hospital stay in the treatment group were shorter than those in the control group(P<0.05).The pain scores at 24 hours after operation/first defecation pain score of the treatment group was significantly lower than those in the control group(P<0.05).After surgery,the QOL scores of the two groups decreased,with the treatment group having higher scores than that of the control group(P<0.05).Compared with the control group,the incidence of postoperative complications in the treatment group was lower,and the difference was significant(P<0.05);However,there was no significant difference in the incidence of postoperative bleeding between the two groups(P>0.05);There was no significant difference in the incidence of anal stenosis 3 months after operation and the recurrence rate 1 year after operation between the two groups(P>0.05).CONCLUSION For patients with mixed hemorrhoids,the therapeutic effect achieved by using polidocanol injection combined with RPH was better.The wounds of the patients healed faster,the postoperative pain was milder,QOL improved,and the incidence of complications was lower,and the short-term and long-term prognosis was good.
文摘BACKGROUND Intraoperative determination of resection margin and adequate residual liver parenchyma are the key points of hepatectomy for the treatment of liver tumors.Intraoperative ultrasound and indocyanine green fluorescence navigation are the most commonly used methods at present,but the technical barriers limit their promotion.AIM To evaluate the value of the three-dimensional location approach with silk thread(3D-LAST)in precise resection of liver tumors.METHODS From September 2020 to January 2022,8 patients with liver tumors including hepatocellular carcinoma,intrahepatic cholangiocarcinoma,hilar cholangiocar-cinoma,and gastric cancer liver metastasis were included in this study.All patients underwent 3D-LAST in precise resection of liver tumors.RESULTS All patients(8/8,100%)underwent the operation successfully without any complications.During the mean follow-up of 8.7 months,all patients survived without tumor recurrence.CONCLUSION In conclusion,the 3D-LAST is a safe and effective new method for liver intraop-erative navigation,which is practical and easy to promote.Core Tip:The aim of this study is to evaluate the value of the three-dimensional location approach with silk thread(3D-LAST)in precise resection of liver tumors.Eight patients with liver tumors including hepatocellular carcinoma,intrahepatic cholangiocarcinoma,hilar cholangiocarcinoma,and gastric cancer liver metastasis underwent the operation successfully without any complications.During the mean follow-up of 8.7 months,all patients survived without tumor recurrence.In conclusion,the 3D-LAST is a safe and effective new method for liver intraoperative navigation,which is practical and easy to promote.INTRODUCTION Hepatectomy is widely used for the treatment of liver tumors.In recent decades,the concept and practice of hepatectomy have developed from irregular,regular and anatomical to the current precise resection.Necessary assistive technologies have enabled these advances.Intraoperative ultrasound(IOUS)localization and indocyanine green(ICG)fluorescence imaging guidance are two frequently-used approaches for laparoscopic hepatectomy[1,2].IOUS is an invaluable auxiliary means widely accepted in surgery for real-time diagnostic information to determine resection range and navigate the surgical path[3].However,the major limitation of IOUS is the time cost during the procedure for paging the sono-graphers and the difficulty of deciphering two dimensional images[4].ICG is a non-toxic water-soluble fluorophore that reveals fluorescence under the near-infrared spectrum[5].Since liver tissue penetration is limited to 5 to 10 mm,that restricted the visualization of deeper tumors by ICG excitation,thereby interfering with its application in laparoscopic hepatectomy[6].IOUS and ICG navigation require specific technical equipment,making implementation difficult in many centers.And these techniques will significantly increase the operation time.Three-dimensional(3D)visualization involves extracting features and producing volumetric images based on computed tomography(CT)through a computer postprocessing technique.This tool offers a reasonable approach to the clinical decision for the potential to display the complex internal anatomy in an intuitive and stereoscopic manner[7].In the past few decades,applying 3D simulation software for liver volume calculation,virtual simulation surgery,portal hypertension monitor,and surgical navigation has proven to be safe and effective[8].Therefore,we propose a new method to find obvious anatomical markers and calculate the resection range according to 3D positioning before operation.During the operation,the scope of resection was delineated with silk thread,and resection was performed.This is a new practical approach,which we named as 3D location approach with silk thread(3D-LAST).RESULTS During the study period from September 2020 to January 2022,5 patients with hepatocellular carcinoma,1 patient with intrahepatic cholangiocarcinoma,1 patient with hilar cholangiocarcinoma,and 1 patient with gastric cancer liver metastasis were assessed for liver resection.There were 5 males and 3 females.The mean age of these patients was 54.3±10.2 years(34-66 years).Preoperative 3D positioning was conducted and the scope of resection was delineated with a surgical suture successfully performed in all 8 patients without complications.The treatment results of these 8 patients are shown in Table 1.The 90-day operative mortality was zero.Complications worse than Dindo-Clavien IIIa was not observed at a mean follow-up time of 8.7 months(4-16 months),there was no evidence of tumor recurrence or extrahepatic metastasis.At the time of reporting,the patients are all alive and lead normal lives.We take one patient as an example,58-year-old male,who found a liver lesion 10 months after gastric cancer surgery.Enhanced CT showed that the lesion was located in the liver S5,about 1.5 cm in diameter,and considered metastatic lesions.We performed 3D-LAST guided hepatectomy on this patient(Figure 1).Other representative 3D-LAST surgical procedures are shown in Figure 2.
