Compliant mechanisms transfer an input force or displacement to another point through elastic body deformation. The field of compliant mechanisms is expected to continue to grow as materials with superior properties a...Compliant mechanisms transfer an input force or displacement to another point through elastic body deformation. The field of compliant mechanisms is expected to continue to grow as materials with superior properties are developed. The paper takes into consideration some typical spring guiding systems, being able to realize translating planar displacement of the link. Some types of compound spring guiding systems, such as S-shaped guiding spring system, U-shaped guiding spring system and four spring guiding system with additional rigid-body link have been considered and analyzed as compliant structures. The mobility as well as guiding accuracy of the developed compliant mechanisms, that is, their capability to realize translating planar displacement of the link, have been researched, and the optimal dimensions of the mechanism have been determined in order to provide minimal guiding inaccuracy.展开更多
In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode cont...In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode controllers. The advantages and disadvantages of the proposed controllers are discussed. Although, PID controller is fast, its response affected considerably by external disturbances. Unlike PID, the sliding mode controller is so robust, but its transient is unsuitable based on application conditions. However, an acceptable controller for ropeless elevator guiding system should guaranty the passengers safety and convenient. Consequently, the response of the system should be fast, robust, and without considerable overshoots and oscillations. These required advantages are compromised in the proposed parallel PID sliding mode controller. The affectivity of the introduced controllers for maglev guiding system is investigated through conducted simulations in MATLAB/Simulink environment. The obtained results illustrate that PID sliding mode controller is a so fast and robust controller for a ropeless elevator maglev guiding system.展开更多
The objective of this research was to enhance the stability and consistency of seed distribution during carrot planting.The impact of the seed guide tube’s structure on seeding quality was examined,leading to the des...The objective of this research was to enhance the stability and consistency of seed distribution during carrot planting.The impact of the seed guide tube’s structure on seeding quality was examined,leading to the design of a cycloidal seed guide system augmented by positive pressure airflow.By conducting kinematic modeling of the collision position of the seeds within the seed guiding system,as well as considering the seed guiding process and the seed drop position,the significant parameters influencing the final velocity of the seeds were determined.Employing a coupled Discrete Element Method-Computational Fluid Dynamics(DEM-CFD)simulation,the effects of different structural and operating parameters of the seed guide tube on the seed trajectory and airflow field were analyzed.A three-factor five-level orthogonal test was then utilized to examine the influence of each factor on each index,with the optimal conditions identified as an inlet airflow velocity of 0.077 m/s,a 45°tilt angle for the airflow branch tube,and a seed initial velocity of 0.1 m/s.Under these parameters,the qualification index was recorded as 94.1%,with a coefficient of variation of 3.2%.Bench testing conducted under the same conditions showed a decrease of 0.07%in the qualification index,and an increase of 1.875%in the coefficient of variation,with errors relative to the simulation results within acceptable bounds.These findings enhance the stability and reliability of the seed guiding system during carrot sowing operations,aligning with the demands of precision sowing.展开更多
With the increasing number of laser beams, the main difficulty in arranging beam guiding systems(BGSs) involves determining the corresponding relationships between the output and input ports to realize the identified ...With the increasing number of laser beams, the main difficulty in arranging beam guiding systems(BGSs) involves determining the corresponding relationships between the output and input ports to realize the identified light path length of all beams. Given the basic constraints of geometric arrangement, a BGS model is established, and a base-line algorithm is proposed to address the difficulty mentioned above. Boundary conditions of target area and target chamber are discussed to increase the number of laser beams, and a maximum value exists for a specific target area. Finally, the compatibility of a cylindrical hohlraum target chamber with a spherical hohlraum is analyzed, and a moveable final optics assembly is proposed to execute the switch between the two different targets.展开更多
A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visua...A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visual guiding mode, for the robot works in an open loop visual servo control mode, the manipulating burden of the operator is reduced largely. In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator. With the help of the operator, the diffieuh problems of finding and handling a target in a complicated environment by the robot can be solved easily.展开更多
