Effect of joints on microwave fracturing of the Bukit Timah granite using an open-ended antenna

Microwave fracturing of rocks before mechanical breakage could improve the performance of mechanical excavators and reduce environmental impacts.Previous research focused on the microwave fracturing of intact rock blocks.By using an open-ended antenna,this paper investigates the effect of pre-existing joints on the microwave fracturing of the Singapore Bukit Timah granite blocks.The results show that the specimens are weakened in the manners of cracking,spalling,melting,or a combination of them.The crack number and the total crack length produced by microwave treatment of jointed rock blocks are slightly smaller than those in the intact rock blocks.The interaction between joints and microwave-induced cracks can be summarized into the following four patterns:(1)microwave-induced cracks become arrested so that the crack propagation is terminated;(2)microwave-induced cracks penetrate the joints and continue to propagate;(3)microwave-induced cracks become deflected along the joints;and(4)microwave-induced cracks propagate forward following the joints.The smaller the approach angle between the microwave-induced crack and the preexisting joint is,the more microwave-induced cracks tend to be arrested at the joint.Increasing the approach angle between the microwave-induced crack and the joint can increase the chance of microwave-induced crack penetrating the joint.The results also show that the smaller the distance is between the microwave radiation point and the joint,the easier it is for microwave-induced cracks to penetrate the joints;otherwise,the microwave-induced crack is more likely to be arrested at the pre-existing joint.

Study on the squeezing effect of open-ended pipe piles

During the installation of a pipe pile,the soil around the pile will be squeezed out. This paper deals with this squeezing effect of open-ended pipe piles using the cylindrical cavity expansion theory. The characteristics of soil with different tension and compression moduli and dilation are involved by applying the elastic theory with different moduli and logarithmic strain. The closed-form solutions of the radius of the plastic region,the displacement of the boundary between the plastic region and the elastic region and the expansion pressure on the external surface of the pipe piles are obtained. When obtaining these solutions,the soil plug in the open-ended pipe pile is considered by employing an incremental filling ratio to quantify the degree of soil plugging. Moreover,the effects of the ratio of tension and compression moduli,angle of dilation and incremental filling ratio on the radius of the plastic region and the expansion pressure on the external surface of the pipe pile are investigated. The parametric analyses show that it is necessary and important to consider the difference between the tension modulus and compression modulus,dilation angle and incremental filling ratio for studying the squeezing effect of open-ended pipe pile installation. It is concluded that the analytical solutions presented in this paper are suitable for studying the squeezing effect of open-ended pipe piles.

Reform and Practice of an Engineering Postgraduate Training Pattern in an Open-Ended Base:Taking Foshan Base as an Example

The flawed engineering practice is considered the main factor that is affecting to the development quality of engineering postgraduates.Taking Foshan Base as an example,this paper has analyzed the operational pattern,practice teaching model,and internal governance system of the open-ended base as a new system for engineering practice and proposed several suggestions for the reformation of engineering postgraduates based on the construction effect.

Design and analyses of open-ended pipe piles in cohesionless soils

Large open-ended pipe pile has been found to be advantageous for use in transportation projects. The current design method, however, is not adequately developed. To close this practice gap, this paper first summarized different design methods for open-ended pipe piles in sandy soils. A major factor for all the design codes is to properly account for the formation and effects of soil plug. The comparison indicates that there is a large variation in the base capacity evaluation among different methods due to the complex behaviors of soil plug. To close the knowledge gap, discrete element method （DEM） was used to simulate the soil plugging process and provide insight on the plugging mechanism. The simulation results show that the arching effect significantly increases the internal unit shear resistance along pipe piles. The porosity distribution and particle contact force distribution from DEM model indicate a large stress concentration occurs at the bottom of the soil plug. Besides, nearly 90% of the plug resistance is provided by the bottom half portion of the soil column. The soil-pile friction coefficient has a significant effect on the magnitude of plug resistance, with the major transition occurred for friction coefficient between 0.3 and 0.4.

Effects of inner sleeves on the inner frictional resistance of open-ended piles driven into sand

In open-ended piles, inner friction is developed between inner pile shaf and the inner soil. Inner frictional resistance depends largely on the degree of soil plugging, which is influenced by many factors including pile diameter, relative density and end conditions of piles. In this paper, effects of inner sleeves on inner frictional resistance are discussed. The experiments were conducted on a medium-dense sandy ground using laboratory-scale piles. It was observed that the piles penetrated under partially-plugged or unplugged state. The results suggest that inner fiictional resistance, Qin increases with sleeve height, l linearly and requires 2D （D is pile outer diameter） of l to produce a large as 50% of Qt by Qin （Qt is total resistance）. The results also indicate that bearing capacity increases with wall thickness at the pile tip, which can be attributed to the increase in annular area. The results also indicate that soil plug height is independent of sleeve height. The results also reveal that the penetration of straight piles is closer to unplugged state than the sleeved piles. The results of incremental filling ratio and plug length ratio also indicate that the degree of soil plugging is affected by the sleeve height.

