采用37.5■锦纶开发多功能弹力Legging面料

文章以37.5■锦纶科技纱线4.4 tex/34 f消光DTY为主纱,夹入2.2 tex黑氨纶材料,采用双面互锁的织造方式,开发出一款集抗菌、凉感、远红外、吸湿速干、防紫外线功能为一体的多功能弹力Legging针织面料。详细介绍该面料的原料选择、织造工艺以及染整工艺,并对面料的基本性能进行测试。结果表明,该面料具有较好的多项功能以及优良的包覆性能,可以满足女子多场景的运动与穿着舒适性的相关需求。

北京2022年冬奥会六足冰壶机器人机构设计与运动规划

When a curling rock slides on an ice sheet with an initial rotation,a lateral movement occurs,which is known as the curling phenomenon.The force of friction between the curling rock and the ice sheet changes continually with changes in the environment;thus,the sport of curling requires great skill and experience.The throwing of the curling rock is a great challenge in robot design and control,and existing curling robots usually adopt a combination scheme of a wheel chassis and gripper that differs significantly from human throwing movements.A hexapod curling robot that imitates human kicking,sliding,pushing,and curling rock rotating was designed and manufactured by our group,and completed a perfect show during the Beijing 2022 Winter Olympics Games.Smooth switching between the walking and throwing tasks is realized by the robot’s morphology transformation based on leg configuration switching.The robot’s controlling parameters,which include the kicking velocity v_(k),pushing velocity v_(p),orientation angle θc,and rotation velocityω,are determined by aiming and sliding models according to the estimated equivalent friction coefficientμ_(equ)and ratio e of the front and back frictions.The stable errors between the target and actual stopping points converge to 0.2 and 1.105 m in the simulations and experiments,respectively,and the error shown in the experiments is close to that of a well-trained wheelchair curling athlete.This robot holds promise for helping ice-makers rectify ice sheet friction or assisting in athlete training.

Smart Gait:A Gait Optimization Framework for Hexapod Robots

The current gait planning for legged robots is mostly based on human presets,which cannot match the flexible characteristics of natural mammals.This paper proposes a gait optimization framework for hexapod robots called Smart Gait.Smart Gait contains three modules:swing leg trajectory optimization,gait period&duty optimization,and gait sequence optimization.The full dynamics of a single leg,and the centroid dynamics of the overall robot are considered in the respective modules.The Smart Gait not only helps the robot to decrease the energy consumption when in locomotion,mostly,it enables the hexapod robot to determine its gait pattern transitions based on its current state,instead of repeating the formalistic clock-set step cycles.Our Smart Gait framework allows the hexapod robot to behave nimbly as a living animal when in 3D movements for the first time.The Smart Gait framework combines offline and online optimizations without any fussy data-driven training procedures,and it can run efficiently on board in real-time after deployment.Various experiments are carried out on the hexapod robot LittleStrong.The results show that the energy consumption is reduced by 15.9%when in locomotion.Adaptive gait patterns can be generated spontaneously both in regular and challenge environments,and when facing external interferences.

Effect of Skeleton Grain Size on the Saturation of Gas Hydrate in Natural Sediments

Natural gas hydrate is prospected as a new and promising,highly clean energy resource that mainly occurs in perma-frost or at continental margins.Its formation is subject to many soil conditions,such as grain size,matrix materials,pore morphology,and permeability.In this study,we propose that grain size is the most decisive parameter that affects the saturation of gas hydrate in sediments based on data from Ocean Drilling Program Leg 164 and Mallik 5L-38,which represent marine sediments and terrestrial sediments,respectively.Our study reveals that high gas hydrate saturation generally occurs in coarse-grained sand,regardless of whether sediment formation is homogeneous or inhomogeneous,and the sorting of sediments may affect the hydrate saturation to a certain degree.Using grain size and sorting of sediments may be the most intuitive proxy method for a rough estimation of hydrate saturation.Further study is necessary to fully understand the relationship between hydrate morphology and sediment grain size,even though massive hydrates are typically found in fine clayey-rich sediments.