We develop two types of adaptive energy preserving algorithms based on the averaged vector field for the guiding center dynamics,which plays a key role in magnetized plasmas.The adaptive scheme is applied to the Gauss...We develop two types of adaptive energy preserving algorithms based on the averaged vector field for the guiding center dynamics,which plays a key role in magnetized plasmas.The adaptive scheme is applied to the Gauss Legendre’s quadrature rules and time stepsize respectively to overcome the energy drift problem in traditional energy-preserving algorithms.These new adaptive algorithms are second order,and their algebraic order is carefully studied.Numerical results show that the global energy errors are bounded to the machine precision over long time using these adaptive algorithms without massive extra computation cost.展开更多
Mechanized construction of micro-catchments for water harvesting （WH） was successfully tested in the Badia （dry rangeland） areas in Syria and Jordan, using the ＂Vallerani＂ plow, model Delfino （50 MI/CM）, manuf...Mechanized construction of micro-catchments for water harvesting （WH） was successfully tested in the Badia （dry rangeland） areas in Syria and Jordan, using the ＂Vallerani＂ plow, model Delfino （50 MI/CM）, manufactured by Nardi, Italy. The plow was able to construct intermittent and continuous contour ridges, and could potentially be used to rehabilitate degraded rangelands. However, one major issue for large-scale implementation is the high cost and time required to manually identify contours for the plow to follow. Most existing auto-guiding systems, as usually used in road construction and agricultural land leveling, were expensive or impractical. The objective, therefore, was to add, adapt, and evaluate an auto-guiding system to enable a tractor to follow contours without demarcation through conventional surveying. A low-cost Contour Laser Guiding （CLG） system, with specifications that suit the contour ridging in undulating topographic conditions of dry rangelands, was chosen, adapted, mounted, and tested, under actual field conditions. The system consisted mainly of a portable laser transmitter and a tractor-mounted receiver, connected to a guidance display panel. The system was field-tested on 95 ha of land where the system capacity was determined under different terrains, slopes （1-8%）, and ridge spacings （4-12 m）. The easy adaptation and implementation of the CLG to the ＂Vallerani＂ unit tripled the system capacity, improved efficiency and precision, and substantially reduced the cost of constructing micro-catchments for WH. The system is recommended for large-scale rangeland rehabilitation projects in the dry areas, not only in West Asia, but worldwide.展开更多
In April this year,the Central Conference on Work Related to Neighboring Countries was successfully convened.General Secretary Xi Jinping delivered an important speech at the conference in which he systematically summ...In April this year,the Central Conference on Work Related to Neighboring Countries was successfully convened.General Secretary Xi Jinping delivered an important speech at the conference in which he systematically summarized the achievements and experience of China's neighborhood work in the new era.展开更多
The intake system of a racing engine plays a crucial role in determining its performance,particularly in terms of volumetric efficiency,power output,and throttle response.According to Formula Society of Automotive Eng...The intake system of a racing engine plays a crucial role in determining its performance,particularly in terms of volumetric efficiency,power output,and throttle response.According to Formula Society of Automotive Engineers(FSAE)regulations,the engine intake systemmust incorporate a 20mmdiameter flow-limiting valve within the intake manifold.This restriction significantly reduces the airflow into the engine,leading to a substantial drop in power output.To mitigate this limitation,the intake system requires a redesign.In this study,theoretical calculations and one-dimensional thermodynamic simulations are employed to determine the optimal parameters for the intake system.A numerical simulation of the intake system’s flow field is then conducted to refine its structure and layout.Finally,experiments are performed on an engine equipped with the optimized intake system,and its feasibility is evaluated based on experimental results.Thefindings indicate that the maximumengine torque increases from56.36 to 59.91 N⋅m,while the maximum power output rises from 59.16 to 63.94 kW.To further enhance performance and adaptability across different competitions,a variable-length intakemanifold control system is also designed,improving both power delivery and overall operational stability of the racing car.展开更多
