查询词典 impact bit

Concretely, firstly with Timoshenko beams, the fundamental formulae of solutions of dynamical equations, boundary conditions and initial conditions have been transformed by Laplace transformation. Secondly, in the Laplace regions , we gain the analytical solutions of impact forces at the impact contact points, shear and maximum inverse stress of beams. Then, by using Durbin numerical inverse method, we gain the numerical solutions of Timoshenko beams under various restriction conditions. Moreover, the graphs about impact forces at the impact contact points, shear and maximum inverse stress of beams can be obtained too.

把Timoshenko梁力学模型动力学方程的基本解形式、边界条件以及初始条件进行Laplace变换，在Laplace区域得到了冲击接触处的冲击力、整个梁的最大弯曲应力和剪力的解析解，然后利用Durbin数值反演的方法得到了各种约束条件下的Timoshenko梁模型时间-空间的数值解，得到了冲击接触处的冲击力、梁各处的最大弯曲应力和剪力的曲线图。

It may be that the particular pretentiousness associated with the verbal use of impact is caused by its derivation from an already questionable metaphoric use of the noun impact, as in phrases such as the political impact of the decision or the impact of the program on the community, in which no more is usually meant than might have been expressed by effects or consequences.

尽管impact 作为"明显地影响"的夸大了的替代可能在一代人之前开始产生，但是现在的年轻一代使用者看上去把它当成了完全标准的、直接的用法，这在共同的和惯例的文章中已经很普遍了。

The vibro-impact systems are familiar with the non-smooth dynamic systems.The dynamics research of the vibro-impact systems not only is significant in theory but also has practical values in engineering.Firstly,using the Poincaré map method,we get an existent criterion of single impact period-n motion in a two-degree-of-freedom vibro-impact system with damper.It is shown that our conclusions are valid through the numerical simulations.Moreover,the satiability of periodic motions is studied and the correspon...

基于Poincaré映射的方法，通过解析的方法导出了一类具有阻尼的两自由度碰撞振动系统的单碰周期n次谐运动存在性判据，经过数值模拟验证了理论分析的正确性，并给出了分析其稳定性的判别公式，通过数值模拟，讨论系统的局部分岔与全局分岔，同时比较了系统参数变化对其周期运动的影响，发现在强阻尼、弱激励、小质量比、较大恢复系数下系统将会出现较多的有规律的周期碰撞。

In other research we can find this situation:children have myth concept in time unit and time unit conversion, include impact of psychological time, impact of numbers, impact of decimal and impact of sexagesimal.

另外在研究中发现，学童在时间单位量与时间单位转换中的迷思概念，包含心理时间的影响，数字大小的影响，十进位的影响，六十进位的影响。

It analyzed impact principle, and researched viscidity and springiness model of soil. So the relation of impact and soil was found, and the dynamic model of impact bar-soil system was established. After analyzing and researching the model, a better dynamic model with soil impact character was gained.

针对土壤的物理特性，对冲击原理进行分析，并对土壤的粘弹性模型进行研究，建立冲击与土壤之间的联系，为土壤压实冲击测量装置建立了冲击杆—土壤系统的动力学模型，并对模型进行分析研究，简化出更适合土壤冲击特性的动力学模型。

Studies on impactrelated minerals, geochemical anomalies, impact microspherules and microtektites enable us to define frequencies, magnitudes and types of impact bodies of extraterrestrial impact events. Impact layers and ejectas may not only provide distinct event markers in highresolution stratigraphical correlation, but also potential interpretations for the catastrophic changes and their causes of life and global environment.

通过对撞击地层层序的时空变化、所包含的撞击成因矿物、撞击微球粒和微玻璃陨石以及古生物和地球化学异常等的研究，可以了解撞击事件的发生频率、幅度和撞击天体的性质等，也为探索生物和地球环境的灾难性变化及其起因提供了新的思路。

In this dissertation, periodic impact motions in vibro-impact systems are studied, and the existence and stability of superharmonic periodic impact motions are obtained. The critical bifurcation parameter intervals of superharmonic periodic impact motions are deduced, and numerical simulations are used to verify the results.

