细及超细粒度金刚石布拉磨具结合剂的研究

针对石材面板磨削用金刚石布拉磨具的工程需要,研发了具有良好自锐性的细及超细粒度金刚石布拉磨具,在磨具结合剂的配方设计及关键工艺技术上有所突破。在烧结温度750℃,压力20MPa等工艺参数下,采用Fe,Ni,Co等硬质添加相改性处理的软质Cu-Sn合金体系,研制出对金刚石把持力强,且具有合适的致密度(93%～94%)、硬度(HRB60～70)、抗弯强度(500～600 MPa)、连续自锐性和良好磨损适配性的磨具结合剂,使得细及超细粒度金刚石布拉磨具成功替代传统菱苦土/碳化硅磨具,生产效率可提高30%,在石材自动化加工流水线上广泛应用。

做一头拉磨的驴

爷爷说，给拉磨的驴蒙上眼睛，是为了让它能专心致志地干活儿。为什么呢？ 爷爷又说，不蒙上眼睛，它东张西望地就只知道玩。

馋嘴猫拉磨(拉场戏)

时间过去。地点农村。人物馋嘴猫男,50岁。姚小宝男,20多岁。(简称小宝)肖玉桃女,20多岁,小宝妻(简称玉桃)〔玉桃上场,焦急地向远处张望,心神不宁、充满焦虑地。玉桃心神不安像掉魂,盼男人又怕男人。民女肖玉桃,嫁姚小宝为妻,

拉磨

磨房里,灰驴正在拉空磨。公鸡看见了,十分奇怪:"驴大哥,磨盘里空了,你怎么不叫主人来添麦子呀""傻瓜才会那样做!"灰驴得意地说,"你想想,是拉空磨轻松省力,

Correlation between Milling Flour Quality of Xinjiang Spring Wheat and Processing Quality of Xinjiang Hand-stretched Noodle

In the research,36 spring wheat cultivars from Xinjiang were used to investigate flour yield,ash content,color,granularity,flour quality,paste quality and gelatinization property and to evaluate processing quality and characters of stretched noodle,in order to explore relationship of milling flour quality with quality property of Xinjiang spring wheat and with processing quality of Xinjiang hand-stretched noodle,which provides theoretical references for improvement of Xinjiang spring wheat cultivars,breeding of specific cultivars（for Xinjiang stretched noodles）,and advancement of stretched noodles.The results indicated that flour color is dominant among flour quality properties of Xinjiang spring wheat,which is of significant correlation with processing quality of stretched noodles.Therefore,in quality improvement of Xinjiang stretched noodles,flour yield of Xinjiang wheat should be enhanced and ash content and damaged starch should be reduced in order to improve quality of flour and stretched noodles from Xinjiang spring wheat.The indices of milling flours for Xinjiang stretched noodles are as follows：flour yield ≥60.77%,ash content ≤ 0.45%,damaged starch≤3.77%,granularity ≤108.14%,brightness（L^＊）≥ 90.86,redness（a^＊）≥-0.82,and yellowness（b^＊） ≤9.00.

管理寓言两则

黑驴和白马；黑猫和白猫。

IMPROVING MATERIAL REMOVAL RATE OF BRITTLE CERAMICS THROUGH HONING INCIDENTAL TENSILE STRESSES

The stress intensity factors and stress conditions of machining cracks are analyzed by fracture mechanics on the basis of honing characteristics and of brittle ceramic mechanical behavior.Because the honing incidental tensile stresses effectively decrease the critical grinding stresses and increase the stress intensity factors of machining cracks,the honing process can be carried out easily.The results show that honing can be an efficient machining method for brittle materials.

Mechanical properties and wear resistance of aluminum composite welded by electron beam

The welding property of TiB2/ZL101 composite was investigated using electron beam（EB） welding experimental system with a function generator.The fine defect-free welding seam was obtained under proper processing parameters and scanning rate.The reinforcement particles TiB2 distributed homogeneously in welding seam without any segregation.The tensile results show that fracture occurs at the base metal and elastic modulus increases compared with base metal.Wear resistance of welding seam is improved greatly compared with base metal.The results show that the TiB2/ZL101 composite can be successfully welded by EB technology.