BACKGROUND Endoscopic ultrasound(EUS)has evolved from a diagnostic tool to a management technique for various gastroenterological conditions,including biliary strictures.AIM To summarize the current evidence on EUS’s...BACKGROUND Endoscopic ultrasound(EUS)has evolved from a diagnostic tool to a management technique for various gastroenterological conditions,including biliary strictures.AIM To summarize the current evidence on EUS’s role in diagnosing and managing biliary strictures.METHODS Two independent reviewers searched five electronic databases(PubMed,CENTRAL,Science Direct,Google Scholar,and EMBASE)for articles published up to January 2025.Included articles met specific criteria,and statistical software was used to analyze reported outcomes.RESULTS Of 935 articles,19 met the inclusion criteria.Ten articles focused on diagnostic EUS,while nine focused on EUSguided therapeutic interventions.EUS fine-needle aspiration demonstrated superior sensitivity[0.43-1.00;95%confidence interval(CI):0.24-1.00]compared to conventional techniques(0.36-0.96;95%CI:0.19-0.99)for diagnosing malignant biliary strictures.Both EUS-fine-needle aspiration and conventional methods exhibited high specificity,with most achieving 100%specificity.EUS-guided interventions showed significantly higher clinical success rates than control interventions(odds ratio=2.89;95%CI:1.22-6.84;P=0.02).No significant difference was observed in technical success rates(odds ratio=0.97;95%CI:0.30-3.16;P=0.96).CONCLUSION EUS is a promising tool for diagnosing and managing biliary strictures.Combining EUS-guided and conventional interventions improves diagnostic performance.Further research is needed to investigate the feasibility and use of EUS-guided interventions in this field.展开更多
Ye Tianshi was a renowned expert in classical formulas during the Qing Dynasty.He created the Light Bitterness and Mild Pungency Method,which is formulated based on the compatibility of“Xing(bitter almond),Kou(Fructu...Ye Tianshi was a renowned expert in classical formulas during the Qing Dynasty.He created the Light Bitterness and Mild Pungency Method,which is formulated based on the compatibility of“Xing(bitter almond),Kou(Fructus amomi rotundus),Ju(tangerine peel),and Jie(platycodon root)”.This method regulates the dispersion and descent of lung Qi to dispel warm-heat pathogens and smooth the Qi movement of the triple energizer.In the treatment of lung system diseases,Ye classified them into two major categories based on etiology and pathogenesis:excess syndrome of nutrient-defense and deficiency syndrome of nutrient-defense.When discussing the treatment of cough caused by phlegm-fluid retention,he frequently referred to Synopsis of the Golden Chamber and attached great importance to summarizing and absorbing the academic thoughts of predecessors.As an accomplished expert in classical formulas,Ye Tianshi followed the academic essence of Xuanyuan and Qi Bo(founders of TCM theory)and respected the principles of Zhang Zhongjing’s classical formulas,integrating these theories in a coherent manner.With his masterful application of classical formulas to achieve remarkable curative effects,Ye’s academic viewpoints on treating lung system diseases still exert a profound influence on the modern clinical diagnosis and treatment of related diseases.展开更多
Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the mu...Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the much smaller time constant, its dynamic model can be greatly simplified. Results and Conclusion In guided bomb guidance/control digital simulation, with the use of the simplified seeker model, simulation time can be reduced without the loss of simulation accuracy.展开更多
A new method based on cross-spectrum estimation for the verification and validation of computer simulation models is expounded in accordance with the characteristics of missile systems. The new method can expose the d...A new method based on cross-spectrum estimation for the verification and validation of computer simulation models is expounded in accordance with the characteristics of missile systems. The new method can expose the differences between two time processes in several aspects and can also give quantitative analysis results about the statistical consistence between them. An application to an actual anti-tank missile system simulation is presented and the calculated results confirm the effectiveness of the method. The approach can also be employed to verify the simulation models of other dynamic systems.展开更多
State Administration for Market Regulation and National Standardization Administration of China have approved the following 76 national standards as guiding technical docoments.
目的:探讨Guided Care护理模式在不孕症体外受精-胚胎移植(In vitro fertilization and embryo transfer,IVFET)助孕患者中的应用效果。方法:选取2022年12月至2024年12月于本院接受IVF-ET助孕治疗的92例不孕症患者作为研究对象,采用随...目的:探讨Guided Care护理模式在不孕症体外受精-胚胎移植(In vitro fertilization and embryo transfer,IVFET)助孕患者中的应用效果。方法:选取2022年12月至2024年12月于本院接受IVF-ET助孕治疗的92例不孕症患者作为研究对象,采用随机数字表法分为对照组和观察组,各46例。对照组患者接受常规护理,观察组患者接受Guided Care护理模式,两组均持续护理2 m。比较两组心理状态、治疗依从性、生活质量以及护理满意度。结果:护理后,观察组抑郁-焦虑-压力量表(Depression Anxiety Stress Scales,DASS)各项评分均较对照组低,Morisky改良版服药依从性量表(Morisky Medication Adherence Scale,MMAS-8)评分、(The Mos 36-item Short Form Health Survey,SF-36)评分及护理满意度均高于对照组(P<0.05)。结论:Guided Care护理模式能够有效改善不孕症患者接受IVF-ET治疗期间的焦虑、抑郁情绪,增强其治疗依从性,对于顺利妊娠具有积极意义,从而获得更高的护理满意度。展开更多
Sensor scheduling is used to improve the sensing performance in the estimation of targets’states.However,few papers are on the sensor scheduling for target detection with guiding information.This letter can remedy th...Sensor scheduling is used to improve the sensing performance in the estimation of targets’states.However,few papers are on the sensor scheduling for target detection with guiding information.This letter can remedy this deficiency.A risk-based target detection method with guiding information is provided firstly,based on which,the sensor scheduling approach is aiming at reducing the risk and uncertainty in target detection,namely risk-based sensor scheduling method.What should be stressed is that the Prediction Formula in sensor scheduling is proposed.Lastly,some examples are conducted to stress the effectiveness of this proposed method.展开更多
