Study of the Lift Force Induced by An Interceptor on A High-Speed Mono-Hull:The Affecting Factors and Estimation Formula

To find a better way to estimate the lift force induced by an interceptor on a high-speed mono-hull ship,a series of high-speed mono-hull ship models are designed and investigated under different conditions.Different lift forces are obtained by numerical calculations and validated by a model test in a towing tank.The factors that influence the force are the interceptor height,velocity,draft,and deadrise angle.The relationship between each factor and the induced lift force is investigated and obtained.We found that the induced lift mainly depends on the interceptor height and advancing velocity,and is proportional to the square of the interceptor height and velocity.The results also showed that the effects of the draft and deadrise angle are relatively less important,and the relationship between the induced lift and these two factors is generally linear.Based on the results,a formula including the combined effect of all factors used to estimate the lift force induced by the interceptor is developed based on systematic analysis.The proposed formula could be used to estimate the lift force induced by interceptors,especially under high-speed condition.

关联规则分析中兴趣度量Lift与Conviction的关系探讨及教育数据验证

关联规则分析是数据挖掘中最常用的研究方法之一。在关联关系的发现过程中兴趣度量是关联规则发现的理论基础,它可以度量规则的重要程度,其中Lift和Conviction这两个度量在数据分析中被广泛应用于筛选关联规则。本文对这两种兴趣度量进行了研究。首先,提出并证明了当后项集固定时,Conviction取值随Lift取值单调增加,且Conviction (Lift)是一个凸函数。然后,证明了当Confidence固定时,Conviction取值随Lift取值单调增加,且Conviction (Lift)是一个凹函数。最后,综合以上两个方面,得到一个重要结论:当后项集保持不变或当Confidence固定时,根据Conviction和Lift筛选出来的规则都是相同的。最后,利用某高校数学类专业三个年级的成绩数据进行了定理及相应结论的验证。

A comparative study on kinetics and dynamics of two dump truck lifting mechanisms using MATLAB simscape

In this paper,two lifting mechanism models with opposing placements,which use the same hydraulic hoist model and have the same angle of 50°,have been developed.The mechanical and hydraulic simulation models are established using MATLAB Simscape to analyze their kinetics and dynamics in the lifting and holding stages.The simulation findings are compared to the analytical calculation results in the steady state,and both methods show good agreement.In the early lifting stage,Model 1 produces greater force and discharges goods in the container faster than Model 2.Meanwhile,Model 2 reaches a higher force and ejects goods from the container cleaner than its counterpart at the end lifting stage.The established simulation models can consider the effects of dynamic loads due to inertial moments and forces generated during the system operation.It is crucial in studying,designing,and optimizing the structure of hydraulic-mechanical systems.

改良LIFT手术联合自体富血小板PRP凝胶技术治疗肛瘘的临床研究

目的:探讨改良括约肌间瘘管结扎术(LIFT)手术联合自体富血小板PRP凝胶技术治疗肛瘘的临床疗效。方法:随机将2021年5月至2023年5月在我院接受治疗的62例肛瘘患者分为对照组和观察组,31例一组。对照组采用改良LIFT手术治疗,观察组予以改良LIFT手术联合自体富血小板PRP凝胶技术治疗。随访两个月,比较两组住院时间,创面愈合时间,创面瘢痕面积,临床疗效,术后疼痛评分,肛门功能评分,并发症发生率。结果:观察组的住院时间和创面愈合时间均短于对照组,创面瘢痕面积少于对照组(P<0.05)。观察组治疗有效率为96.77%,高于对照组的80.65%(P<0.05)。观察组术后1天、7天VAS评分及术后1、2个月Wexner评分均低于对照组(P<0.05)。观察组术后并发症发生为6.45%,低于对照组的25.81%(P<0.05)。结论:肛瘘采用改良LIFT手术联合自体富血小板PRP凝胶技术治疗效果突出,可以缓解术后疼痛,改善肛门功能,减少并发症,促进预后恢复,值得临床推广应用。

Influence of Anteroposterior Symmetrical Aero-Wings on the Aerodynamic Performance of High-Speed Train