近海三角张力腿平台钢筋束假定失效研究

Offshore triceratops is one of the successful manifestations of the form-dominant design approaches deployable in ultra-deepwater oil and gas exploration.The deck’s geometric shape and partial isolation from the legs counteract lateral loads.Legs are position-restrained to the sea bed by taut-moored tendons,while ball joints partially isolate the deck from the buoyant legs.However,compliance in the horizontal plane imposes large displacements,intuiting the necessity to examine tendon failure.Numerical analysis of triceratops under wave and wind combined action is carried out under the postulated conditions of a tendon failure.10-yr,100-yr,and 1000-yr post-Katrina hurricane conditions are assumed as loading to the platform.Results confirm a marginal increase in the natural periods of stiff degrees of freedom even under postulated failure conditions,ensuring good adaptability to ultra-deep water.Under postulated failure,the tension of adjacent tendons varies significantly,causing a shift to the mean position of the platform.Fatigue life is significantly reduced under the postulated failure of tendons,making the platform free-floating without affecting its stability.Results also show that the pitch response of the deck is a clear manifestation of the postulated failure,which is otherwise absent due to the presence of ball joints.The attempted study deliberates on the fatigue life of tendons,assessing the platform’s suitability to ultra-deep waters and identifying the vulnerable legs for the chosen load combinations.

Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight design.Inspired by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an LLU.We propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.The mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah muscle.The mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

Force Compensation Control for Electro-Hydraulic Servo System with Pump-Valve Compound Drive via QFT-DTOC

Each joint of a hydraulic-driven legged robot adopts a highly integrated hydraulic drive unit(HDU),which features a high power-weight ratio.However,most HDUs are throttling-valve-controlled cylinder systems,which exhibit high energy losses.By contrast,pump control systems offer a high efficiency.Nevertheless,their response ability is unsatisfactory.To fully utilize the advantages of pump and valve control systems,in this study,a new type of pump-valve compound drive system(PCDS)is designed,which can not only effectively reduce the energy loss,but can also ensure the response speed and response accuracy of the HDUs in robot joints to satisfy the performance requirements of robots.Herein,considering the force control requirements of energy conservation,high precision,and fast response of the robot joint HDU,a nonlinear mathematical model of the PCDS force control system is first introduced.In addition,pressure-flow nonlinearity,friction nonlinearity,load complexity and variability,and other factors affecting the system are considered,and a novel force control method based on quantitative feedback theory(QFT)and a disturbance torque observer(DTO)is designed,which is denoted as QFT-DTOC herein.This method improves the control accuracy and robustness of the force control system,reduces the effect of the disturbance torque on the control performance of the servo motor,and improves the overall force control performance of the system.Finally,experimental verification is performed using the PCDS performance test platform.The experimental results and quantitative data show that the QFT-DTOC proposed herein can significantly improve the force control performance of the PCDS.The relevant force control method can be used as a bottom-control method for the hydraulic servo system to provide a foundation for implementing the top-level trajectory planning of the robot.

“腿(leg)”隐喻在汉英表达中的认知语言学阐析

身体部位在人类认知体系中处于基础性地位,在获取身体体验的过程中具有独一无二的作用。身体部位之腿(leg)更是人们感知外部世界的重要工具之一。汉英表达中均广泛存在以腿(leg)为源域的腿(leg)隐喻表达。从认知层面的意象角度具体分析腿(leg)的隐喻可知,腿(leg)的意象分为两大类:一类是以腿(leg)的基本外形和功能为主的具体意象,另一类是由其基本外形和功能而衍生出来的抽象意象。汉英民族因为具有相同的身体结构和生理特征,产生了相近的身体体验,而趋近的体验也产生了对等的心理阐释和语言表述,因此汉英语言表达中存在众多相仿或趋同的腿(leg)隐喻。隐喻作为各民族典型的语言现象,势必与不同民族的文化意蕴密不可分。汉英表达中腿(leg)的隐喻义都颇为丰富,有相同之处,也存在典型差异,这主要是由各自的社会文化背景、思维方式、词法规则、词语搭配、主体指代关系和民族特色差异所造成的。