This study is aimed to explore the clinical application of the guiding template designed by three-dimensional printing data for the insertion of sacroiliac screws.A retrospective study of 7 cases (from July 2016 to De...This study is aimed to explore the clinical application of the guiding template designed by three-dimensional printing data for the insertion of sacroiliac screws.A retrospective study of 7 cases (from July 2016 to December 2016),in which the guiding template printed by the three-dimensional printing technique was used for the insertion of sacroiliac screws of patients with posterior ring injuries of pelvis,was performed.Totally,4 males and 3 females were included in template group,aged from 38to 65years old (mean 50.86±8.90).Of them,5 had sacral fractures (3 with Denis type Ⅰ and 2 with type Ⅱ)and 2 the separation of sacroiliac joint.Guiding templates were firstly made by the three-dimensional printing technique based on the pre-operative CT data. Surgical operations for the stabilization of pelvic ring by applying the guiding templates were carried out.A group of 8 patients with sacroiliac injuries treated by percutaneous sacroiliac screws were analyzed as a control group retrospectively.The time of each screw insertion,volume of intra-operative blood loss,and the exposure to X ray were analyzed and the Matta's radiological criteria were used to evaluate the reduction quality.The Majeed score was used to evaluate postoperative living quality.The visual analogue scale (VAS)was applied at different time points to judge pain relief of coccydynia.All the 7 patients in the template group were closely followed up radiographically and clinically for 14 to 20 months,mean (16.57±2.44)months.Totally 9 sacroiliac screws for the S 1 and S2 vertebra were inserted in the 7 patients.The time length for each screw insertion ranged from 450 to 870 s,mean (690.56±135.68)s,and the number of times of exposure to X ray were 4 to 8,mean (5.78±1.20).The intra-operative blood loss ranged from 45to 120 mL,mean (75±23.32)mL.According to Matta's radiology criteria,the fracture and dislocation reduction were excellent in 6cases and good in 1.The pre-operative VAS score ranged from 5.2 to 8.1,mean (7.13±1.00).The average one-week/six-month post-operative VAS was (5.33±0.78)and (1.33±0.66),respectively (P<0.05 when compared with pre-operative VAS).The 12-month post-operative Majeed score ranged from 86 to 92,mean (90.29±2.21).The three-dimensional printed guiding template for sacroiliac screw insertion,which could significantly shorten the operation time,provide a satisfied outcome of the stabilization of the pelvic ring,and protect doctors and patients from X-ray exposure,might be a practical and valuable new clinical technique.展开更多
Delayed liver laceration following transjugular intrahepatic portosystemic shunt (TIPS) is a serious and likely underdiagnosed complication. It is however an important complication following TIPS, which remains one of...Delayed liver laceration following transjugular intrahepatic portosystemic shunt (TIPS) is a serious and likely underdiagnosed complication. It is however an important complication following TIPS, which remains one of the most technically challenging interventional procedures performed. In addition to laceration, a number of complications regarding bleeding and perforation are well described following TIPS procedures. We feel the adoption of techniques such as ours and that of other authors described in the literature using an ultrasoundguided percutaneous transhepatic approach with a small caliber needle provides a safer and less traumatic procedure and should reduce complications of bleeding and almost completely eliminate the risk of liver laceration. Our procedure was successfully performed under conscious sedation rather than general anaesthesia further reducing the overall procedural risk to the patient.展开更多
To reduce defects, such as the shrinkage cavity and the surface cracks caused by non-homogeneous metal flow in extrusion process, an extrusion method was proposed by using a die with the guiding angle. Numerical simul...To reduce defects, such as the shrinkage cavity and the surface cracks caused by non-homogeneous metal flow in extrusion process, an extrusion method was proposed by using a die with the guiding angle. Numerical simulation and experiment were conducted to investigate the metal flow in this extrusion process. It is shown that the stress state at the bottom of the die is changed. The tendency to generate the dead zone is decreased by employing the guiding angle at the die entrance. The shrinkage cavity is reduced because the non-homogeneous metal flow at the final stage of extrusion is improved. The axial stress is decreased greatly so that the surface cracks caused by additional stress are avoided.展开更多
