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1.
Part of the 16S rRNA gene is amplified with PCR and sequenced for 5 populations of common Chinese cuttlefish Sepiella maindroni:three from the South China Sea,one from East China Sea and one from Japan.The result shows that a total of 5 nucleotide positions are found to have gaps or insertions of base pairs among these individuals,and 13 positions are examined to be variable in all the sequences,which range from 494 to 509 base pairs.All of the individuals are grouped into 7 haplotypes (h1-h7).No marked genetic difference is osberved among those populations.All of the individuals from Nagasaki belong to h1 and the h3 haplotype is found only in the coastal waters of China.A→←G transition in Nucleotide 255 is suggested to be taken as a kind of genetic marker to identify the populations distributed in East-South China Sea and the Nagasaki waters of Japan.  相似文献   

2.
The paper analyzes the principle of positioning of waves by notching at the bottom of the waves hi garment draping from the dynamic perspective, and search for the best molding effect under 45?to fabric grain as the model baseline. Wavy and ring deformation laws are proved by the sample photographs.  相似文献   

3.
Design and RAMS Analysis of a Fault-Tolerant Computer Control System   总被引:1,自引:0,他引:1  
This paper presents a fault-tolerant computer system. It is designed as a double 2-out-of-2 architecture based on component redundant technique. Also, a quantitative probabilistic model is presented for evaluating the reliability, availability, maintainability and safety (RAMS) of this architecture. Hierarchical modeling method and Markov modeling method are used in RAMS analysis to evaluate the system characteristics. The double 2-out-of-2 system is compared with the other two systems, all voting triple modular redundancy (AVTMR) system and dual-duplex system. According to the result, the double 2-out-of-2 system has the highest dependability. Especially, the system can satisfy the safety integrity level (SIL) 4, which means the system's probability of catastrophic failure less than or equal to 10-8 per hour, therefore, it can be applied to life critical systems such as high-speed railway systems.  相似文献   

4.
Energy and Exergy Analysis, and Thermoeconomic Performance of a BCHP System   总被引:3,自引:0,他引:3  
Building cooling, heating and power (BCHP) systems should play an important role in achieving the goals of energy efficient use and environment protection in China. It will make big sense when this type of system shows a good performance energetically and economically. An on-site BCHP system being the first in the country was installed and put to use five years ago. As the first step to evaluate the project, com~tations were made based on thermodynamic and themoeconomic theories to evaluate the system on full load and off-design conditions in summer. Discussion and analyses are made mainly in terms of exergetic efficiency and costs of unit amount of useful exergy produced in this paper.  相似文献   

5.
0Introduction Biologicaldiversityconcernedwiththesumofvariouslivingbeingsandtheirprocesses,aswellasthebasisofharmonious coexistencebetweenmanandnatureplaysanimportantroleinecology,economy,esthetics,ethics,etc.Duetodeteriorationofglobal environment,acceler…  相似文献   

6.
Ligularia Cass., (Compositae) is a highly diversified genus, and more than 100 species of which are distributed in the eastern Qinghai-Tibet Plateau and adjacent areas. Ligularia species have been studied with respect to secondary metabolites, and many sesquiterpenes of the furanoeremophilane type have been isolated from them. In order to find correlates among these variations, and ultimately understand the diversity-generating mechanism of Ligularia species in the Hengduan Mountains, we initiated an extensive study that uses furanoeremophilanes as a chemical index and the DNA sequence as a genetic index. Furanoeremophilanes have been detected conventionally by Ehrlich's test, which has been used in a search for novel natural products. As for the DNA sequence, we determined the nucleotide sequence of the atpB-rbcL intergenic region in the present study.  相似文献   

7.
Current distributed parallel file systems and database systems can not satisfy the demands of data-intensive applications, such as storage capacity, access performance, reliability, scalability, and so on. Cluster-based storage sys tems have some shortcomings, too. To solve this kind of problems, a novel PC storage cluster solution is proposed, a distributed storage system based on 3-tiered agent architecture is designed, the system reliability model based on the masterslave backup mode is built, and the system availability is analyzed with the Markov model. According to the system availability formula and the values of the system parameters, the novel system can provide higher reliability and availability to satisfy users' requirements,  相似文献   

8.
Previous work studied a production system including multiple stations (or workshops) consisting of an entry station, a set of workstations, an exit station, and a central station, which could be arranged in any configuration. The central station was introduced into the production system to relax the environment. In this paper, the central station is eliminated. The entry station and all workstations have limited local buffers. A workstation can choose either a buffer or a kanban mechanism to control its work-in-process (WIP). The production system was modeled as a queueing network with blocking in a general configuration. A symmetrical decomposition approach was developed to analyze the production system. The simulation result shows that the decomposition approach works well. Comparison of the new production systems with modified production systems having a common buffer shows that the key for implementing just-in-time production systems is to reduce the uncertainty.  相似文献   

