弯曲点

The generable proximate formula of dynamic stress intercity factor of simple edge crack found bar specimen in three point bending of NanLing marble is gotten and the critical dynamic stress intensity factor of the specimen is also obtained in medium load ratio.

在中等加载速率下，推导出对大理岩带垂直切口三点弯曲圆棒梁试件动应力强度因子的一般近似公式和断裂时的临界动应力强度因子的表达式。

At 54 weeks, plentiful growing bone and bone marrowlike tissue fully filled in pores created by biodegradation of CPC/CS.

方法试验分CPC／CS及CPC两组，三点弯曲试验测试材料的强度和弹性模量；组织学观察材料植入兔股骨22及54周的成骨状况。

Through designing of composition and structure of the bioactive graded coating,innerstress and its distribution in the coating were analyzed and calculated, the resultsshowed that when composition distribution coefficient n was 1.5, a reasonable stressdistribution could be got, that was at the beginning of deposition the suspension containingrichly BG granules was used so that a rich BG granules layer, a good transitional layerbetween BG layer at the bottom and the coating could be obtained at the titanium alloy side,the bottom of the coating; the stress value near the interface and surface and its character,pressure stress or tensile stress, were decided by the character of its composition itself.Changing composition distribution coefficient n could only change the variation tendency ofstress in the coating, but did not change the stress distribution rule in the coating. Thethinner the coating is, the sharper stress variation in the coating is, which does not mean thatthicker coating is better because the thicker the coating is, the little the permitteddeformation of coating is, so the coating thickness should be thinner, for example, about50μm for bending applications, but for applications only bearing pure shear stress, such asroot of tooth implant, the coating can be thicker little, for instance, about 80～100μm. The study on electrification characteristic and electrophoresis deposition of HAand BG granules in aqueous and non-aqueous solution system found that EPD almost didn'toccur in aqueous solution system. However, because HA granules take position charges inabsolute alcohol, a homogeneous EPD be carried out on the cathode titanium alloy slice, but taking negative charge in absolute alcohol the BG granules not be deposited on the cathode. A guided HA crystallizing, 100～300nm, on surface of the BG granules be realized by metathetical reaction, which cover BG granules with HA microcrystals and make the covered BG granules taking position charges in absolute alcohol, sequentially realize the EPCD of the BG and HA granules on the cathode, so it is feasible to make a titanium alloy/BG/HA bioactive graded coating by making use of EPCD technology. The corrosion experiment of rich boron bioglass coating and plasma spray coating showed that split phase, rich boron and rich silicon phase, occurred during its preparation. In basic medium the corrosion behavior of 〓 BG coating showed uniformity corrosion, the corrosion mostly occurred at rich boron phase area, therefore batch formula design of BGshould avoid the occurring of split phase. The corrosion appearance of plasma spray coatingappeared a non-uniform corrosion, mostly occurred at the edge of the laminated HA moltendrops, and emerged an accelerated corrosion tendency, which will easyly lead to corrosioncrackles extending to the interface and the happening of osmotic interfacial corrosion, thatmay be one of the major reasons leading to the coating cracking-off in the later period. Thetesting results of thermal expansion coefficient of 〓 and 〓BG showed the thermalexpansion coefficient of 〓 BG matched with that of titanium alloy better, and 〓 BG couldsinter with titanium alloy into densification enamel layer at low temperature (720℃).

