液体润滑浸渍表面(SLIPS)船舶防污涂层最新研究进展

综述了近3年来关于液体润滑浸渍表面(SLIPS)船舶防污涂层的研究进展,特别是润滑液的选择与涂层的结构设计,以及这些因素如何影响涂层的整体性能,以期为未来的研究提供最新思路及研究方法。

An Insight into the Slips of the Tongue

Spontaneous speech errors(slips of the tongue),although infrequent,reveal what we really think in our mind.And slips of the mind also help us reveal planning units in the production of speech as well as to know a lot about our mental dictionary and second language production as well.This essay will take a deep insight into this language phenomenon.

Effect of structural parameters on the setting performance of plug slips during hydraulic fracturing

Slip is one of the most critical components for the frac plug,which would lodge into the casing and lock the frac plug in place during the setting and anchoring process.However,fracture failure of slip significantly affects the hydraulic fracturing effects and has attracted tremendous attention.In this paper,a three-dimensional contact model is applied to explore the setting process of slip.The effects of key structural parameters such as apex angle,inclination angle,and wedge angle on the contact characteristics of slip are systematically investigated.Numerical results indicate that the maximum contact stress appears at the contact area between slip tooth and the casing’s inner wall.Besides,the maximum contact stress generally increases with the increase of apex angle and inclination angle,while decrease linearly with the rise in the wedge angle.Experimental results show that the slip teeth get blunt and appear severe plastic deformation,which arises from stress concentration.Comparison of biting area indicates that the experimental results are about 21.3%larger,which still have a reasonable agreement with the numerical results.These obtained results can guide the parametric selection of plug slip and other similar components.

Efficient method of cycle slips detection for dual-frequency GPS data

An algorithm has been developed from various exiting techniques, that provides fully automatic cycle-slip detection at the data preprocessing stage. This algorithm, called pair linear combination, operates on undifferenced or double-differenced, dual frequency carrier phase data, and requires the sampling interval is short. Test results carried out in a variety of situations including static and kinematic modes, short and long baseline situation, and low and high data rates were presented.

On the Structure and Functions of the Multiplication Table in the Tsinghua Collection of Bamboo Slips

Among the bamboo slips dating to the Warring States period(475-221 BCE),stored at Tsinghua University,there is an aggregate of 21 specially shaped slips that are painted with red lines on the obverse side.Numbers are written on 20 slips in accordance with certain rules,and on one slip without numbers there are 20 round holes and residues of ribbon.These slips,after being compiled as a whole,serve as a practical calculator in the form of a table,which is designated as Suan Biao算表(the multiplication table).In this paper,the structure and functions of the Suan Biao are discussed by comparing it with other ancient multiplication tables.Specifically,it is noted that the core of the Suan Biao is a multiplication table comprising the numbers 9 to 1 and their products 81 to 1;the other parts are an extension of the core.The Suan Biao employs the decimal place value system and manifested the author’s knowledge of the commutative law of multiplication,the distributive law of multiplication over addition,and fractions.Not only is this table directly applicable to the multiplication of two-digit numbers,but also to division.In addition,certain computations regarding 1/2 or fractions containing 1/2 can be conducted using this table,and it may also be used for extracting roots.The Suan Biao is of great significance for research on ancient mathematics,and its discovery is enormously valuable for studies on arithmetic methods and computational tools in early China.

Seismic response of tunnel under normal fault slips by shaking table test technique

Mountain tunnel crossing a normal fault in seismically active zone is easily affected by normal fault slip and earthquake. It is necessary to study tunnel dynamic response under action of normal fault slip and earthquake. In this paper, a three-dimensional normal fault sliding device was designed, and a shaking table test was carried out to study tunnel seismic performance under normal fault slip. The results show that peak acceleration of lining is dominated by an existence of fault and direction of seismic excitation, not normal fault slip. And the incremental strains of lining in critical zone with 1.7 times fault thickness and centered in faults induced by normal fault slip and seismic excitation are larger than ones only by seismic excitation. And the incremental strains in critical zone increase with the increase of normal fault slip magnitude ranging from 0 to 2 mm. And normal fault slip results in a significant reduction of overall tunnel stiffness subjected to an earthquake. These experimental results provide a scientific reference for prevention and control measurement of tunnel damage under earthquake and normal fault slip.

