没有阻碍的

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 pointed out that not only Foochow didnt offer a good market environment to the sale of import and export articles in the hinterland, which restricts the import and export trade of Foochow Port, but also the bad transportation environment of Min River prevents the circulation of articles by investigating the business environment of Foochow City and the transportation environment of Min River, which is the main channel of goods transportation between Foochow Port and its hinterland.

通过对福州城本身商业环境的考察，通过对福州港与其腹地间商品运输的主要渠道——闽江——运输环境的考察，指出不但福州没有为腹地进口商品的销售和出口商品的外销提供良好的市场环境，从而限制了福州港的进出口贸易，而且闽江恶劣的运输环境，也阻碍了商品的流通。

Take as a single example this easily overlooked little passage from the rondo of the 23rd piano concerto; it is, in its essence, nothing more than a functional bit of connective tissue taking us from one place to another within the movement's structure. Ten brief bars—about 10 seconds—of basic scalar material, doing its job efficiently and economically. But it is at the same time so richly and amusingly characterized, so full of piping energy, with its determined but struggling piano line climbing its stutteringly inexorable way up to the note E, punctuated along its course by deadpan commentary from the winds, sneaking in the D natural that signals the change of key with almost undetectable sleight of hand—the passage almost constitutes a miniature comic universe all by itself.

请听这段在《第23钢琴协奏曲》中常常被人忽视的回旋曲( http：//img.slate.com/media/87/7_mozart488.asf )，没有哪个功能性连结段能比它更好地仅通过乐章结构就将听众带入另一个世界，长约10秒钟的概要部分(brief bars of basic scalar material)不仅经济有效地发挥其职能，同时又表现出丰富、诙谐的特色，充满木管乐器的活力，伴随着坚决但阻碍不断的钢琴的快速音群移入E大调，其行进过程不时被管乐器部加以修饰、注解，自然而然的转为D大调，转调手法之娴熟几乎无法察觉——这段音乐本身创造出一个微缩的喜剧世界。

In this thesis, we find that dlg is indispensible in the establishment of anterior-posterior and dorsal-ventral polarity of drosophila oocyte. Removal of Dlg function from the posterior follicle cells using the FLP/FRT system leads to disruption of oocyte skeleton reconstruction that is elicited by the failure of those posterior cells to differentiate normally in mid-oogenesis. We demonstrate that abnormity of Notch, JAK-STAT and EGFR signal pathway in dlg mutants contributes to this aberrant differentiation. dlg null mutant also blocks the normal differentiation of two groups of anterior follicle cell-stretched cell and centripetal cell, but not border cell, with a lower penetrance. However unlike the result in posterior follicle cells, Notch and JAK-STAT signaling are both undisrupted in all mutant anterior follicle cells, implying other fate determinants may be involved.

我们的研究发现，后端滤泡细胞中的Dlg在果蝇卵子发生中期卵母细胞前后轴和背腹轴建立过程中也是必须的，PFC中dlg完全缺失型突变引起PFC的分化异常，导致卵子发生中期卵母细胞骨架重组异常，Stau、Grk等极性决定蛋白定位错误。dlg突变阻碍了Notch、JAK-STAT、EGFR等调节PFC分化的信号通路的激活。dlg突变的PFC也没有获得前端滤泡细胞命运。dlg突变不影响前端滤泡细胞群中边界细胞的分化，但是在一定程度上影响伸展细胞和向心细胞的分化，并且这种影响不依赖于前端滤泡细胞Notch或JAK-STAT信号激活的异常。

The results indicated that the lignified seed shell had a negative impact on water permeability of seeds,but it was not the main reason for seed dormancy.