文摘When one steps inside Caoxian’s Youai Cloud Warehouse,a livestreaming base dedicated to hanfu,it feels less like a clothing warehouse and more like a time capsule.Thousands of intricately embroidered garments line the racks-from elegant horse-face skirts to modernised editions of traditional Chinese clothing.
文摘In petroleum extraction,the sealing surfaces of bolted joints are susceptible to damage due to the high-temperature and high-pressure conditions in wellbores.This damage adversely affects sealing performance,consequently leading to the failure and damage of threaded connections.In severe cases,it can result in considerable economic losses and trigger safety accidents.The sealing performance of special bolted joints holds crucial importance for production efficiency,output,equipment lifespan,and cost control.Enhancing the sealing perfor-mance of threaded connections can have a positive impact on industrial production and environmental protection.The existing research on American Petroleum Institute threaded joints has been thorough and has obtained a series of excellent results.However,the research on the sealing damage mechanism of threaded connections under complex well conditions lacks sufficient depth and that on new sealing technology is scarce.This study proposes a half-size evaluation test to address the abovementioned problem.Based on this test,an investigation into the sealing performance of threaded connections under high-temperature,cyclic loading,and high-temperature creep conditions is conducted.This study uses a combined approach of finite element methods and experiments to investigate the impact of different makeup torques on the sealing performance of premium threaded connections(PTCs).The results of the half-size evaluation test indicate that temperature notably influences the sealing performance of threaded connections.The continuous action of high temperatures causes contact pressure and sealing performance to decrease,and sealing contact pressure increases after cooling.Finite element and test results show that for a certain joint A,the greater the torque,the higher the critical sealing pressure of the thread,and the better the sealing performance.The research on the sealing damage mechanism of PTCs provides a scientific basis and theoretical guidance for the further optimization and development of PTCs.
文摘As the global textile market continues to expand, demand for sewing threads-a critical auxiliary material-is rising. In recent years, automotive interiors, smart outdoor equipment, and medical and ecofriendly products have emerged as new growth engines for the textile industry. This has propelled specialized niche markets for sewing threads designed for these applications, revealing significant and undeniable potential.
基金Supported by National Natural Science Foundation of China(Grant Nos.U23B20104,52075012 and 52205510).
文摘Threaded fasteners are one of the most commonly used connection methods for mechanical structures.Its primary function is to generate appropriate clamping forces and fasten the connected parts.An inappropriate preload can cause loosening,fatigue fracture,and other problems.This will affect the safety and reliability of mechanical equipment.The precise control of the preload has become a critical issue in mechanical assembly processes.Over the past few decades,various tightening measures and methods have been proposed to address this issue.However,many problems continue to exist with practical applications that have not been reviewed comprehensively and systematically.First,various control methods were summarized systematically,and their advantages and disadvantages in engineering applications were analyzed.Torque control is the most widely used tightening method owing to its simple operation and low cost.Therefore,the research on the torque control method was summarized systematically from three aspects:the torque-preload correlation formula,effective friction radius,and friction characteristics during tightening.In addition,the special circumstances that may increase preload uncertainty were discussed.Finally,based on a summary of the current research status,the prospects for future research were discussed.This study would aid researchers in extensively understanding the problems in preload control.
文摘In cosmetic surgery, golden threads have been used in thread lift procedures, wherein golden threads are placed under the skin of the neck and chin. These are mainly applied in the maxillofacial region adjacent to the sites of dental treatment to achieve cosmetic benefits. However, as dentists typically lack sufficient knowledge about the golden thread lift procedure, it may present a challenge to dental examinations and treatments. It is therefore crucial for dentists to have a comprehensive understanding of the procedure. This case report covers our experience with the dental examination of a patient with golden threads. We emphasize the dental complications and precautions that should be taken for such cases. These golden threads are made of pure gold, nonabsorbable, and can be broken. These can obstruct dental examination, as well as cause metal allergies and foreign body granulomas. Additionally, it is difficult to completely remove these threads when they break apart. In the future, since more patients are expected to undergo this procedure, it is possible to encounter these golden threads as artifacts on imaging. Therefore, it is important to educate dentists about the golden thread lift procedure and its dental implications. It is also imperative to determine whether the patient has undergone the golden thread lift procedure in the medical questionnaire prior to the magnetic resonance imaging examination. Thus, dentists should be able to conduct a detailed interview with the patient, determine the feasibility of examination or treatment, and communicate this assessment to the patient.
基金supported by the Natural Science Foundation of Guangdong Province of China(No.2021A1515012043).
文摘The whole lacrimal passage intubation is widely used in lacrimal surgery.However,one of the most typical complications is the prolapse of the silicone tube from the medial canthus.In case,the bicanalicular silicone tube after whole lacrimal duct intubation has completely prolapsed from the medial canthus before extubation,then cannot be found in the opening of the nasolacrimal duct,and it would be a challenge to reposition or removal.A novel approach to employ a modified suture-probe and silk thread traction technique has been developed,and it is not only safe and effective,but also cost-effective.
