查询词典 cracking

It is shown that preventing welding hot cracking by mechanical methods can avoid the limitation of metallurgical methods and is very effective both for solidification cracking and for liquation cracking, thus has more freedom in choice of the parent metal and filler metal.

研究表明，采用力学方法防止焊接热裂纹可以避免冶金措施的局限性，对两类热裂纹（即焊缝凝固裂纹和近缝区液化裂纹）同样有效，因此，对焊丝成分和母材的选取有较大的自由度，是一种解决焊接热裂纹问题的重要的新途径。

Whether you're verifying the security of your own network or up to something a little more dubious in nature, this guide to cracking a Wi-Fi network's WEP password with BackTrack —followed by this WEP cracking redux post that took WEP cracking out of the command line realm proved popular.

以前总有一些人跟我谈，希望我跳槽，承诺的位置就是类似主编的工作，人最大的自知之明就是莫过于了解自己，我一直以来最不爱干的事就是管别人，平生最大的信条就是小时候我姥姥总说的那句话：是人不用管，管死不成人。

It provided the reference to improve the anti-cracking capability of high strength and high performance concrete from the point of view of constructional technology and curing requirement.The result shows that the more the binder material or sand rate, the more serious the shrinkage cracking. In the concrete with a low water-to-binder ratio, a bit of difference in the dosage of water will result in big difference on the strength and the anti-cracking capability. The occurrence of cracking is mainly at early age (before 1 day). If the surface is plastered again after 2 hours of casting, the anti-cracking capability will nicely improved.

研究结果表明：随着胶结料总量和砂率的增大，高强高性能混凝土的收缩开裂趋于严重；在水胶比较低的情况下，用水量的稍微差别对混凝土的强度和抗裂性能都具有很大的影响；掺入粉煤灰对抗裂有所改善，但是其掺量对抗裂的影响并不是呈定向规律，而是存在着最优掺量；高强高性能混凝土的裂缝主要发生在早期(1d前)，若在浇注后2个小时再次抹面可以很好地改善其抗裂性能。

Targeting the biomass rice stalk,we use linestone as catalyst and cracking catalyse the tar which was pyrolysised from the target.We build the rice straw biomass gasification tar removal catalytic cracking process model by the least squares support vector machine model and optimize the model parameters through genetic algorithm.We also has gotten the best catalytic cracking temperature and gas residence time, making the highest rate of catalytic cracking tar.We made wood biomass as a target analysis so that we can thermally crack tar,and we can use genetic algorithms to optimize the model parameters that is based on the wood biomass gasification pyrolysis tar removal process model through the least-squares fitting method,then we got the best pyrolysis temperature and equivalence ratio,so that it is possible to make the tar content reach the minianum.Based on the least squares support vector machine model,we had established the model of the biomass sawdust Compression molding process and fit the Optimization Parameters objective function of the molding process .

以生物质稻秆为对象，采用石灰石作为催化剂对稻秆热解焦油进行催化裂解，由最小二乘支持向量机模型建立了生物质稻秆气化焦油催化裂解脱除过程的模型，并用遗传算法对模型参数进行了优化，得到了最佳的催化裂解温度和气相停留时间，使得焦油催化裂解率达到最高；以生物质木屑作为分析对象，对其进行热裂解脱焦，并依据最小二乘曲线拟合方法建立了生物质木屑气化焦油热裂解脱除过程的模型，用遗传算法对模型参数进行了优化，得到了最佳的热裂解温度和当量比，使得焦油含量达到最小。

Single-Event Cracking Temperature of Asphalt Pavements Directly from Bending Beam Rheometer Data Aroon Shenoy1 Abstract: Asphalt pavements under low temperature conditions develop transverse cracks as a result of one or a combination of three distress mechanisms:（1）single-event thermal cracking;（2）thermal fatigue; and（3）load-associated thermal cracking.