Normal Fault Slips of the March 2021 Greece Earthquake Sequence from InSAR Observations

In March 2021,a seismic sequence including three Mw>5.5 events struck northern Thessaly,Greece.Owing to the high temporal resolution of Sentinel-1 images which were sampled every 6 days and recorded the three events separately,we are able to map individually the coseismic deformation fields of the three events.Based on their respective coseismic displacements,we determined the geometry of the fault plane for each earthquake with the method of multipeak particle swarm optimization and inverted the best-fitting slip distribution by linear least squares inversion.Modelling results show that the three events occurred successively on 3,4 and 12 March 2021 were all dominated by normal-slip motions on previously unknown faults within the top 15 km of the Earth’s crust.The 3 March 2021 Mw 6.3 earthquake ruptured a northeast-dipping fault with a strike angle of 301°(clockwise from the North)and a dip angle of 46°,producing the maximum slip of about 2.2 m.The slip motion of the 4 March 2021 Mw 5.9 aftershock shows a similar fault geometry(striking 297°and dipping 42°)to the 3 March mainshock,but with a considerably smaller dip-slip component(~0.8 m).The 12 March 2021 Mw 5.6 aftershock occurred on a southwest-dipping fault(striking 100°and dipping 40°)with a normal fault slip of up to 0.5 m.Static Coulomb stress changes triggered by the earthquake sequence imply a promotion relationship between the first 3 March event and the two subsequent events.Due to the coseismic stress perturbation,more than 70%of aftershocks were distributed in areas with increased Coulomb stress and the northwest segment of the Larissa fault close to the seismic sequence was exposed to a relatively high seismic risk.

Estimation of the Degree of Saturation of Shallow Soils from Satellite Observations to Model Soil Slips Occurred in Emilia Romagna Region of Northern Italy

For the development of alert systems for soil slip occurrence, it is important to evaluate the degree of saturation of shallow soils (Sr) over wide areas. Taking into account the possibility to estimate spatial and temporal variation of soil moisture using remote sensing techniques, a possible correlation between Sr and the daily output of a sequential data assimilation system called ACHAB (Assimilation Code for HeAt and moisture Balance) has been studied. ACHAB is based on integrated use of remotely sensed land surface temperature (LST) and common data on meteorological forcing such as air temperature, wind-speed and incident solar radiation. The aim of this study is to understand if it is possible to use ACHAB output (a daily value of evaporative fraction for the whole Italian territory) to define the parameter Sr that could be introduced in a simplified model for the description of soil slip triggering mechanisms on territorial scale.

Slips of the Tongue in Second Language Production

Ever since the publication of Fromkin＇s Slips of the Tongue in 1973, more and more psycholinguists have realized the importance of studying the slips of the tongue. Dell （1986） defined slips of the tongue as ＂unintended, nonhabitual deviation（s） from a speech plan＂. That is, those speech errors are not due to an incomplete or incorrect language system, but to language processing problems. Most of the studies are focused on monohngual models. But, to bilinguals, are L2 slips different from LI slips？ Can those monolingual speech production models also explain L2 speech production？ This article puts together Dell＇s current monolingual model of speech with Poulisse＇s L2 slip project to see how L2 slips can shed light on the process of L2 speech production and L2 learning orocess.

Ternary Hybrid Nanofluid with First and Second Order Velocity Slips: Dual Solutions with Stability Analysis

Modeling the boundary layer flow of ternary hybrid nanofluids is important for understanding and optimizing their thermal performance,particularly in applications where enhanced heat transfer and fluid dynamics are essential.This study numerically investigates the boundary layer flow of alumina-copper-silver/water nanofluid over a permeable stretching/shrinking sheet,incorporating both first and second-order velocity slip.The mathematical model is solved in MATLAB facilitated by the bvp4c function that employs the finite difference scheme and Lobatto IIIa formula.The solver successfully generates dual solutions for the model,and further analysis is conducted to assess their stability.The findings reported that only one of the solutions is stable.For the shrinking sheet case,increasing the first-order velocity slip delays boundary layer separation and enhances heat transfer,while,when the sheet is stretched,the second-order velocity slip accelerates separation and improves heat transfer.Boundary layer separation is most likely to occur when the sheet is shrinking;however,this can be controlled by adjusting the velocity slip with the inclusion of boundary layer suction.

