oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
用差示扫描量热法研究高交联非糊化淀粉的物态性质  [PDF]
张本山,徐立宏,高大维
食品科学 , 2002,
Abstract: ?用差示扫描量热法(dsc技术)对高交联非糊化玉米淀粉和高交联非糊化木薯淀粉,在水分散体系中随温度的升高而发生的物态变化进行了研究,结果表明三氯氧磷高交联变性淀粉,尽管已经失去了糊化的性质而保持颗粒状态,但在相应的原淀粉糊化温度范围内,仍然发生了由多晶态向非晶态的相转变。
铝电解槽用可调控性冷捣糊材料研究  [PDF]
江海霞,阎峰云,杨飞,缪欢,王庆祝
- , 2018, DOI: 10.11951/j.issn.1005-0299.20170322
Abstract: 为降低铝电解槽阴极整体成型用侧部冷捣糊电导率, 提高电流效率, 研究添加红柱石后焙烧温度、添加量对冷捣糊显微结构、导电性能及力学性能的影响.以红柱石为添加剂, 电煅煤、石墨为骨料制备冷捣糊料, 在20 MPa下保压5 min后进行焙烧.采用场发射扫描电子显微镜、X射线衍射仪对焙烧后试样显微结构进行分析, 利用电子式热膨胀仪、高温炭素电阻仪、耐驰抗折弯仪对焙烧后试样性能进行了考察.结果表明:添加红柱石的冷捣糊试样在高温烧结后生成莫来石针状结构和SiO2液相, 能够填充骨料间的部分孔隙, 使试样的致密度提高, 孔隙率下降; 添加红柱石的冷捣糊焙烧体的电阻率和膨胀率相对未添加红柱石试样明显增加, 且随着红柱石含量的增加而增大.红柱石含量为8%的冷捣糊综合性能最佳, 烧结体的体积变化最小, 稳定性最佳, 电阻率明显提高, 抗折强度相对减少, 有望在铝电解槽阴极整体成型过程中得到应用.
In order to decrease the electrical conductivity and improve the current efficiency of the side wall of the aluminum electrolytic cell cathode, we study the effect of calcination temperature and adding amount of andalusite on the microstructure、electrical conductivity and mechanical properties of cold ramming paste.With andalusite as additive, the cold ramming paste was prepared by electric calcined coal and graphite as aggregate, and the roasting was carried out under pressure of 20 MPa for 5 min.The microstructure of sample after baking were studied by using field emission scanning electron microscope and D8ADVANCE x-ray diffraction.The properties of the sample after baking were studied by using DIL402PC electronic watt shrinkage apparatus, carbon resistance meter at high temperature and NETZSCH bending strength tester.The results showed that adding andalusite could produce mullite needle structure and SiO2 liquid phase after sintering at high temperature which could fill some pores between aggregates and thus increase the density of the sample and decrease the porosity.The electrical resistivity and expansion rate of baked-samples were significantly increased without adding samples, while they were increased as the andalusite content was increased. The comprehensive properties were best when the addition content of andalusite was 8%.The volume change of baked-samples was minimum and the stability is best.The resistivity was increased and the bending strength was decreased.It is expected that this research can be applied in the monolithic lining process of aluminum electrolytic cell cathode.
大米粉在挤压蒸煮过程中酶法糊化度数学模型  [PDF]
王宁,卢承前,黄志,薄禾生
食品科学 , 1995,
Abstract: ?本文用brabenderdc2000型试验挤出机挤压膨化市售大米粉,采用中心旋转设计法对实验的过程参数:模头长径比(l/d:3.1~8.3)、模头温度(td:143.8~180.6℃)、螺杆转速(n:140~240r/min)、套筒喂料段温度(a:111.0~156.5℃)、挤压段温度(b:128.0~162.0℃)及被挤出米粉的水分含量(m:18%~30%)等进行分组,并用酶法进行测定产物糊化度(α)。依据不同条件下大米淀粉的糊化度拟合成决定系数为85.78%的含有m、n、l/d、b和td的数学方程。发现:α随l/d、td、m×b、n2的增加而增大;但随m×n、b×td及l/d×td的增加而变小。并加以讨论。
boc调制信号的抗干扰性能研究  [PDF]
杨力 薄煜明 田明浩?
