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
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
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
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
Using step pattern match technology with variational resolution can recognize the position and orientation of the weld seam in the image. According to using the image segmentation method based on pattern match, not on...Using step pattern match technology with variational resolution can recognize the position and orientation of the weld seam in the image. According to using the image segmentation method based on pattern match, not only advanced the speed and anti-jamming capability, but also captured the edge information of the weld seam and the edge of the workpiece, and the image coordinate of the initial welding position can be obtained. The matrix for hand-eye relationship of the robot can be calculated by adopting the rapid calculation method. According to the depth calculating principle with the special point matching using binocular stereovision, the initial welding position can be confirmed by calculating the middle point of the perpendicular line of two radials in the space, and the function to guide the welding robot to the initial welding position can be realized.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
A method is put forward to realize the recognition and guiding of initial welding position. The weld seams are marked with black lines, which simplify the computational complexity of image processing greatly. A two-ti...A method is put forward to realize the recognition and guiding of initial welding position. The weld seams are marked with black lines, which simplify the computational complexity of image processing greatly. A two-time template matching method has been advanced to search for the target point, which is simple and has higher calculation speed. According to the depth computing principle with the special point matching using binocular stereovision, the initial welding position can be confirmed by calculating the middle point of the perpendicular line of two radials in the space. Taking the welding of propellant fuel container for example, good results are obtained with the algorithms. Finally, similar method for terminating welding position is also advanced.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
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
We propose a novel scheme to guide neutral cold atoms in a nanoscale region based on surface plasmons （SPs） of one pair and two pairs of tips of metallic wedges with locally enhanced light intensity and sub-optical ...We propose a novel scheme to guide neutral cold atoms in a nanoscale region based on surface plasmons （SPs） of one pair and two pairs of tips of metallic wedges with locally enhanced light intensity and sub-optical wavelength resolution. We analyze the near-field intensity distribution of the tip of the metallic wedge by the FDTD method, and study the total intensity as well as the total potential of optical potentials and van der Waals potentials for 87 Rb atoms in the light field of one pair and two pairs of tips of metallic wedges. It shows that the total potentials of one pair and two pairs of tips of metallic wedges can generate a gravito-optical trap and a dark closed trap for nanoscale guiding of neutral cold atoms. Guided atoms can be cooled with efficient intensity-gradient Sisyphus cooling by blue-detuned light field. This provides an important step towards the generation of hybrid systems consisting of isolated atoms and solid devices.展开更多
We demonstrated the interaction of a gold cone target with a femto second（fs） laser pulse above the relativistic intensity of 1.37×10 18 μm 2 W/cm 2.Relativistic electrons with energy above 2 MeV were observed...We demonstrated the interaction of a gold cone target with a femto second（fs） laser pulse above the relativistic intensity of 1.37×10 18 μm 2 W/cm 2.Relativistic electrons with energy above 2 MeV were observed.A 25%-40% increase of the electron temperature is achieved compared to the case when a plane gold target is used.The electron temperature increase results from the guiding of the laser beam at the tip and the intense quasistatic magnetic field in the cone geometry.The behavior of the relativistic electrons is verified in our 2D-PIC simulations.展开更多
