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1.
It is shown that the average [O] in the steel can be decreased to 12.86 ppm and there is an optimal [%Si] at the end of melting as 0.11%, at which [O] after vacuum carbon deoxidation (VCD) is minimum. A kinetical model has been deduced to simulate the VCD process. The results show that adding Si before Al is superior to the adding Al before Si with respect to the final [O] in the steel. It is suggested that the melting point of covering slag should be lower than 1550℃, and (FeO+MnO) should be less than 1%, so as to effectively refine GCr15 steel.  相似文献   

2.
In this article, a real number is defined as a granulation and the real space is transformed into real granu-lar space[1]. In the entironment, solution of nonlinear equation is denoted by granulation in real granular space. Hence,the research of whole optimization to solve nonlinear equation based on granular computing is proposed[2]. In classicalcase, we solve usually accurate solution of problems. If can't get accurate solution, also finding out an approximate solutionto close to accurate solution. But in real space, approximate solution to close to accurate solution is very vague concept. Inreal granular space, all of the approximate solutions to close to accurate solution are constructed a set, it is a granulation inreal granular space. Hence, this granulation is an accurate solution to solve problem in some sense, such, we avoid to sayvaguely "approximate solution to close to accurate solution". We introduce the concept of granulation in one dimension real space. Any positive real number a together with movinginfinite small distance ε will be constructed an interval [a-ε,a ε], we call it as granulation in real granular space, denotedby ε(a) or [a]. We will discuss related properties and operations[3] of the granulations. Let one dimension real space be R, where each real number a will be generated a granulation, hence we get a granularspace R* based on real space R. Obviously, R∈R*. Infinite small number in real space R is only O, and there are three in-finite small granulations in real number granular space R* : [0], [ε] and [-ε]. As the graph in Fig. 1 shows. In Fig. 1,[-ε] is a negative infinite small granulation,[ε] is a positive infinite small granulation,[0] is a infinite small granulation.[a] is a granulation of real number a generating, it could be denoted by interval [a-ε,a ε] in real space [3-5].Letf(x)=0 be a nonliner equation,its graph in interval[-3,10]id showed in Fig.2.Where -3≤x≤10 Relation ρ(f‖,ε)is defied is follows:(x1,x2)∈ p(f‖,ε)iff |f(x1)- f(x2)|<εWhere ε is any given small real number.We have five appoximate solution sets on the nonliner equation f(x)=0 by ρ(f‖,ε)∧|f(x)|[a,b]max,to denote by granulations[xi1 xi2/2],[xi3 xi4/2],[xi5 xi6/2],[xi7 xi8/2]and[xi9 xi10/2]respectively,where |f(x)|[a,b]max denotes local maximum on x ∈[a,b].This is whole optimum on nonliear equation in interval [-3,10].We will get best opmension solution on nonliner equation via computing f(x)to use the five solutions dented by grandlation in one dimension real granlar space[2,5].  相似文献   

3.
The protein structure-function relationships are al-ways highlighted in the field of life science. Protein syn-thesis from genomic sequence data is gaining significance in the post-genomic era of biomedical research by pro-viding direct access to functional proteins. The manually or automatically stepwise solid phase peptide synthesis (SPPS) allows peptide of up to 60 residues to be routinely constructed in good yield and high purity[1,2]. The assem-bly of longer proteins via the gene engine…  相似文献   

4.
The wear of cutting tools in the machining of 2024Al alloy composites reinforced with Al2O3 particles using varying sizes and volume fractions of particles up to 23.3vol% was investigated by a turning process using coated carbide tools K10 and TP30 at different cutting speeds. Machining tests were performed with a plan of experiments based on the Taguchi method. The tool life model was developed in terms of cutting speed, size, and volume fraction of particles by multiple linear regressions. The analysis of variance (ANOVA) was also employed to carry out the effects of these parameters on the cutting tool life. The test results show that the tool life decreases with the increase of cutting speed for both cutting tools K10 and TP30, and the tool life of the K10 tool is significantly longer than that of the TP30 tool. For the tool life, cutting speed is found to be the most effective factor followed by particle content and particle size, respectively. The predicted tool life of cutting tools is found to be in very good agreement with the experimentally observed ones.  相似文献   