Radiation of a TM mode from an open end of a three-layer dielectric capillary

Modern trends in beam-driven radiation sources include the interaction of Cherenkov wakefields in open-ended circular waveguides with complicated dielectric linings, with a three-layer dielectric capillary recently proposed to reduce radiation divergence being a representative example [Opt. Lett. 45 5416(2020)]. We present a rigorous approach that allows for an analytical description of the electromagnetic processes that occur when the structure is excited by a single waveguide TM mode. In other words, the corresponding canonical waveguide diffraction problem is solved in a rigorous formulation. This is a continuation of our previous papers which considered simpler cases with a homogeneous or two-layer dielectric filling. Here we use the same analytical approach based on the Wiener–Hopf–Fock technique and deal with the more complicated case of a three-layer dielectric lining. Using the obtained rigorous solution, we discuss the possibility of manipulating the far-field radiation pattern using a third layer made of a low permittivity material.

Realizing profits immediately:disposition effect of open-end fund investors in China

This paper explores the disposition effect, the tendency of investors to hold losing investments too long and sell winning investments too soon, by analyzing a unique data set that consists of the buying and selling positions of open-end fund investors in China. Results show that investors' buying and selling behaviors are significantly affected by fund performance. The reasons that lie behind such results are mainly related to the non-persistence of fund performance. When fund performance is non-persistent, investors are not clear about the future returns on funds. So, investors, especially individual investors, would have to realize the profits on hand immediately. Meanwhile, fund investors are highly sensitive to fund age and loading fees, but not sensitive to management fees charged by funds when they buy or sell fund shares.

Zero-Sequence Current Suppression Strategy for Open-End Winding Permanent Magnet Synchronous Motor Based on Model Predictive Control

Compared with the traditional three-phase star connection winding,the open-end winding permanent magnet synchronous motor(OW-PMSM)system with a common direct current(DC)bus has a zero-sequence circuit,which makes the common-mode voltage and the back electromotive force(EMF)harmonic generated by the inverters produce the zero-sequence current in the zero-sequence circuit,and the zero-sequence current has great influence on the operation efficiency and stability of the motor control system.A zero-sequence current suppression strategy is presented based on model predictive current control for OW-PMSM.Through the mathematical model of OW-PMSM to establish the predictive model and the zero-sequence circuit model,the common-mode voltage under different voltage vector combinations is fully considered during vector selection and action time calculation.Then zero-sequence loop constraints are established,so as to suppress the zero-sequence current.In the end,the control strategy proposed in this paper is verified by simulation experiments.

翻译教学中的开放性翻译定义

人类文化的多样性导致了翻译的多样性,只有"家族相似"才能最好地描述翻译原型范畴内部成员之间的关系。充分必要条件下定义的翻译存在着本质缺陷,翻译定义应该是开放的、非限定性的。翻译教学中采用开放性翻译定义,能避免传统定义给学生带来的单维、僵化的认识,让学生认识到翻译标准的灵活性,从而自觉根据翻译目的、译入语读者的语言规范、文学艺术规范和社会文化语境等灵活调整翻译策略,创造出适应社会需要的翻译作品。

An Assembly Coastal Building Technique in Port Engineering

The assembly coastal building technique initiated at home and abroad,is for a novel vertical standing harbor structure.Its main concept is the assembling components which can be combined and locked together to form a large caisson.Its application and future are discussed for a building.After many years of application and tests,the technique has a high stability,a wide range of application,low workload and fast construction speed.It can be widely applied in future for harbor engineering projects.

从诗歌的不同翻译看意义的不确定性和开放性

语言具有多义性,而诗歌的语言具有其自身的特色,这必然导致译本的多样化。文章重点讨论Gutt关于意义的不确定性和开放性思想,通过对诗歌不同翻译的分析,从一个侧面阐发了诗歌翻译中异人异译现象存在的理论依据,从而表明了诗歌的翻译是灵活而开放的。

MEASUREMENT OF THE DIELECTRIC PROPERTIES OF BIOLOGICAL TISSUE

An open-ended coaxial line reflection method especially suitable for meas-uring the dielectric properties of biological tissue in vivo is described.This method offersthe advantage of not requiring any special preparation of the samples to be measured but aclose contact with the open end of a coaxial line.It is,therefore,very convenient to acquirea large number of measurement data in broad band rapidly.The method may also be usedto measure the properties of other substances.The measuring system consists of a networkanalyzer controlled by a microcomputer and calibrated by using ANA procedure to elimi-hate the influnce of error network introduced by the adapter,some connectors,etc.In or-der to reach higher accuracy,the iterative method is used to determine the parameters ofthe equivalent circuit.Measurements of permeativities of some living tissues have been per-formed in the frequency band of 0.5-2GHz.Compared with the results known in somepapers,the validity of this method has been confirmed.The difference in dielectric proper-ties between living and dead tissues,and the tissue permeativites(ε)versus frequency andduration of measurement after death have also been measured.