This article focuses on two issues. The first concerns definitions of the Northern Sea Route （NSR） in old and new Russian legislation, and the second relates to Russian rules on icebreaker guiding. Based on a compre...This article focuses on two issues. The first concerns definitions of the Northern Sea Route （NSR） in old and new Russian legislation, and the second relates to Russian rules on icebreaker guiding. Based on a comprehensive comparative analysis of relevant Russian legal provisions enacted in 2013 and previous laws in this area, we offer the following conclusions. （1） Our legal analysis indicates that Russia＇s view of the NSR as a historical national transportation route has not changed. However, the new law redefines the scope and coverage of the NSR, which now comprises the internal waters, territorial sea, adjacent zone, and the exclusive economic zone of the Russian Federation. In fact, the new law resolves previous ambiguity regarding extension of the NSR boundary to the high seas. （2） Based on an analysis of the new rules on icebreaker guiding, the article concludes that NSR is transitioning from a mandatory icebreaker guiding regime into a permit regime. This is particularly evident in its provision of a concrete, practical, and predictable clause on permissible or impermissible conditions relating to independent navigation. According to the new rules, it is possible for foreign ships to undertake independent navigation in the NSR. The Russian NSR policy, therefore, appears to have changed significantly, and has future potential for opening the NSR up to the international community.展开更多
Guiding wall is used to change the flow of the oxidation ditch as supporting structure, it widely uses eccentric setting, and its setting parameters are mostly empirical judgments. According to fluent software that si...Guiding wall is used to change the flow of the oxidation ditch as supporting structure, it widely uses eccentric setting, and its setting parameters are mostly empirical judgments. According to fluent software that simulates the velocity distribution of the guiding wall, to discuss the settings of the guiding wall in different length of downstream extension, eccentricity and guiding wall radius, so to work out its optimized settings.展开更多
This paper reports that the transmission of O6＋ ions with energy of 150keV through capillaries in an uncoated Al2O3 membrane was measured, and agreements with previously reported results in general angular distributi...This paper reports that the transmission of O6＋ ions with energy of 150keV through capillaries in an uncoated Al2O3 membrane was measured, and agreements with previously reported results in general angular distribution of the transmitted ions and the transmission fractions as a function of the tilt angle well fitted to Gaussian-like functions were observed. Due tousing an uncoated capillary membrane, our φc is larger than that using a gold-coated one with a smaller value of Ep/q, which suggests a larger equilibrium charge Q∞ in our experiment. The observed special width variation with time and a larger width than that using a smaller Ep/q were qualitatively explained by using mean-field classical transport theory based on a classical-trajectory Monte Carlo simulation.展开更多
In the present research,the gas-assisted laser(GAL)and water-jet guided laser(WGL)processing technologies were applied to machine the ultrathin kerf in the wrought Ti-6Al-4V alloy.The microstructure,microhardness,and ...In the present research,the gas-assisted laser(GAL)and water-jet guided laser(WGL)processing technologies were applied to machine the ultrathin kerf in the wrought Ti-6Al-4V alloy.The microstructure,microhardness,and wear properties of the superficial layer were investigated.The results reveal that the GAL processing could machine the kerf with a high depth-to-width ratio of 12–15,but the increased processing times enhance the depth little.Due to the oxygen entrainment and relatively low heat and mass transferring efficiency,the assisted gas promotes the formation of a scaled recast layer containingβ-Ti phase and oxides,which increases the roughness to 20μm.The WGL processed kerf has a low depth-to-width ratio with a value of 1.9–2.5 and the depth could be increased by increasing the WGL processing times.With the assistance of the water jet,the remelted debris and heat could be eliminated immediately,which restrains the formation of the recast layer and heat-affected zone.The ultrathin oxide outer layer with hundreds of nanometers and ultrafineα-Ti grain inner layer are formed on the surface,which decreases the roughness to 12μm.Compared with the as-received Ti-6Al-4V alloy,the microhardness of GAL processed kerf surface is increased to 382.8 HV accompanied by residual tensile stress,while the microhardness of WGL processed kerf surface is increased to 481.6 HV accompanying with residual compressive stress.In addition,the GAL processing increases the wear rate at room temperature but decreases the wear rate at high temperatures.Comparatively,the WGL processing decreases the wear rate at room and high temperatures,simultaneously.Such wear behaviors could be ascribed to their different superficial microstructures and phase constituents.展开更多
On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousnes...On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousness, shortage of capital and other factors, the rural residents in Chongqing City mainly live scattered. In addition to opportunities of the expansion and drive of city, rural market development, rural resources development, rural industrial development, and rural ecological migration, the model of urban development promotion, the model of market development drive, the model of land development drive, the model of rural industry construction and the model of resettlement and reconstruction are advocated in order to guide the rural residents to adopt relative centralized residence. The suggestions concerning guiding rural residents' relative centralized residence are put forward as follows: firstly, act according to circumstances and conduct scientific planning and design; secondly, propagate extensively and activate famers' willingness; thirdly, first experiment and exert the exemplary guide; fourthly, perfect policy and guarantee farmers' benefit; fifthly, strengthen leadership and decrease the risk of centralized residence; sixthly, boost gradually and realize moderate centralized residence.展开更多