SLIPS功能表面的制备及应用

仿猪笼草唇叶结构的滑移功能表面(SLIPS)是通过将全氟液体、硅油或离子液体等润滑油注入到提前构建好的含有多孔或分级粗糙结构基底制备得到。由于毛细作用力和范德华力,动态油膜能够稳定锁定在粗糙基底中。所得到SLIPS的化学均相表面和特殊的液-固结合界使其展现出优异的液体排斥性、自修复性和高压稳定性等,并在近十年内成为表界面领域内研究热点。其应用领域主要包含防冻、防腐、防海洋污染和实现高透明性材料等,并在液体运输,太阳能电池表面和深海防污等领域展现出巨大应用前景。本文介绍了近五年来SLIPS主要制备与调控方法,还对其在防覆冰,防海洋生物污染与防菌,防腐和透明性等领域新的研究进展进行了阐述。最后,对滑移表面在未来的制备与应用所面临的挑战进行了展望。

A Study of the Key Concepts ＂Heng＂ and ＂Hengxian＇ in the Hengxian on Chu Bamboo Slips Housed at the Shanghai Museum

This essay agrees that the two controversial characters on Slip 12 of the Hengxian 亘先 should be transcribed as ＂ ~ and ＂ ＂ and pronounced as ＂ji＂ 极. Secondly, with respect to six occurrences of the character ＂亘＂ （heng） on Slips 1-9 which Qiu Xigui 裘锡圭 reads as ＂极＂ （ji）, this essay holds that in the end it should be read as ＂恒＂ （heng）, and that the reading provided by Li Ling is acceptable. Therefore, that piece of bamboo slip writing can be named ＂恒先＂ （Hengxian）. Thirdly, ＂亘＂ （heng） and ＂亘先＂ （hengxian）, or ＂恒＂ （heng） and ＂恒先＂ （hengxian）, are two concepts, the latter of which is based on the former. ＂亘＂ （heng） is more fundamental and more important than ＂亘先＂ （hengxian）. Scholars mostly equate ＂恒＂ （heng） with ＂恒先＂ （hengxian）, and even regard ＂恒先＂ as the prior expression of this concept. One can hardly say that this is correct. In the bamboo writing, ＂恒＂ （heng） actually refers to ＂tian dao＂ 天道（heavenly dao）, rather than ＂dao＂ in the Laozi. The so-called ＂恒先＂ （hengxian） suggests the very commencement of the genesis and evolvement of Heavenly dao, which is somewhat equivalent to ＂taishi＂ 太始 （grand commencement） in the Huainanzi 淮南子. Fourthly, in the Hengxian, ＂恒＂ （heng） implies objective and natural laws, while ＂极＂ （ji） suggests ought-to-be rules. ＂极＂ （ji） in the bamboo writing is actually informed by ＂恒＂ （heng）.

Simmered Slips of Naked Oats

IN 1968, I, a middle school graduate, went to live and work as a farmer in Dongru, a small mountain village in north China. Later, I became a shop assistant in the county town. I spent nine years of my life there—from age 17 to 26. The memory of those years has begun to fade; only some words are left here as a reminder of my youth. In May, 1971, the county’s settlement office began transferring the urban educated youth from the countryside into the county-town.

Analysis of flow of visco-elastic nanofluid with third order slips flow condition,CattaneoChristov heat and mass diffusion model

This communication reports,the flow of viscoelastic nanofluid with third order slip flow condition,Cattaneo-Christov heat and mass diffusion model.The joined non-linear ordinary differential equations(ODEs)were acquired from the partial differential equations,which are resulting from conservation of momentum,energy and species.By means of similarity transformations these ODEs were alerted into dimensionless form and solved numerically by means of bvp4c solver.The effects of different parameters on velocity,temperature,and concentration profiles were examined and discussed in depth by means of graphs and tables.The outcomes indicate that the velocity profile along both x and y directions augment with higher values of viscoelastic parameter.The results also confirm that an increment in the values of ratio parameter tends to grow up the velocity profile alongside y-direction.However,the velocity profile along x-direction slows down with increment in the value of third order slip parameter.Also,the results illustrate that diminution in temperature is observed for higher Sc in the region of boundary layer.Besides,both temperature and concentration can be improved via higher Biot number.The upshots also portrayed that the local skin friction coefficient augmented within mounting values of viscoelastic fluid parameter.Furthermore,for finer values of Biot number both local Nusselt number and the local Sherwood number are enlarged.In addition,the most favorable agreement is observed among the results of the present study and those of the earlier studies.

Heat and mass transfer analysis on flow of Williamson nanofluid with thermal and velocity slips:Buongiorno model

The thermal and velocity slips of boundary layer of Williamson nanofluid over a stretching sheet are studied numerically.Buongiorno model is used to explore the heat transfer phenomena caused by Brownian motion and thermophoresis.Using similarity transformations,the governing equations are reduced to a set of nonlinear ordinary differential equations(ODEs).These equations are solved numerically by using Shooting method.The effects of non-Newtonian Williamson parameter,velocity and thermal slip parameters,Prandtl number,Brownian parameter,Schmidt number,Lewis number,Brownian motion parameter,thermophoresis parameter on velocity,temperature and concentration fields are shown graphically and discussed.The results found that the thickness of boundary layer decreases as the slip and thermal factor parameter increases.Further,present results indicate that the nanofluid temperature and concentration are enhanced with a rise of Williamson parameter.The Nusselt number is reduced with an increase of the Lewis and Prandtl numbers.

