Dynamics of a two-module vibration-driven system moving along a rough horizontal plane

A rectilinear motion of a system of two bodies connected by a spring on a rough horizontal plane is studied. The motion of the system is excited by two identical unbalanced rotors based on the respective bodies. Major attention is given to the steady-state motion. A nearly-resonant excitation mode, when the angular velocities of the rotor are close to the natural frequency of the system, is considered. A set of algebraic equations for determining an approximate value of the average steady-state velocity of the entire system is obtained for the case of small friction. It is shown that control of the steady-state motion can be provided by changing the phase shift between the rotations of the rotors and the sign of the resonant detuning measured by the difference between the angular velocity of the rotors and the natural frequency of the system. By varying the phase shift one can control the magnitude of the average velocity, and varying the detuning enables one to change the direction of the motion. This study was partly supported by the German Research Society (DFG) (projects Zi 540-12/1 and SFR 622) and the Russian Foundation for Basic Research (project 09-01-91330). An erratum to this article can be found at     

提高干式气柜回收瓦斯的平稳性和安全性

对卷帘密封干式气柜及其辅助系统在回收瓦斯运行中的主要故障、所采取的对策加以归纳总结,并提出了一些提高安全性的建议。     

高温热管热风炉在白炭黑工业中的应用

对传统的白炭黑干燥技术进行了分析，提出了应用高温热管热风炉为白炭黑喷雾干燥提供热源，并将在某化工厂的应用结果与白炭黑喷雾干燥用燃油热风炉进行了比较。     

溢洪道开挖爆破块度级配控制研究

采用深孔梯段爆破进行溢洪道扩挖时 ,根据岩体的力学特性和工程要求 ,制定合理的爆破方案 ,正确选择爆破参数 ,并采取一系列技术措施控制其特征尺寸 ,使爆破石碴具有一定的块度级配。用YS— 1型压实计检测和灌水法抽验的结果表明 ,碾压 4～ 6遍后的石碴干容重大于 2 0kN/m3,达到较高的填筑密实度 ,完全满足工程要求。     

Elucidation of the formation of CO2 in culinary dry products

 The formation of CO₂ in tomato powder, chosen as an example of a dry culinary product, was investigated at room temperature and at low values of water activity (a _w). CO₂ formation correlated well with parameters that represent the beginning and progression of the Maillard reaction. In the absence of O₂, CO₂ formation decreased. Pectin and depolymerized pectin did not influence CO₂ formation while galacturonic acid (GalA) had a large effect. Determination of ¹³CO₂ in low-moisture model systems revealed that CO₂ was not formed by decarboxylation of GalA alone. Only a small proportion of [1-¹³C]glycine and GalA was degraded by the Strecker pathway; however, glucose reacted with the labelled amino acid forming ¹³CO₂ which amounted to over 90% of the total CO₂ formed. Therefore, CO₂ could be used as an early indicator for the beginning of the Maillard reaction in dry culinary products. Received: 28 October 1996     

腈纶干法纺丝油剂的国产化研制

提出了干法腈纶纺丝油剂应具备的使用性能标准，通过实验室应用性能对比，验证了国产油剂良好的使用性能，为进一步开展工业应用试验提供了基础。     

Triboreactions of graphite with moisture—a new model of triboreactor for integrating friction and wear

In order to account for the influence of environment on the frictional properties of graphite, a new model of tribocontact considering the confined volume under the pin as a triboreactor is proposed. The heart of the reactor is the mechanical production of debris displaying fresh prismatic surfaces. Both the rate of formation and the rate of deactivation of these latter are influenced by the environment and are mutually influencing each the other. The model combines three distinct mechanisms, seldom considered before: (a) the one step embrittlement of graphite governed by the amount of moisture within the contact; (b) the kinetics of water adsorption outside the contact, considered to obey the Elovich equation; (c) the triboreactions between the water and the active surfaces associated with the prismatic surfaces of the graphite debris. The validity of the model is supported by various experimental results.     

An a-Si:H vacuum-compatible photoresist process for fabricating device structures in HgCdTe

A process for transferring patterns into HgCdTe epilayers using a hydrogenated amorphous silicon (a-Si:H) photomask has been demonstrated. a-Si:H films were grown using plasma enhanced chemical vapor deposition (PECVD). A latent image of a projected mask pattern was created at the a-Si:H surface by ultraviolet enhanced oxidation in the load lock of the PECVD vacuum chamber. This image was transformed into a mask by hydrogen plasma removal of the unexposed areas. A hydrogen plasma etch selectivity value greater than 500:1 for oxide and a-Si:H allows patterns as thick as 700 nm to be generated. a-Si:H masks were used to create arrays of mesas in planar HgCdTe epilayers by etching in an electron cyclotron resonance (ECR) plasma reactor. Etch selectivity between a-Si:H and HgCdTe during an ECR hydrogen plasma etch was measured to be greater than 18:1. R_oA values > 10³ were obtained for mid-wavelength infrared diodes made from HgCdTe heterojunctions using a-Si:H masks.     

Development of angle indexes for soil moisture estimation, dry matter detection and land-cover discrimination

A new index was proposed to estimate soil and vegetation moisture based on NIR (858 nm) and SWIR (1240 and 1640 nm) MODIS bands. The Shortwave Angle Slope Index (SASI) parameterizes the general shape of the NIR-SWIR part of the spectrum. We expand on the novel approach used to develop SASI by proposing another index, the Angle at NIR (ANIR). We use laboratory and simulation datasets to validate the ability of SASI to estimate soil and vegetation moisture, and evaluate the advantage for using both SASI and ANIR as land-cover discrimination tools. Our results demonstrate that SASI is a good indicator of soil and vegetation moisture. ANIR shows promise in discriminating dry plant matter from soil and quantifying the amount of dry matter irrespective of changes in soil moisture or green vegetation. When SASI is combined with ANIR, discrimination between soil, dry plant matter, and low to high amounts of green vegetation is significantly improved. Angle indexes are an exciting new way to engineer indexes that contain valuable environmental information not accessible from other indexes.     

干气密封技术及实际应用

分析了干气密封的工作原理,详细介绍了干气密封在800kt/a重油催化裂化装置气压机在使用过程中遇到的各类问题及处理方法.认为最先进的密封技术,只有与装置缓冲气供给系统的有机结合,才能充分发挥其优越性,保证整个机组的长周期运行.