With the full-vector plane-wave method （FVPWM） and the full-vector beam propagation method （FVBPM）, the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in an...With the full-vector plane-wave method （FVPWM） and the full-vector beam propagation method （FVBPM）, the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in anti- resonance guiding photonic crystal fibres （ARGPCFs） are sufficiently analysed. An ARGPCF operating in the near- infrared wavelength is shown. The influences of the high index cylinders, glass interstitial apexes and silica structure on the characteristics of band-gaps and modes are deeply investigated. The equivalent planar waveguide theory is used for analysing such an ARGPCF filled by the isotropic materials, and the resonance and the anti-resonance characteristics r：~n h~ w~｜] r^r~dlrtpd展开更多
The virtual instruments （VIs）, as a new type of instrument based on computer, has many advanced attractive characteristics. This research is based on Vls, and brings condition monitoring and knowledge-based maintena...The virtual instruments （VIs）, as a new type of instrument based on computer, has many advanced attractive characteristics. This research is based on Vls, and brings condition monitoring and knowledge-based maintenance support together through an integrated （including hate.met, ASP. NET, XML tochnique, Vls） network environme~. Within the enviromnent, machining centers operators, engineers or managers can share real-time data through the browser-based interface and minimize machining centers downtime by providing status monitoring and remote maintenance guiding from service centers.展开更多
The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with e...The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with elevated overpotentials,thereby imposing additional constraints on its utilization.Therefore,the pre-design and target-development of inexpensive,high-performance,and long-term stable bifunctional catalysts are urgently needed.In this work,an apically guiding dual-functional electrocatalyst(Ag-FeN_(x)-N-C)was prepared,in which a hierarchical porous nitrogen-doped carbon with three-dimensional(3D)hollow star-shaped structure is used as a substrate and high-conductivity Ag nanoparticles are coupled with iron nitride(FeN_(x))nanoparticles.Theoretical calculations indicate that the Mott-Schottky heterojunction as an inherent electric field comes from the two-phase bound of Ag and FeN_(x),of which electron accumulation in the FeN_(x)phase region and electron depletion in the Ag phase region promote orientated-guiding charge migration.The effective modulation of local electronic structures felicitously reforms the d-band electron-group distribution,and intellectually tunes the masstransfer reaction energy barriers for both ORR/OER.Additionally,the hollow star-s haped hierarchical porous structure provides an apical region for fast mass transfer.Experimental results show that the halfwave potential for ORR is 0.914 V,and the overpotential for OER is only 327 mV at 10 mA cm^(-2).A rechargeable ZAB with Ag-FeN_(x)-N-C as the air cathode demonstrates long-term cycling performance exceeding 1500 cycles(500 h),with a power density of 180 mW cm^(-2).Moreover,when employing AgFeN_(x)-N-C as the air cathode,flexible ZABs demonstrate a notable open-circuit voltage of 1.42 V and achieve a maximum power density of 65.6 mW cm^(-2).Ag-FeN_(x)-N-C shows guiding electron/mass transfer route and apical reaction microenvironment for the electrocatalyst architecture in the exploration prospects of ZABs.展开更多
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.
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。
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Using step pattern match technology with variational resolution can recognize the position and orientation of the weld seam in the image. According to using the image segmentation method based on pattern match, not only advanced the speed and anti-jamming capability, but also captured the edge information of the weld seam and the edge of the workpiece, and the image coordinate of the initial welding position can be obtained. The matrix for hand-eye relationship of the robot can be calculated by adopting the rapid calculation method. According to the depth calculating principle with the special point matching using binocular stereovision, the initial welding position can be confirmed by calculating the middle point of the perpendicular line of two radials in the space, and the function to guide the welding robot to the initial welding position can be realized.