Preparation and mechanical properties of in situ Al_2O_3/Al composites by adding NH_4AlO(OH)HCO_3

Aluminium matrix composite reinforced by Al2O3 particles was produced by adding NH4AlO（OH）HCO3 into molten aluminum.The mechanical properties and wear behavior of the as-fabricated composites were studied.The results show that during stirring γ-Al2O3 particles were formed via decomposition reaction of NH4AlO（OH）HCO3,and the distribution of Al2O3 particles is more uniform in the matrix aluminum than directly added Al2O3 into molten aluminum.The density and the hardness values of the as-fabricated composites increase with increasing the particle volume fraction,while the tensile strength of the composites decreases with increasing the volume fraction of the Al2O3 particles.The wear rate of the composites decreases with increasing the volume fraction of the particle and loading.The in situ formed Al2O3/Al composite by adding NH4AlO（OH）HCO3 shows more superior mechanical and wear behaviors than that prepared by directly adding Al2O3 particles.

Application of ultra-smooth composite diamond film coated WC-Co drawing dies under water-lubricating conditions

A specific revised HFCVD apparatus and a novel process combining HFCVD and polishing technique were presented to deposit the micro-and nano-crystalline multilayered ultra-smooth diamond（USCD） film on the interior-hole surface of WC-Co drawing dies with aperture ranging from d1.0 mm to 60 mm.Characterization results indicate that the surface roughness values（Ra） in the entry zone,drawing zone and bearing zone of as-fabricated USCD coated drawing die were measured as low as 25.7,23.3 and 25.5 nm,respectively.Furthermore,the friction properties of USCD films were examined in both dry sliding and water-lubricating conditions,and the results show that the USCD film presents much superior friction properties.Its friction coefficients against ball-bearing steel,copper and silicon nitride balls（d4 mm）,is always lower than that of microcrystalline diamond（MCD） or WC-Co sample,regardless of the lubricating condition.Meanwhile,it still presents competitive wear resistance with the MCD films.Finally,the working lifetime and performance of as-fabricated USCD coated drawing dies were examined under producing low-carbon steel pipes in dry-sliding and water-lubricating conditions.Under the water-lubricating drawing condition,its production significantly increases by about 20 times compared with the conventional WC-Co drawing dies.

Advanced simulation of die wear caused by wire vibrations during wire-drawing process

An advanced simulation that considers the effect of wire vibrations was proposed for predicting accurately wear profiles of a die used in a wire-drawing process.The effect of wire vibrations,the changes in the wear profiles,and the generation of ringing during die approach were investigated by this simulation.Wire vibrations occurring between the die and the drum are governed by a partial differential equation called the wave equation,which is a function of the wire length,tension,density,and initial wire velocity.The wire-drawing process was simulated by the commercial code Abaqus FEA,and the die wear profiles were predicted by Archard’s wear model.The predicted profiles were compared with measured profiles of a worn drawing die after producing 5 t of AISI 1010 wire;the die was made of tungsten carbide with a Brinell hardness of HB 682.The profiles predicted by considering the effect of wire vibrations are in good agreement with the experimental data,indicating that the advanced simulation can be used to accurately predict the die wear profiles when ringing is observed during die approach.

Dynamic modelling and properties analysis of 3RSR parallel mechanism considering spherical joint clearance and wear

The collision and wear caused by inevitable clearance in kinematic pair have an effect on the dynamic characteristics of the mechanism.Therefore,we established the dynamic model of a 3RSR(R is the revolute joint and S is the spherical joint)parallel mechanism with spherical joint clearance based on the modified Flores contact force model and the modified Coulomb friction model using Newton-Euler method.The standard quaternion was introduced in the constraint equation,and the four-order Runge-Kutta method was adopted to solve the 3RSR dynamic model.The simulation results were compared and analyzed with the numerical results.The geometrical parameters of the worn ball socket were solved based on the Archard wear model,and the geometrical reconstruction of the worn surface was carried out.The geometric reconstruction parameters were substituted into the dynamic model,which was to analyze the dynamic response of the 3RSR parallel mechanism with wear and spherical joint clearance.The simulation results show that the irregular wear occurs in the spherical joint with clearance under the presence of the impact and friction force.The long-term wear will increase the fluctuation of the contact force,thereby decreasing the movement stability of the mechanism.