The running stability of high-speed train is largely constrained by the wheel-rail coupling relationship,and the continuous wear between the wheel and rail surfaces will profoundly affect the dynamic performance of the train.In recent years,under the background of increasing train speed,some scientific researchers have proposed a new idea of using the lift force generated by the aerodynamic wings(aero-wing)installed on the roof to reduce the sprung load of the carriage in order to alleviate the wear and tear of the wheel and rail.Based on the bidirectional running characteristics of high-speed train,this paper proposes a scheme to apply aero-wings with anteroposterior symmetrical cross-sections on the roof of the train.After the verification of the wind tunnel experimental data,the relatively better airfoil section and extension formof anteroposterior symmetrical aero-wing is selected respectively in this paper,and the aero-wings are fixedly connected to the roof of the train through the mounting column to conduct aerodynamic simulation analysis.The research shows that:compared with the circular-arc and oval crosssections,this paper believes that the crescent cross-section can form greater aerodynamic lift force in a limited space.Considering factors such as aerodynamic parameters,ground effect,and manufacturing process,this paper proposes to adopt aero-wings with arc type extension form and connect them to the roof of the train through mounting columns with shuttle cross-section.When the roof of the train is covered with aero-wings and runs at high speed,the sprung load of the carriages can be effectively reduced.However,there are certain hidden dangers in the tail carriage due to the large amount of lift force,so,the intervention of the aero-wing lifting mechanism is required.At the same time,it is necessary to optimize the overall aerodynamic drag force reduction in the followup work.

消肿生肌汤辅助LIFT对高位单纯性肛瘘术后疼痛与康复进程的影响

目的:研究消肿生肌汤辅助经括约肌间瘘管结扎术(Ligation of intersphincteric fistula tract,LIFT)对高位单纯性肛瘘术后疼痛(Visual analogue scale,VAS)评分、康复进程的影响.方法:选取2020年8月至2022年8月于我院确诊的94例肛瘘患者作为研究对象,依随机对照法分为研究组和对照组,各47例.对照组采用LIFT术治疗,研究组在对照组基础上联合消肿生肌汤治疗.比较两组临床疗效、治疗后恢复情况及住院时间、治疗前后视觉模拟评分(VAS)、大便失禁严重性指数(Fecal incontinence severity index,FISI)、Wexner肛门失禁评分(Wexner)、肛肠动力学、相关血清指标水平.结果:研究组总有效率高于对照组(P<0.05);治疗后,研究组VAS、FISI、Wexner评分均低于对照组(P<0.05);研究组直肠静息压(Rectal resting pressure,RRP)、肛管最大收缩压(Analmaximal contraction pressure,AMCP)、肛管静息压(Anal tube resting pressure,ARP)、肛管最长收缩时间(Anal longest contraction,ALCT)水平高于对照组(P<0.05);研究组血清转化生长因子-β1(Transforming growth factor-β1,TGF-β1)、纤维连接蛋白(Fibronectin,FN)高于对照组,淀粉样蛋白A(Serum amyloid A,SAA)、趋化因子5(Chemokine ligand 5,CCL5)低于对照组(P>0.05);研究组恢复情况及住院时间短于对照组(P<0.05).结论:消肿生肌汤辅助LIFT对高位单纯性肛瘘患者术后效果显著,可有效促进患者创口愈合,减少炎症反应,降低肛肠疼痛度,缩短临床康复进程.

Experimental and Numerical Investigation on the Aerodynamic Characteristics of High-Speed Pantographs with Supporting Beam Wind Deflectors

Aiming to mitigate the aerodynamic lift force imbalance between pantograph strips,which exacerbates wear and affects the current collection performance of the pantograph-catenary system,a study has been conducted to support the beam deflector optimization using a combination of experimental measurements and computational fluid dynamics(CFD)simulations.The results demonstrate that the size,position,and installation orientation of the wind deflectors significantly influence the amount of force compensation.They also indicate that the front strip deflectors should be installed downwards and the rear strip deflectors upwards,thereby forming a“π”shape.Moreover,the lift force compensation provided by the wind deflectors increases with the size of the deflector.Alternative wind compensation strategies,such as control circuits,are also discussed,putting emphasis on the pros and cons of various pantograph types and wind compensation approaches.

Analysis of Maximum Liquid Carrying Capacity Based on Conventional Tubing Plunger Gas Lift

