dynamic

摘要： This paper proposes a zero-moment control torque compensation technique.After compensating the gravity and friction of the robot,it must overcome a small inertial force to move in compliance with the external force.The principle of torque balance was used to realise the zero-moment dragging and teaching function of the lightweight collaborative robot.The robot parameter identification based on the least square method was used to accurately identify the robot torque sensitivity and friction parameters.When the robot joint rotates at a low speed,it can approximately satisfy the torque balance equation.The experiment uses the joint position and the current motor value collected during the whole moving process under the low-speed dynamic balance as the excitation signal to realise the parameter identification.After the robot was compensated for gravity and static friction,more precise torque control was realised.The zero-moment dragging and teaching function of the robot was more flexible,and the drag process was smoother.

摘要： The paper presents the construction of a steel footbridge in the People’s Park in Lublin.The initiation and development of the architectural design of an interesting and,as it eventually turned out,aesthetically pleasing footbridge is discussed.Two teams of architects and bridge engineers worked in parallel on the design.The design process of the footbridge structure is discussed along with its trial installation and on-site construction.The span of the footbridge is short,but its structure is innovative.For this reason its numerical model was developed used as a basis for an analysis of the dynamic response of the designed structure.The basic element of the acceptance procedure was constituted by a dynamic test load and an analysis of the pedestrian footbridge user comfort.Last but not least,the final section reviews the aesthetic canons of bridges and focuses on the footbridge in question in this context.A statistical measure of the aesthetic impression induced by a visit to the footbridge was applied resulting in a predictable and obvious final aesthetical assessment.

摘要： Bone remodeling is a lifelong process that gives rise to a mature, dynamic bone structure via a balance between bone formation by osteoblasts and resorption by osteoclasts. These opposite processes allow the accommodation of bones to dynamic mechanical forces, altering bone mass in response to changing conditions. Mechanical forces are indispensable for bone homeostasis;skeletal formation, resorption, and adaptation are dependent on mechanical signals, and loss of mechanical stimulation can therefore significantly weaken the bone structure, causing disuse osteoporosis and increasing the risk of fracture. The exact mechanisms by which the body senses and transduces mechanical forces to regulate bone remodeling have long been an active area of study among researchers and clinicians. Such research will lead to a deeper understanding of bone disorders and identify new strategies for skeletal rejuvenation. Here, we will discuss the mechanical properties, mechanosensitive cell populations, and mechanotransducive signaling pathways of the skeletal system.

摘要： Dear editor,Recently,researchers have obtained many new results about the multi-agent systems(MASs)[1]-[3].In[1],the fixed-time cooperative control(FTCC)algorithm of linear MASs with matched disturbances was proposed.The nonholonomic chained-form dynamics case was considered in[2].In[3],the output tracking problem with data packet dropout was solved for high-order MASs.Moreover,delay frequently occurs because of the non-ideal data transmission[4],and the corresponding FTCC algorithm of MASs with delay was given in[5].

摘要： A novel bidirectional remotely controlled device for static and dynamic compression/decompression using diamond anvil cells(DACs)has been developed that can control pressure in an accurate and consistent manner.Electromechanical piezoelectric actuators are applied to a conventional DAC,allowing applications under a variety of pressure conditions.Using this static and dynamic DAC(s-dDAC),it is possible to addresses the poorly studied experimental regime lying between purely static and purely dynamic studies.The s-dDAC,driven by three piezoelectric actuators,can be combined with a time-resolved spectral measurement system and high-speed imaging device to study the structural changes,chemical reactions,and properties of materials under extreme conditions.The maximum compression/decompression rate or pressure range highly depends on the culet size of the anvil,and a higher compression rate and wider pressure range can be realized in a DAC with smaller anvil culet.With our s-dDAC,we have been able to achieve the highest compression rate to date with a 300μm culet anvil:48 TPa/s.An overview of a variety of experimental measurements possible with our device is presented.

摘要： Dear editor,The existing bad data detection(BDD)cannot effectively detect false data injection attacks(FDIAs)in smart grid.The objectiveness of this letter is to investigate a novel dynamic watermarking(DW)-based extended Kalman filter(EKF)detection method to detect FDIAs.Firstly,security weakness of traditional χ^(2) detector is analyzed,and a novel DW-based EKF detection method is proposed for FDIAs.Secondly,the detection effectiveness and security property of the proposed method are analyzed theoretically,where not only the positive correlation between the detection performance and DW signal intensity but also zero impact of FDIAs not being detected on smart grid(SG)are revealed.Finally,the effectiveness of the proposed method is confirmed by experimental results.

摘要： DEAR EDITOR,Spermatogenesis is the process by which male gametes are formed from spermatogonial stem cells(SSCs)and it is essential for the reliable transmission of genetic information between generations.After birth,prospermatogonia(ProSG)give rise to SSCs.While mouse spermatogenesis is relatively well studied,we are only just beginning to unravel this process in larger animals.Here,we analyzed key developmental transitions and differentiation trajectories by profiling neonatal,juvenile,and adult testes through single-cell sequencing(scRNA-seq).We found that SSCs were established at 30 days old,and that CDH1 was a novel cell surface marker for porcine ProSG and undifferentiated spermatogonia.