谈日语二外教学的探求

提出在日语二外教学中采用（Open-ended）化型教学方式，加强情感交流，建立和谐融洽的师生关系，注重文化知识的导入。充分利用语言优势，培养出符合社会对“双语”人才的需求。

从狂欢、对话的未完成性看巴赫金的真理观

巴赫金对狂欢节的辞旧迎新内蕴、怪诞人体形象的生死边缘意义、广场语言的褒贬融合等双重性意义的把握,以及他关于对话、话语的阐述,无不强调其未完成性、开放性,这是巴赫金真理观的经典表述。这种表述使其诗学理论充满现代思想的敞开性。

开放与杂和:法国译学研究现状之管窥——兼评《什么是翻译学?》

《当代法国翻译理论》一书十年前对当时法国翻译理论研究状况所作的评价出发,指出该书编著者所说的旨在"构建翻译学的基本框架"的理论著作十年后依然缺席于法国译学研究诸多成果的事实。作者通过对论文集《什么是翻译学?》(Qu’est-cequela traductologie?)的介绍,特别是对其中具有代表性的几篇论文的详细评介,对上述这种"缺席"做出了合理的解释,同时揭示出当代法国译学研究所具有的"开放"与"杂和"的特点。

You Need to Know More to Understand My Scoring on the Survey: Free-Text Comments as Part of a PROM-Survey of Men with Prostate Cancer

Prostate cancer and its treatment have long-term implications for men’s lives. We aimed to describe the content, extent, and frequency of written comments to the open-ended question, “Further comments?” in the patient-reported outcome measures questionnaire. During the study period, 897 men participated;372 wrote 747 free-text comments in the questionnaire. These comments were analysed using qualitative content analysis and were grouped into four categories: 1) prostate cancer’s influence on health;2) clarifications of answers to the survey;3) descriptions of well-being despite the cancer;and 4) experiences of care and the need for contact with health care. The distribution of the comments shifted over time. The open-ended question not only allowed the participants to explain their other responses and describe important aspects of their lives during and after treatment, something not normally covered by a questionnaire, but it also indicated their experiences of health care services along the patients’ PC-trajectory. This further raises the issue of including an open-ended item in a forced-choice survey into the ethical realm to ensure that proper care is taken of participants’ answers and thoughts.

海德格尔与皮克林论物的开放性存在——兼论一种现象学式的科学存在论

海德格尔解构了传统西方哲学中有关何谓人与物的对象性、概念认知性的理解,将人与物看作是可能性的开放性存在,这是因为存在(而非存在物层面上的东西)是存在物之存在的根据或原因,而作为此在的人的存在是通达存在本身的必然途径;皮克林在科学哲学领域沿袭了海德格尔关于物是开放性存在的思想,并且认为人类力量与物质力量在科学实践中都作为"开放性的终结"而存在,科学的本质并非对外在世界的表征与描摹,而是人类力量与物质力量在实践中"共舞""冲撞"的结果,它们在阻抗与适应的辩证法过程中相互交织、相互界定和共同演化。皮克林由此阐明了世界的本质乃是一个开放式终结演化的活生生的场所,并由此构建了一种现象学式的科学存在论思想。

PRELIMINARY STUDY ON OPEN END JET SPINNING

A new concept of spinning-open-end jet-spinning, which combines the advantages of the false twist jet spinning and open end winning, was proposed, and a device was designed to practice this concept. The property of thc open-end jet spun yarn was measured and discussed in comparison with that of some other spun yarns.

An Analysis of the Causes and Countermeasures of China＇s Pension ＂Empty Account＂

This paper analyzes and explains the causes of the ＂empty account＂ of our country＇s basic pension personal account based on the specific economic conditions and social backgrounds of each period in China. Explained that the ＂empty account＂ phenomenon of pension insurance is not universally believed to be caused by ＂high accumulation and low consumption＂economic development policies.The author puts forward two ideas for ＂filling up the air＂ in the individual pension account： 1. Ensure that the basic pension maintains its value.2. Accelerate the construction of individual pension accounts.

网络时代的语文阅读教学初探

文章着眼于现在的时代——网络时代的前提下，探讨在现在的语文阅读教学中如何开展教学工作，从四个方面谈想法：语文阅读教学要体现个性化；语文阅读教学要突出主动性；语文阅读教学要突出开放性；语文阅读教学要突出人文性。