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61.
通过对循环陪集的研究及利用分圆多项式的一个性质,得到了设计距离为7的q元BCH码的周期分布计算公式:码的周期分布为q的幂,当码的周期不等于某些特殊值时,幂为码长与周期的最大公因数.当码的周期为特殊值时,幂为n/b-m[6/b],这里n是码的长度,b是由n和码的周期决定的2到6之间的整数,m是q模n的指数.由此计算公式和Mobius反转公式给出了无内周期码字个数的计数结果. 相似文献
62.
Peng Xianghe Fan Jinghong Ma Mingtu 《保鲜与加工》1992,(3):73-79
In order to describe nonproportional cyclic plasticity of polycrystalline metallic materials, the hardening function is separated into three factors, in which,f1 is related to the hardening parameter determined by plastic strain range, and f2 and f3 are related to the change of plastic deformation path characterized by a measure of nonproportionality. The main features of this work are: (a)cyclic hardening is described by f1, and additional hardening is separated into instantaneous and hereditary one which is described by f2 and f3 respectively; (b)a general form of the evolution of f1(i= 1,2, 3) is proposed; (c)parameters a1 and a3 are introduced to keep the memory to the largest cyclic hardening and additional hardening respectively; (d)various hardening mechanisms are embedded into a thermomechanically consistent constitutive equation. The capability of the developed model is verified with the analysis of biaxially nonproportional experiments by Benallal et al, Tanaka et al and Ohashi et al. 相似文献
63.
Briquette specimens made of outburst coal are taken as research objects, and both mechanical properties evolution under cyclic loading and law of hysteretic curve evolution under different loading level are studied. The results show that hysteretic loop is composed of load-unload curve when briquette specimens are studied under cyclic loading, and secondary hysteretic loop is produced from the second cycle. The area composed by hysteretic curve becomes smaller with the addition of cycle numbers. The relation between deformation response and loading level is very close. Load-unload curve of hysteretic curve is expressed by conic, and the change law of fitting parameters of conic is very regular with the addition of cycle numbers, but the regularity of the law with loading level isn’t very obvious; the minis sign of fitting parameters of conic is opposite. 相似文献
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65.
OBJECTIVE: To evaluate the mechanical properties of the 18 and 36 kg Securos Cranial Cruciate Ligament Repair System. STUDY DESIGN: In vitro mechanical evaluation. SAMPLE POPULATION: Loop constructs of 18, 27, and 36 kilogram test (kgt) nylon leader line (NLL) secured with Securos crimp-clamps (SCC, n=40 per NLL test weight) or by a clamped square knot (CSK; n=40/NLL test weight). METHODS: The 36 kg SCC were used for the 27 and 36 kgt NLL, and 18 kg SCC were used for the 18 kgt NLL. Loop constructs were mounted on a material testing machine, and distracted at 500 mm/min for static tests, and for cyclic tests at 500 mm/min to a distraction limit of 6 mm (18 kgt) or 7.5 mm (27 and 36 kgt) for 49 cycles, until failure. Constructs were tested at 20 degrees C except for 1 group of 27 kgt CSK loops tested at 40 degrees C. Load at failure, elongation, and stiffness was recorded and compared between groups under static or cyclic testing conditions. RESULTS: All 27 and 36 kgt loops failed by disruption of NLL contained within the knot or crimp-clamp, whereas 18 kgt SCC loops failed by the NLL pulling through the crimp-clamp. The 18 kg SCC loops had considerable variability in ultimate load and elongation (coefficient of variation 29.6% and 18.3%, respectively). There was no significant difference in elongation between 27.3 kgt CSK loops tested at 20 degrees C and 40 degrees C. Generally, in both static and cyclic testing, SCC constructs formed with 27.3 or 36.4 kgt NLL performed as well or better than CSK constructs, resulting in loops that were strong, underwent minimal elongation, and had high stiffness. CONCLUSION: The results support use of the 36 kg Securos system but not the 18 kg Securos system (with the clamp and crimping device used). The significantly lower load required for failure, slippage through the clamp, and substantial variability suggested that the crimp tube diameter or the crimping device tested may be inappropriate for use with 18 kgt NLL. CLINICAL RELEVANCE: Surgeons should be aware that crimp-clamp design is important in controlling suture slippage or breakage within the clamp, and that novel systems should undergo mechanical testing with the size suture material they are intended to secure before clinical use. 相似文献
66.
