并发的

However, while a computer's resources are substantial,they are limited and, with two or more concurrentusers, conflicts over processor time, main memory space, and peripheral device allocations are inevitable.

尽管一台计算机的资源相当丰富。但它的资源还是有限的。对于两个或更多的并发用户，在处理器的时间、主存储器的空间和外围设备的分配等方面的冲突是不可避免的。

To prepare studying hierarchical intelligent control system of material flows in mineral processing plant further, picturing, transition rulers, analytic methods, relevance matrix and dynamic equation, defect in applying of Petri network, fall short of orient object models applying are discussed after technology of formalization model built, non-formalization built and compound model. And Petri network system with time attribute is expanded opening network system with interface of input and output. The network system expanded with all attributes of basic Petri network model has hierarchy and recursiveness, can be analyzed with mathematical tools of network system and can deal with concurrent and asynchronously also.

为了对选矿厂生产物流递阶智能控制系统的进一步研究奠定基础，本文在讨论了形式化建模技术、非形式化建模技术和复合模型的基础上，研究和分析了Petri网的图形表示、变迁规则、分析方法、关联矩阵与动态方程、Petri网模型应用中的缺陷、面向对象模型应用中的不足，并把采用赋时的Petri网系统扩展成为对外界有输入和输出接口的开放网系统，扩展后的Petri网具有递阶性和递归性，同时保持基本Petri网的所有性质，使模型仍可采用网系统数学工具进行分析，并可处理生产物流系统中的并发性和异步性。

The above method can be used as a general method of determining molecular weight distribution of polymers.4.Solid-state ~1H wide-line NMR and ~(31)p magic angle spinningNMR were applied to a series of PEI/DNA complex samples with different PEI molecular weights and nitrogen/phosphatemolar ratios,in order to disclose the influence of various structural factors on the interactions and morphology.The results of ~1H NMR spectra showed that the linewidth of the PEI signal was greatly broadened with increasing the N/P ratio.Meanwhile,in the ~(31)p M_AS experiment,the signal was found to shift upfield with the increase of the N/P ratio.Both ~1H and ~(31)P NMR experiments demonstrated that the interaction between two constituents and subsequently the morphology of the complexes vary with the N/P ratio.

首次将固体核磁共振应用到聚合物/DNA复合物体系，观察复合物体系中不同N/P比对其相互作用和相结构的影响，研究表明N/P比的变化对聚乙烯亚胺/DNA基因递送体系分子水平上相互作用有着很大的影响；另外，还发现不同分子量的聚乙烯亚胺聚合物载体在N/P比为3的情况下对复合物中DNA的微观尺度没有明显影响；通过氢的自旋扩散实验，首次测得在PEI/DNA复合物体系中DNA相尺寸的大小，并发现在体系中N/P比达到3以上的复合物中DNA和PEI达到了分子水平上的相容。

Further more, we discuss four related issues:(1) Through reducing the number of operations in history buffer, we can optimize the efficiency for running continuously;(2) Support Undo operation for collaborative document editor through involving a delete counter for each object;(3) Introduce a new timestamp model to support concurrent operations in a single site for shared data;(3) Through involving a NOOP operation and executing transaction operation with all related NOOP operations to guarantee transaction operation is serialized.

进一步，本文讨论了一致性维护的四个相关问题：（1）通过精简操作的历史队列，实现算法持续执行时的效率优化；（2）通过引入对象节点的删除计数器，实现对文档的协同编著中的Undo操作支持；（3）介绍了一个新的支持单站点上共享数据的并发操作的时间戳模型；（4）通过引入空操作NOOP且保持事务操作和相应的NOOP操作同时执行，保证事务操作的序列化。

Results: 1. The value of all experimental indexes decreased significantly after heat stress, and reached the lowest at the time 2-8 hours after heat stress. This indicates that the immunity of the mice is damaged to the largest extent at 2-8 hours after heat stress. 2. L-arginine supplementation with appropriate dose could remit the acute atrophying of thymus and spleen tissue caused by heat stress. 3. After L-arginine supplementation with appropriate dose, the lymphocyte proliferation, the level of concentration of IL-2 and * expression of IL-2R raised in the group with room temperature; in the heat stress group the level of three indexs decrease significantly. Furthermore, the decrease of the group given 1 .Smglg.bw L-arginine is the smallest. This result indicates that the concentration of 1 .Smglg.bw L-arginine supplementation could remit the depressment of the immunity caused by heat stress. 4. The [Ca2~] in activated thymocytes of the group with L-arginine -2- supplementation is significantly higher than that of the group with water supplementation. This indicates that L-arginine supplementation could protect thymoeytes of mouse under heat stress. We also found that the fluorescence intensity of [Ca2~] in activated thymocytes of the group given 1 .Smglg.bw L-arginine is the highest.

结果：1、热应激后小鼠的各项免疫指标均有显著性下降，其中在2.8小时降到最低，提示在这个时间段小鼠的免疫功能受到最大损害；2、适量补充精氨酸有助于缓解热应激导致小鼠胸腺和脾脏的急性萎缩；3、常温组，补充适量精氨酸后小鼠淋巴细胞增殖活性、IL-2的浓度及IL-2R的表达均有显著性上升，而热应激后三指标均显著降低，其中在精氨酸给予浓度为1.5mg/g.bw时三指标的降低程度最少，提示该浓度可最大程度缓解热应激对小鼠免疫功能的抑制；4、补充精氨酸组的活化胸腺细胞［Ca~(2+)］较给水组有显著性上升，说明精氨酸对热应激小鼠胸腺细胞具有保护作用，并发现在精氨酸给予浓度为1.5mg/g.bw时活化胸腺细胞的胞浆钙离子荧光强度达到最大；5、热应激后小鼠血清NO的浓度均有不同程度的上升，补充精氨酸后血清NO上升更加明显，但并非随精氨酸给予浓度的增加而增加。

This paper introduces the concepts of CSCW, describes the present state and discusses the problems to be solved, primarily focusing on human computer interaction, concurrency control and collaboration management. According to the research on cooperative characteristics of user actions in CSCW systems, this paper proposes a software architecture model of cooperative systems, Arbor. Its main contents include: Layered structure The Arbor model divides a cooperative system into five layers according to functional decomposition: device layer, concept layer, intention layer, cooperation layer, and computation layer. It deifies user actions and reifies the results of the actions to implement multi-level collaboration among multiple users. Multi-level collaboration obtains finegrained collaboration of the cooperative system and improves its collaboration efficiency.

本文首先介绍了计算机辅助协同工作的基本概念，着重从人机接口，并发控制和协同管理等功能方面介绍了协同系统的现状及其软件结构存在的问题，然后，基于对协同系统中用户动作的协同需求和协同特性的研究，针对目前协同软件系统存在的问题，提出了一种协同系统软件结构模型Arbor，它的主要内容包括：层次结构 Arbor模型从功能上将协同软件系统分为五层：设备层、概念层、意图层、协同层和计算层，它通过对用户动作的多层抽象和对动作结果的多层例化，实现多用户之间的多层次协同及感知，层次结构增强了系统的灵活性和适应性，方便了系统的开发，同时，多层次协同的方法获得了细粒度的协同感知，提高了协同效率。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失