9.
A 1.4Kb DNA fragment containing 3‘ flanking sequence of fibroin gene of silkworm, Antheraea perny/, was obtained from the silk gland‘s mRNA of 5th larva. Analysis of this sequence with another A. pemyi fibroin protein (accession No. 1383241) revealed that it consists of a completely open reading frame (ORF), which includes 14 polyalanine-containing units (motifs) and 100bp 3‘-UTR. The sequence of the predicted amino acid reveals the highest level of overall iden-tity (90%) with 1383241. It was found that it loses a repeat region at the upstream of TAA codon and some mutations. A putative polyadenylation signal AATAAA tail was found in position 1300, which follows the termination codon.  相似文献   

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11.
Digital broadcasting system has become a highlight of research on computer application. To respond to the changes of the playbill in the broadcasting system in real time, the response time of the system must be studied. There is scarcely the research on this area currently. The influence factors in the response time are analyzed; the model on the response time of the system service is built; how the influence factors affect the response time of the system service is validated; and four improvement measures are proposed to minimize the response time of system service.  相似文献   

12.
Towing tractor drivelines are lightly damped non-linear systems. Interactions between components can cause dynamic behavors such as gear gap impact in gear transmissions, shuffle and clonk phenomena in driveline. The torsional vibration of driveline has an important effect on grand engineering vehicle vibration and noise. Through analyzing torsional vibration equations of driveline, torsional vibration model of driveline is developed by using Matlab/Simulink software, Shuffle and clonk phenomena are observed in torsional vibration. The modeling method of analysizing driveline torsional vibration can be used to research and improve similar eagineering vehicle driveline behavors.  相似文献   

13.
This paper discusses a scheme of digital Reactor Protection System (RPS). Advanced parallel processing channels, consisting of a microprocessor-based unit and a General Array Logic (GAL)-based unit have been configured in each of the redundant trains to eliminate the risk of common-mode failure of digital RPSs through the way of diversified equipment. Also several digital techniques are also applied to improve the system design. For example, the Voltage/Frequency (V/F) converter is applied to achieve the digitization of the measurement channel. GAL components greatly simplify the hardware circuit design. Two types of communication buses are designed to improve the reliability of data transmission. By all these means, the reliability of RPS can be expected to achieve a great improvement.  相似文献   

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This paper presents a study on species diversity and its ecological service function in the plateau area in western Sichuan. The results show that species diversity in the plantations on the cutover land has a tendency to increase and that its ecological service function is to be improved with stand age growing. The species diversity in forest communities is also gradually increased on different succession stage till reaching a climax level. But the species diversity in the climax community is slightly decreased before it reaches a relatively constant status. Ecological service function of diversity is gradually strengthened with the progress of succession. In addition, species diversity in a stand in a similar site and at a same age differs among forest types. Species diversity index within a coniferous and broad-leaved mixed forest is larger than that within a coniferous forest. Meanwhile, species diversity enriches as the tree density increases.  相似文献   

17.
IntroductionAllovertheworld ,thetrendhasturnedagainstpay as you go (PAYG )socialsecuritysystemstoofferapensionsystembasedonfunding .Whenlifeexpectancyissteadilyincreasing ,mosttraditionalPAYGsystemshavebeenperceivedtobeinastateofcrisis.ShouldthePAYGsystembereplacedwithafundedsystem ,andifso ,why ?Manyauthorshaveexpressedmanydifferentopinionsonthisproblem ,andthematterhasbeenanalyzedwithinhighlysophisticatedtheoreticalandempiricalmodels.Someauthors,likeFeldstein(1995 ) ,Kotlikoff,Smetter…  相似文献   

18.
IntroductionSturgeons,fish of extremely great commercialvalue,belong to one of the mostancientgroups ofthe Osteichthyes.They are widely distributed in theNorthern Hemisphere above the 3 0 th parallel,andwithin this zone they are found everywhere alongthe coasts of the Atlantic,the Pacific,theMediterranean and the Black Sea,as well as inrivers,lakes and inland seas. Their abundance inthis huge range differs greatly:in many parts ofthe range they are found only as isolated,sparsepopulations,a…  相似文献   

19.
IntroductionIn rowing,as in many sports,the goal is to getfrom startto finish as fastas possible.Informationabout the boat movement is very important inrowing training and competition.Examples ofuseful information include boat velocity,strokerate,single stroke distance,boat track,andtraining distance.Analyzing these parameters canhelp to evaluate the rowing techniques and tomonitor rowers'performance.With traditionalmethods we can only obtain stroke rate using ameter on the boat or from video…  相似文献   

20.
I.IntroductionEdieisthemaincharacterinthestory‘Snowed-Up:AMistletoeStory’.RichardJef-fries,theauthor,toldastory,intheformofadi-ary,ofayounggirlof19andothermen,LordBil-berton,Mr.AldermanThriggandLieut.PhilipAurelles.ThethreemenalllovedEdieandwantedtomarryher,butEdielovedonlyPhilip.Herlovewasagainstherfatherswill.Theconflictwentonunderthesettingofasuddenbutcontinuoussnow-fall.Whenthesnowfallended,sodidthestory.Whatsinterestinginthestoryisthat,afterspend-ings…  相似文献   

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