摘要： A Z-pinch dynamic hohlraum can create the high-temperature radiation field required by indirect-drive inertial confinement fusion.A dynamic hohlraum with peak radiation temperature over 300 eV can be obtained with a>50 MA Z-pinch driver according to the scaling law of dynamic hohlraum radiation temperature vs drive current.Based on a uniform 300 eV radiation temperature profile with a width of 10 ns,three double-shell capsules with radii of 2,2.5,and 3 mm are proposed,and the corresponding fusion yields from a one-dimensional calculation are 28.8,56.1,and 101.6 MJ.The implosion dynamics of the 2.5 mm-radius capsule is investigated in detail.At ignition,the areal density of the fuel is about 0.53 g/cm^(2),the fuel pressure is about 80 Gbar,and the central ion temperature is about 4.5 keV,according to the one-dimensional simulation.A two-dimensional simulation indicates that the double-shell capsule can implode nearly spherically when driven by the radiation field of a Z-pinch dynamic hohlraum.The sensitivities of the fusion performance to the radiation temperature profiles and to deviations in the capsule parameter are investigated through one-dimensional simulation,and it is found that the capsule fusion yields are rather stable in a quite large parameter space.A one-dimensional simulation of a capsule embedded in 50 mg/cm^(3)CH foam indicates that the capsule performance does not change greatly in the mimicked environment of a Z-pinch dynamic hohlraum.The double-shell capsules designed here are also applicable to laser indirect-drive inertial fusion,if a laser facility can produce a uniform 300 eV radiation field and sustain it for about 10 ns.

摘要： High-fat diet(HFD)is demonstrated to disturb the bile acid metabolism.The rhythm of bile acid metabolism can also be affected by uridine,whose metabolism exhibits a daily rhythm.However,the mechanism of dynamic uridine administration affecting bile acid during HFD remains unclear.In this study,C57BL/6J mice were fed HFD(the control group;CON)or HFD with oral administration of uridine in the daytime(DUR)and nighttime(NUR)to investigate the mechanism of the effect of uridine on the bile acid.This study showed that the mRNA expression of uridine transporters and circadian clock genes in the jejunum was affected by zeitgeber time(ZT)(P<0.001).Genes related to the metabolism of pyrimidines in the liver showed a high dependence on daily rhythm(P<0.01),and DUR remarkably up-regulated the expression of ribonucleotide reductase regulatory subunit M2(RRM2)(P<0.05)compared to the CON group.Importantly,the mRNA expression of bile acids nuclear receptors,bile acid synthesis,and transporters in the liver showed significantly rhythmically changed(P<0.05),and the expression of cholesterol 7-alpha-hydroxylase(CYP7A1),fibroblast growth factor receptor 4(FGFR4),Na^(+)/taurocholate co transporting polypeptide(NTCP),and bile salt export pump(BSEP)mRNAs of mice with uridine administration increased significantly(P<0.05).The mRNA expression of the transporters of cholesterol and bile acids in the ileum was also affected by ZT(P<0.01)and significantly dependent on uridine administration(P<0.05).The expression of FXR and SHP was significantly affected by ZT and uridine,respectively.In conclusion,dynamic administration of uridine could regulate the rhythm of gene expression of pyrimidine and bile acid metabolism in the liver and ileum of HFD-fed mice,which contributed to the further study of circadian rhythmic physiological and pathological changes of bile acids.

摘要： We propose a dynamic automated infrastructure model for the cloud data centre which is aimed as an efficient service stipulation for the enormous number of users.The data center and cloud computing technologies have been at the moment rendering attention to major research and development efforts by companies,governments,and academic and other research institutions.In that,the difficult task is to facilitate the infrastructure to construct the information available to application-driven services and make business-smart decisions.On the other hand,the challenges that remain are the provision of dynamic infrastructure for applications and information anywhere.Further,developing technologies to handle private cloud computing infrastructure and operations in a completely automated and secure way has been critical.As a result,the focus of this article is on service and infrastructure life cycle management.We also show how cloud users interact with the cloud,how they request services from the cloud,how they select cloud strategies to deliver the desired service,and how they analyze their cloud consumption.

摘要： 本发明涉及一种制备包含镍、铝、氧和硫且具有通式Ni

摘要： 本实用新型涉及一种Dynamic螺钉，包括万向钉，外座，以及中间体；其中所述球状部连接在所述螺纹部的端部；所述中间体容纳部形成在所述冠状部的内部，所述冠状部的端部设置有所述多个凸起部，所述多个凸起部分别设置有钩部；两个夹持部连接所述插入部，所述球状部容纳部形成在所述插入部内部；所述两个夹持部形成夹持固定杆的夹持空间；所述中间体设置在所述外座的所述中间体容纳部内；所述万向钉的球状部设置在所述插入部的球状部容纳部内；所述万向钉的球状部可在所述球状部容纳部内转动，从而调节所述万向钉的固定角度；本实用新型的Dynamic螺钉采用万向钉调节固定角度，零扭矩，固定更简洁，方便调节，更高效，更短的手术时间。