Restless head syndrome:A retrospective study

BACKGROUND Restless legs syndrome(RLS)is characterized by an urge to move with an unpleasant sensation in the lower limbs.RLS typically affects the legs.However,it can also affect several other body regions,such as the arms,abdomen,face,neck,head,and genital area.There are only a few reports of the RLS variant affecting the head.AIM To assess the epidemiological,clinical,and other aspects of the RLS variant affecting the head.METHODS We conducted a retrospective study of 17 adult patients(>18 years)who met the RLS criteria and simultaneously experienced RLS-like symptoms in the head.RESULTS The median age at which symptoms appeared was 41.6 years.Males and females were equally affected(1.1:1).All 17 patients had uncomfortable sensations in the lower legs.Insomnia or disturbed sleep was the most common comorbidity(n=16,88.2%).However,headache was the most common presenting or primary symptom(n=10,70.5%).Dizziness or an abnormal sensation in the head was the second most common presenting symptom(5 patients,29.4%).Other presenting features were leg pain,backache,and generalized body pain.All patients responded favorably to dopaminergic medications.CONCLUSION If RLS-related unpleasant sensations and pain are felt in the head,they may be misinterpreted as headache,dizziness,or psychosomatic symptoms.RLS and headaches in a subset of patients may be two phenotypic manifestations of the same disorder.

Prevalence of Bacterial and Fungal Infected Chronic Leg Ulcers at a Teaching Hospital in Ghana

Background: Chronic ulcers are responsible for considerable morbidity and significantly contribute to the escalation in the cost of health care. Chronic leg ulcers (CLUs) are susceptible to microbial infections and serious complications such as tissue necrosis and osteomyelitis, can result without the timely control of infections. Recent studies have also reported an increase in the association of fungal infections with chronic non-healing ulcers. Aim: To determine the prevalence of bacterial and fungal infections among patients reporting with chronic leg ulcers in participants without co-morbidities. Methods: A prospective cross-sectional study was conducted among patients with chronic leg ulcers at the National Reconstructive Plastic Surgery and Burns Centre, Korle-Bu Teaching Hospital (NRPS/BC-KBTH) and those who consented were enrolled. Characteristics of the wound as well as micro-organisms cultured from wound swabs were recorded. Results: A total of 50 participants were enrolled for the study with the mean (SD) age of 40.7 (10.7) years. Eighty percent of the participants presented with post traumatic leg ulcers with 80% being artisans and traders in the age group 31 - 50 years. There was no statistically significant association between sex and the organism cultured for post traumatic and cellulitis (p-value > 0.05). The prevalence of bacterial and fungal infection was 79.3% and 20.7% respectively. Pseudomonas species was the most isolated bacteria (61.5%) while Aspergillus niger was the most isolated fungi (41%). Conclusion: From this study, fungal infections should be included in managing chronic leg ulcers, especially among artisans, famers and gardeners even though there was a significantly higher burden of bacterial infections.

来看看谁是最火辣的丝袜控 Leggings,“女王”的新宠

秋天，丝袜总是必不可少的时尚单品，而黑丝浪潮也已经流行了不是一年两年了，你还在干篇一律地选择最基本、最普通、最传统的黑色丝袜？来看看这些丝袜控的“新宠”吧，看她们的造型搭配，谁最有气场？谁穿得最有特色？谁才是真正的Leggings Queen？

基于CFD和热阻网络法的C型舱LEG船温度场分析及热应力计算

为解决C型舱LEG船进行温度场计算时,CFD方法难以计入结构细节以及热阻网络法处理热对流精度较低的问题,提出将2种方法相结合的船体结构温度场计算方法。在CFD计算时,只考虑主要结构,将计算结果作为热阻网络法的输入,而在热阻网络法中考虑结构细节。实船计算结果显示,该方法高效可靠,避免了2种方法的缺点,可以合理地求解船体结构的温度场,是一种工程上实用的方法。计算还表明,对于温度梯度大的关键结构区域,结构强度评估需要考虑热应力。

Inverted Modelling:An Effective Way to Support Motion Planning of Legged Mobile Robots