计算机科学 , 2008,
Abstract: boc调制技术在扩频通信中的应用已日趋广泛。为此,本文在对boc调制信号的功率谱和自相关特性进行深入研究,以及将其与bpsk调制相比存在的优势进行深入分析的基础上,以boc(10,5),bpsk(10.23)为例,进行了基于fft的同步捕获环路的设计与仿真,并重点就不同干信比条件下两者的捕获性能进行了分析。结果表明,在一定条件下boc调制信号具有更好的抗干扰能力,为进一步抗干扰技术的研究提供了理论基础。
熔模精铸用的蜡模激光焊接法  [PDF]
东华
材料工程 , 1989,
Abstract: 熔模精铸用的蜡模,由于不能一次成型,须先做成几块,然后焊接起来。组合模型的方法通常是先将这些模块置入夹具中,用加热的烙铁将模块焊好。为了使焊接部位表面平滑,焊后还要重新用铬铁和压勺压平。因此,既浪费时间又要求操作者要有熟练的技术。
用降模法施工楼层平台  [PDF]
工业建筑 , 1978, DOI: 10.13204/j.gyjz197802004
Abstract: 冶金系统多层框架工业厂房由于工艺的需要,框架楼层平台都较复杂,利用液压滑模法施工,不能一次解决楼层平台的施工问题。框架结构滑模中主、次梁一次滑升方案的局限性也较大,原因是上下楼层平台梁变化很大,梁轴线不能上下对中,给操作带来
钛合金精密铸造用陶瓷模壳研究  [PDF]
贾清,崔玉友,,
金属学报 , 2004,
Abstract: 对适用于钛合金精密铸造用陶瓷模壳的制备工艺进行了系统的实验分析,表征了以过渡金属氧化物溶胶为粘结剂、稳定氧化锆为耐火材料的料浆的性能并讨论了相关参数的影响,对比研究了级配粉与均匀细粉制作的模壳的表面质量.结果表明,粗/细粉含量等级配参量和粉液比通过影响密度、粘度、滞流率以及涂层厚度等工艺参数而影响模壳的表面质量.在上述分析基础上确定了适用于本实验条件下钛合金精密铸造用陶瓷模壳的制备工艺参数.
A Time-Domain Fingerprint for BOC Signals  [cached]
Muth B,Oonincx P,Tiberius C
EURASIP Journal on Advances in Signal Processing , 2007,
Abstract: Binary offset carrier (BOC) describes a class of spread-spectrum modulations recently introduced for the next generation of global navigation satellite systems (GNSSs). The design strategies of these BOC signals have so far focused on the spectral properties of these signals. In this paper, we present a time-domain fingerprint for each BOC signal given by a unique histogram of counted time elapses between phase jumps in the signal. This feature can be used for classification and identification of BOC-modulated signals with unknown parameters.
淀粉糊老化动力学研究  [PDF]
赵思明,熊善柏,俞兰苓
食品科学 , 2002,
Abstract: ?以稻米为原料,采用旋转粘度仪研究较稀浓度淀粉糊的老化动力学。结果表明:不同类型稻米淀粉糊均呈假塑型流体的特征。随存放时间的延长,其流变指数上升,淀粉糊的刚性增大。淀粉糊的老化接近一级化学反应动力学模型,其反应级数稍大于1。用流变指数能较好的描述淀粉糊的老化动力学特征。淀粉糊的老化与其分散相的凝聚、沉淀和连续相的特性有关。当引入连续相流变指数和分散相沉淀率变量时,老化动力学模型的拟和精度进一步提高。直链淀粉和支链淀粉的相互作用会加剧老化进程。
阴米淀粉糊的流变特性  [PDF]
杨超,赵娜,田斌强,邓乾春,谢笔钧,孙智达
食品科学 , 2010,
Abstract: ?考察两优培九、荆糯六号大米以及阴米淀粉糊在不同质量浓度和温度下的流变特性,结果表明:这两种大米和阴米淀粉糊都是典型的非牛顿型和剪切变稀流体,黏度随剪切速率的增加而降低;同时用幂律函数描述淀粉糊的流变特性,拟合精度较高。淀粉糊的动态流变行为表现为:在升温初期,储能模量(g′)和耗能模量(g″)的值先显著下降,进而平缓下降,在90℃时出现不同程度的升高,随后又下降。损耗因子(tanδ)随温度的升高呈现先下降后上升的趋势。原米淀粉糊的黏性大弹性小,而阴米淀粉糊的弹性大黏性小。
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.