单项裂解温度的沥青路面，直接从弯梁流变数据aroon shenoy1摘要：沥青路面在低温条件下，发展横向裂缝是由于一项或多项三名遇险机制：( 1 )单项的热裂解；( 2 )热疲劳；( 3 )负荷相关热裂解。

The effect of zeolites ion-exchanged by transition metals on thermal catalytic cracking reaction is studied. The product distributions of the cracking reactions catalyzed by theβor ZSM-5 zeolites exchanged with transition metals are different from that catalyzed by corresponding Hzeolites, which means the mechanism of cracking reactions has varied. Group Ⅷ metals Fe, Co, Ni and Cu, Zn are shown to be of strong catalytic activity of oxidative dehydrogenation, while Ti and Cr are not of oxidative activity. Catalyzed by zeolites or catalyst containing Ag, conversion of thermal catalytic cracking reactions and the yield of ethylene increase while the yield of propylene does not decrease. Silver can not only promote the formation of carbonium ion, but also convert carbonium ion into free-radical via redox reaction. The weak adsorption of olefins on silver reduces the occurrence of hydrogen transfer and dehydrogenation. As a result, the yield of light olefins is favored by silver in the catalyst.

采用过渡金属交换的分子筛作为催化剂，进行催化热裂解制取乙烯的反应，研究发现，在β沸石分子筛和ZSM-5分子筛中引入过渡金属后，催化热裂解反应的产物分布与相应的氢型分子筛相比有了较大的变化，说明过渡金属的加入对于催化热裂解反应的机理具有影响，Ⅷ族金属如Fe、Co、Ni和第Ⅰ、Ⅱ副族Cu、Zn表现出较强的氧化脱氢活性，产物中氢气、焦炭的产率很高，Ti、Cr则未表现出氧化作用：分子筛及催化剂中引入银后，催化热裂解反应的转化率和乙烯的产率有了提高，丙烯产率没有很大的变化，说明银在催化热裂解反应中能够促进正碳离子的生成，又有可能通过氧化-还原作用部分改变反应机理，促进了自由基的生成，并且由于银对烯烃的吸附很弱，其氢转移反应和脱氢、加氢活性比较低，有利于烯烃产率的提高。

There existed very significant positive correlations among the fruit cracking rate, cracking index and the contents of souble solids,total sugar,deoxidize sugar,fructose and sucrose and the activities of PPO,PAL;and very significant negative correlation among the fruit cracking rate,cracking index and the contents of protopectin and Ca.

果面碎裂裂果率、果面碎裂裂纹指数同苹果果实的可溶性固形物、总糖、还原糖、果糖、蔗糖均呈极显著的正相关；同PPO、PAL的酶活性也呈极显著的正相关；与果皮的果胶含量、Ca含量呈极显著的负相关。

As can be seen from the literature which I have consulted, universal agreements has been reached as to the mechanism of low-temperature cracking of AC pavement (including contracting cracking cause by one substantial drop in temperature and thermal fatigue cracking). But the research on the low-temperature cracking is still immature up to now, which can justify the absence of related indices of low-temperature cracking of all AC pavement design methods.

但是，从查阅的文献可以看出，对于沥青路面产生低温开裂（包括一次性大幅降温引起的收缩开裂和温度疲劳开裂）的机理，人们的认识是一致的；但是，对于沥青路面低温开裂等问题的研究至今仍不够成熟，世界各国的沥青路面设计方法中均未引入低温开裂的有关指标就说明了这一点。

Under the ratios of various initial cracking relative length,height and volume of gas concrete beam,the whole curve of opening displacement s at several testing points about fracture toughness,fracture energy,and in the area of load,cracking-tip-opening-displacement,cracking tip opening displacement cracking-tip-area are researched systematically.

在本研究中对加气混凝土梁在不同初始裂纹相对长度、不同高度以及不同体积比例等情况下的断裂韧性、断裂能以及载荷—裂纹口张开位移—裂纹尖端张开位移—裂纹尖端前沿区若干测点张开位移全曲线进行了系统研究。

The effect factors analysis based on FEM shows that: Raising the strength of concrete and the thickness of cover concrete would delay the cracking of concrete; Stress superposition would appear due to the influence of adjacent rebar, and increasing the rebar space would postpone the time of cover cracking; Stirrup could suppress the cracking of cover concrete, however, the effect is limited and the corrosion-degree-ratio and corrosion expansive force would not increase until the cover concrete cracking happens completely.

结合有限元分析结果，对影响锈胀开裂的各因素进行了分析，结果表明：提高混凝土强度、增加保护层厚度有助于延缓保护层的开裂；相邻钢筋的存在会使钢筋之间的混凝土出现应力叠加现象，箍筋对混凝土保护层内由锈胀产生的应力具有抑制作用，但是在保护层完全开裂之前，箍筋的抑制作用有限。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。