Something on the Stylistic Factor of TOEFL Criterion

Variety is a term used in sociolinguistics and stylistics to refer to any system of linguistics expressionwhose use is governed by situational variables. This article discusses what kind of attitude should be taren towards the criterion prescribed by theTOEFL compilers of checking the answers to those texts.     

English Grammar Lecture Series(4) ARTICLE(冠词)(2)

3.Definite article the The definie article the is primarily used for specific reference-referenceto a particular example (or particular examples)of a class of thing.Us-ing the definite article,the speaker assumes that the litstener can identifythe example that is referred to either from the linguistic context or from     

Experiment and Simulations on Lubrication Performance of EMP Journal Bearing

In recent years, much attention has been devoted to the design and operation of bearings made of elastic metal plastic (EMP). The surface of the bearing bush is covered by a layer of polymer PTFE(polytetrafluoroethylene). The physical performances of the polymer are quite different from that of metal. It can reduce friction because of its lower surface energy, and it is more difficult for the fluid to be adhered. Consequently, the slip will exist at the oil-bush interface. The journal bearings made of this material are researched in this article. Through test, the existence of slip is proven and the equation of the slip velocity for the EMP journal bearing is established when shear stress up to a certain value. Thus, the classical Reynolds equation is modified. The lubrication mechanism is analyzed by some simulation results.     

Effects of rarefaction on the characteristics of micro gas journal bearings

Given the definition of the reference Knudsen number for micro gas journal bearings, the range in the number is related to the viscosity of air at different temperatures. A modified Reynolds equation for micro gas journal bearings based on Burgdorfer＇s first-order slip boundary condition is proposed that takes into account the gas rarefaction effect. The finite difference method （FDM） is adopted to solve the modified Reynolds equation to obtain the pressure profiles, load capacities and attitude angles for micro gas journal bearings at different reference K_nudsen numbers, bearing numbers and journal eccentricity ratios. Numerical analysis shows that pressure profiles and non-dimensional load capacities decrease markedly as gas rarefaction increases. Attitude angles change conversely, and when the eccentricity ratio is less than 0.6, the attitude angles rise slightly and the influence of the reference Knudsen number is not marked. In addition, the effect of gas rarefaction on the non-dimensional load capacity and attitude angle decreases with smaller bearing numbers.     

English Grammar Lecture Series(3)ARTICLE(冠词)(1)

1.Generic refefence(类指)vs specific reference(特指)Consider the following examples:The panda is a rare animal.The panda gave birth to a healthy baby last night.In the first sentence,the definite article(定冠词)in the panda denotes thewhole species;whereas in the second,it points to one specific animal.We refer to them as generic reference and specific refefence respectively.     

Relationship among Teacher,Students and Teaching Material based on Balance Theory

Balance theory holds that when the subject is in the unbalanced state,there is two basic way to eliminate this situation.One is to change his attitude on the cognitive object;the other is to change the subject’s attitude on reference person.To ex plain the relationship among teacher,students and teaching material by applying the Balance theory can help us find and solve problems during the education.It can generate motivation to restore a new balance to promote the development of education.     

Static load test and load transfer mechanism study of squeezed branch and plate pile in collapsible loess foundation

As a special geological phenomenon, the character of collapsible loess foundation is collapsible when penetrated by water. This character leads to the soil losing load bearing capacity largely and may lead to foundation failure. Pile is a popular foundation used in collapsible loess. The squeezed branch and plate pile is a new type of pile developed in recent years and has not be used in a project before. In this paper three squeezed branch and plate piles are tested in collapsible loess after immersion processing. The results may be used for reference in similar construction project, and to provide theoretical references for de- signing of the squeezed branch and plate piles in engineering practice.     

A Study of Cohesive Devices in English IM

The main purpose of the present research is to reveal features of the use of cohesive devices in English IM(Instant Message).In order to be accurate and explicit,Oxford WordSmith Tools(Version 4.0) is applied to investigate the frequency of each type of cohesive devices used by online-communicators.Cohesion in English IM is characterized by a number of distinguishing features:1) this genre of discourse makes abundant use of cohesive ties such as personal reference,lexical reiteration and ellipsis;2) substitution and comparative reference are rarely applied;3) The variety of conjunctions used is limited,and the most frequently used conjunctions are and,so,but and or.In analyzing the cohesive effect of each cohesive device,it is held that in order to overcome the limitations of the messaging systems and to achieve smooth communication,participants mainly adopt explicit cohesive ties which could achieve stronger force of cohesion in IM communication.     