AIM: To evaluate accuracy of axis alignment and refractive results of toric phakic intraocular lens(IOL) implantation using a digital imaging system. METHODS: This retrospective study investigated toric implantable co...AIM: To evaluate accuracy of axis alignment and refractive results of toric phakic intraocular lens(IOL) implantation using a digital imaging system. METHODS: This retrospective study investigated toric implantable collamer lens(ICL) implantation in 30 eyes of 21 patients with myopic astigmatism more than 2.0 D guided with digital imaging system. Data were collected during the first week after phakic IOL implantation.RESULTS: Thirty eyes of 21 patients were included in our study. Patients includes 9 males and 12 females. The mean age of the patients was 26.5±7.1(range 21-44)y. The mean preoperative manifest astigmatism was 3.2±1.7(range from 2.25 to 4.75) D. The mean postoperative uncorrected distance visual acuity(UCDVA) were 0.07±0.07(range from 0.1 to 0.0) log MAR. The mean postoperative residual refractive cylinder was 0.25±0.29(range 0-0.75) D. Eyes with postoperative residual refractive cylinder of 0.5 D or less represented 80%(24 eyes). The mean postoperative toric IOL misalignment measured by the OPD scan III was 1.9°±1.45°(range from 0 to 5°). CONCLUSION: Image guided system allows accurate alignment of toric ICL. This is associated with good postoperative visual acuity and low residual refractive astigmatism which correlates with the precision of toric phakic IOL alignment.展开更多
文摘Compliant mechanisms transfer an input force or displacement to another point through elastic body deformation. The field of compliant mechanisms is expected to continue to grow as materials with superior properties are developed. The paper takes into consideration some typical spring guiding systems, being able to realize translating planar displacement of the link. Some types of compound spring guiding systems, such as S-shaped guiding spring system, U-shaped guiding spring system and four spring guiding system with additional rigid-body link have been considered and analyzed as compliant structures. The mobility as well as guiding accuracy of the developed compliant mechanisms, that is, their capability to realize translating planar displacement of the link, have been researched, and the optimal dimensions of the mechanism have been determined in order to provide minimal guiding inaccuracy.
文摘In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode controllers. The advantages and disadvantages of the proposed controllers are discussed. Although, PID controller is fast, its response affected considerably by external disturbances. Unlike PID, the sliding mode controller is so robust, but its transient is unsuitable based on application conditions. However, an acceptable controller for ropeless elevator guiding system should guaranty the passengers safety and convenient. Consequently, the response of the system should be fast, robust, and without considerable overshoots and oscillations. These required advantages are compromised in the proposed parallel PID sliding mode controller. The affectivity of the introduced controllers for maglev guiding system is investigated through conducted simulations in MATLAB/Simulink environment. The obtained results illustrate that PID sliding mode controller is a so fast and robust controller for a ropeless elevator maglev guiding system.
基金the National Natural Science Foundation of China(Grant No.52275258)Taishan Scholar Youth Expert Project(Grant No.tsqn202306243)Natural Science Foundation of Shandong Province(Grant No.ZR202111230084).
文摘The objective of this research was to enhance the stability and consistency of seed distribution during carrot planting.The impact of the seed guide tube’s structure on seeding quality was examined,leading to the design of a cycloidal seed guide system augmented by positive pressure airflow.By conducting kinematic modeling of the collision position of the seeds within the seed guiding system,as well as considering the seed guiding process and the seed drop position,the significant parameters influencing the final velocity of the seeds were determined.Employing a coupled Discrete Element Method-Computational Fluid Dynamics(DEM-CFD)simulation,the effects of different structural and operating parameters of the seed guide tube on the seed trajectory and airflow field were analyzed.A three-factor five-level orthogonal test was then utilized to examine the influence of each factor on each index,with the optimal conditions identified as an inlet airflow velocity of 0.077 m/s,a 45°tilt angle for the airflow branch tube,and a seed initial velocity of 0.1 m/s.Under these parameters,the qualification index was recorded as 94.1%,with a coefficient of variation of 3.2%.Bench testing conducted under the same conditions showed a decrease of 0.07%in the qualification index,and an increase of 1.875%in the coefficient of variation,with errors relative to the simulation results within acceptable bounds.These findings enhance the stability and reliability of the seed guiding system during carrot sowing operations,aligning with the demands of precision sowing.
文摘With the increasing number of laser beams, the main difficulty in arranging beam guiding systems(BGSs) involves determining the corresponding relationships between the output and input ports to realize the identified light path length of all beams. Given the basic constraints of geometric arrangement, a BGS model is established, and a base-line algorithm is proposed to address the difficulty mentioned above. Boundary conditions of target area and target chamber are discussed to increase the number of laser beams, and a maximum value exists for a specific target area. Finally, the compatibility of a cylindrical hohlraum target chamber with a spherical hohlraum is analyzed, and a moveable final optics assembly is proposed to execute the switch between the two different targets.
