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复方发酵促进剂对米曲霉沪酿3.042生物活性的影响 被引量:6
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作者 叶磊 何立千 赵和 《中国调味品》 CAS 北大核心 2002年第7期9-12,共4页
就复方发酵促进剂对米曲霉沪酿 3 0 4 2生物活性的影响进行了研究 ,结果表明该促进剂可明显提高米曲霉产蛋白酶的能力 ,最佳添加浓度为 4~ 6× 1 0 - 5 g g培养基时 ,可促进米曲霉生长、繁殖 ,使沪酿 3 0 4 2的蛋白酶产量增加 2 0 ... 就复方发酵促进剂对米曲霉沪酿 3 0 4 2生物活性的影响进行了研究 ,结果表明该促进剂可明显提高米曲霉产蛋白酶的能力 ,最佳添加浓度为 4~ 6× 1 0 - 5 g g培养基时 ,可促进米曲霉生长、繁殖 ,使沪酿 3 0 4 2的蛋白酶产量增加 2 0 %左右 ;该促进剂还具有保护主酶活性等多重功效。 展开更多
关键词 复方发酵促进剂 米曲霉沪酿3.042 生在性 蛋白酶 酱油
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Existence for positive steady states of an eco-epidemiological model
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作者 王雅萍 陈文彦 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期119-122,共4页
An eco-epidemiological model with an epidemic in the predator and with a Holling type Ⅱ function is considered.A system with diffusion under the homogeneous Neumann boundary condition is studied.The existence for a p... An eco-epidemiological model with an epidemic in the predator and with a Holling type Ⅱ function is considered.A system with diffusion under the homogeneous Neumann boundary condition is studied.The existence for a positive solution of the corresponding steady state problem is mainly discussed.First,a prior estimates(positive upper and lower bounds) of the positive steady states of the reaction-diffusion system is given by the maximum principle and the Harnack inequation.Then,the non-existence of non-constant positive steady states by using the energy method is given.Finally,the existence of non-constant positive steady states is obtained by using the topological degree. 展开更多
关键词 eco-epidemiological model EXISTENCE positive steady states
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Global Existence and Lifespan of Solutions to the Cauchy Problems for the Nonlinear Schrodinger Equations
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作者 秦玉明 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第1期63-72,共10页
This paper deals with the global existence,asymptotic property and lifespan of solutions to the Cauchy problems for a class of nonlinear Schrodinger equation.
关键词 Schrodinger equation LIFESPAN asymptotic property
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Eco-Reason the Philosophical Thinking on the Limitation Existence 被引量:4
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作者 TangDaixing 《Ecological Economy》 2005年第2期12-18,共7页
The philosophical root of all human beings’ existence crisis in the contemporary times is the philosophy of the unlimited theory. The inner spiritual supporting force is the construction from its theoretical reason t... The philosophical root of all human beings’ existence crisis in the contemporary times is the philosophy of the unlimited theory. The inner spiritual supporting force is the construction from its theoretical reason to its scientific reason. Its essential ideas stem from the people-centered theory, the view of happiness in the material- purposed theory, the communist life style, the material hegemonist principle, and the rational action principles of economic technology. In the 21st century, in order to deal with the dangerous situation of human beings’ exist- ence from the root, the philosophy of the limitation theory must be established, which has the eco-reason as the value support, integrates all the original wisdom of human beings and reflects human’s spiritual needs of the age as well as the direction of human future development. The whole percept of this new philosophy is that “all things have souls”; its basic law of existence is “the ceaseless life circle”; its survival goal is the view of happiness in the harmony of material and spirit; its social action guidance and principle are (environment, society, humanity) the environment ecologism and the integral-and-mutual action principle (of human beings &society, individual &society, and present age & posterity). 展开更多
关键词 limitation theory eco-reason spirit of circulatory life limitation existence principles of limitation existence.
