双重作用的

AIM The purpose is to search for new antidiabetic drugs.

目的 ：寻找新型具有双重作用的降血糖药物。

1Niche construction can lead to stable coexistence of diverse genotypes in spatially structured population, which supports a stable polymorphism even without heterozygote superiority.(2)With habitat deterioration, niche construction accelerates the formation of steady polymorphism and hence impedes the harmful influences of environment on the population, which might embody a life-history strategy of organism under the unfavorable environment.(3)Niche construction results in the coexistence with alternative polymorphism through genotype-environment feedback and limited gene flow.(4)The niche-constructing organism is an active force to alter its environment and hence the direction of natural selection in order to better survival.(5)Spatial dynamics and distribution pattern of metapopulation are profoundly influenced by time-lagged niche construction.(6)Metapopulation size can reach a fixed level in the recency effect and equal weighting of time lag but is statistical stability in primacy effect, which implies the primacy effect is most remarkable.(7)The increment in the relative weightingof each generation\' niche construction and the length of time lag are significant factors for system destabilization.(8)Moderate capacity of positive niche construction benefits the metapopulation persistence.(9)The narrowing of niche breadth can decrease the metapopulation size and thereby increase the extinction risk.(10)The coupled function of time lag and niche construction make the system oscillation and generate the spiral wave, spiral-broken and circular wave in heterogeneous habitat.The spatial distributions of metapopulation and resource content are complementary due to a phase lag of their both frequencies.(12)Metapopulation persistence with niche construction depends not only on the balance between colonization and extinction, but also on the balance between the ability of niche construction and natural dissipation of habitat.(13)Metapopula-tion can survive under certain condition when the percent of suitable patches in habitat is lower than the ration of extinction to colonization.(14)Two thresholds exist in the process of transition of habitat quality dynamics from unsuitable to suitable, which include the intensity of niche construction and the initial condition of system.(15)Metapopulation size is positive correlated with the ability of positive niche construction, which means that organism or population who has strongly positive influences on their environment plays an important role to maintain the available habitat.

通过上述几个方面的研究，主要得出以下15条结论：(1)生态位构建可使空间结构种群，甚至是在没有杂合子优势的条件下，形成多种可能的稳定基因型分布模式；(2)随着环境的破坏与恶化，种群的生态位构建作用加速其较早形成稳定多态以阻碍环境对种群的不利影响，解释了有机体在不利环境下的一种生活史对策；(3)生态位构建作用通过基因型—环境反馈机制及有限的基因交流导致基因型多态的稳定共存；(4)有机体的生态位构建作用是一种积极的动力改变环境进而改变其自然选择的方向；(5)生态位构建的时滞作用对集合种群动态和空间分布产生深刻影响；(6)集合种群大小在时滞的崭新效应和等权重效应下达到一固定值，而在首位效应下达到统计稳定，表明首位效应的影响最显著；(7)首位效应下生态位构建相对权重的增量和时滞的长度是影响系统不稳定性动态的关键因素；(8)适中的生态位构建强度有利于集合种群的续存；(9)生态位宽度变窄会减少集合种群的数量从而增加其灭绝风险；(10)时滞和生态位构建的双重作用使系统产生周期振荡，并在异质性环境中产生稳定的螺旋波，破碎的螺旋波和环形波三种分布模式；(11)集合种群与资源含量的空间分布因为相滞而互补；(12)具有生态位构建的集合种群续存不仅取决于侵占率与灭绝率之间的平衡，而且依赖于生态位构建能力同其生境的自然消耗速率之间的妥协；(13)当生境中适合侵占的斑块比例小于其侵占率与灭绝率之比时，生态位构建作用促使集合种群在一定条件下续存：(14)生境斑块的状态从不适合到适合转变过程中存在生态位构建强度和系统初始条件这两个阈值；(15)集合种群的大小同正生态位构建能力正相关，意味着对环境具有较强正作用的有机体对维持有效生境起积极作用。

It is demonstrated that CPT is an anti-tumor agent with double effect due to its inhibition effect both on tumor cell colony and endothelial cell colony.

表明喜树碱对肿瘤细胞群和内皮细胞群均具有抑制作用，为具有双重作用的抗肿瘤药。

In this thesis, the scope of negatives can be well explained by the c-command notion, but the c-command relation involved in double negation is more complicated than the monosyllabic negatives. Apart from the discussion on the three topics, the frequency of the negatives in Dunhuang Bianwen is listed in each section.

在双重否定部分，发现它主要的作用在加强语气，而其否定范围也同样可利用c-统制概念来说明，只是双重否定的c-统制关系远较单纯否定词来得复杂。

Patients were treated after 1999 using peripheral anticoagulant therapy plus enterectomy and transmesenteric arterial catheterized and thrombolytic therapy with urokinase,no patient died.

急性门静脉系静脉血栓形成应尽早诊治，选择性肠系膜上动脉造影并留置导管持续给予溶栓治疗是一具有诊断与治疗双重作用的好方法

In order to overcome the difficulty of making a through investigation of each fracture in natural systems, a new concept of quasi double-porosity-medium was put forword and a new mcdel was also developed based on the partition of dominant fractured networks and quasi porous matrixes according to the transmissive and storage mechanism of frae tured medium.

双重介质水流耦合离散模型的建立，改变了以往对双重介质的概化和假设，能如实的反映裂隙系统和孔隙岩块的组合关系，不仅能描述裂隙系统的导水作用和孔隙岩块的贮水作用，还能描述孔隙岩块的渗透特征。对两类空隙系统间的水交替特点有了新的认识，并对以往的结论提出异议。

Effects of proton number, doping degree and so on were discussed by means of a new model.

有实验资料表明质子在膜中的大多数输送是链段运动和质子跃迁双重作用的结果，利用模拟参数本文将输送的质子数表征为链段运动和质子跃迁两项和的形式。

When the relative soil water content were 55%-40%, the main reasons of the photosynthetic rate declined were stomatic limitation. When the relative soil water content were 20%, the main reasons of the photosynthetic rate declined were nonstomatic limitation.

干旱胁迫下，光合速率的下降是气孔因素与非气孔因素双重作用的结果：轻度干旱胁迫下（土壤相对含水量55%~40%）气孔限制是光合速率下降的主要原因，而严重干旱胁迫下（土壤相对含水量20%）非气孔限制是光合速率下降的主要原因。

This dual role equips them with the valuable experience of being a change agent.

这种双重作用的装备与变革是一个宝贵的经验。

It is a very helpful treatment for cellulites, because here accumulated toxins are associated with fluid retention, so the detoxifying and diuretic actions of Juniper work hand in hand.

它还可以治疗蜂窝性组织炎，因为这也是毒素累积和体液迟滞所引发的病症，使用具有解毒和利尿双重作用的杜松精油疗理功效特别好。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。