无明显结构的
- 与 无明显结构的 相关的网络例句 [注:此内容来源于网络,仅供参考]
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The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.
理论分析和试验研究表明: 1球轴承振动是钢球—滚道接触副中的各种摩擦学作用引起的,具有摩擦动力学的本质,任何对接触副的摩擦学特性有影响的因素都将对球轴承的振动和噪声特性产生影响; 2中心轴向载荷作用下,载荷增大使球轴承的固有振动频率升高,载荷越大同样的载荷增幅引起的频率升幅减小,足够大的中心轴向载荷作用下载荷的变化对球轴承振动的频率特性不会产生明显的影响; 3轴向和径向联合载荷作用下,径向载荷不大时球轴承振动的固有频率基本不变,但是可能引起变刚度激励的非线性振动,出现新的频峰,过大的径向载荷将使部分钢球脱离接触,使球轴承的振动和噪声呈现不稳定状态; 4润滑对球轴承的振动和噪声特性有重要的影响,良好的润滑对振动有明显的抑制作用,润滑不充分时,振动和噪声的水平会有明显增高,一定条件下还会激发接触副中的谐振,发出啸声,造成接触表面的伤害,无润滑干接触时,短时的运转就会损伤接触副表面,使振动和噪声迅速增大,并随时可能引发严重的磨损和卡滞失效;接触副润滑良好时,油膜的"刚化效应"使球轴承振动的固有频率有所提高,润滑剂中含有弥散性污浊时,振动的幅度总体升高,但弥散性污浊不会改变球轴承振动的频率特性;浙江大学博士学位论文:球轴承振动的研究 5低速时,球轴承振动的基本特征呈现不稳定状态,随着转速的提高,球轴承振动的频率特性趋于稳定,固有频率频峰升高; 6理论分析表明,干接触时钢球和滚道表面波纹度的某些谐波分量能激励球轴承的振动,振动的幅值与谐波幅值成正比,实际球轴承中钢球的分布不可能完全均匀,波纹度的激励作用会随时发生;润滑接触的分析表明,波纹度的任意谐波分量均能激励球轴承的振动; 7球轴承的几何和结构参数分析表明,球轴承尺寸越大,径向、轴向和角振动的固有频率越低;钢球中心圆直径增大,球轴承的径向和轴向振动的固有频率基本不变,角振动的固有频率有所上升,振动的幅频特性基本不变;径向游隙加大使球轴承的径向振动固有频率降低,轴向和角振动的固有频率有所升高,径向振动幅频特性的幅值升高,而轴向和角向降低;钢球的数量增多使球轴承振动的固有频率上升,幅频特性的幅值下降,径向振动的幅值下降最为明显;外圈沟曲率半径系数增大使球轴承径向振动的固有频率升高,轴向和角振动的固有频率降低,径向幅频特性基本不变,轴向和角向幅频特性幅值升高;内圈沟曲率半径系数增大使径向、轴向和角振动固有频率均下降,振动幅频特性的幅值均有升高; 8试验对比表明,传感器采用探针式安装时,由于探针接触副接触特性的影响,钡(量得到的球轴承振动信号有失真,采用专门设计和制作的试验球轴承,以固定式安装加速度计,首次测量得到了球轴承振动的真实信号,通过对振动信号的分析,验证了球轴承振动的理论模型; 9)基于时间序列分析的AR模型适用于大样本球轴承振动信号的分析,以样本长度的均方根值作定阶上界,FPE做判阶准则,给出的AR谱光滑,频率分辨率高,是球轴承振动分析的简便而可靠的手段; 10以时频域分析的小波包变换分析球轴承异音信号能够比较好地定位和聚焦异音发生的时间,时间间隔,频率范围,同样是球轴承振动分析的可靠的手段,可用作球轴承故障诊断技术。
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Results Punctiform erosion, hemorrhage were observed by nake eyes in each groups. Epithelium cellular necrosis, defluxion, neutrophil being dominant in propria lamina and intact glandular were observed with microscopy. The erosion became severe with the successive stimulate of ethanol. There is no difference between distillate spirit and sodium chloride rats in Guth in 7th day, but Guth in distillate spirit rats was higher than that in sodium chloride rats in 30th day. PGE2, TGF-α contents in gastric mucosa of treated group increased significangly compared with control group. PGE2 showed no difference between each group in 7th and 30th day; TGF-α in gastric mucosa of distillate spirit and sodium chloride rats decreased after 1 month.