5.
正博士后[美国]Northwestern University Northwestern University opens a post-doctoral researcher position.The focus of their research is Alzheimer’s disease pathogenesis withparticular emphasis on the beta-secretase enzyme,BACE1.Thepostdoctoral research project will include investigations of the role ofBACE1 in Alzheimer’s disease and its potential as a therapeutictarget,and the normal physiological functions of the enzyme in vivo.Applicants must have a PhD in a field of the life sciences and/or MDdegree.Preference will be given to individuals with expertise in  相似文献   

6.
IntroductionGenistein is a naturally occurring phytoestrogenpresent in a variety of plant foods,includingsoybean[1] .It is known to inhibit both tyrosineprotein kinases and DNA topoisomerase II.Akiyama et al.[2 ] described the ability of genisteinto specifically inhibit protein tyrosine kinase( PTKs) ,presumably at the level of the ATPbinding site.PTKs seem to play a key role intumorigenesis and are known to be associated withgrowth control receptors such as epidermal growthfactors[3] ,p…  相似文献   

7.
As the China-western cultural exchanges of in recent years strengthen day by day,the diet used to be simple in our daily life is becoming more and more abundant,and presents the trend of the pluralism.This paper studies on Chinese dietary cultural and foreign dietary cultural,letting readers have a clear understanding of the effects of western dietary culture on Chinese people's life and Chinese economy.How to lead people to establish a correct consumption view is an important problem,throwing away its dross,picking up quintessence,and using western culture to improve people's life and China's economic development.  相似文献   

8.
The author analyzes the existing problems in English for Tourism class and possible reasons why students are not highly motivated in oral communication practice : unconsciousness of the ongoing changing tourism industry, failure in their past learning, fear of losing faces, lack of words , structures and cultural background etc. Aiming to change the present situation and stimulate students'motivation in speaking, she offers some possible ways to the problems based on her perspectives:(1) choose authentic materials relevant to student's future career;(2)adapt a more current course book which is more authentically tourist-based in content.(3)adapt authentic video and TV tourist based materials related to the experience of tourism.(4)adapt authentic materials to make it more accessible and comprehensible by adding some proper authentic materials from different sources and tasks.(5)organize team activities based on authentic situations without changing the dialogue format in order to maintain redundancy of communication but in a real life focus.  相似文献   

9.
王福宁 《科技信息》2013,(8):180-182
The Great Gatsby is a significant classic in American literature and Fitzgerald is also considered as a chronicler of the"Jazz Age".The women characters play an important role in revealing the theme of the novel.The paper analyzes these women characters and points out their function juxtaposed against Gatsby.These women are all the victims of a society of wealth in American twenties.Compared to Fitzgerald's life,his attitude toward women and love is ambivalent.What happens to Gatsby is a warning to the rest of mankind.In the progress of realizing our own dream,we should be and can be soberer than those protagonists in the novel.  相似文献   

10.
博士研究生奖学金 [英国] University of Cambridge The Centre aims to promote the study of placental biology, with special reference to the trophoblast. It is offering up to three PhD studentships commencing in October 2009. These may be held in any relevant department within the University or its affiliated institutes.  相似文献   

11.
12.
This paper is a brief study on the characterization of Jude the Obscure, and will be focus on the chief character Jude Fawley. This novel, first published in 1895, wasThomas Hardy's last and best literary success. There are six main characters in this novel: Jude Fawley, Susanna Bridehead, Arabella Donn, Richard Phillotson, Aunt Drusilla, Little Father Time (Little Jude). This analysis of the distinct depictions of the typical characters will be helpful to the understanding of the gap between the ideal life a man wishes to lead and the squalid existence he is fated to live in such social environment as Jude is confronted with.  相似文献   

13.
IntroductionMCo O3cobaltite oxides with perovskite structureare of considerable interest due to their variousmagnetic and electrical properties[1,2 ] .(RE) Co O3perovskite shows semiconductor behavior anddoped(RE) Co O3such as La Ni1-x Cox O3(x=0 .6)shows metallic behavior[3 ,4 ] .These cobaltiteoxides can be used as ceramic electrodes forelectronic devices,secondary batteries and fuelbatteries[5,6] .Furthermore,(RE) Co O3cobaltiteoxide with perovskite structure is also a goodcatalystfo…  相似文献   

