并发性

Stochastic Petri Nets has good ability for dynamic analysis of concurrency, asynchronism and uncertainty of systems. It is particularly suitable for system modeling and dependability analysis.

随机Petri网对系统的并发性、异步性和不确定性具有很强的动态分析能力，特别适合系统建模和可信赖性分析。

Surveillance: routine follow-up in a metabolic clinic; monitoring for hyperammonemia and secondary deficiency of essential amino acids; monitoring older individuals for signs of impending hyperammonia (i.e., mood changes, headache, lethargy, nausea, vomiting, refusal to feed, ankle clonus) and elevated plasma glutamine concentration.

监控：在代谢诊所里日常的随访；监测高血氨和必须氨基酸的并发性缺乏；监测较年长患者的高血氨前驱期症状（例如情绪改变、头痛、嗜眠、恶心、呕吐、拒绝进食、脚踝阵挛）和升高的血浆谷氨酰胺。

Objective To investigate the clinical features, causes of blindness and diagnosis of Vogt Koyanagi Harada syndrome Methods The data of 157 patients with VKH syndrome were reviewed and analyzed Patients were carefully examined with slit lamp, ophthalmoscope, three mirror lens, fundus fluorescein angiography, indocyanine green angiography and HLA typing Results Headache was noted in 73 5% of these patients Simultaneous involvement of both eyes occurred in 80 8% of these patients Chroiditis,papilledema and edema of the retina adjacent to the optic nerve were noted in 100% of these patients in the posterior uveitis stage, whereas recurrent granulomatous anterior uveitis (98 4%),"sunset glow" fundus (95 8%) and Dalen Fuchs nodules (71 2%) were the common ocular findings in the recurrent anterior uveitis stage The common causes of blindness were papillitis, exudative retinal detachment and complicated cataract in the posterior uveitis stage, anterior uveal involvement stage and its recurrent stage Poliosis (36 3%) and alopecia (35 0%) were the most common extraocular findings Early irregular patches of fluorescence, followed by localized hyperfluorescent spots were the typical findings of FFA Dilation of choroidal vessels and leakage of ICG from the choroidal vessels were the common ICGA findings The prevalence of HLA DR4 and HLA DRw53 in patients (54 9% and 71 8% respectively) was significantly higher than that in controls (14 7% and 38 2% respectively) Conclusions VKH syndrome is characterized by chroiditis, papillitis or neuroretinitis in the posterior uveitis stage, followed by a generalized uveitis with a typical recurrent granulomatous anterior uveitis Extraocular findings and relevant examinations including FFA, ICGA and HLA typing are helpful to the diagnosis of VKH syndrome

目的探讨Vogt-Koyanagi-Harada综合征患者的临床特征、盲目原因及诊断等有关问题。方法对在1996年1月至2000年12月间就诊资料完整的157例VKH综合征患者进行回顾性分析，并对裂隙灯、眼底镜、三面镜、荧光素眼底血管造影(fundus fluorescein angiography，FFA)、吲哚青绿血管造影(indocyanine green angiography，ICGA)及人类白细胞抗原分型等检查结果进行分析。结果 VKH综合征最常见的前驱症状为头痛(102例，73.5%)，双眼同时患病118例(80.8%)；后葡萄膜炎期眼部主要表现为脉络膜炎、视乳头及附近视网膜水肿(100.0%)；前葡萄膜炎反复发作期眼部表现为复发性肉芽肿性前葡萄膜炎(128例，98.4%)、晚霞状眼底改变(95.8%)及Dalen-Fuchs结节(71.2%)；后葡萄膜炎期、前葡萄膜受累期及前葡萄膜炎反复发作期导致盲目的主要原因分别为视乳头炎、视网膜脱离及并发性白内障；毛发变白(36.3%)及脱发(35.0%)是最常见的眼外表现；炎症活动期FFA典型表现为斑驳状高荧光，ICGA发现脉络膜血管扩张、通透性增高等改变；VKH综合征患者HLA-DR4及HLA-DRw53的阳性率(54.9%及71.8%)显著高于正常对照组(14.7%及38.2%)。结论 VKH综合征患者在后葡萄膜炎期眼部典型表现为双侧脉络膜炎、视乳头炎或神经视网膜炎，随后出现以反复发作的肉芽肿性前葡萄膜炎为特征的全葡萄膜炎。眼外症状及相关的辅助检查包括FFA、ICGA 及HLA分型等有助于VKH综合征的诊断。

The discordance between inheritance and concurrency is one of the difficulties in the combination of concurrency and object orientation, such as inheritance anomaly.

并发性与面向对象结合的一个语义困难就是继承与并发性之间的不协调性，如继承反常现象。

Petri Nets is a graphics and digital system modeling tool, which provides an efficient way to describe and analyze the complex system that is concurrency, asynchrony, distributivity, or nondeterminacy.

摘 要：Petri网作为一种图形化、数学化的系统建模工具，为描述和分析具有并发性、异步性、分布式、非确定性等特征的复杂系统提供了强有力的手段。

Appendicitis, mesenteric lymphadenitis, and subsequent risk of ulcerative colitis: cohort studies in Sweden and Denmark

阑尾炎，肠系膜淋巴结炎与并发性溃疡性结肠炎的危险：在瑞典和丹麦的队列研究

The designing and analyzing of security protocols remains a challenge for the subtlety of security goals, the uncertainty of penetrator model, the complexity of the running environment, and the high concurrency of protocol sessions.

由于协议安全属性的多样性和微妙性、攻击者模型的不确定性、协议运行环境的复杂性和协议会话的高并发性，安全协议的设计与分析至今仍是一项具有挑战性的工作。

A kind of web models of software developing based on improved Petri Net is introduced.

依据网络的并发性以及任务的流程性，提出一种基于Petri网的软件开发模型。

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。

Second, it models and simulates dynamically the parallel, asynchronous, distributed and concurrent workflow of machinery of cluster with intuitionistic and visual figure, and give the effective controlling strategy of optimal collocating and dynamic attemperation, be dead against the asynchronism and concurrent character of machinery of cluster, which result from that MAS loosens the restricting for centrality, programming and gradation controlling and offers the mechanism of separated controlling, meeting an emergency and parallel disposing.

由于多智能主体技术放松了对集中式、规划、顺序控制的限制，提供了分散控制、应急和并行处理，本文针对基于多智能主体的机群工作流的异步性和并发性采用Petri网技术通过直观、形象的图形，对并行、异步、分布、并发的机群工作流进行了建模分析和动态模拟，并提出了机群的优化配置和动态调度的控制策略。3。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