This paper presents an effective way to support motion planning of legged mobile robots—Inverted Modelling,based on the equivalent metamorphic mechanism concept.The difference from the previous research is that we herein invert the equivalent parallel mechanism.Assuming the leg mechanisms are hybrid links,the body of robot being considered as fixed platform,and ground as moving platform.The motion performance is transformed and measured in the body frame.Terrain and joint limits are used as input parameters to the model,resulting in the representation which is independent of terrains and particular poses in Inverted Modelling.Hence,it can universally be applied to any kind of legged robots as global motion performance framework.Several performance measurements using Inverted Modelling are presented and used in motion performance evaluation.According to the requirements of actual work like motion continuity and stability,motion planning of legged robot can be achieved using different measurements on different terrains.Two cases studies present the simulations of quadruped and hexapod robots walking on rugged roads.The results verify the correctness and effectiveness of the proposed method.

A molecular toolkit to boost functional genomic studies in transformation-recalcitrant vegetable legumes

Dear Editor Legumes,the second-largest family of crops,contribute over one-third of human dietary proteins.Soybean(Glycine max L.),common bean(Phaseolus vulgaris L.),pea(Pisum sativum L.),and cowpea(Vigna unguiculata L.)are among the most widely culti-vated crop legumes for grain and vegetable and are essential for food security globally.

Potential sex differences in activation of pain-related brain regions in nonhuman primates with a unilateral spinal nerve ligation

The lack of truly robust analgesics for chronic pain is owed,in part,to the lack of an animal model that reflects the clinical pain state and of a mechanismbased,objective neurological indicator of pain.The present study examined stimulus-evo ked brain activation with functional magnetic resonance imaging in male and female cynomolgus macaques following unilateral L7 spinal nerve ligation and the effects of clinical analgesics pregabalin,duloxetine,and morphine on brain activation in these macaques.A modified straight leg raise test was used to assess pain severity in awake animals and to evo ke regional brain activation in anesthetized animals.The potential effects of clinical analgesics on both awake pain behavior and regional brain activation were examined.Following spinal nerve ligation,both male and female macaques showed significantly decreased ipsilateral straight leg raise thresholds,suggesting the presence of radicula rlike pain.Morphine treatment increased straight leg raise thresholds in both males and females whereas duloxetine and pregabalin did not.In male macaques,the ipsilateral straight leg raise activated contralateral insular and somatosensory cortex(Ins/SII),and thalamus.In female macaques,the ipsilateral leg raise activated cingulate cortex and contralateral insular and somatosensory cortex.Straight leg raises of the contralateral,unligated leg did not evoke brain activation.Morphine reduced activation in all brain regions in both male and female macaques.In males,neither pregabalin nor duloxetine decreased brain activation compared with vehicle treatment.In females,however,pregabalin and duloxetine decreased the activation of cingulate cortex compared with vehicle treatment.The current findings suggest a diffe rential activation of brain areas depending on sex following a peripheral nerve injury.Diffe rential brain activation observed in this study could underlie qualitative sexual dimorphism in clinical chronic pain perception and responses to analgesics.Future pain management approaches for neuropathic pain will need to consider potential sex differences in pain mechanism and treatment efficacy.

A new passive transfemoral prosthesis mechanism based on 3R36 knee and ESAR foot providing walking and squatting

Researchers have proposed various linkage mechanisms to connect knee and ankle joints for above-knee prosthe-ses,but most of them only offer natural walking.However,studies have shown that people assume a squatting posture during daily activities.This paper introduces a novel mechanism that connects the knee joint with the foot-ankle joint to enable both squatting and walking.The prosthetic knee used is the well-known 3R36,while the energy storing and return(ESAR)prosthetic foot is used for the ankle-foot joint.To coordinate knee and ankle joint movements,a six-bar linkage mechanism structure is proposed.Simulation results demonstrate that the proposed modular transfemoral prosthesis accurately mimics the motion patterns of a natural human leg during walking and squatting.For instance,the prosthesis allows a total knee flexion of more than 140°during squatting.The new prosthesis design also incorporates energy-storing mechanisms to reduce energy expenditure during walking for amputees.