The Channel Branches & Network Vessels on the Tianhui Lacquered Meridian Figurine——Taking the Heart-Regulated Channel as an Example

Along with the surge of unearthed medical literature and cultural relics in recent years,a network of channels in the system of medical conduit vessels(meridians) during the early Western Han dynasty has become much clearer gradually.In it,the increasing number of channel branches,network vessels and needle insertion holes(acupoints) is an important feature of the development of channel medicine during the Western Han dynasty.This is not only a reflection of the expanding requirements of the theoretical system of the main trunk channels and other vessels,but also an inevitable result of the continuous enrichment and accumulation of clinical experience.This article integrates the information about channel branches,network vessels,inscriptions,dots and further relics on the Tianhui(天回) Lacquered Meridian Figurine to compare the unearthed literature of the channel genre with the transmitted classical literature about acupuncture.The “Heart-Regulated Channel” in Medical Manuscripts on Bamboo Slips from Tianhui(《天回医简》) serves as an example to explain the occurrence,development and changes of the channel branches and network vessels in the early system of medical channels.

WHEN DID CHINESE SILK REACH ROME?

The silk commerce comprises a significant section of the classical economy,yet its initial nature and process along the various trade routes remain largely unexplored.Therefore,this paper endeavors to delineate the primary stage of long-distance silk trade,with the objective of revealing a vital interconnection between the Roman Empire and the Han Dynasties at opposite ends of the known world from a mercantile perspective.Starting from the discussion of the relation between the ethnic designation Seres and its alternative meaning of silk,this paper identifies the earliest references to silk in Greco-Roman literature.Subsequently,it demonstrates the evolution and dynamic transformations from the primary northern steppe silk routes to a southern maritime horizon.In addition to the fundamental Greek and Latin sources that offer insight into the condition of the silk trade in its western terminus,records in the Hanshu and the Houhanshu describe the eastern leg.

Revealing the role of pyramidal slip in the high ductility of Mg-Li alloy

The high ductility of Mg-Li alloy has been mainly ascribed to a high activity of pyramidal<c+a>slip to accommodate plastic strain.In the present study,however,a quantitative analysis reveals that Li-addition can only slightly stimulate the activation of pyramidal<c+a>slip under compression along the normal direction of a hot-rolled Mg-4.5 wt.%Li plate,with a relative activity of approximately 18%.Although the limited activity of pyramidal<c+a>slip alone cannot accommodate a large plastic strain,it effectively reduces the number of{10.11}−{10.12}double twins,which are believed to be favorable sites for crack initiation.The evidently reduced activity of double twins leads to a lower cracking tendency,and therefore improves ductility.

Origin of nucleation and growth of extension twins in grains unsuitably oriented for twinning during deformation of Mg-1%Al

A large number of anomalous extension twins,with low or even negative twinning Schmid factors,were found to nucleate and grow in a strongly textured Mg-1Al alloy during tensile deformation along the extruded direction.The deformation mechanisms responsible for this behaviour were investigated through in-situ electron back-scattered diffraction,grain reference orientation deviation,and slip trace-modified lattice rotation.It was found that anomalous extension twins nucleated mainly at the onset of plastic deformation at or near grain boundary triple junctions.They were associated with the severe strain incompatibility between neighbour grains as a result from the differentbasal slip-induced lattice rotations.Moreover,the anomalous twins were able to grow with the applied strain due to the continuous activation ofbasal slip in different neighbour grains,which enhanced the strain incompatibility.These results reveal the complexity of the deformation mechanisms in Mg alloys at the local level when deformed along hard orientations.

足式机器人SLIP模型向上跳跃台阶的运动控制

由于存在地势起伏,台阶对足式机器人运动稳定性会带来较大挑战.弹簧负载倒立摆模型(SLIP)作为研究足式机器人的优良模板,能否完成向上跳跃台阶的动作与其腿部摆角,起跳位置和跳跃高度都有密切的关系.由于调整模型腿部摆角规律容易引发运动失效,故本文在算法中引入虚拟弹簧腿,根据虚拟弹簧腿的运行规律确定合理起跳位置,根据起跳位置来控制系统跳跃高度进而完成跳跃台阶的动作.最后利用仿真软件进行多组仿真,结果表明本文算法对起跳区间划分合理,对起跳高度控制精准,能够实现SLIP模型跳跃台阶前后的稳定运动.