文摘We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuration lessens wear, increases load capacity, and improves efficiency. The threaded chain consists of nut-shaped links. This paper presents the results of tests carried out on a prototype with a reduction ratio of 46.
文摘A young artist reinvents an old sartorial skill from rural ethnic communities into globally recognized high fashion.LACKING a unified writing system,the ancestors of the Miao people,an ethnic group primarily living in mountainous areas in central and southwestern China,encoded their history in the exquisite design of traditional clothing,especially embroidery.They express reverence for nature and appreciation of life with needles and threads.
基金supported by National Key R&D Program of China(2022YFB3605100)the National Science Fund for Distinguished Young Scholars of China(62425408)+5 种基金the National Natural Science Foundation of China(62204241,U22A2084,and 62121005)Key Research and Development Projects of Jilin Provincial Science and Technology Development Plan(20240302027GX)the Natural Science Foundation of Jilin Province(20230101345JC,20230101360JC,20230101107JC)the Youth Innovation Promotion Association of CAS(2023223)the Young Elite Scientist Sponsorship Program By CAST(YESS20200182)the CAS Talents Program.
文摘High-quality AlN epitaxial layers with low dislocation densities and uniform crystal quality are essential for next-gener-ation optoelectronic and power devices.This study reports the epitaxial growth of 6-inch AlN films on 17 nm AlN/sapphire tem-plates using metal-organic chemical vapor deposition(MOCVD).Comprehensive characterization reveals significant advance-ments in crystal quality and uniformity.Atomic force microscopy(AFM)shows progressive surface roughness reduction during early growth stages,achieving stabilization at a root mean square(RMS)roughness of 0.216 nm within 3 min,confirming suc-cessful 2D growth mode.X-ray rocking curve(XRC)analysis indicates a marked reduction in the(0002)reflection full width at half maximum(FWHM),from 445 to 96 arcsec,evidencing effective dislocation annihilation.Transmission electron microscopy(TEM)demonstrates the elimination of edge dislocations near the AlN template interface.Stress analysis highlights the role of a highly compressive 17 nm AlN template(5.11 GPa)in facilitating threading dislocation bending and annihilation,yielding a final dislocation density of~1.5×10^(7) cm^(-2).Raman spectroscopy and XRC mapping confirm excellent uniformity of stress and crystal quality across the wafer.These findings demonstrate the feasibility of this method for producing high-quality,large-area,atomically flat AlN films,advancing applications in optoelectronics and power electronics.
文摘This paper focuses on the effect of welding parameters on microstructure and tensile strength of joints welded by friction-stir welding(FSW).The effects of pin profile(threaded conical,non-threaded conical and triangular pin),tool rotational speed(800,1000,1250 and 1600 r·min^(-1))and welding speed(63,80,100 and 125 mm·min^(-1))on the mechanical and microstructural properties of joints welded in 5-mm 7075-T6 were investigated.The results depict that the pin profile has a major role in the shape and grain size of the weld nugget zone(WNZ).In other words,a wider weld nugget and a finer grain size by threaded conical pin are obtained in WNZ.The attained data of tensile tests show that the maximum ultimate tensile strength(UTS)belongs to the threaded conical pin which is attributed to a finer grain size generated in the weld nugget zone.Additionally,it is found that the tensile strength increases with the welding speed increasing,whereas rotational speed has a bilateral effect on the tensile strength.The microhardness tests show that the minimum hardness is obtained in the heat-affected zone(HAZ).
基金supported by the National Natural Science Foundation of China(Nos.51874201 and 52074184)Natural Science Foundation project of Liaoning Province(2023-MS238)+1 种基金Liaoning Revitalization talents program(XLYC2203009)the Fundamental Research Funds for the Universities of Liaoning Province。
文摘It is common for the rotating pin largely plunging into lower sheet to break up lap interface of Friction Stir Lap Welding(FSLW)joint,but the unavoidable up-bending morphology of hook outside Nugget Zone(NZ)largely reduces the joint bearing ability.Based on the novel Opposite-directions Flowing FSLW(OF-FSLW)by the self-developed rotating tool with an Xshaped right-left thread pin,the 2024 aluminum alloys lap joint was successfully welded in this study.The migration law of lap interface during welding was investigated by the experimental and numerical methods,and then how the rotating pin and its rotating velocity affect the formation and strength of OF-FSLW joint was further analyzed.The results show that the Material Concentrated Zone(MCZ)which formed above the original lap interface made the hook bend downward,the NZ greatly enlarged and the beginning part of cold lap compressed and thickened,thereby heightening the joint bearing ability.For the OF-FSLW joint,its maximum tensile strength was403 MPa,and the corresponding joint efficiency of 90.8%was an incredible and superb value for the 2000 series heat-treatment strengthened aluminum alloys friction stir welded joint.The OF-FSLW technology by the rotating tool with an X-shaped right-left thread pin is proven to be a greatly effective approach for manufacturing the aluminum alloys lap joint with superb strength.
