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991.
This paper presents a fault-tolerant multicast scheme for hypercube multicomputers. The method is based on the routing capability information that is stored in each node. In comparison with the previous schemes, this information is able to capture the fault status more precisely. Two multicast algorithms are presented in the paper. These algorithms multicast messages in an attempt to minimize derouting so that time optimality can be achieved. Moreover, the routing capability information is used to guide derouting in an efficient manner when such needs arise. The amount of traffic incurred is addressed in the paper. The hardware design for the algorithms is also discussed. Extensive simulation has been conducted to evaluate the performance of the scheme. The results show the effectiveness of the proposed algorithms  相似文献   
992.
高韧性—70℃低温钢WHD4(09MnNiDR)的性能及应用   总被引:1,自引:0,他引:1  
陈晓  郭爱民 《宽厚板》1998,4(1):21-25
本文研究了武钢研制生产的高韧性—70℃低温钢WHD4(09MnNiDR)钢板的全面力学性能、焊接性能.介绍该钢在大型石油、化工设备中的应用实例.结果表明该钢具有优异的低温韧性和优良的焊接性能,是制造低温压力容器等设备的理想用材.  相似文献   
993.
OBJECTIVE: To examine the effect of cataract extraction (CE) after trabeculectomy on intraocular pressure (IOP) control. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: A total of 115 consecutive patients who underwent extracapsular CE (N = 58) or phacoemulsification (N = 57) with intraocular lens (IOL) placement after trabeculectomy were studied. INTERVENTION: Cataract extraction with IOL after trabeculectomy was performed. MAIN OUTCOME MEASURES: Preoperative, intraoperative, and postoperative factors were evaluated for association with loss of IOP control requiring additional medications, bleb needling, or further glaucoma surgery, using Kaplan-Meier survival analysis and Cox multivariate proportional hazards survival regression. RESULTS: After mean postoperative follow-up of 21.1 +/- 14.3 months, additional glaucoma medication or needling of the filtering bleb to maintain IOP control was required in 35 eyes (30.4%) and was significantly associated with intraoperative iris manipulation and early postoperative peak IOP greater than 25 mmHg. Additional glaucoma surgery was eventually required in 11 eyes (9.6%) and was significantly associated with age of 50 years or younger, preoperative IOP greater than 10 mmHg, and early postoperative peak IOP greater than 25 mmHg. The cumulative proportion of patients who did not require reoperation for glaucoma was 93% and 90% at 1 and 2 years, respectively. The mean IOP at last visit had increased 1.6 mmHg above the pre-CE level and did not vary significantly after the first postoperative month. The median interval from CE to the addition of glaucoma medication or bleb needling was 1.6 months (within 3 months in 20 of 33 eyes) and that from nonsurgical intervention to further glaucoma surgery was 3.6 months (before the 7th postoperative month in 6 of 11 eyes). Of 19 eyes with hypotony (IOP < or = 6 mmHg) before CE, 11 eyes remained hypotonous after CE despite an increase in the mean IOP from 4.6 to 7.5 mmHg. CONCLUSIONS: When CE is performed after trabeculectomy, age of 50 years or younger, preoperative IOP greater than 10 mmHg, intraoperative iris manipulation, and early postoperative IOP greater than 25 mmHg are associated with worsened postoperative IOP control. Most bleb failures occur soon after CE. Resolution of pre-existing hypotony after CE is unpredictable.  相似文献   
994.
本文介绍一种由机械装置,高精度圆光栅编码器,光栅位移传感器,微型计算机,接口控制电路等组成的多测头凸轮轴测量系统,该系统安装调整方便,定位准确,测量精度高,操作简单,工作可靠,能快速实现对凸轮轴的自动测量。  相似文献   
995.
996.
本文研究了在咪唑存在下 meso—四—(4—甲氧基—3—磺酸苯基)卟啉(TMPPS_4)与锌显色反应的最佳条件,建立了测定锌的新方法,灵敏度高,锌量在0—1.2μg/10mL 范围内遵守比耳定律,用于测定粮食中的锌时结果满意  相似文献   
997.
