多分支井完井技术发展综述

多分支井是21世纪钻井领域的新兴技术,多分支井的技术难度很大,尤其是多分支井完井,完井成功与否直接关系到多分支井的应用效果。本文围绕多分支井完井过程中的关键技术和难点,简要介绍了多分支井的主要类型和适用储层条件,重点论述多分支井完井技术的发展现状和国内外先进的工艺和井下装备,指出优化空间构型、保证多分支井的连接性、隔离性、可进性是完井成功的关键。

特高压输变电设备应用于工程的分析研究

文章针对特高压工程所需的主要输变电设备,对其技术要求和技术参数、生产条件和生产能力进行了调研,并对其工程应用的可行性进行了分析研究。认为国内外研制生产的特高压输变电设备的技术水平和供货能力可满足我国特高压榆变电工程建设的需要,而且大部分设备的生产制造可实现国产化。

Hybrid particle swarm optimization with differential evolution and chaotic local search to solve reliability-redundancy allocation problems

In order to solve reliability-redundancy allocation problems more effectively, a new hybrid algorithm named CDEPSO is proposed in this work, which combines particle swarm optimization （PSO） with differential evolution （DE） and a new chaotic local search. In the CDEPSO algorithm, DE provides its best solution to PSO if the best solution obtained by DE is better than that by PSO, while the best solution in the PSO is performed by chaotic local search. To investigate the performance of CDEPSO, four typical reliability-redundancy allocation problems were solved and the results indicate that the convergence speed and robustness of CDEPSO is better than those of PSO and CPSO （a hybrid algorithm which only combines PSO with chaotic local search）. And, compared with the other six improved meta-heuristics, CDEPSO also exhibits more robust performance. In addition, a new performance was proposed to more fairly compare CDEPSO with the same six improved recta-heuristics, and CDEPSO algorithm is the best in solving these problems.

Finite element and experimental analyses of cylindrical hole flanging in incremental forming

The influence of the size of pre-cut hole of blank on the formability of cylindrical hole flanging in single point incremental forming（SPIF） was studied. The flange is produced in four stages starting from 45° to 90° and employing aluminum as the test material. It is shown that the hole size has significant effects on the stress/strain distribution on the cylindrical flange. The magnitude of hoop strains increases and the flange thickness increases as the hole size increases. Likewise, the von Mises stress reduces with the increasing of hole size. Further, there is a threshold value of hole size（i.e., 80 mm） below which severe stresses occur, which lead to sheet fracturing thus failing the successful forming of cylindrical flange. Moreover, the formability reduces as the hole size is increased above the threshold size. Finally, it is concluded that 80 mm is the threshold size of hole for maximizing the formability of aluminum sheet in incremental hole flanging.

AN EXAMPLE OF THREE-DIMENSIONALPROGRESSIVE SLOPE FAILURE

In fact, the failure of any slope takes place progressively, but the progressive failure mechanism has not been emphasized sufficently in the present stability analysis of slopes. This paper provides an example of the progressive slope failure which took place at Pingzhuang west surface coal mine and was numbered the 26th slide. The three-dimensional reliability model for progressive slope failure is used to study the failure process of the 26th slide. The outcomes indicate that the progressive failure is indeed the failure mechanism of the slide.

Transition‐metal‐free three‐component acetalation‐pyridylation of alkenes via photoredox catalysis

A general transition‐metal‐free photoinduced acetalation‐pyridylation of alkenes using diethoxyacetic acid and cyanopyridine was developed under mild conditions.By employing 4CzIPN as the photocatalyst and Cs_(2)CO_(3) as the base,a diverse range of styrene derivatives and cyanopyridines worked well to give the desired products.The versatility of this method is highlighted by its application in the construction of various functional groups and the late‐stage modification of drugs.Importantly,some of the synthesized compounds showed good in vitro antitumor activity,indicating that this protocol is of significance and potential for antitumor drug development.

Methodology for estimating probability of dynamical system's failure for concrete gravity dam

Methodology for the reliability analysis of hydraulic gravity dam is the key technology in current hydropower construction.Reliability analysis for the dynamical dam safety should be divided into two phases:failure mode identification and the calculation of the failure probability.Both of them are studied based on the mathematical statistics and structure reliability theory considering two kinds of uncertainty characters(earthquake variability and material randomness).Firstly,failure mode identification method is established based on the dynamical limit state system and verified through example of Koyna Dam so that the statistical law of progressive failure process in dam body are revealed; Secondly,for the calculation of the failure probability,mathematical model and formula are established according to the characteristics of gravity dam,which include three levels,that is element failure,path failure and system failure.A case study is presented to show the practical application of theoretical method and results of these methods.

Research of CAN Bus in the Coal Mine Field Data Transmission based on Reliability

Under the current situation, China＇ s rapid economic development, various new science, emerge in an endless stream of new technology, under the environment of coal mine industry, seize the opportunity, by virtue of its original advantages, coupled with technology introduction and innovation consciousness of the play, ushered in a new period of development, into the modern coal mining era. CAN bus technology is a new technology which has the typical data transmission in coal mining, the introduction of a certain degree of CAN bus technology, not only improve the efficiency of data transmission, at the same time, in terms of reliability and greatly enhance. In this paper, to a certain extent on the introduction of the CAN bus technology, and on this basis, based on the CAN bus in the coal mine field data transmission reliability research and analysis

Study on the Evaluation of Urbanization Quality and Promotion Measures

Development of the city itself is a major reflection of the quality of urbanization; urbanization promote efficiency is the basic premise of urbanization; fair and coordinated urban-rural relation is the guarantee, and the goal of urbanization. Quality of urbanization contains its process and result, as well as efficiency and fairness. It also covers quality of not only urban and rural area, but also coordinated and interacted relations of them. Follow principles of being typical, systematic and operational, we can build quality evaluation system from the aspect of its develop level, efficiency and rural-and-urban coordination. Finally, we can choose proper measures to make reasonable assessment of urbanization in China, and improve the quality of urbanization by learning from others.