China’s unconventional gas fields have a large number of low-productivity and low-efficiency wells, many of whichare located in remote and environmentally harsh mountainous areas. To address the long-term stable productionof these gas wells, plunger-lift technology plays an important role. In order to fully understand and accurately graspthe drainage and gas production mechanisms of plunger-lift, a mechanical model of plunger-liquid column uplift inthe plunger-lift process was established, focusing on conventional plunger-lift systems and representative wellboreconfigurations in the Linxing region. The operating casing pressure of the plunger-lift process and the calculationmethod for the maximum daily fluid production rate based on the work regime with the highest fluid recovery ratewere determined. For the first time, the critical flow rate method was proposed as a constraint for the maximumliquid-carrying capacity of the plunger-lift, and liquid-carrying capacity charts for conventional plunger-lift withdifferent casing sizes were developed. The results showed that for 23/8 casing plunger-lift, with a well depth ofshallower than 808 m, the maximum drainage rate was 33 m3/d;for 27/8 casing plunger-lift, with a well depth ofshallower than 742 m, the maximum drainage rate was 50.15 m3/d;for 31/2 casing plunger-lift, with a well depthof shallower than 560 m, the maximum drainage rate was 75.14 m3/d. This research provides a foundation for thescientific selection of plunger-lift technology and serves as a decision-making reference for developing reasonableplunger-lift work regimes.

Trajectory compensation for multi-robot coordinated lifting system considering elastic catenary of the rope

The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the kinematic and dynamic analysis of the lifting system,the elastic catenary mod-el considering the elasticity and mass of the flexible rope is established,and the effect of the deform-ation of the flexible rope on the position and posture of the suspended object is analyzed.According to the deformation of flexible rope,a real-time trajectory compensation method is proposed based on the compensation principle of position and posture.Under the lifting task of the low-speed move-ment,this is compared with that of the system which neglects the deformation of the flexible rope.The trajectoy of the lifting system considering the deformation of flexible rope.The results show that the mass and elasticity of the flexible rope can not be neglected.Meanwhile,the proposed trajectory compensation method can improve the movement accuracy of the lifting system,which verifies the ef-fectiveness of this compensation method.The research results provide the basis for trajectory plan-ning and coordinated control of the lifting system。

Research on the Lifting Path of Data Literacy Ability of Applied University Teachers under the Perspective of Organizational Learning

With the arrival of the big data era, the modern higher education model has undergone radical changes, and higher requirements have been put forward for the data literacy of college teachers. The paper first analyzes the connotation of teacher data literacy, and then combs through the status quo and dilemmas of teachers’ data literacy ability in applied universities. The paper proposes to enhance the data literacy ability of teachers from the perspective of organizational learning. Through building a digital culture, building a data-driven teaching environment, and constructing an interdisciplinary learning community to further promote the application of the theory and practice of datafication inside and outside the organization, and ultimately improve the quality of teaching.

Abdominoplasty, Liposuction and Brazilian Butt Lift (BBL) in Kinshasa in the Democratic Republic of Congo. My Experience in This Aesthetic Plastic Surgery with Black African Women in a Low-Income Country

Background: In low-income African countries, the demand and use of plastic surgery operations including abdominoplasty, liposuction and Brazilian butt lift (BBL) are increasing. The goal of this work is to present my experience and the challenges of this aesthetic plastic surgery among black African women. Material and Methods: A retrospective study was conducted about the abdominoplasties, liposuctions and Brazilian butt lift (BBL) which I operated in public and private hospitals at Kinshasa (Democratic Republic of Congo) in black African women. It covers a period of 13 years, going from December 1, 2010 to December 1, 2023. For this study, I had at least 6 months period (to Juin 1, 2024) to assess the occurrence of early and late postoperative complications. Results: I performed 84 abdominoplasties, 144 liposuctions and 23 Brazilian butt lifts (BBL). The average age at the time of abdominoplasty was 44 years with extremes ranging from 26 to 55 years and a concentration of cases (60.7%) in the age group of 40 to 49 years. The age group of 20 to 29 years old represented the lowest rate of requests for abdominoplasty (4.7%). Patients with a BMI of 30 to 2 were the majority (61.9%), followed by those between 25 to 2 (29.7%). 67.8% of patients were obese (BMI ≥ 30 kg/m2). The average age at the time of liposuction was 41 years with extremes ranging from 21 years to 69 years;and more than half of cases (68%) in the age group between 30 and 49 years. As for Brazilian butt lift (BBL), the average age was 33 years with extremes ranging from 24 to 42 years and a concentration of patients (91.3%) between 20 and 39 years. The immediate postoperative complications of abdominoplasties observed were: seroma in 7% of cases, hematoma and partial infection of the surgical site in 5% of cases. Pathological scars (hypertrophic, keloid) after abdominoplasties were observed in 9% of cases. The most common complication of liposuction was contour deformity. I observed 16 patients (11.1%) with soft-tissue depressions or elevations, skin panniculus or folds. For Brazalian Butt Lift (BBL), complications like asymmetry for 2 patients (8.9%), contour irregularities for 2 patients (8.9%), and excessive fat removal for 6 patients (26%), had observed. I have not recorded any cases of death or pulmonary embolism. Conclusion: I perform aesthetic plastic surgery procedures in black African women with a high socioeconomic standard of living compared to the average of the general population. The renunciation of planned surgery is motivated by the impossibility of paying the cost of the operation as well as by popular and religious perceptions regarding cosmetic surgery. The results of these aesthetic plastic surgery procedures carried out are very satisfactory for them. The challenges to overcome are mainly threefold: the unforeseeable complications of these cosmetic plastic surgery procedures, popular and religious perceptions of cosmetic surgery as well as the poverty of the population.