基金Supported by the National High Technology Research and Development Program of China （No. 2003AA421030） and the National Science Foundation of China （No. 60375026）.
文摘A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visual guiding mode, for the robot works in an open loop visual servo control mode, the manipulating burden of the operator is reduced largely. In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator. With the help of the operator, the diffieuh problems of finding and handling a target in a complicated environment by the robot can be solved easily.
基金supported by National Natural Science Foundation of China(Nos.11901564,11775222 and 12171466)Geo-Algorithmic Plasma Simulator(GAPS)Project。
文摘We develop two types of adaptive energy preserving algorithms based on the averaged vector field for the guiding center dynamics,which plays a key role in magnetized plasmas.The adaptive scheme is applied to the Gauss Legendre’s quadrature rules and time stepsize respectively to overcome the energy drift problem in traditional energy-preserving algorithms.These new adaptive algorithms are second order,and their algebraic order is carefully studied.Numerical results show that the global energy errors are bounded to the machine precision over long time using these adaptive algorithms without massive extra computation cost.
文摘Mechanized construction of micro-catchments for water harvesting （WH） was successfully tested in the Badia （dry rangeland） areas in Syria and Jordan, using the ＂Vallerani＂ plow, model Delfino （50 MI/CM）, manufactured by Nardi, Italy. The plow was able to construct intermittent and continuous contour ridges, and could potentially be used to rehabilitate degraded rangelands. However, one major issue for large-scale implementation is the high cost and time required to manually identify contours for the plow to follow. Most existing auto-guiding systems, as usually used in road construction and agricultural land leveling, were expensive or impractical. The objective, therefore, was to add, adapt, and evaluate an auto-guiding system to enable a tractor to follow contours without demarcation through conventional surveying. A low-cost Contour Laser Guiding （CLG） system, with specifications that suit the contour ridging in undulating topographic conditions of dry rangelands, was chosen, adapted, mounted, and tested, under actual field conditions. The system consisted mainly of a portable laser transmitter and a tractor-mounted receiver, connected to a guidance display panel. The system was field-tested on 95 ha of land where the system capacity was determined under different terrains, slopes （1-8%）, and ridge spacings （4-12 m）. The easy adaptation and implementation of the CLG to the ＂Vallerani＂ unit tripled the system capacity, improved efficiency and precision, and substantially reduced the cost of constructing micro-catchments for WH. The system is recommended for large-scale rangeland rehabilitation projects in the dry areas, not only in West Asia, but worldwide.
文摘In April this year,the Central Conference on Work Related to Neighboring Countries was successfully convened.General Secretary Xi Jinping delivered an important speech at the conference in which he systematically summarized the achievements and experience of China's neighborhood work in the new era.
基金supported by the Key Laboratory of Automotive Power Train and Electronics(Hubei University of Automotive Technology)(ZDK1201505)Auto Parts TechnologyHubei Province Collaborative Innovation Project(2015XTZX04).
文摘The intake system of a racing engine plays a crucial role in determining its performance,particularly in terms of volumetric efficiency,power output,and throttle response.According to Formula Society of Automotive Engineers(FSAE)regulations,the engine intake systemmust incorporate a 20mmdiameter flow-limiting valve within the intake manifold.This restriction significantly reduces the airflow into the engine,leading to a substantial drop in power output.To mitigate this limitation,the intake system requires a redesign.In this study,theoretical calculations and one-dimensional thermodynamic simulations are employed to determine the optimal parameters for the intake system.A numerical simulation of the intake system’s flow field is then conducted to refine its structure and layout.Finally,experiments are performed on an engine equipped with the optimized intake system,and its feasibility is evaluated based on experimental results.Thefindings indicate that the maximumengine torque increases from56.36 to 59.91 N⋅m,while the maximum power output rises from 59.16 to 63.94 kW.To further enhance performance and adaptability across different competitions,a variable-length intakemanifold control system is also designed,improving both power delivery and overall operational stability of the racing car.
