一类修正Navier-Stokes方程解的大时间行为

O.A.Ladyzhenskaya于1966年放弃了速度梯度很小的限制,提出了一类描述三维非稳态不可压缩粘性流体运动规律的修正Navier-Stokes方程.本文研究有界区域上这一修正Navier-Stokes方程解的大时间行为,证明当外力为零时,解的衰减速度是精确的指数型.而且能量的涡度拟能当时间趋于无穷大时,其极限是Stokes算子的一个特征值.     

带松弛项的单个守恒律方程解的大时间状态估计

论文考虑一维空间中带松弛项的单个守恒律方程. 文[4]通过对线性化方程Green函数的估计得到整体解的逐点估计,论文在此基础上进一步得到解的大时间状态估计和Lp模估计,并反映出"弱"惠更斯原理.     

半空间一维可压缩Navier-Stokes方程解的渐进性

讨论了半空间中满足无渗透边界条件的一维黏性可压缩热传导流体的流动，给出了在小扰动和非等温条件下稀疏波的渐进稳定性。当速度在边界上为零时，证明了一维可压缩Navier-Stokes方程的解在半空间中随时间的增大而趋向于本文所定义的3-稀疏波。所用的证明方法为能量方法。     

流向变换反应器方程组模型解的大时间性态研究

对流向变换反应器周期操作的非线性反应-对流-扩散偏微分方程组数学模型解的大时间性态进行了分析，定义了对应于此方程组模型的循环定态问题的弱解，在比较符合实际情况的假设条件下，证明了对应的循环定态问题的弱解存在，且时间趋于无穷时模型的解趋于此循环定态问题的弱解。     

流向变换反应器模型解的大时间性态的研究

流向变换反应器周期操作模型一般为非线性反应对流-扩散方程的新型定解问题。利用抛物型方程的极值原理得出的方程解的最大模估计,对单方程的流向变换反应器模型解的大时间性态进行了一些分析,证明了当反应交换项关于浓度或温度变量单调递减时其循环定态解的存在性,并且当t→∞时,模型解会趋于循环定态解。     

Asymptotic behavior of solutions for the one-dimensional drift-diffusion model in the quarter plane

In this paper, we study the classical drift-diffusion model arising from the semiconductor device simulation, which is the simplest macroscopic model describing the dynamics of the electron and the hole. We prove the global existence of strong solutions for the initial boundary value problem in the quarter plane. In particular, we show that in large time, these solutions tend to the nonlinear diffusion wave which is different from the steady state, at an algebraic time-decay rate. As far as we know, this is the first result about the nonlinear diffusion wave phenomena of the solutions for the one-dimensional drift-diffusion model in the quarter plane.     

一类时滞抛物型系统周期解的存在稳定性

利用上、下解方法及不动点理论研究了一类反应项非单调的时滞抛物型系统,构造了非单调反应项的上、下控制函数,并证明了所构造的函数满足Lipschitz条件及单调性,克服了反应项非单调无法利用单调迭代方法的局限性,为讨论反应项非单调的微分方程提供了一种有效方法,并获得了此系统边值问题周期解存在性的充分条件;另外,还给出了证明其周期解稳定性的方法,推广了已有的一些结果.     

Reproductive biology and prospects for conservation ofCaldesia parnassifolia (Alismataceae)—A threatened monocot in China

Caldesia parnassi folia (Bassi ex Linn.) Parl. in China has declined in number in recent years and is increasingly faced with the risk of extirpation arising from anthropogenic changes associated with rapid urbanization and expansion of both agriculture and infrastructure. To aid in provision of the data needed for effective conservation of the species, studies on the habitat, pollination ecology, and breeding system ofC. parnassi folia were carried out on natural populations occurring in Southeastern China. Flowering in the study populations extended for more than eighty days beginning in early summer. Floral anthesis occurred in the morning hours and proceeded rapidly, lasting about 45 min. Flowers lasted ca. 8 h.Caldesia parnassi folia is self-compatible; however autogamy resulted in lower seed set than geitonogamy and xenogamy as well as free pollination. The data on pollen/ ovule (P∶O) ratio is consistent with a partially selfing and outcrossing mating system. Interpopulational crosses yielded similar seed set to within-population crosses. Agamospermy did not occur in the study populations. Propagation is achieved through seeds as well as through turions which commonly occur in the inflorescences. Flies (Insecta; Diptera) were the most frequent visitors to the flowers ofC. parnassi folia; however bees (Insecta; Hymenoptera) composed a larger proportion of effective pollinators. The Syrphidae speciesSphaerophoria indiana (Bigot) presents evidence of oligolectic foraging behavior. Recommendations are made on the immediate steps necessary for conservation ofCaldesia species in China. Foundation item: Supported by the State Key Basic Research and Development Plan of China (973) (G2000046805) and the National Natural Science Foundation of China (30070055) Biography: Robert Wahiti, Gituru (1967-), male, Kenya, Ph. D., research direction: plant biosystematics.     

Synthesis and micellization behavior of stimuli-responsive polypeptide hybrid triblock copolymer

Polypeptide hybrid triblock copolymer, poly（L-glutamic acid）-b-poly（propylene oxide）-b-poly （L-glutamic acid） （PLGA-b-PPO-b-PLGA）, was synthesized by the ring-opening polymerization of benzyI-L- glutamic N-carboxyanhydride （BLG-NCA） using poly（propylene glycol） bis（2-aminopropyl ether） as initiator, followed by the subsequent deprotection step. The obtained double hydrophilic triblock co- polymer exhibits ＂schizophrenic＂ micellization behavior in aqueous solution upon dually playing with solution pH and temperature. The multi-responsive micellization behavior of this polypeptide hybrid triblock copolymer has been thoroughly investigated by 1H NMR, laser light scattering （LLS）, tempera- ture-dependent optical transmittance, and circular dichroism spectroscopy （CD）.     