结果 茅台组、乙醇组、生理盐水组胃黏膜均肉眼可见程度不同的点状糜烂、出血;光镜下黏膜部分上皮坏死脱落,固有层以中性粒细胞为主炎性细胞浸润,腺体结构基本完整,病变随时间延长有所加重,Guth积分1周茅台组与生理盐水组差异无统计学意义,1月两者相比差异有统计学意义;茅台组、乙醇组胃黏膜组织内PGE2水平与生理盐水组相比明显增高,同时TGF-α表达增强;但PGE2水平各组间1周与1月相比差异无统计学意义;TGF-α表达强度在茅台组、生理盐水组1月后逐渐降低,差异有统计学意义。
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The shape of chloroplast didn't change after seedling was treated by GA〓, but the number of lamllasomes increased, and starch grain enhanced. These changes were accord to that of the rate of photosynthesis. Mitochondria varied greatly, the structure of mitochondria could see vaguely and carinace almost deliquesce after 4days. Enrolucrum emerged until the seventh day after treatment and endomembrance of mitochondria recovered gradually, cristae could be seen. On the other hand, the endomembrance of mitochondria in CK (normal non-bolting) was obvious and the quantity of cristae in the mitochondria was much more than the GA〓 treatment. This showed that respiration might decrease after GA〓 treatment while reduced the depletion of photosynthesis products and enhanced bolting.
GA〓处理后抽苔过程中叶绿体形状未发生变化,但类囊体增多,淀粉粒增多,这种变化与光合速率的变化吻合;线粒体变化较大,处理后4天线粒体结构较模糊,嵴不清晰,7天时外膜形成,内膜也逐渐恢复,能见到嵴,而对照线粒体内膜结构明显,嵴清晰数量也多,说明GA〓处理后,呼吸作用降低,减少光和产物的消耗;细胞膜无破损,较光滑完整,说明对细胞膜没有伤害。
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Results The TCD manifestations of patients with semicoma have no characteristic change.
结果 浅昏迷患者的TCD表现无特征性改变,当出现中度昏迷或深昏迷时,颅内幕上结构损害患者TCD表现与文献报告相似,颅内幕下结构损害、代谢及弥漫性脑病患者大脑中动脉血流速度改变不明显,但死亡的18例病人中有13例出现了收缩期末血流速低于舒张期末血流速。
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Results The TCD manifestations of patients with semicoma have no characteristic change. In moderate or deep coma patients, who have intracranial supratentorial injury, the TCD manifestations are similar to related documents. The blood flow velocity of middle cerebral artery of patients with subtentorial brain injury or metabolic or diffused brain diseases have no obvious change. But in the 18 dead cases, there are 13 whose blood fiow velocity of end systolic stage are lower than those of end diastolic stage.
结果 浅昏迷患者的TCD表现无特征性改变,当出现中度昏迷或深昏迷时,颅内幕上结构损害患者TCD表现与文献报告相似,颅内幕下结构损害、代谢及弥漫性脑病患者大脑中动脉血流速度改变不明显,但死亡的18例病人中有13例出现了收缩期末血流速低于舒张期末血流速。
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Results The TCD manifestations of patients with semicoma have no characteristic change.In moderate or deep coma patients,who have intracranial supratentorial injury,the TCD manifestations are similar to related documents.The blood flow velocity of middle cerebral artery of patients with subtentorial brain injury or metabolic or diffused brain diseases have no obvious change.But in the18dead cases,there are13whose blood fiow velocity of end systolic stage are lower than those of end diastolic stage.
结果 浅昏迷患者的TCD表现无特征性改变,当出现中度昏迷或深昏迷时,颅内幕上结构损害患者TCD表现与文献报告相似,颅内幕下结构损害、代谢及弥漫性脑病患者脑中动脉血流速度改变不明显,但死亡的18例病人中有13例出现了收缩期末血流速低于舒张期末血流速。
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Dealcoholization temperature markedly influences the surface area and porosity of the resultant MAO-supports. When the support was pretreated at lower or higher temperature, the corresponding MAO-support shows very low surface area;2.XRD and IR analyses indicate that MAO has reacted with the residual ethanol in the supports, which is an important manner to get MAO fixed on the carrier. Morever, XPS analyse indicates that MAO can also be coordinated with MgCl_2, which is another way to get MAO fixed on the support;3.ICP and EDX analyses indicate that dealcoholization temperature not only determined the element content on the solid catalyst, but also influences the element distribution on the carrier;4.The activities of the supported phenoxy-imine catalysts and the properties of resultant polymers are strongly dependent on the dealcoholization temperature. The support (MSP-5) obtained by treating MgCl_2·2.56C_2H_5OH at 160℃for 4 h, then modified by MAO is very effective for immobilizing complex 3, the resultant solid catalyst (MSPC-5) shows very high activity in ethylene polymerization, and its kinetics of polymerization is stable during the reaction process. Finally, PEs with spherical morphology and high bulk density (over 0.35g/ml) were obtained, without reactor fouling;5.In this work, polymerization conditions such as alkylaluminums, Al/Zr ratio, temperature and H_2 had a pronounced effect on the activity of MSPC-5 and properties of PE;(3). New MgCl_2-Supported Single-Site Catalysts for Ethylene PolymerizationIn this work, a kind of new MgCl_2 support was obtained by anhydrous MgCl_2 co-milled with solid MAO, and it is a creative contribution. Then some single-site catalysts were supported on the new MgCl_2 support, and the resulted solid catalysts were tested in ethylene polymerization, the results indicated that:1.XRD and IR analyses indicate that MAO does be coordinated with MgCl_2, which is in good agreement with the results obtained by XPS;2.co-mlling time had no obvious effect on the texture of support after 12 hours;3.In this work, MgCl_2 was co-milled with solid MAO for different hours, and then complex 3 was supported on these co-milled supports. It was found that co-milling time markedly influences the activity of solid catalysts, but it had negligible effect on the kinetic profile and the properties of resultant PE.