Improved Simulation Method for Soil-Geogrid Interaction of Reinforced Earth Structure in FEM

The interaction between geogrid and soil is crucial for the stability of geogrid-reinforced earth structure. In finite element （FE） analysis, geogrids are usually assumed as beam or truss elements, and the interaction between geogrid and soil is considered as Coulomb friction resistance, which cannot reflect the true stress and displacement developed in the reinlbrcement. And the traditional Lagrangian elements used to simulate soil always become highly distorted and lose accuracy in high-stress blocks. An improved geogrid model that can produce shear resistance and passive resistance and a soil model using the Eulerian technique, in combination with the coupled Eulerian-Lagrangian （CEL） method, are used to analyze the interaction between geogrid and soil of reinforced foundation test in ABAQUS. The stress in the backfill, resistance of geogrid, and settlement of foundation were computed and the results of analysis agree well with the experimental results. This simulation method is of referential value for FE analysis of reinforced earth structure.

Wear Behavior of Diamond-Coated Drawing Dies

The failure behavior of diamond-coated die was investigated experimentally and analytically through finite element method (FEM) simulation in the present work. Diamond coatings were fabricated by straight hot filament chemical vapor deposition (CVD) passing through the interior hole of the drawing die using a mixture of hydrogen and acetone as source gases. The performance tests were made under real drawing condition. Scanning electron microscopy (SEM) was used for the study of coating wear after die service. The coating wear appears on two regions of the reduction zone: one is near the entrance where the contact begins, and the other is at the end of the reduction zone. FEM simulation was made for calculating the von Mises stresses distribution on the coating and substrate during the drawing process. The present work was of great practical significance for the improvement of drawing performance of diamond-coated drawing dies.

郭义教授传统针刺手法发挥

郭义教授先后跟随诸位针灸名家学习,不仅继承他们的临床思想和家传手法,同时完善手法并创建多种具有自己特色的独特针法。"孔雀开屏"(穴取风府、风池、天柱、翳风、完骨)是郭义教授总结出治疗颈椎病、脑血管疾病等多种病症的一组穴方;"潜龙入海"(穴取太冲、陷谷、侠溪及第3、4趾间,指蹼缘后方赤白肉际)用于治疗肝阳上亢、上热下寒等病症;"山羊胡飘"[廉泉,旁廉泉(廉泉穴旁开1寸处)]可以改善局部循环,助于咽部功能的恢复;传统"老驴拉磨"(多用于中脘、下脘等腹部穴位)手法常用来治疗胃腹部疾病,治疗神志病是郭义教授总结的异病同治的典范。

风从村庄吹过

一 雨后,虹卧于村西的小河上。树绿如翡翠。鸟阵掠过田野。 二姑父依靠在门边,呆呆地凝望着屋后的山坡,许久不肯移身。忽然,一滴浊泪滑落,无声地坠落在天井的青石壁上。苔藓微颤。

聪明人

一个聪明人在乡下散步，看到磨房里面一头毛驴在拉磨，脖子上头挂着一串铃铛。于是聪明人向磨房主道：“你为何要在毛驴的脖子上挂一串铃铛呢？”

让企业像长江一样经经久不衰

青藏高原被人们称为"世界的三极"。发源于这里的细流据不完全统计有成千上万条,可绝大多数流着流着中断了,只有长江黄河两条大河历尽千难万险席卷千山万水,一泻万里勇往直前地注入大海,胜利地完成了从无到有,从小到大,从无名到举世闻名的历程。论其成因,我认为主要优势有三:1、起点高;2、方向明;3、胸怀广。