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1概述众所周知,在水泥原料粉磨工艺中,采用立磨系统比球磨系统具有粉磨效率高、烘干能力大、噪音低、扬尘少、可节能20%以上等优点,获得越来越广泛的应用。原有的立磨内置选粉装置,设备已经相当成熟,但有许多方面仍需改善,特别是磨内气力提升物料能耗较高,不能满足用户 相似文献
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采用自孕育法在线制备Mg-9Zn-2Al镁合金半固态浆料,研究了等温温度为585℃时,等温时间对Mg-9Zn-2Al镁合金半固态组织演变的影响.结果表明,随着保温时间的延长,晶粒先球化而后恶化,并且不断长大,保温4~8 min时,其晶粒较好,尺寸为65~72 μm,圆整度在1.2~1.3之间.在此过程中,组织的演变主要经历高熔质点相的析出及较小过冷度下的瞬态形核、镁原子堆积促使初生相的长大和α相的合并长大三个阶段. 相似文献
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Compressive sensing(CS) techniques offer a framework for the detection and allocation of sparse signal with a reduced number of measurements.This paper proposes a novel SAR range compression,namely compressive sensing with chirp scaling(CS-CS),achieving the same range resolution as conventional SAR approach,while using fewer range samplings.In order to realize accurate range cell migration correction(RCMC),chirp scaling principle is used to construct reference matrix for compressive sensing recovery.Additionally,error diagrams are designed for measurement of the performance of CS-CS,and some experiments of using real data are performed to deal with the errors caused by three conditions:SNR,sparsity and sampling. 相似文献
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本文谈及了我国食物资源与环境的总体情况,并对食物生产潜力和供需情况进行了分析,提出了食物资源可持续利用和发展的对策建议. 相似文献
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铜精炼过程能耗模糊自适应变权重组合预测模型及其应用 总被引:3,自引:0,他引:3
基于已有的铜精炼过程的能耗数据,引入了各预测方法的预测相对误差、预测对象的变化趋势、灰色基本权重和自适应调节系数等概念,建立了铜精炼过程的能耗模糊自适应变权重组合预测模型。结果表明,此模糊自适应变权重组合预测模型的精度较高,并且平均误差和预测平方根误差均较小。该组合预测模型为铜精炼过程的能源需求决策提供了有力支持。 相似文献
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王春生 《世界制造技术与装备市场》2005,(4):36-40
第九届中国国际机床展览会上展出锻压机械类展品的参展商49家,国内参展商(包括台湾地区及香港特别行政区)24家,国外参展商25家。共展出锻压机械类展品87台套,其中国内展品48台套,国外展品39台套。本届展览会有展品的国外参展商数量与上届持平,而展品数量增加近1倍;有展品的国内参展商数量比上届减少55%,展品数量减少40%。 相似文献
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冰浆输冷空调系统设计方法的研究 总被引:1,自引:0,他引:1
冰浆作为载冷剂具有节能、环保、高效等优点。该文就夏季工况对某办公大楼以冰浆为载冷剂的空调系统的管道系统进行了设计计算同时对其冬季供暖时使用情况进行了校核,最终得出冬夏共用管道系统时所对应的含冰率,以期为该类空调系统的设计提供一种设计方法。 相似文献
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Cognitive radio networks are a promising solution to the spectrum scarcity issue. In cognitive radio networks, cooperative spectrum sensing is critical to accurately detect the existence of a primary user (PU) signal, because the local spectrum sensing by a single secondary user (SU) has low reliability. Unfortunately, cooperative spectrum sensing is vulnerable to the spectrum sensing data falsification (SSDF) attack. Specifically, a malicious user can send a falsified sensing report to mislead other (benign) SUs to make an incorrect decision on the PU activity, to cause either denial of service to benign SUs or harmful interference to PUs. Therefore, detecting the SSDF attack is extremely important for robust cooperative spectrum sensing. This paper proposes a distributed defense scheme, termed conjugate prior based SSDF detection (CoPD), to countermeasure the SSDF attack. CoPD can effectively exclude the malicious sensing reports from SSDF attackers, so that benign SUs can effectively detect the PU activity. Furthermore, CoPD can also exclude abnormal sensing reports from ill-functioned SUs. Simulation results indicate that CoPD achieves very good performance to accomplish robust cooperative spectrum sensing. 相似文献
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