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Existence and Life Span of Periodic Solutions for the First Order Quasilinear Hyperbolic Equations
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作者 王有安 王艳玲 《Chinese Quarterly Journal of Mathematics》 CSCD 1997年第3期87-94, ,共8页
In this paper the authors consider Cauchy problem of first order quasilinear hyperbolic and prove that existence of its periodic solutions and estimates of life span of solutions. This results reveals the relationship... In this paper the authors consider Cauchy problem of first order quasilinear hyperbolic and prove that existence of its periodic solutions and estimates of life span of solutions. This results reveals the relationship of dissipation and smoothness of periodic solutions. 展开更多
关键词 periodic solution DISSIPATION life span
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Negative regulation of receptor tyrosine kinases: unexpected links to c-Cbl and receptorubiquitylation 被引量:5
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作者 Chanan RUBIN Gal GUR Yosef YARDEN 《Cell Research》 SCIE CAS CSCD 2005年第1期66-71,共6页
Intracellular signals mediated by the family of receptor tyrosine kinases play pivotal roles in morphogenesis, cell fate determination and pathogenesis. Precise control of signal amplitude and duration is critical for... Intracellular signals mediated by the family of receptor tyrosine kinases play pivotal roles in morphogenesis, cell fate determination and pathogenesis. Precise control of signal amplitude and duration is critical for the fidelity and robustness of these processes. Activation of receptor tyrosine kinases by their cognate growth factors not only leads to propagation of the signal through various biochemical cascades, but also sets in motion multiple attenuation mechanisms that ulti- mately terminate the active state. Early attenuators pre-exist prior to receptor activation and they act to limit signal propagation. Subsequently, late attenuators, such as Lrig and Sprouty, are transcriptionally induced and further act to dampen the signal. Central to the process of signaling attenuation is the role of the E3 ubiquitin ligase c-Cbl. While Cbl- mediated processes of receptor ubiquitylation and endocytosis are relatively well understood, the links of Cbl to other negative regulators are just now beginning to be appreciated. Here we review some emerging interfaces between Cbl and the transcriptionally induced negative regulators Lrig and Sprouty. 展开更多
关键词 ENDOCYTOSIS growth factor ONCOGENE signal transduction UBIQUITIN tyrosine kinase.
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Limiting stand density and basal area projection models for even-aged Tecomella undulata plantations in a hot arid region of India
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作者 Vindhya Prasad Tewari 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第1期13-18,I0001,共7页
This paper presents equations for estimating limiting stand density for Z undulata plantations grown in hot desert areas of Raj asthan State in India. Five different stand level basal area projection models, belonging... This paper presents equations for estimating limiting stand density for Z undulata plantations grown in hot desert areas of Raj asthan State in India. Five different stand level basal area projection models, belonging to the path invariant algebraic difference form of a non-linear growth function, were also tested and compared. These models can be used to predict future basal area as a function of stand variables like dominant height and stem number per hectare and are necessary for reviewing different silvicultural treatment options. Data from 22 sample plots were used for modelling. An all possible growth intervals data structure was used. Both, qualitative and quantitative criteria were used to compare alternative models. The Akaike's information criteria differ- ence statistic was used to analyze the predictive ability of the models. Results show that the model proposed by Hui and Gadow performed best and hence this model is recommended for use in predicting basal area development in 12 undulata plantations in the study area. The data used were not from thinned stands, and hence the models may be less accurate when used for predictions when natural mortality is very significant. 展开更多
关键词 model evaluation path invariant algebraic difference form growth function potential density qualitative and quantitative criteria RAJASTHAN
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Fresh Water Demand Minimization in Residential Urban Buildings
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作者 Antonios Saragkas George Paschalidis 《Journal of Environmental Science and Engineering(A)》 2015年第4期210-214,共5页
In the last decades, there is a lot of discussion in many scientific fields, about the high importance of water as a basic element for the existence and the maintenance of life, aiming to the right and proper usage of... In the last decades, there is a lot of discussion in many scientific fields, about the high importance of water as a basic element for the existence and the maintenance of life, aiming to the right and proper usage of water in our everyday basic water-needs due to its limited resources and the growing demand. This research deals with simple ways and technological systems applicable in urban residential buildings for the better management of domestic fresh water, as far as its maintenance and sustainability. Main aim of the survey is the effective minimization of urban daily water usage. All measurements of water quantities have estimated in the imperial gallon (1 gallon = 4.546 liter), and in liter (1 liter = 0.2 gallon). 展开更多
关键词 Efficient urban water management sustainable buildings water resources sustainability
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POSITIVE PERIODIC SOLUTIONS OF PREDATOR-PREY SYSTEMS WITH INFINITE DELAY 被引量:9
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作者 WANG KE FAN MENG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2000年第1期43-54,共12页
Conditions for existence of positive periodic solutions of nonautonomous, nonconvoluton type predator-prey system with infinite delay are given.