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.
基金This project is supported by National Natural Science Foundation of China(No.60474036) and Shanghai Municipal Science and Technology CommitteeFoundation, China (No.021111116).
文摘A method is put forward to realize the recognition and guiding of initial welding position. The weld seams are marked with black lines, which simplify the computational complexity of image processing greatly. A two-time template matching method has been advanced to search for the target point, which is simple and has higher calculation speed. According to the depth computing principle with the special point matching using binocular stereovision, the initial welding position can be confirmed by calculating the middle point of the perpendicular line of two radials in the space. Taking the welding of propellant fuel container for example, good results are obtained with the algorithms. Finally, similar method for terminating welding position is also advanced.
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 Basic Research Program of China(Grant No.2011CB013004)the National Natural Science Foundation of China(Grant No.50975128)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK2011462)the Postdoctoral Science Foundation of China(Grant No.20100481093)
文摘We propose a novel scheme to guide neutral cold atoms in a nanoscale region based on surface plasmons （SPs） of one pair and two pairs of tips of metallic wedges with locally enhanced light intensity and sub-optical wavelength resolution. We analyze the near-field intensity distribution of the tip of the metallic wedge by the FDTD method, and study the total intensity as well as the total potential of optical potentials and van der Waals potentials for 87 Rb atoms in the light field of one pair and two pairs of tips of metallic wedges. It shows that the total potentials of one pair and two pairs of tips of metallic wedges can generate a gravito-optical trap and a dark closed trap for nanoscale guiding of neutral cold atoms. Guided atoms can be cooled with efficient intensity-gradient Sisyphus cooling by blue-detuned light field. This provides an important step towards the generation of hybrid systems consisting of isolated atoms and solid devices.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10975121 and 11174259)the Foundation of National Key Laboratory of Plasma Physics
文摘We demonstrated the interaction of a gold cone target with a femto second（fs） laser pulse above the relativistic intensity of 1.37×10 18 μm 2 W/cm 2.Relativistic electrons with energy above 2 MeV were observed.A 25%-40% increase of the electron temperature is achieved compared to the case when a plane gold target is used.The electron temperature increase results from the guiding of the laser beam at the tip and the intense quasistatic magnetic field in the cone geometry.The behavior of the relativistic electrons is verified in our 2D-PIC simulations.
基金Marine Science Research Project for Public Welfare "Assessment for Navigability of Arctic Sea Route and Research & Demonstration for Prediction System for Sea Route" (Grant no. 201205007-6)Research Project of Polar Right and Interest, the Department of International Cooperation of the State Oceanic Administration, China
文摘This article focuses on two issues. The first concerns definitions of the Northern Sea Route （NSR） in old and new Russian legislation, and the second relates to Russian rules on icebreaker guiding. Based on a comprehensive comparative analysis of relevant Russian legal provisions enacted in 2013 and previous laws in this area, we offer the following conclusions. （1） Our legal analysis indicates that Russia＇s view of the NSR as a historical national transportation route has not changed. However, the new law redefines the scope and coverage of the NSR, which now comprises the internal waters, territorial sea, adjacent zone, and the exclusive economic zone of the Russian Federation. In fact, the new law resolves previous ambiguity regarding extension of the NSR boundary to the high seas. （2） Based on an analysis of the new rules on icebreaker guiding, the article concludes that NSR is transitioning from a mandatory icebreaker guiding regime into a permit regime. This is particularly evident in its provision of a concrete, practical, and predictable clause on permissible or impermissible conditions relating to independent navigation. According to the new rules, it is possible for foreign ships to undertake independent navigation in the NSR. The Russian NSR policy, therefore, appears to have changed significantly, and has future potential for opening the NSR up to the international community.
文摘Guiding wall is used to change the flow of the oxidation ditch as supporting structure, it widely uses eccentric setting, and its setting parameters are mostly empirical judgments. According to fluent software that simulates the velocity distribution of the guiding wall, to discuss the settings of the guiding wall in different length of downstream extension, eccentricity and guiding wall radius, so to work out its optimized settings.