文摘BACKGROUND Endoscopic ultrasound(EUS)has evolved from a diagnostic tool to a management technique for various gastroenterological conditions,including biliary strictures.AIM To summarize the current evidence on EUS’s role in diagnosing and managing biliary strictures.METHODS Two independent reviewers searched five electronic databases(PubMed,CENTRAL,Science Direct,Google Scholar,and EMBASE)for articles published up to January 2025.Included articles met specific criteria,and statistical software was used to analyze reported outcomes.RESULTS Of 935 articles,19 met the inclusion criteria.Ten articles focused on diagnostic EUS,while nine focused on EUSguided therapeutic interventions.EUS fine-needle aspiration demonstrated superior sensitivity[0.43-1.00;95%confidence interval(CI):0.24-1.00]compared to conventional techniques(0.36-0.96;95%CI:0.19-0.99)for diagnosing malignant biliary strictures.Both EUS-fine-needle aspiration and conventional methods exhibited high specificity,with most achieving 100%specificity.EUS-guided interventions showed significantly higher clinical success rates than control interventions(odds ratio=2.89;95%CI:1.22-6.84;P=0.02).No significant difference was observed in technical success rates(odds ratio=0.97;95%CI:0.30-3.16;P=0.96).CONCLUSION EUS is a promising tool for diagnosing and managing biliary strictures.Combining EUS-guided and conventional interventions improves diagnostic performance.Further research is needed to investigate the feasibility and use of EUS-guided interventions in this field.
文摘Ye Tianshi was a renowned expert in classical formulas during the Qing Dynasty.He created the Light Bitterness and Mild Pungency Method,which is formulated based on the compatibility of“Xing(bitter almond),Kou(Fructus amomi rotundus),Ju(tangerine peel),and Jie(platycodon root)”.This method regulates the dispersion and descent of lung Qi to dispel warm-heat pathogens and smooth the Qi movement of the triple energizer.In the treatment of lung system diseases,Ye classified them into two major categories based on etiology and pathogenesis:excess syndrome of nutrient-defense and deficiency syndrome of nutrient-defense.When discussing the treatment of cough caused by phlegm-fluid retention,he frequently referred to Synopsis of the Golden Chamber and attached great importance to summarizing and absorbing the academic thoughts of predecessors.As an accomplished expert in classical formulas,Ye Tianshi followed the academic essence of Xuanyuan and Qi Bo(founders of TCM theory)and respected the principles of Zhang Zhongjing’s classical formulas,integrating these theories in a coherent manner.With his masterful application of classical formulas to achieve remarkable curative effects,Ye’s academic viewpoints on treating lung system diseases still exert a profound influence on the modern clinical diagnosis and treatment of related diseases.
文摘Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the much smaller time constant, its dynamic model can be greatly simplified. Results and Conclusion In guided bomb guidance/control digital simulation, with the use of the simplified seeker model, simulation time can be reduced without the loss of simulation accuracy.
文摘A new method based on cross-spectrum estimation for the verification and validation of computer simulation models is expounded in accordance with the characteristics of missile systems. The new method can expose the differences between two time processes in several aspects and can also give quantitative analysis results about the statistical consistence between them. An application to an actual anti-tank missile system simulation is presented and the calculated results confirm the effectiveness of the method. The approach can also be employed to verify the simulation models of other dynamic systems.
文摘State Administration for Market Regulation and National Standardization Administration of China have approved the following 76 national standards as guiding technical docoments.
文摘目的:探讨Guided Care护理模式在不孕症体外受精-胚胎移植(In vitro fertilization and embryo transfer,IVFET)助孕患者中的应用效果。方法:选取2022年12月至2024年12月于本院接受IVF-ET助孕治疗的92例不孕症患者作为研究对象,采用随机数字表法分为对照组和观察组,各46例。对照组患者接受常规护理,观察组患者接受Guided Care护理模式,两组均持续护理2 m。比较两组心理状态、治疗依从性、生活质量以及护理满意度。结果:护理后,观察组抑郁-焦虑-压力量表(Depression Anxiety Stress Scales,DASS)各项评分均较对照组低,Morisky改良版服药依从性量表(Morisky Medication Adherence Scale,MMAS-8)评分、(The Mos 36-item Short Form Health Survey,SF-36)评分及护理满意度均高于对照组(P<0.05)。结论:Guided Care护理模式能够有效改善不孕症患者接受IVF-ET治疗期间的焦虑、抑郁情绪,增强其治疗依从性,对于顺利妊娠具有积极意义,从而获得更高的护理满意度。
基金supported by National Natural Science Foundation(grant 61573374)。
文摘Sensor scheduling is used to improve the sensing performance in the estimation of targets’states.However,few papers are on the sensor scheduling for target detection with guiding information.This letter can remedy this deficiency.A risk-based target detection method with guiding information is provided firstly,based on which,the sensor scheduling approach is aiming at reducing the risk and uncertainty in target detection,namely risk-based sensor scheduling method.What should be stressed is that the Prediction Formula in sensor scheduling is proposed.Lastly,some examples are conducted to stress the effectiveness of this proposed method.