Task-Oriented Topology System Synthesis of Reconfigurable Legged Mobile Lander Integrating Active and Passive Metamorphoses

To explore hostile extraterrestrial landforms and construct an engineering prototype,this paper presents the task-oriented topology system synthesis of reconfigurable legged mobile lander(ReLML)with three operation modes from adjusting,landing,to roving.Compared with our preceding works,the adjusting mode with three rotations(3R)provides a totally novel exploration approach to geometrically matching and securely arriving at complex terrains dangerous to visit currently;the landing mode is redefined by two rotations one translation(2R1T),identical with the tried-and-tested Apollo and Chang'E landers to enhance survivability via reasonable touchdown buffering motion;roving mode also utilizes 2R1T motion for good motion and force properties.The reconfigurable mechanism theory is first brought into synthesizing legged mobile lander integrating active and passive metamorphoses,composed of two types of metamorphic joints and metamorphic execution and transmission mechanisms.To reveal metamorphic principles with multiple finite motions,the finite screw theory is developed to present the procedure from unified mathematical representation,modes and source phase derivations,metamorphic joint and limb design,to final structure assembly.To identify the prototype topology,the 3D optimal selection matrix method is proposed considering three operation modes,five evaluation criteria,and two topological subsystems.Finally,simulation verifies the whole task implementation process to ensure the reasonability of design.

Effect of Specific Verbal Instructions on the Identification of Pain Location during a Passive Straight Leg Raise Test

Musculoskeletal pain is common. Because pain is subjective, objectively describing it is crucial. However, pain assessment may cause distress in patients;therefore, physical therapists (PTs) should conduct these tests quickly and accurately. Simple and clear instructions are recommended for pain assessment. However, few studies have provided evidence to support this hypothesis. Correspondingly, this study aimed to confirm the effectiveness of specific verbal instructions for pain location during five consecutive Passive Straight Leg Raise (PSLR) tests. The 28 asymptomatic participants (age 27.4 ± 9.6 years) who provided informed consent received five consecutive PSLR tests: three without and two with specific verbal instructions to ascertain pain intensity, quality, and location. The participants drew pain locations on a body chart and described the pain intensity and quality after each test. All participants were interviewed regarding the differences they noted in the presence and absence of specific verbal instructions. Each pain location was classified into one of ten areas for statistical analysis. The proportion of participants who changed the pain location was compared between the tests using McNemar’s test, and the kappa coefficient was confirmed for consistency of pain location. There was a significant difference in the proportion of participants who changed their pain location between the second and third tests and from the third to the fourth test (McNemar’s test: p = 0.003). Kappa coefficients had low consistency (κ = 0.28) just after receiving the specific verbal instructions in the fourth test compared to the third test. Consistency improved in the fifth test (κ = 0.57);93% of the participants answered that the pain location had become clearer. This study revealed the effects of specific verbal instructions in identifying pain locations. This detailed information may help PTs provide appropriate treatment and contribute to reducing pain in clinical settings.

Investigation of the mechanism of action of Sanwu Huangqin Tang in the treatment of restless leg syndrome based on network pharmacology,molecular docking technology and molecular dynamics simulation

Background:Through the use of network pharmacology and molecular docking approaches,this study will examine the pharmacological effects of Sanwu Huangqin Tang on restless legs syndrome in order to better understand the mechanism of action of Traditional Chinese medicine(TCM)on RLS.Method:Utilise the TCMSP database to collect and select the drug components of Sanwu Huangqin Tang,and the Uniprot database to identify pertinent targets;RLS-related disease targets were obtained from GeneCards,DrugBank,and OMIM databases;and STRING and Cytoscape 3.9.1 software were used to generate an interaction network.KEGG pathway analysis and GO enrichment analysis were performed utilizing the DAVID database.Use Autodock for analyzing the relationships between targets and core components.Result:By using a network pharmacology approach,83 active ingredients and 50 drug-disease intersecting targets were derived for Sanwu Huangqin Tang.The molecular docking results showed that the drug components had strong affinity with the average target targets.Conclusions:This study provides new insights into the mechanism through which Traditional Chinese Medicine(TCM)treats Restless Legs Syndrome(RLS).Furthermore,it lays the foundation for additional research into the mechanism of treatment for RLS through the intervention that addresses various targets and pathways using the active ingredients identified by Sanwu Huangqin Tang.