将Ti6Al4V合金在1000℃下进行真空热处理会降低其力学性能，且合金内的V元素会向表面富集，因此，钛合金真空热处理和表面涂层的烧结温度不能过高，即应低于其相转变点；通过对生物活性梯度涂层的组成和结构的设计，分析和计算了梯度涂层内的应力大小和分布，结果表明：对于本研究，当成分分布系数n=1.5时，可以获得较合理的涂层力学性能，即在沉积开始时，采用富含BG颗粒的悬浮液，以便在钛合金侧获得同底层BG有良好过渡的富BG涂层；梯度涂层界面和表面的应力大小、性质由材料组成本身的性质决定，改变成分分布系数，只能改变涂层内应力变化的趋势；涂层的厚薄不影响涂层内的应力分布规律，但涂层越薄，涂层内的应力变化越快，但这并不意味着涂层越厚越好，因为涂层越厚，涂层允许的变形越小，对于应用于弯曲受力部位的涂层而言，涂层应薄一点为好(50μm)；而对于仅纯受剪切应力的部位，如牙根种植体，涂层可适当加厚(80～100μm)；通过对HA和BG颗粒在水溶液体系和非水溶液体系中的带电特性和电泳沉积的研究发现，它们在水溶液体系中很难发生电沉积；在无水乙醇溶液中，HA颗粒带正电，可在阴极钛合金片上发生均匀的电泳沉积，而BG颗粒则带负电荷；利用复分解反应法，可以制得100～300nm的HA，通过诱导HA在BG颗粒表面结晶，可对BG颗粒进行表面包覆，获得了被HA包覆的BG颗粒，改变了BG颗粒表面的带电特性，使BG和HA颗粒在无水乙醇中均带上正电荷，从而实现了HA和BG颗粒在阴极上的共沉积。

In this paper, the fracture behavior of nitramine propellant under different temperatures and crack lengthes has been studied through three methods, i.

本文用紧凑拉伸、三点弯曲和单边裂纹拉伸等三种实验方法对硝胺火药在不同温度和不同裂纹深度下的断裂性能进行了研究。

Methods30 nonextraction patients treated in the department of orthodontics in Shandong University in the same time period were enrolled in this study. The threepoint bending test was used to measure the strain and stress of arch wires at 37?℃.

方法选取山东大学口腔医学院正畸科同一时期内收治的30例上颌后牙段基本无拥挤的非拔牙矫治患者，利用三点弯曲试验装置（MTS Tytron 250， USA），检测未经使用、使用4周、8周及12周的镍钛弓丝在37？

It is known that the fatigue crack propagation rate is decidedby the stress-strain state of the crack tip at that time. According tolinear elastic Paris relation, this paper has suggested the three-point bendspecimen in which, from linear elastic to overall yielding ragions,da/dNis represented by the retation:da/dN=C_1~r.

由于疲劳裂纹扩展速率/决定于当时裂纹顶端附近的应力应变状态，本文根据线弹性范围内的Paris关系，提出三点弯曲试样在线弹性至全屈服范围内，/应服从下述关系：/=C_1~r。

Elastic modulus of specimen processed by PPT method and HP method are obtained by adopting three-point bend test and tensile test of unnotched specimen respectively.

采用无缺口试件的三点弯曲试验，得出PPT法制备的试件的弹性模量；通过柔度变化率曲线上的第一转折点得出基体的破坏应变，并由此得到基体的强度。

Loriformis differs as follows: main stem undeveloped; sheaths of cauline leaves ciliate only on 1 side of mouth; cincinni subcapitate; pedicels slightly curved; seeds finely white reticulate, neither pitted nor verrucose.

不过，M。 loriformis 的不同如下：主茎不发达；茎生叶的鞘具缘毛的只在口的1边；蝎尾状聚伞花序近头状；花梗稍弯曲；种子白色细网状，既不具洼点也不瘤状。

By the way of X-ray stress measurement, the characteristics of residual stress distribution of specimens, which were shot peened and polished, were studied; by the way of three-point bending fatigue tests, the influence of polishing after shot peening on fatigue properties was studied; on this basis, the reason why Shot Peening Standards provide that the depth of metal removal does not exceed 10% of the specified arc height was analysed.

文中指出300M钢喷丸强化工艺中打磨对喷丸效果的影响问题；通过X射线应力测定，研究喷丸及打磨后试样的残余应力分布及变化的特点；通过三点弯曲疲劳试验，研究喷丸后打磨对试样疲劳性能的影响；在此基础上，分析喷丸标准中规定喷丸后打磨去除量不可以超过阿尔门强度值的1/10的原因。

Breaking energy Strength concrete Precasting crack Bending at three points

断裂能；强度；预制裂缝；三点弯曲

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。