XPS研究结果表明,MAO不仅仅只和乙醇作用,MAO还与MgCl_2本身有一定的作用,这是一个极为重要的发现;3、通过ICP和EDX表征,发现载体的脱醇温度直接影响着元素在固体催化剂中的含量及分布;4、脱醇温度极大地影响着负载苯氧基亚胺类催化剂的活性和聚合物的性能,特别是原始载体经160℃活化4小时制备得到的固体催化剂MSPC-5的活性明显高于其他脱醇温度条件下制得的固体催化,并且催化剂寿命长,表现出稳定的动力学行为,最终获得了高堆密度(大于0.35g/ml)的球形聚乙烯颗粒;5、本文选择MSPC-5为研究对象,考察了聚合反应参数对催化剂的活性及其聚合物的影响,研究发现:不同的烷基铝对催化剂具有非常重要的影响,特别足TIBA对MSPC-5的助催化活性最高,烷基铝的加入量有一个较佳值,聚合温度为80度时活性最高,H_2的加入使催化剂的活性明显降低且聚合物的分子量也减小;、新型氯化镁载体负载单活性中心催化剂催化乙烯聚合本文创造性采用固体MAO与无水氯化镁直接进行共研磨,制备出了一种的新型的氯化镁载体,并将该载体用于多种单活性中心催化剂的负载化研究,研究表明:1、通过BET、XRD的表征,再次证实了MAO与MgCl_2之间具有直接作用,与XPS的研究结果相一致;2、当研磨时间高于12小时时,延长研磨时间对载体的结构没有显著的影响;3、将配合物3负载于共研磨时间不同的一系列载体上,乙烯聚合结果表明,尽管共研磨时间对负载催化剂的活性具有明显的影响,但是它对聚合物的性能以及催化剂的影响不明显。
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Dealcoholization temperature markedly influences the surface area and porosity of the resultant MAO-supports. When the support was pretreated at lower or higher temperature, the corresponding MAO-support shows very low surface area; 2.XRD and IR analyses indicate that MAO has reacted with the residual ethanol in the supports, which is an important manner to get MAO fixed on the carrier. Morever, XPS analyse indicates that MAO can also be coordinated with MgCl_2, which is another way to get MAO fixed on the support; 3.ICP and EDX analyses indicate that dealcoholization temperature not only determined the element content on the solid catalyst, but also influences the element distribution on the carrier; 4.The activities of the supported phenoxy-imine catalysts and the properties of resultant polymers are strongly dependent on the dealcoholization temperature. The support (MSP-5) obtained by treating MgCl_2·2.56C_2H_5OH at 160℃for 4 h, then modified by MAO is very effective for immobilizing complex 3, the resultant solid catalyst (MSPC-5) shows very high activity in ethylene polymerization, and its kinetics of polymerization is stable during the reaction process. Finally, PEs with spherical morphology and high bulk density (over 0.35g/ml) were obtained, without reactor fouling; 5.In this work, polymerization conditions such as alkylaluminums, Al/Zr ratio, temperature and H_2 had a pronounced effect on the activity of MSPC-5 and properties of PE;(3). New MgCl_2-Supported Single-Site Catalysts for Ethylene Polymerization In this work, a kind of new MgCl_2 support was obtained by anhydrous MgCl_2 co-milled with solid MAO, and it is a creative contribution. Then some single-site catalysts were supported on the new MgCl_2 support, and the resulted solid catalysts were tested in ethylene polymerization, the results indicated that: 1.XRD and IR analyses indicate that MAO does be coordinated with MgCl_2, which is in good agreement with the results obtained by XPS; 2.co-mlling time had no obvious effect on the texture of support after 12 hours; 3.In this work, MgCl_2 was co-milled with solid MAO for different hours, and then complex 3 was supported on these co-milled supports. It was found that co-milling time markedly influences the activity of solid catalysts, but it had negligible effect on the kinetic profile and the properties of resultant PE.
