It has been testified in many experiments that the fatigue fracture process is affected by the initiation, propagation, conjunction and interference process of short cracks, and sometimes the short-crack phase occupies more than eight percent of the total life.

The medium-temperature hot isostatic pressure (HIP) treatment can increase the total life to 2.4 times as that without the HTP, HIP treatment results in the increasing of both surface hardness and the residual compersive stress increases, which delay micro-cracks initiating and growing.

Based on the analysis of present aircraft structural life index and its determination,the concept of Aircraft Structural Life Envelope(ASLE) is presented,as well as the approach to the establishment of ASLE. The schematic diagram of ASLE is given based on the total life and the time interval between overhauls.

In the end, the article gives the conclusion as following: the main landing gear strut cylinder of type B aircraft first repairing period is 4000 landing and take-offs, examine interval is 1500 landing and take-offs and the total life is 6000 landing and take-offs.

It has been testified in many experiments that the fatigue fracture process is affected by the initiation, propagation, conjunction and interference process of short cracks, and sometimes the short-crack phase occupies more than eight percent of the total life.

The medium-temperature hot isostatic pressure (HIP) treatment can increase the total life to 2.4 times as that without the HTP, HIP treatment results in the increasing of both surface hardness and the residual compersive stress increases, which delay micro-cracks initiating and growing.

Based on the analysis of present aircraft structural life index and its determination,the concept of Aircraft Structural Life Envelope(ASLE) is presented,as well as the approach to the establishment of ASLE. The schematic diagram of ASLE is given based on the total life and the time interval between overhauls.

In the end, the article gives the conclusion as following: the main landing gear strut cylinder of type B aircraft first repairing period is 4000 landing and take-offs, examine interval is 1500 landing and take-offs and the total life is 6000 landing and take-offs.

The results of the univariate analysis showed that disease duration, number of STDs diagnoses, amateur sports and amusement, character, satisfaction degree with total life and level of STDs knowledge were the influencing factors of anxiety status, while disease duration, occupation, number of STDs diagnoses, amateur sports and amusement, character, degree of life regulation, satisfaction degree with total life, satisfaction degree with economics and satisfaction degree with family unity were the influencing factors of depression status respectively.

The results of multiple linear regression analysis showed that the major influencing factors of anxiety status were number of STDs diagnoses, disease duration, satisfaction degree with total life, amateur sports and amusement, while the major influencing factors of depression status were number of STDs diagnoses, satisfaction degree with total life, disease duration, and degree of life regulation respectively.

Recent emphasis on the total life approach in the design of turbine discs necessitates better understanding of the interactive fatigue crack propagation and low-cycle fatigue behavior at high temperatures.

Under all conditions, Stage I fatigue crack growth occupied 50 to 80 pct of the total life.

It is shown that the total life of a parallel system with independent and identical (i.i.d.) exponential components is smaller in the right spread order than an exponential life with the same mean as the system.

The main factor responsible for fracture is found to be the coalescence of dispersed cracks, especially at the final stage, which accounts for about 30% of the total life.

This period accounts for about 89.5% of the total life of the specimen for steel 45 and about 81.6% for steel 12KhN3A.

The development of a complex electronic system may be divided into several stages. Let λ1 be the failure rate of the system in the i-th stage. In many situations, the reliability of the system increases stage by stage, i. e. λ1>λ2>…> λm. we choose the prior distributions of λ's to be such that the Bayes confidence interval of A followed from the posterior density function is equivalent to the result of the classical statistics. Let f1 (τ1|λ1) be the conditional probability function, where τ1 is the total...

The development of a complex electronic system may be divided into several stages. Let λ1 be the failure rate of the system in the i-th stage. In many situations, the reliability of the system increases stage by stage, i. e. λ1>λ2>…> λm. we choose the prior distributions of λ's to be such that the Bayes confidence interval of A followed from the posterior density function is equivalent to the result of the classical statistics. Let f1 (τ1|λ1) be the conditional probability function, where τ1 is the total life time in the i-th stage, then the posterior density function isthe marginal posterior density function of Am iswhere is, the space formed by is the domain of λj, and is the subspace of 0. The r-confidence interval of λm is(o, λm…), whereIn classical statistics, we can only use rm to calculate the r-confidence interval for Am, because the statistics r, (i = 1,2, …, m-1) belong to another population. But now we can use the formulas derived in this paper to calculate the r-confidence interval for Am not only by using rm, but also by using τ1, τ2, …, rm-1. The size of the sample of the m-th stage using this method will be smaller than the sample of the m-th stage using the classical statistics.

The embryonic and postembryonic development of the Cladoceran Moina affinis at 30℃ and 20℃ has been studied in the laboratory.The duration of embryonic and postembryonic development is inversely proportional to the temperature. Embryonic development lasts 18—20 hrs at 30℃ and 42—48 hrs at 20℃. The total life span is 15.7 days at 30℃ and 33.3 days at 20℃.There are only two pre-adult instars followed by thirteen adult instars at 30℃ whereas at 20℃ there are three pre-adult instars followed by twelve adult...

The embryonic and postembryonic development of the Cladoceran Moina affinis at 30℃ and 20℃ has been studied in the laboratory.The duration of embryonic and postembryonic development is inversely proportional to the temperature. Embryonic development lasts 18—20 hrs at 30℃ and 42—48 hrs at 20℃. The total life span is 15.7 days at 30℃ and 33.3 days at 20℃.There are only two pre-adult instars followed by thirteen adult instars at 30℃ whereas at 20℃ there are three pre-adult instars followed by twelve adult instars.The rate of egg production on a cumulative basis varies with temperature. It is found that at 30℃ Moina affinis has a higher rate of egg production (a=1.1811) than at 20℃ (a=0.9643)The data on the life cycle of Moina affinis has been compared with other five cladoceran species.

This article gives several new results of the characters of stationary non-after-effect streams under rather weak assumptions on distribution functions. The results in theorem 1 and 2 are concerned with total life. In theorem 3 and 4, the stationary non-after-effect streams are defined by using relevant conditional distribution, which is quite heuristic, and moreover, the distributions concerned are very similar to uniform distribution and can thus be easily tested. All of the result can be used in...

This article gives several new results of the characters of stationary non-after-effect streams under rather weak assumptions on distribution functions. The results in theorem 1 and 2 are concerned with total life. In theorem 3 and 4, the stationary non-after-effect streams are defined by using relevant conditional distribution, which is quite heuristic, and moreover, the distributions concerned are very similar to uniform distribution and can thus be easily tested. All of the result can be used in Poisson stream parallelly.