钡的
- 与 钡的 相关的网络例句 [注:此内容来源于网络,仅供参考]
-
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。
-
The crystal structure of the marine 1 nm manganate is quite different with that of the land base todorokite, and it has more similarities with the synthetic 1 nm manganate of buserite instead, therefore the marine 1 nm manganate and todorokite are the distinct manganates. The 1 nm manganate can be transformed into 0.7 nm manganate by losing some water caused by drying, and the 0.7 nm manganate might not be the original manganate phase in polymetallic nodules, but is more likely to be the phase transformation product of 1 nm manganate.
大洋多金属结核中的1nm锰矿相常以陆上钡镁锰矿命名,但两者在晶体结构等方面有很大的差别,并不属同一种矿物,1nm锰矿相与人工合成的布塞尔矿却有更多的相似性。1nm锰矿相会因干燥失水而相变成0.7nm锰矿相,因此结核中的大多数0.7nm锰矿相很可能不是原生矿物,而仅仅是1nm锰矿相的相变产物。
-
Similar experiments, but using Chemical Release Modules, have been launched from Churchill, Manitoba. In 1980, Brian Whelan's "Project Waterhole" disrupted an aurora borealis, bringing it to a temporary halt. In February 1983, the chemical released into the ionosphere caused an aurora borealis over Churchill. In March 1989, two Black Brant X's and two Nike Orion rockets were launched over Canada, releasing barium at high altitudes and creating artificial clouds.
同样的但是采用化学释放模型的实验,在加拿大马尼托巴的丘吉尔被启动。1980年,布瑞安威兰的"水洞项目"中断了一次北极光,使之暂时停止。1983年2月,排放进电离层的化学物质引发了丘吉尔上空的北极光。1989年3月,两艘"黑雁X"和两艘"耐克奥瑞恩"火箭在加拿大上空被发射,在高纬度释放钡产生人工云。
-
The principle and three adding methods of additives carbon for elevating utilization rate of electrode materials were introduced;The forming methods of barium plumbate membrane for preventing corrosion of positive electrode grid were analyzed;The effect and principle of additive calcium sulfate for improving the high rate discharge performance of VRLA batteries were reported.
综述了电极和电解液一些添加剂的作用及其在阀控铅蓄电池中的应用情况;介绍了提高电极活性物质利用率的添加剂的3种添加方法和原理;分析了防止正极板栅腐蚀的添加剂在板栅表面形成铅酸钡膜的3种方法;报道了硫酸钙添加剂在改善高倍率放电性能方面的效果和工作原理。
-
The low-phosphorus and low-carbon Al-Si-Mn ferroalloy is produced with aluminium and common silicomanganese in certain proportion and through adding proper amount of Ca-Ba dephosphorizing agent for high temperature dephosphorizing and decarbonizing and adding proper amount of pure aluminum and clean waste steel.
本发明按一定比例的铝、普通硅锰合金,加适量的钙、钡系脱磷剂进行高温脱磷脱碳,再根据产品成份的要求补加金属锰,加入所需的纯铝及纯净废钢,获得的低磷低碳铝硅锰铁合金的组成为:Al 5~20%,Mn 50~70%,Si 8~20%,C≤1.0%,P≤0.1%,S≤0.03%,余量为Fe。
-
Results ①Five days after abdominal application of Xiaoji power(0.1 g per mouce),the medicine showed a very significant effect in enhancing gastrointestinal propulsive function.② Xiaoji powder not only had relaxing effect on the normal smooth muscle in vitro,but also had a strong spasmolytic effect on acetylcholine,green bariuminduced spasm of intestinal smooth muscle.The experiment was based on 10 μg atropine sulfate as a positive control to carry out control experiments.It showed the graphics of atropine sulfate in spasmolytic role.③Xiaoji powder navel paste therapy played a positive role in adjusting the gastrointestinal electric disorder caused by deficiency of spleen Qi,and could restore it to its normal state.
结果 (1)以0.1 g/只消积散给予小鼠腹部用药5 d,即显示非常显著的增强胃肠推进功能作用;(2)消积散不仅对正常离体平滑肌有舒张作用,同时对由于乙酰胆碱、氯化钡引起的肠平滑肌痉挛也有强的解痉作用,该实验是以硫酸阿托品10 μg作为阳性对照药进行对照实验,显示了硫酸阿托品的解痉作用图形;(3)消积散敷脐对脾虚引起的胃肠电紊乱有明显的调节作用,使脾虚大鼠的胃肠电基本恢复到正常状态。
-
The material is prepared by mixing barium titanate 80~99% and acetylene black 1~5% with PbO-B2O3 0~15% proportionally, grinding in agate grinder or in ball mill, press forming at pressure 2~10Mpa under vacuum or protecting gas environment.
按80%~99%的钛酸钡、1%~5%的乙炔黑和0%~1 5%的PbO-B2O3玻璃粉的比例混合后,在玛瑙研钵中研磨或者在球磨机中研磨,以压力为2~10MPa压制成型,该陶瓷材料的制备需要在真空或者保护气体的保护下进行。
-
Advances on the development of new oxidation reagents and methodologies and their applications in both target-and diversity-oriented synthesis have been regularly surveyed and constituted one of the most extensively and actively investigated areas of current organic synthesis.1 In this context,a plethora of oxidants,including those small organic molecule-based reagents (such as Dess-Martin periodinane,Swern oxidation,Moffatt oxida- tion,Corey-Kim oxidation,and 三氧化硫/pyridine)and metal-based systems(such as Jones reagent,Collins reagent,pyridinium chlorochromate,pyridinium dichromate,barium permanganate, manganese dioxide,ruthenium tetroxide,silver carbonate,and Oppenauer oxidation),have been identified to be powerful tools promoting conversion of various alcohols into their corresponding aldehyde or ketone products and thus evolved as a most important class of tools in synthetic chemists'arsenal.
关于新的氧化试剂和方法,在两个目标和多样性为导向的发展及其应用合成的进步定期调查,构成一个最广泛,积极探讨在这方面,过多的地区目前有机合成。1氧化剂,包括有机小分子为基础的试剂(如Dess - Martin氧化剂,斯文氧化反应,氧化法特,科里,金氧化,三氧化硫/吡啶)和金属为基础的系统(如琼斯试剂,柯林斯试剂,吡啶氯铬,吡啶铬,钡锰,二氧化锰,四氧化钌,银碳酸盐和开瓶器氧化),已被证实为推动中相应的醛或酮醇转化的各种产品,功能强大的工具,因而作为一个最重要的阶级演变在阿森纳的工具合成化学家。
-
By and large seed 7-12, 4-6 species are the main materials such as quartz sand, limestone, feldspar, soda ash, boric acid, lead compounds, barium compounds, and so on, according to theintroduction of the oxide in the glass structure of the role, Into the glass forming oxides of raw materials, intermediate raw materials of oxide, network-oxide materials, according to the introduction of the nature of the oxide, acid oxides can be divided into raw materials, base metal oxide materials.
大体由7-12种组成,主体料有4-6种,如石英砂、石灰石、长石、纯碱、硼酸、铅化合物、钡化合物等,按所引入氧化物在玻璃结构中的作用,可分为玻璃形成氧化物的原料、中间体氧化物的原料、网络外体氧化物的原料,按所引入氧化物的性质,可分为酸性氧化物的原料、碱金属氧化物的原料。
- 推荐网络例句
-
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。
-
There is no differences of cell proliferation vitality between labeled and unlabeled NSCs.
双标记神经干细胞的增殖、分化活力与未标记神经干细胞相比无改变。