Research of Inclusion Complexation of 4,4＇-Thiodiphenol Effected by β-Cyclodextrin in Aqueous Solutions and the Effect on Photodegradation

The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum and quantum-chemical calculation with Gaussian 98 software. The results show that the inclusion behavior of TDP is quite different in acidic solutions （pH 5.9） from that in alkaline solutions （pH 10.0）. This behavior difference is attributed to the different formula structures in aqueous solutions at acidic and alkaline pH values that are demonstrated by quantum- chemical modeling and calculation. TDP forms a 1 ： 1 fl-CD inclusion complex in aqueous solutions. The equiiibrium constant K was calculated to be 553.49 L/mol at pH 5.9 and 1 318.20 L/mol at pH 10.0 respectively for the inclusion complex reaction by using the modified Benesi-Heldbrand equation. After inclusion TDP＇s structure is changed especially at the inclusion part with the bond order becoming larger, which results in inhibitive photodegradation during direct photooxidation and H2O2 assisted photooxidation.     

中国杜鹃花保育研究进展

本文从栽培技术、育种方法两方面总结了中国杜鹃花(Rhododendron)的保育研究进展,针对目前我国杜鹃花保育工作方法单一、野生资源保护和开发利用力度小、目标选育不够深入等不足,提出重点研究复合育种技术、加强野生杜鹃花保育研究,发挥资源优势,培育特色品种、有针对性地进行目标选育等建议,以期为今后我国杜鹃花的保育和应用发展提供参考。     

Strong Law of Large Numbers and Complete Convergence for Sequences of φ-Mixing Random Var, ables

We give some theorems of strong law of large numbers and complete convergence for sequences of φ-mixing random variables. In particular, Wittmann＇s strong law of large numbers and Teicher＇s strong law of large nnumbers for independent random variables are generalized to the case of φ -minxing random variables.     

一类含有p-Laplacian算子二阶三点边值问题正解的存在性

运用求积分的方法研究了含有一维p-Laplacian算子的二阶三点边值问题:{(|u′(t)|p-2 u′(t))′+λf(u(t))=0,t∈(0,1),u(0)=0,u(1)=u(η)多重正解的存在性,其中p∈(1,2],0η1是常数,λ∈(0,+∞)是一个参数,对于常数r0时,f∈C1([0,r),[0,+∞)),在(0,r)上f(s)0,且lim s→r-(r-s)p-1 f(s)=+∞。     

局部紧Lindelöf空间的序列覆盖映象

利用特定的覆盖性质，借助序列覆盖映射，建立局部紧Lindeloef空间和CS覆盖、sn覆盖、cs^＊覆盖之间的联系，以及局部紧Lindeloef空间的序列覆盖映象特征，得到并深化局部紧Lindeloef空间的一些相应结果，完善了局部紧Lindeloef空间的映射理论。     

无穷区间上含有p-Laplacian算子的n阶积分边值问题正解的存在性

运用Leray-Schauder非线性抉择定理研究了一类无穷区间上含有p Laplacian算子的n阶微分方程积分边值问题:﹛(φp(x(n-1)))′(t)+a(t)f(t,x(t),x′(t))=0,0t+∞,x(0)=α∫+∞ηg(τ)x(τ)dτ,x′(0)=x″(0)=…=xn-2(0)=0,t→+∞lim x(n-1)(t)=0解的存在性,其中η∈[0,+∞),α∈[0,+∞)且f∈C([0,+∞)×R×R,[0,+∞))。     

一类分数阶q-差分方程正解的存在性与不存在性

考虑一类q-差分方程正解的存在性与不存在性问题,运用锥上Guo-Krasnosel''skill不动点定理,分别获得了存在一个正解、两个正解及不存在正解的充分条件.     

云南红豆杉小孢子发生和雄配子发育的研究方法比较

 以云南红豆杉为实验材料,比较了石蜡切片法、洋红简易染色法和整体染色透明法研究小孢子发生过程的效果,分析了用石蜡切片法及离体培养法研究雄配子体发育优缺点.在离体培养中,对比了不同的蔗糖质量浓度、培养温度及染色方法对实验结果的影响,从而为针叶树种雄性生殖系统发育过程研究提供参考.结果显示:整体透明染色法操作简单,能够反应小孢子发育过程中各个阶段的细胞结构,是用于小孢子发育过程研究的比较理想的方法;对于雄配子体发育过程的研究,需要用石蜡切片法与离体培养法相结合,在离体培养中,采用雄球花表面灭菌,自然散粉,低糖低温培养有利于防止污染,洋红染色法方便快捷,不需要特别的设备,是离体培养时比较理想的染色方法.     

Process View of Reflection Mechanism for Reuse Software Architecture

Reflection mechanism for reuse software architecture （RMRSA） divides a software architecture into base-level architecture and meta-level architecture logically. Base-level architecture is the ordinary architecture; meta-level represents and manipulates the reusable meta-information of base-level architecture explicitly. Through reflection, the modification of meta-level architecture will result in the modification of the architecture in base-level. Then we can gain a new base-level architecture design. In this paper, we use π-calculus to define the constituents and their interaction processes of RMRSA, by these definition, we specify the business function in base-level at runtime, and illustrate the reflection mechanism between the base-level architecture and meta-level architecture.