lift⁃off制程PEB温度对负性光阻显影后截面Profile的影响

本文研究了lift⁃off(揭开-剥离)制程曝光后烘烤温度(post exposure bake,PEB)对负性光阻显影截面Profile(光刻胶结构)的影响。结果表明:在保留原有PEB盘面加热的方式前提下通过增加PEB盘盖加热功能进行烘烤,通过控制PEB盘面温度可调整光阻关键尺寸(critical dimension,CD)及截面Profile形貌,通过控制PEB盘盖加热可调整截面Profile光阻顶端形貌及强度,可显著改善负性光阻显影后截面Profile难以调整的问题。另外,不同的盘面温度、不同盘盖温度以及不同的显影时间相互配合,可以实现一种负性光阻产生不同截面光刻胶结构效果,可以实现同种光阻lift⁃off制程多样化。

A STUDY ON THE MECHANISM OF HIGH-LIFT GENERATION BY AN AIRFOIL IN UNSTEADY MOTION AT LOW REYNOLDS NUMBER

The aerodynamic force and flow structure of NACA 0012 airfoil performing an unsteady motion at low Reynolds number (Re = 100) are calculated by solving Navier-Stokes equations. The motion consists of three parts: the first translation, rotation and the second translation in the direction opposite to the first. The rotation and the second translation in this motion are expected to represent the rotation and translation of the wing-section of a hovering insect. The flow structure is used in combination with the theory of vorticity dynamics to explain the generation of unsteady aerodynamic force in the motion. During the rotation, due to the creation of strong vortices in short time, large aerodynamic force is produced and the force is almost normal to the airfoil chord. During the second translation, large lift coefficient can be maintained for certain time period and (C) over bar (L), the lift coefficient averaged over four chord lengths of travel, is larger than 2 (the corresponding steady-state lift coefficient is only 0.9). The large lift coefficient is due to two effects. The first is the delayed shedding of the stall vortex. The second is that the vortices created during the airfoil rotation and in the near wake left by previous translation form a short 'vortex street' in front of the airfoil and the 'vortex street' induces a 'wind'; against this 'wind' the airfoil translates, increasing its relative speed. The above results provide insights to the understanding of the mechanism of high-lift generation by a hovering insect.

Surface integral analogy approaches for predicting noise from 3D high-lift low-noise wings

Three surface integral approaches of the acoustic analogies are studied to predict the noise from three concep- tual configurations of three-dimensional high-lift low-noise wings. The approaches refer to the Kirchhoff method, the Ffowcs Williams and Hawkings （FW-H） method of the permeable integral surface and the Curle method that is known as a special case of the FW-H method. The first two approaches are used to compute the noise generated by the core flow region where the energetic structures exist. The last approach is adopted to predict the noise specially from the pressure perturbation on the wall. A new way to con- struct the integral surface that encloses the core region is proposed for the first two methods. Considering the local properties of the flow around the complex object-the actual wing with high-lift devices-the integral surface based on the vorticity is constructed to follow the flow structures. The surface location is discussed for the Kirchhoff method and the FW-H method because a common surface is used for them. The noise from the core flow region is studied on the basis of the dependent integral quantities, which are indicated by the Kirchhoff formulation and by the FW-H formulation. The role of each wall component on noise contribution is analyzed using the Curle formulation. Effects of the volume integral terms of Lighthill＇s stress tensors on the noise pre-diction are then evaluated by comparing the results of the Curle method with the other two methods.

