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1.
转杯纺纺制竹节纱的研制   总被引:2,自引:0,他引:2  
分析了转杯纺纺制竹节纱的三种主要方案,并对其适用性进行了相应的比较,通过实际试纺16s竹节纱阐述了转杯纺纺制竹节纺的工艺流程、AUTOCORO-288转杯纺纱机纺制竹节纱的机构改造及参数设定情况.  相似文献   

2.
一、引言 2004年.马钢三炼钢由于4#转炉工程建设的需要,对LF精炼炉整体移位改造,其中,电气方面进行了全面改造:一是PLC控制系统由S5系统改造为S7系统;二是电极控制系统南原来的模拟控制系统改造为一套以S7-300CPU为核心的PLC控制电极调节系统。  相似文献   

3.
一、引言 2004年,马钢三炼钢由于4#转炉工程建设的需要,对LF精炼炉整体移位改造,其中,电气方面进行了全面改造:一是PLC控制系统由S5系统改造为S7系统;二是电极控制系统由原来的模拟控制系统改造为一套以S7-300CPU为核心的PLC控制电极调节系统.  相似文献   

4.
传统的加热炉电气控制系统普遍采用继电器控制技术,由于采用固定接线的硬件实现逻辑控制,使控制系统的体积增大,耗电多,效率不高且易出故障,不能保证正常的工业生产。随着计算机控制技术的发展,传统继电器控制技术必然被基于计算机技术而产生的PLC控制技术所取代。而PLC本身优异的性能使基于PLC控制的温度控制系统变得经济、高效、稳定且维护方便,这种温度控制系统对改造传统的继电器控制系统有普遍性意义。本文题材来源于2010年第四届西门子杯控制技能仿真挑战赛赛题,其中对工艺过程和控制算法进行了较为详细的阐述。  相似文献   

5.
阐述了JWF1612型转杯纺纱机电控系统中DeviceNet总线的通信特点、线路构成,分析了该机硬件及线路结构以及如何在PLC软件编程中通过DeviceNet总线交换数据,使系统运行稳定可靠。  相似文献   

6.
可编程序控制器(PLC)以其高可靠性、灵活性、通用性等特点,成为实现工业生产自动化的支柱产品。本文介绍了PLC在湿法鱼粉生产线改造中的应用,利用PLC代替继电器控制,可简化控制线路,提高控制系统的可靠性,体现了PLC控制系统优于传统的继电器控制系统。  相似文献   

7.
本文采用现代测试手段,分析了自排风式转杯纺纱机的转杯系统(包括转杯、轴承、蜗壳、密封圈及活络通道)的噪声特性,设计了一个降低噪声的装置。使该系统的噪声降低了3~5dB(A),而对成纱质量则无任何影响。  相似文献   

8.
许惠君 《科技资讯》2013,(13):108-109
提出了基于单片机的高精度直流电机控制转速的控制方案,以ATmega16单片机为核心,采用传感器与CPU定时/计数器配合来测速,采用键盘进行数据输入,通过嫡程实现了电机转速超限.报警等功能。该装置可以应用于要求转速精确的电器产品中,使直流电机的各种潜在能力得到充分的发挥。  相似文献   

9.
设计了一种由AVR单片机ATmega16L控制AD9954实现的程控信号源电路,给出单音频、RAM控制和线性扫频3种模式下AD9954输出信号的调控方法.此设计可以方便地实现对信号源电路输出频率、相位和工作模式的控制,使信号源电路能输出高稳定度、高分辨率的信号.  相似文献   

10.
介绍了自动平衡实验系统的设计,该系统由加速度传感器、ATmega16单片机、步进电机和平衡支架组成.单片机系统实现了对传感器的数据采集、步进电机的控制和上位机的串口通信.通过上位机(Lab-VIEW)与单片机串口通信,能够实现步进电机的“自动水平”和“既定角度转动”两种功能.  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.
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   

13.
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   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
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   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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