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At present, due to factors such as politics, economy, environment and energy saving, less new petrochemical plants were constructed in China.
It should be determined whether or not to continue to operate based on the actual conditions of pressure vessels, the damage mechanism, failure mode, inspection results and other factors. (3) Replacing vessels that have reached the end of their original specified design lives is expensive and time consuming.
These risk factors identification and analysis system is constructed by fully considering the several aspects of relations the safety of the overage service pressure vessel, the future service time, person, environment, management, etc.
The possibility of failure for overage service pressure vessel is mainly considered from the three aspects of equipment body, management and operation condition, to find factors that affect the probability of accidents from different angles with preventive ideas.
Hu, Fatigue Properties of Overrunning X20 Main Steam Pipe (in Chinese), Metallic Functional Materials, (1) (2013) 23-26

And structure performance of carbon fiber precursor directly affects its mechanical properties.
Results and discussion Effect of HCl concentration on fractal dimension Fig.2 Effect of HCl concentration on fractal dimension HCl concentration, as an important factor of the cure reaction, has certain influence on the woodiness carbon fiber surface fractal dimension.
(3)Curing process factors have the different level influence on surface fractal dimension woodiness of carbon fiber precursor.
Direct fractal measurement and multifractal properties of fracture surface.

The results showed that, under reasonable process conditions, the physical and mechanical properties of self-bonding wood-based panels could close to the properties of formaldehyde resin wood-based panels [3, 4].
Pretreatment has played a considerable role in improving adhesive properties in the interface of the wood unit (veneer, particle, fiber, wood, etc.).
How to reduce these negative factors on the impact of acid pretreatment is an important research subject in acid pretreatment.
After white-rot fungi treatment, long and straight fibers become longer and thicker, which is conducive to enhancing mechanical properties of wood-based panel.
Zhao: Influence of Different Treatments on Wood Crystal Properties, Journal of Northwest Forestry University, Vol.22, (2007), p.169-171 [13] W.W.

Study on the Foaming Behavior of PS-CO2 by Using Water or Ethanol as Co-Blowing Agent Yiwei Luo1,a, Chunling Xin1,b, Jiao Sun1,c, Baorui Yan1,d and Yadong He1, 2,e 1 College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing, China 2 Engineering Research Center of Ministry of Education for Polymer Processing Equipment, Beijing, China aluoyiwei221@gmail.com, bxincl@mail.buct.edu.cn, csunjiao1212@163.com, dyanbr@mail.buct.edu.cn, eheyd@mail.buct.edu.cn Keywords: co-blowing agent; sorption; microcellular foaming; performance Abstract.
Supercritical carbon dioxide (CO2) is a universal blowing agent for polystyrene (PS) foaming due to its nontoxic and nonflammable properties [2].
These factors lay the foundation for the preparation of low-density foams.
It was found that cell size increased owing to the existence of co-blowing agent, and the performances of PS foams were affected by not only temperature and pressure, but also the sort of blowing agent.

Introduction Due to its excellent mechanical properties, much attention has been focused on the manufacture of ultra-fine grained cemented carbide [1].
The starting temperature of the carburization is the most important factor that affects the particle size of tungsten carbide.
It can be seen that the starting temperature is the determinant factor of particle size of tungsten carbide since particle growth mostly occurs before carburization.

The rest part is widely used as ceramics in various industries, such as refractories, mechanical parts, abrasives, insulators, etc. [2].
The chemical and physical properties of boehmite are very dependent on the experimental factors of its synthesize [3].The crystallization size of boehmite decides the application of alumina.
According to our results, the pseudoboehmite seeding does affect the morphology and particle size of pseudoboehmite which is quite meaningful.

On the other hand, Ogawa et al. applied the process consists of laser milling and micro end milling because the laser could remove independently of its mechanical properties [3].
In general, the cutting energy is consumed in several ways as follows [4]: 1. as shear energy on the shear plane 2. as friction energy on the tool face 3. as surface energy due to the formation of new surface area in cutting 4. as momentum energy due to the momentum change associated with the metal as it cross the shear plane then, 1. and 2. are more important factors than others.
The results are concluded as follows: (1) The surface roughness of the irradiated area increases as the energy density of laser is increased, the frequency of the pulse irradiation does not affect the change in surface roughness

Micro-experimentation research on Compression Sensitivity of Carbon Fiber Concrete Jing Wu 1,a, Aiqin Xu2,b 1College of Science, Naval University of Engineering, Wuhan, 430033, China 2Branch of Mechanical and Electrical Information, Lishui Vocational and Technical College, Lishui, 323000, China aprettygirl.wj@163.com, bxaqzht@163.com Keywords: Carbon fiber Concrete; compression sensitivity; strain; resistance Abstract.
Introduction Carbon fiber reinforced cement-based composite material is a by a variety of different physical and chemical properties in the form of micro-and macro-composite which consists of heterogeneous composite materials.
Its pressure sensitive subject to many factors, including carbon fibers in contact with the cement matrix interface phase constituted (interfacial layer) is the stress, and other messaging bridge will directly affect the carbon fiber cement-based composites [2-4].

Material Properties.
However, there are some local stress concentration areas on the control arm’s bracket, and the maximum stress in some local areas reaches 304Mpa, which greatly affects the fatigue life although its magnitude is less than yield limit.
Although there are some numerical distinctions in a certain degree on the number of the stress cycles between the finite element calculation result and the test result, which relates to many other factors [5,6], the finite element calculation result trending to conservatism, is reasonable.
References [1] Bum Suk Kim, Maksym Spiryagin, Bong Soo Kim and Hong Hee Yoo: Analysis of the Effects of Main Design Parameters Variation on the Vibration Characteristics of a Vehicle Sub-frame, Journal of Mechanical Science and Technology, vol 23(2009), p. 960-963

Introduction Inverted pendulum system has the high order order, unstable, multivariable and strong coupling typical object properties.The study of it can effectively reflect many typical problems in control, such as nonlinear problem, robustness problem and stabilization problems, etc.[1] Therefore, many experts and scholars at home and abroad have seen it as a typical object of study.
The model of inverted pendulum In Fig.1,the mechanical parts of inverted pendulum is mainly composed of the car, pendulum rod, guide rail, drive belt and pulley ,and control object is composed of the car and swinging rod; Electrical part is mainly composed of servo motor , driver, and protect circuit of photoelectric encoder.[2,3] Assumption: M is the quality of car; m is the quality of swinging rod; b is the car friction coefficient; l is the length of the pendulum rod axis of rotation to the rod center of mass; I is swinging rod inertia; F is the force on the car; x is the position of car; Φ is angle of swinging rod and the vertical direction; Θ is the angle of swinging rod and vertically downward direction (considering the initial position of swinging rod is vertical downward).
(9) Where σ is the response time of the loop, andare the response shape factors.
When increasing λ, response speed become slow,On the contrary, response speed become faster ,and the process has small overshoot,and appear the lower robustness at the same time.So λ not only determines the rapidity of the closed-loop system, but also affects the robustness of the closed-loop system.