结果表明：(1)美国桂花种子木质化种壳对种子的吸水透性有一定的阻碍作用，但不是引起种子休眠的主要原因；(2)美国桂花种子的胚没有休眠，离体胚在光照培养7 d开始萌动；(3)胚乳被严密包裹的机械作用使胚无法获得萌发所必需的水分和氧气，这可能是导致种子休眠的最主要的原因。

Heidegger culturally misreads Zhuang Zi's poetic thought because of the heterogeneity between Chinese and Western cultures and the differences in academic ideals and academic personality. In this sense, there must be some differences between Heidegger's poetics and Zhuang Zi's poetic thought. But with the factual relationships and possible academic links between both and similarities between foundamental modes of thinking, general theoretical approches, major ways of thinking and basic ways of discoursing, most of the above-mentioned differences do not form obstacles to an effective exchange between Heidegger and Zhuang Zi, and on the contrary, form a 'hermeneutic distance'inciting a fresh dialogue and a fresh thought.

由于中西文化的异质性所带来的文化隔膜，再加之学术理念、学术个性的不同，海德格尔对庄子诗学思想也不可避免地存在着某些明显的&文化误读&（譬如，用《庄子·达生》篇&梓庆为〓&的故事去批评美学研究中&质料内容二分&的思维模式等等），海德格尔诗学与庄子诗学思想之间也不可避免地存在着一定程度的差异；但由于二者之间客观存在着的真实的事实联系与可能的学理联系，以及在根本的思维方式、总体的理论路向、主要的运思方法和基本的言说方式等方面的一致或接近，这些差别中的大多数并没有成为足以阻碍海德格尔与庄子进行有效交流的鸿沟；反倒成了引发新鲜对话、产生新鲜思考的&解释学的距离&。

Part three mainly explores therelationship between risk bearing and concerning systems,putting forward opinions such as that iffault guarantee liability of goods is not the obstacle of the transference of risk bearing,transference of risk bearing is not the obstacle of fault guarantee liability of goods;if the sellerdelivers the object to the delivery place according to the contract or the legal provisions while thebuyer does't accept the goods according to the agreement,or the goal of contract can't beachieved because that the object's quanlity can meet the requirement of the contract,the buyerrefuses to accept the object or rescinds the contract,the occupant has the obligation to keep it ingood condition and prevent the enlargement of damage or ease the damage according to theprinciple of good faith.

第二节，主要探讨了风险负担与相关制度的关系。如认为物的瑕疵担保责任不阻碍风险负担的移转，风险负担的移转亦不排斥物的瑕疵担保责任；在出卖人按照约定或依照法律的规定将标的物置于交货地点而买受人违反约定没有收取时，或者因标的物质量不符合质量要求，致使不能实现合同目的的，买受人拒绝接受标的物或解除合同的，货物的占有者或代为保管者基于诚实信用的原则应尽妥善保管的义务，防止损害的扩大或减轻损害。

Politic and statute play an important nole in adjusting economy,when economic entanglement affects the law,the law seems very important .

政治和法律是调节经济的重要杠杆，当这些经济的纠葛作用在法律上时，法律也就显的格外重要，尤其是在一个争议引起另一个争议的时候，调整民事诉讼的民事诉讼法就有着弥足珍贵的价值，而作为民事诉讼核心地位的第三人诉讼制度也就有着它举足轻重的意义，但是偏偏是这么一个重要的制度，我国的法律却存在着不健全，无论是法律条文还是在司法实践中，这么一个制度都没有发挥它应有的作用，甚至还在某种程度上阻碍了法制的进程，本论文就将在下面全面的剖析该项制度。

Politic and statute play an important nole in adjusting economy,when economic entanglement affects the law,the law seems very important .

政治和法律是调节经济的重要杠杆，当这些经济的纠葛作用在法律上时，法律也就显的格外重要，尤其是在1个争议引起另1个争议的时候，调整民事诉讼的民事诉讼法就有着弥足珍贵的价值，而作为民事诉讼核心地位的第3人诉讼制度也就有着它举足轻重的意义，但是偏偏是这么1个重要的制度，我国的法律却存在着不健全，无论是法律条文还是在司法实践中，这么1个制度都没有发挥它应有的作用，甚至还在某种程度上阻碍了法制的进程，本论文就将在下面全面的剖析该项制度。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。