Use of High-Resolution Ultrasound (HRU) in the Assessment of Deep Injections of CHAP-Hyaluronic Acid (CHAP-HA) Fillers for Midface Lift

High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The formations of pools or pearls in HA fillers could be observed real time during injection. The plane of injection could be determined accurately, and there were no specimen manipulation artifacts. It was observed that HA gel fillers with differing production technologies showed distinct spread and distribution patterns in the periocular tissues on HRU examination. The authors used HRU to assess deep injections of CHAP-Hyaluronic Acid (CHAP-HA) fillers for midface lift. 10 patients who underwent bilateral midface deep injections using CHAP-HA filler were examined with HRU before and immediately after treatment, and in 2 weeks and one month later. The CHAP-HA appeared as hypoechoic densities within the preperiosteal plane in HRU. CHAP-HA adopted variable morphology within the tissue depending on individual tissue densities and the compliance of the tissues in the plane of injection. CHAP-HA was unidentifiable with surrounding tissue after one month in 13 of the 20 injection sites. HRU allows in vivo study of CHAP-HA injection behavior and could be a tool for further studies of HA-tissue reactions.

Numerical study of the influence of spoiler deflection on high-lift configuration

This paper numerically studies the influence of the downward spoiler deflection on the boundary layer flow of a high-lift two-element airfoil consisting of a droop nose, a main wing, a downward deflecting spoiler and a single slotted flap. Both of the boundary layer of the upper surface of the spoiler and the confluent boundary layer of the upper surface of the flap become thicker, as the downward spoiler deflection increases. Compared to the attached flow at the angle of attack of 10°, the flow of the upper surface of the spoiler becomes separated at the angle of attack of 16° when the spoiler deflection is large enough, which corresponds to the boundary layer flow reversal in velocity profiles.

WALL INTERFERENCE CORRECTIONS FORHIGH-LIFT EXPERIMENT

in this paper a method is outlined to compute wall-interferenee in closedlow speed wind tunnel for 3D high lift test using wall pressure at optimum points andthe influence function (WPIF method for short). The experimental results of a high liftmodel in small wind tunnel are corrected by applying the WPIF method. The correctedresults are compared with the wall interference-free data of this high lift model in largewind tunnel. It is shown that the WPIF method is desirable for the correction of lift,drag and pitch moment.

Dynamic Stall on High-Lift Airfoil 30P30N in Ground Proximity

Computational prediction of stall aerodynamics in free air and in close proximity to the ground considering the 30P30N three-element high-lift configuration is carried out based on CFD simulations using the OpenFOAM code and Fluent software. Both the attached and separated flow regimes are simulated using the Reynolds Averaged Navier-Stokes (RANS) equations closed with the Spalart-Allamaras (SA) turbulence model for static conditions and pitch oscillations at Reynolds number, Re = 5 x 106 and Mach number, M = 0.2. The effects of closeness to the ground and dynamic stall are investigated and the reduction in the lift force in close proximity to the ground is discussed.

Dynamic Analysis of Pipeline Lifting Operations for Different Current Velocities and Wave Heights

Pipelines are widely used for transporting oil resources in the context of offshore oil exploitation.The pipeline stress-strength analysis is an important stage in related design and ensuing construction techniques.In this study,assuming representative work environment parameters,pipeline lifting operations are investigated numerically.More specifically,a time-domain coupled dynamic analysis method is used to conduct a hydrodynamic analysis under different current velocities and wave heights.The results show that proper operation requires the lifting points are reasonably set in combination with the length of the pipeline and the position of the lifting device on the construction ship.The impact of waves on the pipeline is limited,however lifting operations under strong wind and waves should be avoided as far as possible.

比较TROPIS术联合引流挂线与LIFT术治疗高位经括约肌肛瘘的临床研究

本研究的目的是比较TROPIS术联合引流挂线与LIFT术治疗高位经括约肌肛瘘的临床疗效。方法 选取 2019 年3月至2021 年12 月在我院就诊的86 位高位经括约肌肛瘘患者为研究对象,随机分成TROPIS组和LIFT组,每组43 例。比较术后6个月的一期愈合率和愈合时间、手术时间、出血量,疼痛、术后肛门功能评分和复发率。结果 TROPIS组的一期愈合率为 86.0%,LIFT组的一期愈合率为 67.4%,差异有统计学意义(P=0.04)。LITF组的愈合时间较TROPIS组短(25.8天vs 28.8天 P <0.001);TROPIS组的手术时间较LIFT组短(46.9分vs52.8分P =0.001 ); TROPIS组术后VAS疼痛评分均高于LIFT组(P<0.001);术后6个月的Wexner失禁评分两组差异无统计学意义(p=0.66)。TROPIS组与LIFT组复发率分别为 2.32%和 6.98%,差异无统计学意义(P = 0.61)结论TROPIS联合挂线术和LIFT术均是治疗高位经括约肌肛瘘简单、安全、有效的手术方法。TROPIS术具有愈合率高、手术时间短的优点。