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81.
房营光 《广东工业大学学报》1993,(1)
本文利用小参数摄动法研究了非线性弹性岩土中孔室对平面波的散射和动应力集中问题,对于圆孔情况给出了各渐近方程的解析解和应力集中系数的数值结果。 相似文献
82.
LH Cohn 《Canadian Metallurgical Quarterly》1996,5(2):120-121
This paper presents 5 patients with repeated recurrence of osteosarcoma (RROS). The primary focus of 3 patients were in the distal portion of femur, and 2 patients were in the proximal portion of tibia. Three patients, whose chest X ray film were negative, were treated by amputation and chemotherapy. Two patients had isolated metastatic focus 1.5 cm in diameter in lung, were treated by amputation after 1 week of chemotherapy and then treated by lobectomy after 2 weeks of chemotherapy. After operation, the chemotherapy was carried out for 3 courses of treatment. The roentgenogram of chest and affected limb were taken once every two months. There were metastatic focuses found in the lung of 1 patient and in the distal portion of femur of 2 patients. One patient was operated on for 4 times. Up to now, 3 patients have been living for 5 years and 2 patients for 6 years after operation. 相似文献
83.
The vast majority of recombinant polytropic murine leukemia viruses (MuLVs) generated in mice after infection by ecotropic MuLVs can be classified into two major antigenic groups based on their reactivities to two monoclonal antibodies (MAbs) termed Hy 7 and 516. These groups very likely correspond to viruses formed by recombination of the ecotropic MuLV with two distinct sets of polytropic env genes present in the genomes of inbred mouse strains. We have found that nearly all polytropic MuLVs identified in mice infected with a substrain of Friend MuLV (F-MuLV57) are reactive with Hy 7, whereas mice infected with Moloney MuLV (Mo-MuLV) generate major populations of both Hy 7- and 516-reactive polytropic MuLVs. We examined polytropic MuLVs generated in NFS/N mice after inoculation with Mo-MuLV-F-MuLV57 chimeras to determine which regions of the viral genome influence this difference between the two ecotropic MuLVs. These studies identified a region of the MuLV genome which encodes the nucleocapsid protein and a portion of the viral protease as the only region that influenced the difference in polytropic-MuLV generation by Mo-MuLV and F-MuLV57. 相似文献
84.
Blood flow is a critical parameter for obtaining satisfactory temperature distributions during clinical hyperthermia. This study examines the changes in blood flow distribution in normal porcine skeletal muscle before, during and after a period of regional microwave hyperthermia. The baseline blood flow distribution during general anaesthesia and after the insertion of the thermal probes was established independently in order to isolate the changes due to hyperthermia. General anaesthesia alone and thermocouple insertion during anesthesia had no significant effect on the muscle blood flow distribution. Regional microwave heating generated a non-uniform blood flow distribution which was a function of the tissue temperature distribution. Blood flow was greater in those tissues samples in which higher temperatures were recorded and less in those sampled further from the applicators peak SAR (Specific Absorption Rate). The increase in blood flow appears to be primarily a local phenomenon. Although muscle blood flow may be considered to be uniform prior to heating, this does not hold during hyperthermia treatment. Therefore, the non-uniform nature of the blood distribution during heating should be incorporated into any practical bioheat transfer model. 相似文献
85.
重馏分油加氢脱氮反应动力学模型的研究 总被引:10,自引:1,他引:9
简要地介绍了一些典型的模型氮化物的HDN反应规律。根据胜利VGO在3722B催化剂上的大量HDN实验数据,提出了如下的HDN基本反应动力学方程:dCNdt=-k1+K*CNCNPH2为了扩大上式的应用范围,详细分析了各种因素(如原料油种类和馏程及H2S等)对HDN的影响,并开发了相应的经验关联式,从而得到了一个较完整的馏分油HDN反应动力学模型。验证实验表明,该模型是成功的。 相似文献
86.
87.
冷成型模具低温锌系磷化 总被引:4,自引:1,他引:3
研制出适用于冷成型模具高硬度表面的低温锌系磷化工艺。其中磷化液含Zn(H2 PO4 ) 2 ·2H2 O 6 0g/L ,Zn(NO3) 2 ·6H2 O 90g/L ,NaNO2 1.5g/L ,稀土促进剂 0~ 1.0g/L ,游离酸度 4~ 6点 ,总酸度 70~ 75点。该磷化液在 4 0℃下 ,处理 30~ 4 0min后可获得厚约 10 μm的磷化膜。性能测试表明 ,其减摩、润滑性能良好 ,摩擦系数约降 0 .1,与未处理试样相比磨损量下降 96 % ,附着力 1级。 相似文献
88.
介绍一种用于生产聚氨酯泡沫夹克管保温层的新材料聚酯聚醚,报道选用这种材料生产泡沫夹克管的工艺及工要工艺参数和产品达到的技术指标及现场应用情况。 相似文献
89.
该文分析某微型起爆器引起的一起误爆事故,指出该起爆器设计上的缺陷及其对作业安全的威胁,提出防患建议。 相似文献
90.
In this paper, we study the minimum cross-entropy optimization problem subject to a general class of convex constraints. Using a simple geometric inequality and the conjugate inequality we demonstrate how to directly construct a "partial" geometric dual program which allows us to apply the dual perturbation method to derive the strong duality theorem and a dual-to-primal conversion formula. This approach generalizes the previous results of linearly, quadratically, and entropically constrained cross-entropy optimization problems and provides a platform for using general purpose optimizers to generate ε-optimal solution pair to the problem. 相似文献