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1.
研究在Unix系统和NT系统中RDP设备驱动程序的设计原理和实现方法.采用了分层结构设计RDP驱动程序,将RDP置于磁盘驱动程序层次之上,避免了直接操作具体的硬件设备.通过对磁盘I/O请求的挂接和处理,实现故障切换和负载均衡.在路径发生故障时由RDP驱动程序将I/O切换到其他路径,以提高系统的可用性.实现了3种算法,通过将I/O负载均衡分布在各SCSI路径,以增加系统I/O处理能力.  相似文献   

2.
单片机系统中PS/2键盘驱动程序的设计   总被引:1,自引:0,他引:1  
介绍了PS/2协议及PS/2标准键盘的第2套扫描码和命令集,给出了在单片机系统中支持PS/2键盘的硬件连接方式以及利用Keil C51语言实现的驱动程序设计和部分代码.驱动程序在单片机系统中实现了对PS/2标准104键盘的支持;该程序在AT89C51单片机上运行通过,同时还可以方便地移植到其他单片机或嵌入式系统中.  相似文献   

3.
新型实时操作系统在继电保护装置中的应用   总被引:1,自引:0,他引:1  
为了提高继电保护装置的可靠性和稳定性,改善其可移植性和可扩展性,基于优先级可剥夺式调度策略,在TMS320F2812 DSP硬件平台上,实现了uC/OS-Ⅱ实时操作系统的移植.以中低压输电线路继电保护装置为例,提出了该装置的保护方案,通过划分不同的任务实现了保护装置的多种功能.根据网络化继电保护装置的需要,在操作系统里嵌入TCP/IP网络协议栈.实现了网络通信功能.采用uC/OS-Ⅱ的继电保护装置能够很好地满足电力系统的实时性要求.  相似文献   

4.
本文提出并实现了一种在VAX机环境下的Rdb/VMS数据库通用数据装载工具,讨论了设计思想与实现技术.实践表明,它能自动生成任一Rbd/VMS数据库中任一用户关系的数据装载程序,具有实用性和通用性.  相似文献   

5.
在商用数据库管理系统DM4中设计并实现了过程SQL语言DMPL/SQL.提出了DMPL/SQL语言解释器的总体结构.该解释器由编译器和虚拟机两部分构成.编译器分析源代码并生成中间代码,虚拟机以立即或延迟的方式对中间代码进行解释执行.介绍了实现DMPL/SQL语言解释器的关键技术.为提高程序的执行效率,在名字解析、SQL语句的执行以及异常处理等阶段采用了多种优化方法.该语言目前已广泛使用于基于DM4的数据库应用中.  相似文献   

6.
嵌入式Internet系统中TCP/IP协议的实现   总被引:1,自引:0,他引:1  
分析了由8位和16位MCU组成的嵌入式系统的特点,研究了嵌入式系统中TCP/IP协议栈的体系结构,提出了嵌入式系统中TCP/IP协议选择的方法和功能裁剪的策略,阐述了嵌入式系统实现TCP/IP协议过程中需要解决的关键问题,给出了协议处理的总流程.在对各协议控制字段进行深入分析的基础上,从编程和应用的角度给出了具体的解决方案和实现方法.实验表明,方案和方法对嵌入式Internet系统设计具有一定的参考价值.  相似文献   

7.
基于C/S与B/S混合模式的软件体系结构   总被引:6,自引:0,他引:6  
对软件体系结构进行了介绍,比较了C/S与B/S结构的特点,阐述了实现B/S结构的关键技术.指出在实际设计中可采用C/S与B/S相结合的软件系统结构,并根据C/S与B/S混合软件体系结构的2个模型,给出了实现该种结构的应用实例.  相似文献   

8.
介绍了基于 C/S(客户/服务器)模式的机械制造业网络MIS档案人事管理信息系统的结构和功能.讨论了网络环境中系统实现的一些设计策略和实现技术.  相似文献   

9.
针对用于PCIE2.0物理层的8b/10b编码器及其扩展的16b/20b编码器,设计了一种新的实现方式.将8b/10b编码分为5b/6b编码和3b/4b编码两个子模块,根据PCIE2.0协议中规定的编码表采用极性分组和卡诺图化简的方式得到子模块逻辑表达式并组合实现8b/10b编码.然后分析了由其扩展的16b/20b编码器中3种不同流水线级数的实现方式,使用Synopsys的Design Compiler工具在SMIC55 nm工艺下进行综合,在250 M时钟频率下的组合逻辑资源面积仅为223μm2 ,并根据综合结果分析了流水线级数对编码器性能的影响.  相似文献   

10.
通过控制膜生物反应器(MBR)中溶解氧(DO)浓度、碳氮比(C/N)、污泥浓度(MLSS)和水力停留时间(HRT)等摸索了实现同步硝化反硝化的工艺条件,同时对好氧反应器中实现同步硝化反硝化的机理进行了探讨.化学需氧量(COD)在250 mg/L左右,C/N为10~30∶1,MLSS为5 g/L,HRT为5.0 h,DO为0.6~0.8 mg/L时,总氮去除率达86.0%,取得了良好的总氮去除效果,表明由于好氧反应器中缺氧区的存在,控制好操作条件可以实现同步硝化反硝化.体系中氨氮、硝态氮浓度的变化与总氮去除的关系说明短程反硝化现象的存在,而且在实现同步硝化反硝化过程中发挥着重要的作用.  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 Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
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   

18.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

19.
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   

20.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

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