基金supported by the National Natural Science Foundation of China(Grant No 10775063)
文摘This paper reports that the transmission of O6＋ ions with energy of 150keV through capillaries in an uncoated Al2O3 membrane was measured, and agreements with previously reported results in general angular distribution of the transmitted ions and the transmission fractions as a function of the tilt angle well fitted to Gaussian-like functions were observed. Due tousing an uncoated capillary membrane, our φc is larger than that using a gold-coated one with a smaller value of Ep/q, which suggests a larger equilibrium charge Q∞ in our experiment. The observed special width variation with time and a larger width than that using a smaller Ep/q were qualitatively explained by using mean-field classical transport theory based on a classical-trajectory Monte Carlo simulation.
基金the financial support for this research by the National Key Research and Develop-ment Program of China(No.2018YFC1106702)the Natural National Science Foundation of China(NSFC)(No.51805525)+5 种基金the Natural Science Foundation of Zhejiang Province(Nos.LY21E050018,LY18E050027)the Innovation Guidance Foun-dation of Innovation Academy for Light-duty Gas Turbine of Chinese Academy of Sciences(No.CXYJJ20-QN-10)the Zhejiang Basic Public Welfare Research Program(No.LGG20E050009)the Ningbo 2025 Major Science and Technology Project(No.2022Z013)the Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515011301,2019A1515110067,and 2020A1515110055)the Shenzhen Basic Research Project(Nos.JCYJ20210324120001003,JCYJ20200109144608205,and JCYJ20200109144604020).
文摘In the present research,the gas-assisted laser(GAL)and water-jet guided laser(WGL)processing technologies were applied to machine the ultrathin kerf in the wrought Ti-6Al-4V alloy.The microstructure,microhardness,and wear properties of the superficial layer were investigated.The results reveal that the GAL processing could machine the kerf with a high depth-to-width ratio of 12–15,but the increased processing times enhance the depth little.Due to the oxygen entrainment and relatively low heat and mass transferring efficiency,the assisted gas promotes the formation of a scaled recast layer containingβ-Ti phase and oxides,which increases the roughness to 20μm.The WGL processed kerf has a low depth-to-width ratio with a value of 1.9–2.5 and the depth could be increased by increasing the WGL processing times.With the assistance of the water jet,the remelted debris and heat could be eliminated immediately,which restrains the formation of the recast layer and heat-affected zone.The ultrathin oxide outer layer with hundreds of nanometers and ultrafineα-Ti grain inner layer are formed on the surface,which decreases the roughness to 12μm.Compared with the as-received Ti-6Al-4V alloy,the microhardness of GAL processed kerf surface is increased to 382.8 HV accompanied by residual tensile stress,while the microhardness of WGL processed kerf surface is increased to 481.6 HV accompanying with residual compressive stress.In addition,the GAL processing increases the wear rate at room temperature but decreases the wear rate at high temperatures.Comparatively,the WGL processing decreases the wear rate at room and high temperatures,simultaneously.Such wear behaviors could be ascribed to their different superficial microstructures and phase constituents.
基金Supported by the Research on the Mechanism and System of Guiding Farmers' Relatively Centralized Residence (0106002442003)Research Program of the Comprehensive Matching Reform Subject of Coordinating City and Village in 2009
文摘On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousness, shortage of capital and other factors, the rural residents in Chongqing City mainly live scattered. In addition to opportunities of the expansion and drive of city, rural market development, rural resources development, rural industrial development, and rural ecological migration, the model of urban development promotion, the model of market development drive, the model of land development drive, the model of rural industry construction and the model of resettlement and reconstruction are advocated in order to guide the rural residents to adopt relative centralized residence. The suggestions concerning guiding rural residents' relative centralized residence are put forward as follows: firstly, act according to circumstances and conduct scientific planning and design; secondly, propagate extensively and activate famers' willingness; thirdly, first experiment and exert the exemplary guide; fourthly, perfect policy and guarantee farmers' benefit; fifthly, strengthen leadership and decrease the risk of centralized residence; sixthly, boost gradually and realize moderate centralized residence.