Effect of boundary conditions and convection on thermally induced motion of beams subjected to internal heating

Numerical exercises are presented on the thermally induced motion of internally heated beams under various heat transfer and structural boundary conditions. The dynamic displacement and dynamic thermal moment of the beam are analyzed taking into consideration that the temperature gradient is independent as well as dependent on the beam displacement. The effect of length to thickness ratio of the beam on the thermally induced vibration is also investigated. The type of boundary conditions has its influence on the magnitude of dynamic displacement and dynamic thermal moment. A sustained thermally induced motion is observed with progress of time when the temperature gradient being evaluated is dependent on the forced convection generated due to beam motion. A finite element method (FEM) is used to solve the structural equation of motion as well as the heat transfer equation.     

Evaluation of packet loss impairment on streaming video

Video compression technologies are essential in video streaming application because they could save a great amount of network resources. However compressed videos are also extremely sensitive to packet loss which is inevitable in today's best effort IP network. Therefore we think accurate evaluation of packet loss impairment on compressed video is very important. In this work, we develop an analytic model to describe these impairments without the reference of the original video (NR) and propose an impairment metric based on the model, which takes into account both impairment length and impairment strength. To evaluate an impaired frame or video, we design a detection and evaluation algorithm (DE algorithm) to compute the above metric value. The DE algorithm has low computational complexity and is currently being implemented in the real-time monitoring module of our HDTV over IP system. The impairment metric and DE algorithm could also be used in adaptive system or be used to compare different error concealment strategies.     

Study on the applicability of frequency spectrum of micro-tremor and dynamic characteristics of surface ground in Asia area

INTRODUCTION It is well known that micro-tremor observation is one of the most convenient methods for investi- gating the dynamic characteristics of the surface ground and the affected structure (Bard, 1998; Dow- rick, 1997). Micro-tremor is a kind of geophysics information related to soil formation of site, corre- sponding to engineering geological condition. The frequency characteristics of micro-tremor can be obtained by spectral analyses of its signals, which can be used to probe into…     

Analyzing Brexit Speeches of the UK Prime Ministers: an Intertextuality Approach

Brexit has a profound effect on the UK,the EU,even the whole world.The reference of Xin Bin’s specific intertextuality framework is used as a proper approach to analyzing Brexit speeches delivered by David Cameron,Theresa May,and Boris Johnson-the predecessors and the present UK Prime Minister.Through analyzing,it is identified that the Prime Ministers share a similar attitude to the value proposition of Brexit,but have both similarities and differences in their thoughts of Brexit policies and future directions after Brexit.The research takes an integral analysis of Brexit,and hence provides a new perspective.     

Remediation of Cr（Ⅵ） in solution using vitamin C

The effectiveness of vitamin C in treating Cr(Ⅵ)-contaminated water is being evaluated. Cr(Ⅵ) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(Ⅵ) to essentially nontoxic Cr(Ⅲ). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(Ⅵ) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration.The reaction mechanism of Cr(Ⅵ) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(Ⅵ)-contaminated soils and groundwater.     

Risk Assessment and Optimisation of Blast Mitigation Strategies for Design and Strengthening of Built Infrastructure

A probabilistic risk assessment procedure is developed which can predict risks of explosive blast damage to built infrastructure, and when combined with life-cycle cost analysis, the procedure can be used to optimise blast mitigation strategies. The paper focuses on window glazing since this is a load-capacity system which, when subjected to blast loading, has caused significant damage and injury to building occupants. Structural reliability techniques are used to derive blast reliability curves for annealed and toughened glazing subjected to explosive blast for a variety of threat scenarios. The probabilistic analyses include the uncertainties associated with blast modelling, glazing response and glazing failure criteria. Damage risks are calculated for an individual window and for windows in the facade of a multi-storey commercial building. The paper shows an illustrative example of how this information, when combined with risk-based decision-making criteria, can be used to optimise blast mitigation strategies.     