XPS研究结果表明,MAO不仅仅只和乙醇作用,MAO还与MgCl_2本身有一定的作用,这是一个极为重要的发现; 3、通过ICP和EDX表征,发现载体的脱醇温度直接影响着元素在固体催化剂中的含量及分布; 4、脱醇温度极大地影响着负载苯氧基亚胺类催化剂的活性和聚合物的性能,特别是原始载体经160℃活化4小时制备得到的固体催化剂MSPC-5的活性明显高于其他脱醇温度条件下制得的固体催化,并且催化剂寿命长,表现出稳定的动力学行为,最终获得了高堆密度(大于0.35g/ml)的球形聚乙烯颗粒; 5、本文选择MSPC-5为研究对象,考察了聚合反应参数对催化剂的活性及其聚合物的影响,研究发现:不同的烷基铝对催化剂具有非常重要的影响,特别足TIBA对MSPC-5的助催化活性最高,烷基铝的加入量有一个较佳值,聚合温度为80度时活性最高,H_2的加入使催化剂的活性明显降低且聚合物的分子量也减小;、新型氯化镁载体负载单活性中心催化剂催化乙烯聚合本文创造性采用固体MAO与无水氯化镁直接进行共研磨,制备出了一种的新型的氯化镁载体,并将该载体用于多种单活性中心催化剂的负载化研究,研究表明: 1、通过BET、XRD的表征,再次证实了MAO与MgCl_2之间具有直接作用,与XPS的研究结果相一致; 2、当研磨时间高于12小时时,延长研磨时间对载体的结构没有显著的影响; 3、将配合物3负载于共研磨时间不同的一系列载体上,乙烯聚合结果表明,尽管共研磨时间对负载催化剂的活性具有明显的影响,但是它对聚合物的性能以及催化剂的影响不明显。
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There were no statistically differences between the 8th~ 14thday, the 15th - 21th day post-BC and the control group. During the rt~24tkday post-BC , pycnosis degeneration or necrosis neurons of the locus cerebral cortex, dorsal hippocampus, dentate fornix were significantly increased, then decreased gradually, but recovered to normal by the 24thday after BC, and especially in parietal cortex and piriform cortex the necrosis neurons were significantly increased than temporal cortex , and there were no statistically difference berween the left and the right side. Pycnosis degeneration or necrosis neurons in the brainstem reticular formation were markedly increased in the 4thday after BC, and there were no statistically difference among the other groups and the control group.
与对照组相比,BC后在大脑皮质、背侧海马和齿状回部位,固缩变性和不完全坏死细胞数先显著增加(P<0.05),然后逐渐减少,至24d基本恢复正常;顶叶、梨状皮质比颞叶皮质变性坏死细胞多,差异有高度显著性(P<0.01);大脑左侧比右侧变性坏死细胞稍少但差异无显著性;在BC后4d,脑桥核、斜方体核平面的脑干网状结构中固缩变性和不完全坏死细胞数明显增多(P<0.05),其它组间无显著性差异。
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In order to make these silver paste successfully used in commercial, a clear understanding is required for the complex relation between different parameters such as particles size, solid volume fraction, packing density on suspension printing and deformation and the mechanism of silver powder sintering shrinkage and the inorganic adhesive effect under the batch manufacture condition.The main emphasis of our researches was to improve the silver paste properties by developing a reliable, screen-printing paste suitable for fine lines and lower sintering porosity and good interface between thick film and glass substrate.
为开发电学性能稳定、高导电率、具有良好细线印刷性能及优良附着性的高性能电子浆料,本研究着眼于对影响参数进行详细剖析,找到关键控制参数,通过研究微观结构与粉末参数的对应关系,找到如何能制备出具有致密的厚膜结构与较低的孔隙率,并且其浆体与有机载体的界面区也要有明显的改善的电子浆体;同时对批量生产的银粉的形态与粉末烧结反应的收缩现象,无铅玻璃体系对银膜致密化等过程进行研究,获得致密高导的无铅银浆料。
- 推荐网络例句
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I didn't watch TV last night, because it .
昨晚我没有看电视,因为电视机坏了。
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Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.
今年以来,在北京的很多小区里,电梯液晶电视被撤了下来。
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I'm running my simile to an extreme.
我比喻得过头了。