文摘This study is aimed to explore the clinical application of the guiding template designed by three-dimensional printing data for the insertion of sacroiliac screws.A retrospective study of 7 cases (from July 2016 to December 2016),in which the guiding template printed by the three-dimensional printing technique was used for the insertion of sacroiliac screws of patients with posterior ring injuries of pelvis,was performed.Totally,4 males and 3 females were included in template group,aged from 38to 65years old (mean 50.86±8.90).Of them,5 had sacral fractures (3 with Denis type Ⅰ and 2 with type Ⅱ)and 2 the separation of sacroiliac joint.Guiding templates were firstly made by the three-dimensional printing technique based on the pre-operative CT data. Surgical operations for the stabilization of pelvic ring by applying the guiding templates were carried out.A group of 8 patients with sacroiliac injuries treated by percutaneous sacroiliac screws were analyzed as a control group retrospectively.The time of each screw insertion,volume of intra-operative blood loss,and the exposure to X ray were analyzed and the Matta's radiological criteria were used to evaluate the reduction quality.The Majeed score was used to evaluate postoperative living quality.The visual analogue scale (VAS)was applied at different time points to judge pain relief of coccydynia.All the 7 patients in the template group were closely followed up radiographically and clinically for 14 to 20 months,mean (16.57±2.44)months.Totally 9 sacroiliac screws for the S 1 and S2 vertebra were inserted in the 7 patients.The time length for each screw insertion ranged from 450 to 870 s,mean (690.56±135.68)s,and the number of times of exposure to X ray were 4 to 8,mean (5.78±1.20).The intra-operative blood loss ranged from 45to 120 mL,mean (75±23.32)mL.According to Matta's radiology criteria,the fracture and dislocation reduction were excellent in 6cases and good in 1.The pre-operative VAS score ranged from 5.2 to 8.1,mean (7.13±1.00).The average one-week/six-month post-operative VAS was (5.33±0.78)and (1.33±0.66),respectively (P<0.05 when compared with pre-operative VAS).The 12-month post-operative Majeed score ranged from 86 to 92,mean (90.29±2.21).The three-dimensional printed guiding template for sacroiliac screw insertion,which could significantly shorten the operation time,provide a satisfied outcome of the stabilization of the pelvic ring,and protect doctors and patients from X-ray exposure,might be a practical and valuable new clinical technique.
文摘Delayed liver laceration following transjugular intrahepatic portosystemic shunt (TIPS) is a serious and likely underdiagnosed complication. It is however an important complication following TIPS, which remains one of the most technically challenging interventional procedures performed. In addition to laceration, a number of complications regarding bleeding and perforation are well described following TIPS procedures. We feel the adoption of techniques such as ours and that of other authors described in the literature using an ultrasoundguided percutaneous transhepatic approach with a small caliber needle provides a safer and less traumatic procedure and should reduce complications of bleeding and almost completely eliminate the risk of liver laceration. Our procedure was successfully performed under conscious sedation rather than general anaesthesia further reducing the overall procedural risk to the patient.
文摘To reduce defects, such as the shrinkage cavity and the surface cracks caused by non-homogeneous metal flow in extrusion process, an extrusion method was proposed by using a die with the guiding angle. Numerical simulation and experiment were conducted to investigate the metal flow in this extrusion process. It is shown that the stress state at the bottom of the die is changed. The tendency to generate the dead zone is decreased by employing the guiding angle at the die entrance. The shrinkage cavity is reduced because the non-homogeneous metal flow at the final stage of extrusion is improved. The axial stress is decreased greatly so that the surface cracks caused by additional stress are avoided.
文摘AIM: To evaluate accuracy of axis alignment and refractive results of toric phakic intraocular lens(IOL) implantation using a digital imaging system. METHODS: This retrospective study investigated toric implantable collamer lens(ICL) implantation in 30 eyes of 21 patients with myopic astigmatism more than 2.0 D guided with digital imaging system. Data were collected during the first week after phakic IOL implantation.RESULTS: Thirty eyes of 21 patients were included in our study. Patients includes 9 males and 12 females. The mean age of the patients was 26.5±7.1(range 21-44)y. The mean preoperative manifest astigmatism was 3.2±1.7(range from 2.25 to 4.75) D. The mean postoperative uncorrected distance visual acuity(UCDVA) were 0.07±0.07(range from 0.1 to 0.0) log MAR. The mean postoperative residual refractive cylinder was 0.25±0.29(range 0-0.75) D. Eyes with postoperative residual refractive cylinder of 0.5 D or less represented 80%(24 eyes). The mean postoperative toric IOL misalignment measured by the OPD scan III was 1.9°±1.45°(range from 0 to 5°). CONCLUSION: Image guided system allows accurate alignment of toric ICL. This is associated with good postoperative visual acuity and low residual refractive astigmatism which correlates with the precision of toric phakic IOL alignment.
