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991.
通过系统地阐述连续采煤机的截割参数的意义和它们之间的相互关系,利用类比和试验的手段总结出了截割部主要参数的计算方法,为连续采煤机截割部参数的计算提供了完整的思路。为装运、行走、整机的设计、计算提供了有益的参考。 相似文献
992.
上海市邯郸路地道为长距离浅埋式地道,全长1 285 m。深基坑开挖、支撑和大方量混凝土浇捣的质量控制是工程施工的技术重点和难点。从施工前准备及技术交底、施工温度应力控制和裂缝控制等3个方面,详细介绍了底板大梁浇筑工艺、浇筑层厚度控制、振捣的时间点等重点交底内容;在施工中采取掺和粉煤灰及微型膨胀剂(UEA)等措施,控制施工温度应力;强调了冬季防止大体积混凝土裂缝所采用的4种措施。 相似文献
993.
随着建坝条件的复杂化,在覆盖层上建坝逐渐成为了一发展趋势。本文简要介绍了新疆深厚
覆盖层地基上不同土石坝的建坝经验,分析了深厚覆盖层上建坝的一些技术问题及相应的处理措施。 相似文献
994.
Abstract Antiferroelectric compositions, such as PbZrO3, are attractive candidates in charge storage devices and actuator/transducer applications in MEMs technology. Thin films of PbZrO3were deposited on Pt coated Si substrates by a pulsed excimer ablation process. The process of field induced ferroelectric phase switching involves the domain wall reorientation in the polycrystalline thin films. The presence of grain boundaries and various defects in the polycrystalline thin films acts as the pinning sources for the various domain walls. These defects capture the charge carriers in the presence of external applied field and hinders further switching of the dipoles in the domains, thereby increases the response times and threshold voltages for the devices operations. Understanding of the trapping phenomenon in these films is very essential. Using Lampert's theory of space charge limited conduction both shallow and deep trap energies were estimated approximately from charge transport analysis. 相似文献
995.
996.
D. Vásquez-Sandoval J. Pavez C. Carlesi A. Aracena 《Fullerenes, Nanotubes and Carbon Nanostructures》2018,26(2):123-129
A short-time and low-cost synthesis route was used to produce large lateral size (from 2 to 15 μm) from monolayers to few layers of graphene by a two-step process of electrochemical exfoliation with a deep eutectic solvent in a mixture with water that can be reused, and ultrasonic bath. The graphene was characterized by SEM, TEM, AFM, Raman and electrochemical activity. During the electrochemical exfoliation, high expanded graphene particles were obtained and these were dispersed in a mixture of water with 5%wt ethylene glycol by an ultrasonic bath in order to complete the exfoliation process. An enhancement of the electrical conductivity of these dispersions was obtained with the increase of graphene concentration, 0.38 mg/mL, which best result was achieved with 30 wt% water and a DC voltage of 10 V. It was possible to add a conductive layer to a glass substrate with the graphene obtained and Tyndall effect was observed. 相似文献
997.
LI SongLin LAI XiaoLing LIU BaoFeng WANG ZhiSuo HE JiaYong & SUN Yi Geophysical Prospecting Center China Earthquake Administration Zhengzhou China Seismological Bureau of Henan Province Zhengzhou 《中国科学:技术科学(英文版)》2011,(6)
A 2-D model of lithospheric velocity structures in the southern part of the North China Craton was obtained using data from the Zhucheng-Yichuan deep seismic sounding profile.Results show that there are great differences in lithospheric structures between two sides of Taihang Mountain.In the eastern region,the lithosphere is thinner,with a thickness of about 70-80 km,while in the western region,the thickness is 85-120 km.There is a jump of the lithospheric thickness across Taihang Mountain gravity anomaly b... 相似文献
998.
探讨DDC在建筑电气设计中的应用,以DDC为核心设计变风量空调末端(VAV BOX)控制器,介绍控制算法设计,工程实验运行和数据分析证明能够满足现场运行要求。 相似文献
999.
The corrosion–erosion behavior of carbon steel N80 and austenitic stainless 316L are investigated both in water–quartz slurry and saline–quartz slurry. The sample mass losses after each test and the roughness of sample surfaces are measured and a potentiostat is used to gain the polarization curves. The worn surfaces and the corrosion–erosion wear mechanism are analyzed using scanning electron microscopy (SEM) and 3D ultra‐deep microscopy. Results show that the Ra for N80 is much larger than 316L under the same experimental condition, and the weight losses of the two materials show a similar trend except for tests with higher impact angles. The lowest Rsm for 316L matches along with the highest Rsm for N80 at the 45 min testing time. According to the obtained results of the corrosion–erosion mechanism of the N80 and 316L based on the SEM and 3D ultra‐deep microscopy, the conclusion is drawn that the ploughing and crashing are the major mechanisms for the forming of surface morphologies and the mass removal. Different impact angles and materials affect the corrosion–erosion process to some extent. 相似文献
1000.