14.
Rheumatoid arthritis (RA), which is marked by inflammatory synovitis, is a common, chronic autoimmune-disease, whose pathogenesis is complex and still unclear. In order to explore the effects of heat and hyposmotic stimuli on synoviocytes in rheumatoid arthritis, the changes of [Ca^2+]i induced by heat, hyposmotic and 4α-PDD stimuli were observed in synoviocytes. [Ca^2+]i elevation induced by heat 28℃, hyposmotic and 4α-PDD stimuli is found to be positively relative to increasing temperature, decreasing osmolality and rising concentration of 4α-PDD. Results show that there is reciprocity among these stimuli and desensitization, and that [Ca^2+]i elevation depends on Ca^2+ influx, but not necessarily links to Ca^2+ release from intracellular stores and voltage-dependent Ca^2+ channel in synoviocytes. The above characteristics of Ca^2+ influx are similar to those of TRPV4. A probable mechanism has been suggested that heat and hyposmotic stimulation might increase the level of [Ca^2+]i by activating the TRPV4-like channel and Ca^2+ influx in the synoviocytes.  相似文献   

15.
The pretreatment of rice straw is often used to enhance the hydrolysis. 1-allyl-3-methylimidazolium chloride([AMIM]Cl) is a kind of low viscous,nontoxic and recyclable ionic liquid. It was used to treat rice straw and improve the enzymatic hydrolysis of rice straw in this study. The factors influencing the pretreatment were as follows:the dosage of rice straw in [AMIM]Cl,crush mesh of rice straw,pretreatment temperature and time. After the pretreatment with a 3 %(the weight ratio of rice straw to ionic liquid) rice straw dosage in [AMIM]Cl at 110 ℃ for 1 h,the yield of reducing sugar of regenerated rice straw by 33 U/mL cellulase hydrolysis was 53.3 %,which was two times higher than that of un-treated rice straw(23.7 %) . More researches regarding straw biorefinery to bacterial cellulose are being performed in the lab and prospective results will be published in near future.  相似文献   

16.
17.
With the wide application of coating materials in aerospace and other fields, their safety under fatigue conditions in service is important.However, research on the fatigue properties of ceramic hard coatings started late, and a unified standard is yet to be established to evaluate the fatigue life of hard coating–ductile substrate systems.Studies also present different opinions on whether coatings can improve or reduce the fatigue life of substrates.In this paper, the influence of the properties of ceramic coatings on fatigue performance is reviewed, and the effects of coating on the mechanism of fatigue crack initiation in substrates are discussed, aiming to help readers understand the fatigue behavior of hard coating–ductile substrate systems.  相似文献   

18.
0 IntroductionI t’s very important to assure the security of the keys inmany applied fields. A critical technique to prevent the keyfrom leaking is to adopt the threshold cryptosystem. It wasfirst introduced by Shamir in 1979[1] and by Desmedt in1987[2]. In this system, each group, instead of each groupmember, publishes a single group public key. The received ci phertext can only be deciphered properly when the number ofparticipating group members is larger than or equal …  相似文献   

19.
Let q be an integer, f(x)=a_kx~k+…+a_1x+a_0 be a polynomial withintegral coefficients and (a_1,…,a_k,q)=1. Also set Ss(q,f(x))=sum from x=1 to q e~(2πif(?)lq) (1) In 1940, Hua Loo Keng~([1]) first obtained that S(q,f(x))=O(q~(1-1/k+(?))), (2)where the exponcnt 1-1/k is best possible. Since then many mathematicians have sought to improve the constant implied by O in (2). The best two results were obtained by Chen Jing run~([2] and ~[3] in 1977. The result of [2] is  相似文献   

20.
Carbon disulfide is an important sulfur-containing compound in the environment, and its oxidation produces about 30% of the atmospheric COS[1]. In situ measure- ments show that CS2 is widespread in the sea surface wa- ters[2―4], and more recently, the continental water seems to be especially rich sources of CS2 due to industrial waste- water effluents. It is generally accepted that the ocean is an important source for atm. CS2, and Xie et al.[5] found that marine photochemical reaction of…  相似文献   

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