基金partly supported by the National Key Basic Research Special Foundation of China (Grant Nos. 2010CB327605 and 2010CB328300)the National High-Technology Research and Development Program of China (Grant No. 2009AA01Z220)+3 种基金the Key Grant of the Chinese Ministry of Education (Grant No. 109015)the Discipline Co-construction Project of Beijing Municipal Commission of Education,China (Grant No. YB20081001301)the Open Fund of Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications),Chinese Ministry of Educationthe Specialized Research Fund for the Doctoral Program of Beijing University of Posts and Telecommunications (Grant No. CX201023)
文摘With the full-vector plane-wave method （FVPWM） and the full-vector beam propagation method （FVBPM）, the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in anti- resonance guiding photonic crystal fibres （ARGPCFs） are sufficiently analysed. An ARGPCF operating in the near- infrared wavelength is shown. The influences of the high index cylinders, glass interstitial apexes and silica structure on the characteristics of band-gaps and modes are deeply investigated. The equivalent planar waveguide theory is used for analysing such an ARGPCF filled by the isotropic materials, and the resonance and the anti-resonance characteristics r：~n h~ w~｜] r^r~dlrtpd
基金This work was supported by National Key Laboratory Foundation for FMS No. 51458100505JB3501
文摘The virtual instruments （VIs）, as a new type of instrument based on computer, has many advanced attractive characteristics. This research is based on Vls, and brings condition monitoring and knowledge-based maintenance support together through an integrated （including hate.met, ASP. NET, XML tochnique, Vls） network environme~. Within the enviromnent, machining centers operators, engineers or managers can share real-time data through the browser-based interface and minimize machining centers downtime by providing status monitoring and remote maintenance guiding from service centers.
基金the financial support of the National Natural Science Foundation of China(52002079,22378074,22179025 and U20A20340)the Guangdong Basic and Applied Basic Research Foundation(2022A1515140085)+2 种基金the Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202209)the Guangzhou Hongmian Project(HMJH-20200012)the Foshan Introducing Innovative and Entrepreneurial Teams(1920001000108)。
文摘The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with elevated overpotentials,thereby imposing additional constraints on its utilization.Therefore,the pre-design and target-development of inexpensive,high-performance,and long-term stable bifunctional catalysts are urgently needed.In this work,an apically guiding dual-functional electrocatalyst(Ag-FeN_(x)-N-C)was prepared,in which a hierarchical porous nitrogen-doped carbon with three-dimensional(3D)hollow star-shaped structure is used as a substrate and high-conductivity Ag nanoparticles are coupled with iron nitride(FeN_(x))nanoparticles.Theoretical calculations indicate that the Mott-Schottky heterojunction as an inherent electric field comes from the two-phase bound of Ag and FeN_(x),of which electron accumulation in the FeN_(x)phase region and electron depletion in the Ag phase region promote orientated-guiding charge migration.The effective modulation of local electronic structures felicitously reforms the d-band electron-group distribution,and intellectually tunes the masstransfer reaction energy barriers for both ORR/OER.Additionally,the hollow star-s haped hierarchical porous structure provides an apical region for fast mass transfer.Experimental results show that the halfwave potential for ORR is 0.914 V,and the overpotential for OER is only 327 mV at 10 mA cm^(-2).A rechargeable ZAB with Ag-FeN_(x)-N-C as the air cathode demonstrates long-term cycling performance exceeding 1500 cycles(500 h),with a power density of 180 mW cm^(-2).Moreover,when employing AgFeN_(x)-N-C as the air cathode,flexible ZABs demonstrate a notable open-circuit voltage of 1.42 V and achieve a maximum power density of 65.6 mW cm^(-2).Ag-FeN_(x)-N-C shows guiding electron/mass transfer route and apical reaction microenvironment for the electrocatalyst architecture in the exploration prospects of ZABs.
