解开计算机硬盘死锁的一种方法

本文介绍硬盘逻辑死锁的原因，并给出了解开硬盘死锁的思路和详细的程序。     

FMS动控软件的死锁问题及其检测方法

对于一个ＦＭＳ动近软件的调试环境系统来说，能够榆出被测软件中可能发生的死锁问题是系统能够下沉运行的必要条件之一。在被测系统Ｐｅｔｒｉ网模型的基础上，本文提出了一个实用的死锁检测和回避的方法，这种方法计算量小，具有通用性。     

FMS运控软件的死锁问题及其检测方法

对于一个ＦＭＳ运控软件的调试环境系统来说，能够检查出被测软件中可能发生的死锁问题是系统能够正常运行的必要条件之一．在被测系统Ｐｅｔｒｉ网模型的基础上，本文提出了一个实用的死锁检测和回避的方法，这种方法计算量小，具有通用性     

计算机硬盘不能正常启动故障的分析与处理

计算机在使用过程中经常出现硬盘不能正常启动现象，硬盘启动失败将导致计算机的系统软件和应用软件无法运行，计算机不能正常工作。下面就如何解决计算机硬盘不能正常启动的问题，谈谈自己的体会：首先要保证硬盘系统配置正确，才能使计算机正常工作。因此在对硬盘不能起动故障作出处理之前，首先要检查硬盘的配置参数是否正确。一、正确配置硬盘参数硬盘的配置参数由主机上的ＣＭＯＳ存储器保存，标准ＣＭＯＳ配置包括日期和时间、基本存储器的容量、扩展存储器容量、软盘驱动器类型、硬盘驱动器类型、初始显示方式、系统缺省操作速度及键…     

对付计算机病毒的一着—对硬盘主引导记录和DOS分区表的备份和重写

本文提供对付计算机病毒的一种实用方法，予先对未感染计算机病毒的硬盘主引导记录和ＤＯＳ分区表进行备份，当主引导记录和ＤＯＳ分区表受到破坏或感染上不可消去的病毒时，再将备份的主引导记录和ＤＯＳ分区表重写到硬盘，本文提供一个源程序，用以实现这种方法。     

CHOICE命令与菜单技术的应用

采用了菜单技术及ＤＯＳ６．０中的ＣＨＯＩＣＥ交互式命令，编制了硬盘批处理程序，并应用于微机室硬盘操作管理。     

关于计算机操作系统中死锁问题的讨论

本文就死锁的概念、必要条件和若干可能发生死锁的问题作了深入浅出的分析、讨论，希望本文的讨论有利于读者对死锁问题的深刻理解，并深入研究解决死锁问题的方法。     

IBM─PC微机与多处理机的中断通信

实现了以ＩＢＭ－ＰＣ为主机，用ＲＳ４２２方式连接多台ＭＣＳ－５１单片机的通信系统。该系统完全以中断方式收发数据，比传统的单片机查询方式每字节大约节省时间６ｍｓ（约３０００条指令）；同时解决了通信数据误码、通信死锁等问题。该系统通信软件结构清晰，便于增加功能。     

常见计算机CMOS故障的排除

通过对微型计算机的ＣＭＯＳ故障,如硬盘丢失、设置ＣＭＯＳ口令等现象的分析,提出了如何解决硬盘丢失和解除ＣＭＯＳ口令的具体方法     

修改DOS扩展分区的方法

本文分析了硬盘的分区表，提出了修改硬盘分区表以修改ＤＯＳ扩展分区的方法，用这种方法时可保持原ＤＯＳ分区的内容不变。     

The characteristic blue spectra of accretion disks in quasars as uncovered in the infrared

Quasars are thought to be powered by supermassive black holes accreting surrounding gas. Central to this picture is a putative accretion disk which is believed to be the source of the majority of the radiative output. It is well known, however, that the most extensively studied disk model-an optically thick disk which is heated locally by the dissipation of gravitational binding energy-is apparently contradicted by observations in a few major respects. In particular, the model predicts a specific blue spectral shape asymptotically from the visible to the near-infrared, but this is not generally seen in the visible wavelength region where the disk spectrum is observable. A crucial difficulty has been that, towards the infrared, the disk spectrum starts to be hidden under strong, hot dust emission from much larger but hitherto unresolved scales, and thus has essentially been impossible to observe. Here we report observations of polarized light interior to the dust-emitting region that enable us to uncover this near-infrared disk spectrum in several quasars. The revealed spectra show that the near-infrared disk spectrum is indeed as blue as predicted. This indicates that, at least for the outer near-infrared-emitting radii, the standard picture of the locally heated disk is approximately correct.     