Magnetometer-only linear attitude estimation for bias momentum pico-satellite

Satellite attitude information is essential for pico-satellite applications requiring light-weight, low-power, and fast-computation characteristics. The objective of this study is to provide a magnetometer-only attitude estimation method for a low-altitude Earth orbit, bias momentum pico-satellite. Based on two assumptions, the spacecraft spherical symmetry and damping of body rates, a linear kinematics model of a bias momentum satellite＇s pitch axis is derived, and the linear estimation algorithm is developed. The algorithm combines the linear Kalman filter （KF） with the classic three-axis attitude determination method （TRIAD）. KF is used to estimate satellite＇s pitch axis orientation, while TRIAD is used to obtain information concerning the satellite＇s three-axis attitude. Simulation tests confirmed that the algorithm is suited to the time-varying model errors resulting from both assumptions. The estimate result keeps tracking satellite attitude motion during all damping, stable, and free rotating control stages. Compared with nonlinear algorithms, such as extended Kalman filer （EKF） and square root unscented Kalman filer （SRUKF）, the algorithm presented here has an almost equal performance in terms of convergence time and estimation accuracy, while the consumption of computing resources is much lower.     

Influence of Electrolyte on ESR of Medium Voltage Wet Tantalum Capacitors

In this paper, the influence of working electrolyte on high-frequency electrical performance of wet tantalum capacitors is studied. Emphasis is especially put on the study of the contribution of depolariser in reducing Equivalent Series Resistance(ESR). According to the theory of depolarization in electrochemistry and the theory of cathode capacitance of electrolytic capacitor, different kinds of depolarisers are added separately into the foregone electrolyte. Then capacitors are assembled with tantalum cores dipped with the compounded electrolytes. The best depolariser and its concentration in the whole electrolyte could be selected according to the test results of the capacitance and ESR of the capacitors. The results of our experiment show that depolariser Fe2 (SO4)3 used in working electrolyte of 100 V/IO0 μF wet tantalum capacitors can help to obtain lower ESR and higher capacitance at frequency from 0.1 kHz to 100 kHz.     

Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks

In this paper, numerical method is used to study the strain rate effect on masonry materials. A typical unit of masonry is selected to serve as a representative volume element (RVE). Numerical model of RVE is established with detailed distinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor (DIF) of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results.     

Experimental study on complete stress-deformation curves of larger-size concrete specimens subjected to uniaxial tension

INTRODUCTION Failure of reinforced and pre-stressed concrete structures is initiated in many instances by cracking of plain concrete. The post-cracking softening behavior of concrete subjected to tension has been realized for many years (Li et al., 1993). However, the resistance of cracked concrete is generally ignored in conven-tional design practice. Until recently it has become increasingly evident that it is necessary to account for the post-cracking resistance of concrete when per-f…     

Experimental study on behaviors of polypropylene fibrous concrete beams

Synthetic fibers made from nylon or polypropylene have gained application when loose and woven into geo textile form although no information on the matrix＇s mechanical performance is obtained so that more understanding of their structural contribution to resist cracking can be determined. This paper presents the results of an experimental investigation to determine the performance characteristics of concrete reinforced with a polypropylene structural fiber. In this investigation ＂Fiber mesh＂ brand of fibers manufactured by SL Concrete System, Tennessee, USA and marketed by M/S Millennium Building System, Inc., Bangalore, India are used. The lengths of the fibers used were 24 mm. Fiber dosages used were 0.9, 1.8, 2.7 kg/m^3. A total of three mixtures, one for each fiber dosage were made. A standard slump cone test was conducted on the fresh concrete mix with and without fibers to determine the workability of the mix. The test program included the evaluation of hardened concrete properties such as compressive, split tensile, modulus of rupture and flexural strengths. The increase in compressive strength is about 36.25%, 26.20%, and 23.75% respectively that of plain concrete. This increase in strength was directly proportional to amount of fibers present in the mix. The increase in flexural strength for Mixes I-III is about 21%, 16.6%, and 23% respectively that of plain concrete specimens. An experimental investigation was also made to study the behaviors of reinforced fibers concrete beams （with longitudinal reinforcements） under two-point loading. The deflection and crack patterns were also studied. The improvements in strength and ductility characteristics were discussed.     

An Analysis of Emily Dickinson’s“I’m Nobody! Who are you?”

Emily Dickinson is a witty and great poet in the 19th century.She is sensitive and full of humanity.She was living in almost total seclusion and wrote in secret whatever she was to feel,to see,to hear.The article is aimed to introduce Dickinson’ s attitude towards public life and her writing technique by analysing the poem," I’ m Nobody! Who are you?"