磷酸二酯酶基因在小型猪骨骼肌组织的表达 总被引:4,自引:0,他引:4
提取中国实验用小型猪骨骼肌组织总RNA,应用反转录聚合酶链反应测定磷酸二酯酶(PDE)同工酶在骨骼肌组织中的表达分布。结果可见PDE1A、1C、2A、3A、3B、4A、4B、4C、4D、5A、7A、7B、8A、8B、9A和11A共16种PDE同工酶mRNA在中国实验用小型猪骨骼肌组织中表达,其中PDE1A、1C、2A、3A、4B、4C、8A和8B共8种在人和其他动物骨骼肌组织中的表达分布未见报道,PDE1B和10A3种同工酶未见表达。16种PDE同工酶mRNA在骨骼肌组织中的表达,从电泳条带上可以看到各种PDE表达量存在着差异,但需要进一步做定量分析加以评定。 相似文献
67.
AIM:To observe the changes of AC activity and content of cAMP at different time point in hypothalamus of rats with fever and hypothermia. METHODS:Radioisotope method was used to measure the enzymatic activity of AC and the content of cAMP. RESULTS:(1)The fresh yeast caused fever after making model 4 h(P<0.01). AC activity reached a peak value 3 h after making model (P<0.05), subsequently AC activity rapidly decreased and increased again over normal level (P<0.01);The change of cAMP content was positively related to the body temperature. (2) Aminopyrine induced rat hypothermia state after making model 15 min (P<0.05). AC activity rapidly weakened and cAMP content rapidly descended to the lowest value at making model 45 min, subsequently AC activity and cAMP content in hypothalamus gradually increased again to normal range. CONCLUSION:(1)In fever model, it might be an important cause of febrile response that AC induced increase in intracellular cAMP content; (2) In hypothermia model, the significant decrease of AC activity and cAMP content indicate that cAMP might play a role in keeping hypothermia. 相似文献
68.
治理林业“两危”必须遵循林业资金运动规律,建立适合林业特点的资金循环体制和营林会计标准体系;建立林业专业银行;理顺财政体制;提高固定资产折旧率,改革企业折旧制度。 相似文献
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70.
Annita Seok Kian Yong Wai Yee Mok Mohammad Lal Mohamad Tamrin Rossita Shapawi Yang‐Su Kim 《Aquaculture Research》2020,51(6):2252-2260
This trial was conducted to evaluate the effects of nucleotides on growth of whiteleg shrimp, Litopenaeus vannamei, and the survival and metabolic responses to ammonia stress test. Experimental diets were as follows: low fish meal diet (LFMD), and four LFMD test diets, each supplemented with 0.1% guanosine monophosphate (GMP), 0.1% inosine monophosphate (IMP), 0.1% mixture of GMP and IMP and 0.1% mixture of GMP, IMP, uridine monophosphate (UMP) and cytidine monophosphate (CMP). The shrimp specimens (initial body weight: 0.99 ± 0.01 g) were randomly allocated into five groups and fed four times daily for 8‐weeks. After the trial, final body weight was recorded and haemolymph was withdrawn for haematological analysis. The shrimp was then challenged with 70 mg/L ammonia (LC50) for 10 days. Survival and haemolymph of the shrimp were taken after exposure to ammonia. The highest growth performance was observed in the shrimp fed diet supplemented with GMP (p < .05), while survival was not influenced by the test diets in the feeding trial. In the ammonia challenge test, the highest survival was observed in the shrimp fed GMP supplemented diet compared to others. The plasma protein, glucose and cholesterol levels increased in all the treatments while triglycerides level decreased post challenge. Cortisol level recovered at day 10th after the challenge. Shrimps fed with nucleotides diets showed higher protein and glucose level compared to control groups post challenge. In general, nucleotides supplemented in the diet enhanced growth, improved stress resistance while modulating the haemolymph metabolites in L. vannamei under ammonia stress. 相似文献