Phenotypic plasticity can explain evolution of sympatric polymorphism in the hairy snail Trochulus hispidus （Linnaeus, 1758）

Morphological variation of snails from the genus Trochulus is so huge that their taxonomy is unclear. The greatest variability concerns forms hispidus and sericeus/plebeius, which are often considered as separate species. To evidence the species barriers, we carried out crossbreeding ex- periments between these two sympatric morphs. Moreover, we compared the shell morphology of laboratory-bred offspring with their wild parents to test if the variation can be explained by the phenotypic plasticity model. We found that the two Trochulus morphs show no reproductive bar- riers. The fecundity rates, the mean clutch size, and F~ viability observed for all crosses were not significantly different. In hybrid crosses （in F2 generation）, we also recorded reproduction compati- bility, similar fecundity, and hatching success as in their parents. Accordingly, phylogenetic ana- lyses revealed the significant grouping of sequences from these different morphs and supported no constrains in reproduction between them. Comparison of shell morphology between wild and laboratory samples showed that various characters appeared highly plastic. The average shell shape of the hispidus morph changed significantly from flat with wide umbilicus to elevated with narrower umbilicus such as in the sericeus/plebeius morph. All these findings indicate that the examined morphs do not represent separate biological species and the evolutionary process is not advanced enough to separate their genetic pool. Therefore, phenotypic plasticity has played a sig- nificant role in the evolution of Trochulus shell polymorphism. The two morphs can evolve inde- pendently in separate phylogenetic lineages under the influence of local environmental conditions.

Availability Equivalence Analysis of a Repairable Multi-State Series-Parallel System

The availability equivalence of different designs for a repairable multi-state series-parallel system(RMSPS) is discussed in this paper.The system components are assumed to be independent,and their failure and repair rates to be constant.The system availability is defined as the ability of the system to satisfy consumer demand.Factor improvement method and standby redundancy method are used to improve the system design.To evaluate availability of the both original and improved systems,a fast technique,based on universal generating function,is adopted.The availability equivalence factor is introduced to compare different system designs.Two types of availability equivalence factors of the system are derived.A numerical example is provided to illustrate how to utilize the obtained results.

Exact Controllability and Asymptotic Analysis for Shallow Shells

The authors consider the exact controllability of the vibrations of a thin shallow shell, of thickness 2ε with controls imposed on the lateral surface and at the top and bottom of the shell. Apart from proving the existence of exact controls, it is shown that the solutions of the three dimensional exact controllability problems converge, as the thickhess of the shell goes to zero, to the solution of an exact controllability problem in two dimensions.

Bounds of Efficiency at Maximum Power for Normal-, Sub- and Super-Dissipative Carnot-Like Heat Engines

The Carnot-like heat engines are classified into three types （normal-, sub- and, super-dissipative） accord- ing to relations between the minimum irreversible entropy production in the ＂isothermal＂ processes and the time for completing those processes. The efficiencies at maximum power of normal-, sub- and super-dissipative Carnot-like heat engines are proved to be bounded between ηc/2 and ηc/ （2 - ηc ）, ηc /2 and ηc, 0 and ηc/ （2 - ηc ）, respectively. These bounds are also shared by linear, sub- and super-linear irreversible Carnot-like engines [Tu and Wang, Europhys. Left. 98 （2012） 40001] although the dissipative engines and the irreversible ones are inequivalent to each other.

Impulse Observability and Impulse Controllability of Regular Degenerate Evolution Systems

Impulse observability and impulse controllability of regular degenerate evolution systems are discussed by using functional analysis and operator theory in Banach space. Necessary and sufficient conditions for the impulse observability and impulse controllability of the system are obtained. This research is theoretically important for studying the design of the degenerate evolution system.

Plantinga＇s Evolutionary Argument against Naturalism Revisited

Alvin Plantinga＇s Evolutionary Argument against Naturalism （hereafter ＂EAAN＂） is an argument intended to prove that atheism is not highly probably true in the Darwinian framework. Many critics believe that this argument Cannot work. I am one of them; but I have a different perspective. In my view, although EAAN was originally elaborated for defending theism, the failure of EAAN itself will not consequently undermine theism （as a religious position）, but will definitely undermine reliabilism （as an epistemological position）. My points include： （1） in Plantinga＇s epistemological reliabilist narrative, it is quite hard to clarify the meaning of the term ＂reliability＂ （as a key word of his whole narrative）, and it is the ambiguity of this term that makes some steps in Plantinga＇s argument more confusing than it ought to be; （2） conversely, if he wiped out this terminological ambiguity, the whole EAANnarrative based on ＂reliability＂ would have to be given up, and this cost may be too high for any EAANadherent to pay.

China' s Fundamental Research in Energy Utilizations and Environment

The progress in the science of energy utilizations will act crucial effect on the developments of energy science and technology, which will then promote social and economical developments and fulfill requirements for the national strategic objectives. For the sake of sustainable development, a harmonious blend of energy utilizations and environment considerations will become one of the vital topics in the future research area of energy science. It is suggested that clean and high-efficiency utilization of traditional or fossil energy resources, fundamental investigations on the energy and environment theory, renewable energy utilizations, and the development of nuclear energy are selected as priority research areas during the period of the Tenth Five-year Plan of China, according to the development trend of the world energy science and the research background of Chinese energy science, It is expected to promote the interdisciplinary investigations in the science of energy utilizations and provide scientific and technological supports for the development of related advanced high technologies,