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1.
介绍了一种木材干燥自动监控系统,该系统以89C51单片机为核心,将检测到的木材干燥过程中的各种参数与设定值进行比较处理,然后控制有关阀门的开关,达到自动控制整个干燥过程的目的。通过RS-232实现与上位机的通讯,可实现木材干燥的远程控制。  相似文献   

2.
介绍了用MCS一51单片机控制定量发放物料的电子称重系统,描述了该系统的工作原理及软硬件设计。  相似文献   

3.
物料干燥特性模拟   总被引:1,自引:1,他引:1  
研制了一种功能较齐全的物料干燥特性试验装置,可用于模拟空气集热器——干燥室型太阳能干燥装置的运行条件。用它做了20余种物料的干燥特性模拟研究,其结果为太阳能干燥装置的设计提供了理论依据,对已有太阳能干燥装置的工况调整和运行管理也有指导意义,对使用常规能源的干燥装置亦有参考价值。  相似文献   

4.
刘泽勇 《甘肃科技》2000,16(5):71-71
干燥过程在国民经济的各部门有着广泛的应用干燥的产品便于加工运输贮存和使用从化学工业的产品如肥料染料无机盐到医药工业 粮食食品饲料均离不开干燥过程通过干燥使产品具有良好的扩散性均一性正确地完成干燥过程有利于保证和改进产品的质量 ,对提高生产促进经济的发展有十分重要的作用1 气流干燥技术干燥方法比较多气流干燥是对流干燥方法中的一种由于这种干燥方法的空气温度便于调节可以控制物料的温度产品不致过热而变质产品质量好所以在工业生产中得到应用其原理是将加热后的空气通入干燥器以对流传热的方式将热量传给湿物料湿物料中…  相似文献   

5.
静电干燥特性的研究   总被引:20,自引:1,他引:19  
对几种不同的热敏性物料(辣椒、西洋参、金霉素等),通过静电干燥试验研究,得出比加热干燥可缩短约一半的时间,且有效成份和色泽不变的结论.还对静电干燥的机理进行了探讨,提出静电场能传质的机制.为热敏性物料的干燥提供出一种全新的技术  相似文献   

6.
初始非饱和多孔物料对冷冻干燥影响理论分析   总被引:1,自引:0,他引:1  
为提高过程的经济性,提出了液体物料初始非饱和冷冻干燥的技术思想.推导了冷冻干燥质、热耦合传递模型,模型采用了新的吸附-解吸平衡关系,并考虑了吸湿效应.控制方程用有限容积法进行数值求解.待干水溶液中的溶质选用典型的药物赋形剂———甘露醇.结果表明,初始非饱和多孔物料能够显著减少干燥时间,达到强化冷冻干燥的目的.随初始孔隙率ε0(1-S0)的不断增大,干燥时间逐渐缩短;在物料初始饱和度S0为0.30~0.35时,干燥时间达到最短.依据干燥过程中饱和度和温度的分布,分析了物料内部质、热传递机理和干燥速率控制因素.对有效质量扩散系数KS和有效导热系数λ+KTΔH的分析显示,随着冷冻干燥的进行,物料瞬时孔隙率ε0(1-S)不断增大,过程将由传质控制逐渐变为传热控制.  相似文献   

7.
水平转盘与转鼓微波干燥均匀性的实验研究   总被引:1,自引:0,他引:1  
针对微波干燥存在的主要问题--干燥的不均匀性,提出利用改变物料在微波场中的位置来改善物料对微波能吸收的均匀性,从而达到微波干燥的均匀性.以黄豆为物料,比较了水平转盘与转鼓两种结构在不均匀的微波场中对物料干燥均匀性的影响.结果表明:转鼓微波干燥比水平转盘微波干燥更加均匀,对于不均匀的微波场,利用物料的随机运动可改善微波干燥的均匀性,从而提高干燥产品的品质.  相似文献   

8.
以AT89552单片机为核心元件,设计一种简易行车抓斗控制及称重显示系统装置。该装置中的智能物料搬运装置可以实现物料的搬运,并对搬运的物料称重,通过LCD12864液晶屏和LED数码管显示物料的重量。整个系统的工作通过4×4矩阵按键来控制,可以分别实现手动和自动搬运物料。对该系统的工作性能进行测试,结果表明,该系统工作安全稳定,称重精确度高,性能可靠,具有良好的应用前景和推广价值。  相似文献   

9.
本文通过对四种中药材的干燥性能试验,探讨了影响物料干燥过程的主要因素,给出了干燥过程的数学模型,为设计物料干燥装置和提高热能利用率提供了依据.  相似文献   

10.
离心流化床中多孔介质干燥的传热传质研究   总被引:1,自引:1,他引:0  
通过对典型的多孔湿物料在离心流化床中干燥过程的理论分析,将含湿多孔介质传热传质过程和物料与气流之间的外部传递过程相耦合,导出了离心流化床的控制方程组,在此基础上,可以对离心流化床中湿物料的干燥过程进行数值模拟。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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