中文题名碰振或约束系统的全局分析及稳定性研究副题名外文题名 Studies on global analysis and stability in vibro-impact or constraint systems 论文作者张彦梅导师陆启韶教授学科专业一般力学与力学基础研究领域\研究方向学位级别博士学位授予单位北京航空航天大学学位授予日期2002 论文页码总数95页关键词碰振系统转子系统多体系统碰撞振动馆藏号BSLW /2003 /O322 /1 本论文讨论了碰撞振动系统的周期碰撞运动，得到了超谐周期碰撞运动的存在性和稳定性，推导出亚谐周期运动的临界分岔参数区间，并利用数值模拟进行验证。

But, the characteristics of its adhered-elastic fracture in high temperature and brittle fracture in low temperature were discovered during impact load test The impact fracture mechanism of the high-energy nitroamine propellant had been put forward by studying the fracture appearances of impact fracture surface, the expansion of secondary crack and the weakness or failing of mechanical structure combined with the analysis of impact fracture properties and dynamic adhered-elastic properties and structures.

通过研究冲击断裂表界面的断口形貌、二次裂纹的发展、材料的力学结构缺陷或弱点，并结合冲击断裂性能、动态粘弹性能及结构分析，提出了硝胺发射药的冲击断裂破坏机理。

The coal impact breaking mechanism and impact coal cutter were introduced in the paper, the primary task of this project, study on the dynamic characteristic of hydraulic impact system of impact coal cutter, was pointed out.

本文介绍了冲击式破煤机理的提出和冲击式采煤机的研究现状，然后指出了本课题的主要任务是研究液压冲击系统的动态特性。

Friday, rubber, plastics, rubber adhesive tape test series grinding test machine, wear test machine, wear testing machine, folding machine, foam compression stress test machine, foam plastic repeated compression test machines, test material removed machine, Determination of the plastic melt index machine, impact testing machine, heating distortion temperature testing machine, falling ball impact test machine, rigid plastic drop hammer impact test machine, plastic film drop hammer impact testing machine, high temperature ashing furnace, temperature testing machine tape retention, Tape retention test machine, the beginning of sticky tape ball test machine, color device, industrial projectors, coordinate measuring instrument.

五、橡胶、塑胶、胶带试验系列橡胶胶磨试验机、磨耗试验机、耐磨试验机、耐折试验机、泡棉压缩应力试验机、发泡塑反复压缩试验机、试料磨平机、塑胶熔融指数测定机、冲击试验机、加热变形温度试验机、落球冲击试验机、硬质塑胶落锤冲击试验机、塑胶膜落锤冲击试验机、高温灰化炉、恒温胶带保持力试验机、胶带保持力试验机、胶带初粘性滚球试验机、色差仪、工业投影仪、三座标测量仪。

A historical region of southwest France between the Pyrenees and the Garonne River. The duchy of Aquitaine was joined with France after the marriage of Eleanor of Aquitaine to King Louis VII in1137, but its possession was disputed after her subsequent marriage to Henry II of England.

阿基坦法国西南部一个历史地区，位于比利牛斯山和加隆河之间，在1137年阿基坦的埃莉诺与国王路易斯七世结婚之后阿基坦公国加入法国，但当她再嫁英国亨利二世后，其归属权便受到争议

There are moments when I look at the smiling , happy faces of my expectant staff and wonder how they will cope when confronted by an outraged housemaster along with an unrepentant and recalcitrant bleached blond teenager in 18 years ' time .

有时候，我看着那些满怀期待的员工微笑，幸福的脸，想着当他们遇到一位愤怒的宿舍管理员和一位不知悔改，叛逆，而且将头发染成白色的18岁少年时，他们会如何处理。