关键词 Positive periodic solutions Predator-prey system Infinite delay
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Analysis of a mutualism model with stochastic perturbations 被引量:3
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作者 Mei Li Hongjun Gao +1 位作者 Chenfeng Sun Yuezheng Gong 《International Journal of Biomathematics》 2015年第6期19-36,共18页
This paper is concerned with a mutualism ecological model with stochastic perturba- tions. The local existence and uniqueness of a positive solution are obtained with positive initial value, and the asymptotic behavio... This paper is concerned with a mutualism ecological model with stochastic perturba- tions. The local existence and uniqueness of a positive solution are obtained with positive initial value, and the asymptotic behavior to the problem is studied. Moreover, we show that the solution is stochastically bounded, uniformly continuous and stochastic perma- nence. The sufficient conditions for the system to be extinct are given and the conditionsfor the system to be persistent are also established. At last, some figures are presented to illustrate our main results. 展开更多
关键词 Ito's formula mutualism model persistent in mean EXTINCTION uniformlycontinuous.
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Solvability of Multi-Point Boundary Value Problem
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作者 张慧星 刘文斌 +1 位作者 张建军 陈太勇 《Journal of Mathematical Research and Exposition》 CSCD 2009年第4期693-699,共7页
This paper deals with the existence of solutions for the problem{(Фp(u′))′=f(t,u,u′),t∈(0,1), u′(0)=0,u(1)=∑i=1^n-2aiu(ηi),where Фp(s)=|s|^p-2s,p〉1.0〈η1〈η2〈…〈ηn-2〈1,ai(i=1,2,…,n-... This paper deals with the existence of solutions for the problem{(Фp(u′))′=f(t,u,u′),t∈(0,1), u′(0)=0,u(1)=∑i=1^n-2aiu(ηi),where Фp(s)=|s|^p-2s,p〉1.0〈η1〈η2〈…〈ηn-2〈1,ai(i=1,2,…,n-2)are non-negative constants and ∑i=1^n-2ai=1.Some known results are improved under some sign and growth conditions. The proof is based on the Brouwer degree theory. 展开更多
关键词 p-Laplace multi-point boundary value problem RESONANCE degree theory.
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Existence of Nontrivial Solutions for p-Laplacian Variational Inclusion Systems in R^N 被引量:1
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作者 Zifei SHEN Songqiang WAN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2011年第4期619-630,共12页
The authors study the existence of nontrivial solutions to p-Laplacian variational inclusion systems where N ≥ 2, 2 ≤ p ≤ N and F : R^2 →% is a locally Lipschitz function. Under some growth conditions on F, and b... The authors study the existence of nontrivial solutions to p-Laplacian variational inclusion systems where N ≥ 2, 2 ≤ p ≤ N and F : R^2 →% is a locally Lipschitz function. Under some growth conditions on F, and by Mountain Pass Theorem and the principle of symmetric criticality, the existence of such solutions is guaranteed. 展开更多
关键词 Mountain pass theorem P-LAPLACIAN Principle of symmetric criticality Variational inclusion systems (PS)-condition Locally Lipschitz functions
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An ecological model with the p-Laplacian and diffusion
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作者 S. H. Rasouli 《International Journal of Biomathematics》 2016年第1期157-163,共7页
We study the existence of positive solutions of a population model with diffusion of the form {-△pu=aup-1-f(u)-c/ua,x∈Ω,u=0,x∈Ω where △p denotes the p-Laplacian operator defined by △pz =div(|z|P-2z), p 〉... We study the existence of positive solutions of a population model with diffusion of the form {-△pu=aup-1-f(u)-c/ua,x∈Ω,u=0,x∈Ω where △p denotes the p-Laplacian operator defined by △pz =div(|z|P-2z), p 〉 1, Ω is a bounded domain of RN with smooth boundary, α∈ C (0, 1), a and e are positive constants. Here f : [0, ∞) → R is a continuous function. This model arises in the studies of population biology of one species with u representing the concentration of the species. We discuss the existence of positive solution when f satisfies certain additional conditions. We use the method of sub- and super-solutions to establish our results. 展开更多
关键词 Ecological model infinite semipositone sub- and super-solutions.
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