A major difference between transdetermination and homeosis

IN Drosophila, the adult structures arise from nests of larval cells called imaginal disks, whose state of determination with respect to disk type is usually fixed. However, two processes are known which can change determination from one disk type to another; one occurs in situ and is due to homeotic mutations, and the other is seen after culture of disk material and is called transdetermination. Similarities between the two, notably the lack of intermediate states, have led to the idea that they are different aspects of the same phenomenon(1,2). The existence of homeotic mutations argues that determination in normal development is underlain by a genetic switching mechanism(3,4); transdetermination could result from epigenetic changes in this system. If this is so then the two phenomena should have characteristics in common. Studies of homeotic mutants have shown that a structure in one disk is always transformed into a specific structure from the other disk(5,6); for example clones of bithorax in an anterior dorsal position in the haltere show anterior dorsal wing structures(5). This is used as a criterion of homology, and also indicates that all disks use the same positional information(7). Differences between disks must be due to different interpretation of this information, mediated in some way by the wild-type alleles of the homeotic genes. It is not yet known whether transdetermination also shows position-specific transformation; if the two phenomena are closely related then this should be the case. It is often assumed to be so, because there have been reports of transdetermination between leg and antenna in which structures such as claw and arista, thought from homeotic mutants to be homologous, are found adjacent to one another in implants(1). However, these findings could also be explained by non-homologous transdetermination followed by either movement together of homologous structures due to preferential cell affinities, or intercalary regeneration between the non-homologous structures. Also, regeneration before transdetermination can give misleading results. One cannot simply ask to what structures a given disk fragment will transdetermine as the fragment might regenerate the rest of the disk first, and non-regenerating (that is duplicating) fragments do not appear to transdetermine (unpublished observations, and ref. 8). One solution to these problems is to find a disk in which transdetermination occurs only in one part, and this is the case in the foreleg disk. The experiments reported here were designed to find whether this part transdetermines to a homologous part of the wing disk.     

The magnetic nature of disk accretion onto black holes

Although disk accretion onto compact objects-white dwarfs, neutron stars and black holes-is central to much of high-energy astrophysics, the mechanisms that enable this process have remained observationally difficult to determine. Accretion disks must transfer angular momentum in order for matter to travel radially inward onto the compact object. Internal viscosity from magnetic processes and disk winds can both in principle transfer angular momentum, but hitherto we lacked evidence that either occurs. Here we report that an X-ray-absorbing wind discovered in an observation of the stellar-mass black hole binary GRO J1655 - 40 (ref. 6) must be powered by a magnetic process that can also drive accretion through the disk. Detailed spectral analysis and modelling of the wind shows that it can only be powered by pressure generated by magnetic viscosity internal to the disk or magnetocentrifugal forces. This result demonstrates that disk accretion onto black holes is a fundamentally magnetic process.     

光盘存储技术,产品和市场的发展（下）

本文介绍了在与磁存储技术对比和竞争中各种光盘存储技术的发展，从家用小型光盘系列到专业用数字光存储系统，分析了今后光盘存储技术的发展方向，主要为提高光盘存储密度和数据传输速率，以及需要解决的关键技术问题，并列出了可能发展途径，介绍了光盘技术市场的发展状况，指出它是多媒体技术系统中的主要介质，将成为光电子技术领域中最主要的产业之一。     

圆域B样条曲线插值问题的研究

基于B样条曲线的理论，给出了圆域B样条曲线的递归算法，并在此基础上，对于带有误差的测量数据，即由于误差的原因分布在平面上一系列的小区域内的测量数据，给出了利用圆域B样条曲线进行插值的算法．所得到的固域B样条曲线具有局部性、连续性等良好性质，通过数值实验表明该算法是可行并且有效的．     

碟形弹簧的工程设计计算方法

通过对碟形弹簧受力分析，绘制出参数速查图表，提出一种碟形弹簧的工程计算方法，只须利用几个图表，便可简地地确定碟簧的主要参数。     

高性能光盘系统径向动态特性数学模型研究

研究了光盘机械系统的径向动态特性,给出了描述该特性的完备数学模型.将根据该模型进行数值计算的结果和当前高性能光盘国际标准规定的性能参数进行比较,验证了该模型的正确性;在此基础上,研究了改善现有光盘机械系统径向动态特性的途径.研究表明,影响光盘径向动态特性的关键参数是比值K,适当减小K能大幅降低径向偏摆及偏摆加速度.研究了光盘机械系统动态特性对下一代光存储系统结构的影响,并指出下一代超高密度光存储系统必须采用固定式装夹形式.     

如何制作网络装机启动盘

就Ghost启动光盘的制作过程作了详细说明。先制作Ghost启动软盘，然后使用winimage等软件将软盘制作成为光盘启动映像文件，使用nero刻录软件刻成启动光盘。     

线性代数课程增加盖尔圆定理的思考

矩阵对角化是线性代数的重要内容,现行课本已经给出了矩阵可对角化的一些条件,利用特征值和特征向量的某些特性来判断矩阵可否对角化。有一类矩阵对角化问题不能用这些方法来证明,为此引入了盖尔圆定理,利用盖尔圆定理可以给出该类矩阵对角化问题的证明。利用盖尔圆定理解决了矩阵论中的一个典型问题,因此在线性代数课程中增加盖尔圆定理是很有必要的。     

检测、预防计算机病毒的方法

要使计算机里存储的信息免遭破坏，预防计算机感染病毒或及时发现病毒是非常重要的。本文介绍一种通过检测主导扇区、引导扇区，中断向量表以及若干文件长度的方法，以及时检测出病毒。在检测程序运行后，确认系统不被病毒感染的情况下，再通过修改INT113H的中断向量对任何的写盘操作进行提示。只有用户确认后能执行写操作，从而起到防止病毒感染的作用。