液压支架泄漏故障分析及工作性能的改善

通过对液压系统各单元分析后认为,将高压平面截止阀改装成一个控制兼检测的多功能液控阀组,能大大降低窜液故障的发生,提高干线液压系统的抗干扰能力,保持系统压力与流量的恒定,最终实现支架性能的稳定与可靠.     

液压支架的发展与前瞻

介绍液压支架的发展及在综合机械化采煤中的地位,比较目前国内外液压支架材料应用、制造技术、加工工艺、配套元件、控制系统等方面的差异,阐述新材料、新工艺、纯水液压技术、高科技在液压支架上的应用,提出未来液压支架的设计理念和发展前景。     

矿用支架液压旋转卸车平台的研制

针对大型及高端大采高液压支架在煤矿井下工作面卸车的要求,利用液压传动技术,研制了矿用支架液压旋转卸车平台。液压旋转卸车平台由液压缸实现支撑和卸车平台的旋转控制,配合支架运输平车和拖运绞车,实现液压支架在工作面整体卸车。     

基于VB6.0的液压支架模型智能设计系统

传统液压支架产品的设计和应用随着液压支架应用范围的持续扩展,逐渐出现了滞后现象。因此,有必要结合液压支架的现实使用需求,开发一种新型液压支架设计平台。借助蓝光数字矿山地理信息平台,采用VB6.0编程语言实现了液压支架设计系统的参数化与标准化。在液压支架模型建立过程中,现有Delauany三角剖分方法可用于任意多边形的三角剖分。该软件缩短了开发周期,简化了设计流程,降低了设计成本,并提高了设计效率,从而有效增强了产品的市场竞争力。     

液压支架立柱二级伸缩油缸维修安装工艺工装的设计

液压支架是井下采煤工作面的支护设备,立柱是液压支架的主要承载部件用于支撑工作面顶板的压力,将载荷传递到底座上,而且还是液压支架升降的执行元件阻挡顶板冒落的岩石进入作业空间,以保证人员和机器的安全.由于并下顶板压力大,环境恶劣,液压支架还要作业移动,使油缸内的密封元件和钢筒内表面容易损坏,为此就要及时更换密封元件对油缸维修.因此,立柱维修质量的好坏,对于液压支架运行工作状况至关重要.     

综采液压支架电液控制系统设计与研究

根据液压支架电液控制系统在煤矿综采工作面的开采要求,设计了综采工作衙液压支架电液控制系统和功能,设计了电液控制阀,介绍了其结构及工作原理;实验结果表明所设计的综采液压支架电液控制系统能达到加快移动速度、提高支架操作灵活性目的．可实现综采液压支架远程控制及综采工作面少人或无人操作,有效改善工作面生产条件,提高生产效率．实现安全生产的目的,可为煤炭的高效安全开采提供帮助。     

一种新型全自动智能旋流式高压反冲洗过滤站的研制

本文针对目前井下液压过滤器安全性和可靠性低的问题,深入分析液压支架自动反冲洗过滤站液压系统原理,设计开发了一种全自动智能旋流式高压反冲洗过滤站,兼有过滤介质和自身清洗两种功能,能有效地保证液压支架系统清洁度高的要求,从而提高液压支架系统的可靠性,延长乳化液阀的使用寿命,为煤矿安全高效生产带来一定的便利性。     

液压支架连接头结构研制

液压支架连接头是液压支架与刮板输送机连接的重要零件。国内首家采用铆焊结构及低合金结构钢板材制造的连接头,为连接头结构创新开创了先河,从技术及材质上保证了液压支架与刮板输送机连接的可靠性,减少了事故率,保证了设备的开机率。     

初撑力在液压支架设计与生产中的应用

阐述液压支架初撑力的产生，分析设计和使用液压支架中的初撑力的影响因素，提出防止初撑力不足的基本途径。     

综采工作面整组液压支架起吊装置的研制

研发一种综采工作面整组液压支架起吊装置,能够实现液压支架的整体吊起,以及放下时与平车螺栓孔的对正固定,整组支架的起吊、及左右移动全部靠液压油缸的动作来实现.该装置解决了以往支架回撤、搬家倒面时,需要在工作面解体再拉到顺槽装车的难题.其应用能降低工人的劳动强度、提高工作效率、消除安全隐患.     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.