Relationship between mutagenic activity of drinking water and incidence of liver cancer was studied in Fusui County with micronucleus technique in the root tips of vicia faba. Results showed there existed substance that caused chromosome aberration in the drinking pond water of Fusui County. Micronucleus effects on the root tips of vicia faba induced by the substance in different kinds of drinking water coincided with the incidence of liver cancer (r = 0.86, P < 0.05). It suggested the existence of these chemical mutants in the water may be one of the important factors that caused high incidence of liver cancer. It provided experimental evidence for the etiological theory of liver cancer caused by the pollution of drinking water.  相似文献   
998.
Before use of cardiovascular surgical techniques and procedures in humans, many experiments, e.g., hypothermic circulatory arrest and cardiopulmonary bypass using the heart-lung machine, have been performed in the dog. As a consequence experimental canine cardiovascular surgery is highly developed. This has not resulted in the routine performance of open heart surgery in veterinary medicine, probably because of the high costs. Cardiovascular surgery in the dog is generally limited to interventions not depending on hypothermic circulatory arrest or cardiopulmonary bypass. The clinical cardiovascular surgery in dogs can be divided into routine and more specialized interventions. The first category includes correction of peritoneopericardial diaphragmatic hernia, pericardial fenestration in dogs with pericardial effusion, treatment of persistent right aortic arch, and patent ductus closure. The specialized interventions include dilation of pulmonic and aortic stenoses and pacemaker implantation. The diagnosis and surgical treatment of such diseases is described. New developments in cardiovascular surgical treatment that can be expected include catheter techniques for occlusion of shunts and dilations using balloons, because the financial costs of these procedures are not prohibitive.  相似文献   
999.
We established an in vitro model of the phagocytosis of Mycobacterium tuberculosis by human peripheral blood monocytes to evaluate the subsequent inhibition of intracellular replication of the organism. Highly purified T cells (94% CD3(+)/CD16(-)) or natural killer (NK) cells (96% CD16(+)/CD3(-)) isolated by Percoll discontinuous density gradient of peripheral blood mononuclear cells were incubated with M. tuberculosis-infected monocyte monolayers. Monocytes were lysed immediately and at 4, 7, and 10 d after infection for quantification of intracellular replication, which was assessed by quantitative plating techniques as colony-forming units (CFU). Whereas control monocytes permitted intracellular replication, T cells activated monocytes to kill 77% (p < 0.01) of intracellular M. tuberculosis compared with control monocytes by 10 d after infection. NK cells activated monocytes to kill 84% (p < 0.01) of M. tuberculosis in comparison with control monocytes. Lymphokine (IL-2)-activated-killer (LAK) cells were capable of activating monocytes to kill 97% (p < 0.01) of the intracellular organisms compared with control monocytes. In purified protein derivative (PPD)-positive donors, PPD-specific-CD4(+) lymphocytes stimulated monocytes to kill intracellular M. tuberculosis in a Class II major histocompatibility complex-restricted manner. In contrast, in PPD-negative donors, CD4(-) lymphocytes activated monocytes in a genetically unrestricted manner. Both T cell supernatant and NK cell supernatant generated from cocultivation with M. tuberculosis-infected monocytes also activated monocytes to augment mycobactericidal function. In conclusion, T cells, NK cells, LAK cells, and their supernatants activated mycobactericidal function of monocytes, although these pathways of activation differed in terms of antigenic specificity and genetic restriction.  相似文献   
1000.
陶瓷模用α半水石膏的研究   总被引:1,自引:0,他引:1  
理论上提出了影响陶瓷模用半水石膏常,高温性能的主要因素,即结晶形态.标准稠水度,初凝时间,抗折强度,进行了实验验证,确定了相应的制作技术,获得了性能优良的陶瓷模用α半水石膏。  相似文献   
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