中分

Different parts of twenty dominant plant species in five plantation communities on the subtropical hilly lands in Heshan of Gunagdong as well as the litters from three of the five plantation communities were sampled, and their gross caloric value and ash content were measured by using a PARR-1281 oxygen bomb calorimeter and a muffle furnace.

从广东鹤山南亚热带丘陵5种人工林群落中采集20种主要植物器官及3种群落凋落叶样品，利用PARR-1281氧弹热量计和马福炉分别测定样品的干质量热值和灰分含量，再计算去灰分热值；按器官、个体和生长型等比较分析植物的热值和灰分特征。

The results show that as the crown density reduces the foresttype diversity increases and as the diversity goes up the stability of stand comes down; that the forest is under regressive succession and its stability now is the lowest; that the growth of spruce and fir trees has obviously a n...

结果表明：该林区的林分类型多样性随郁闭度的降低而增加，林分的稳定性随多样性的增加而降低，林分处于逆向演替过程中，林分的稳定性处于最低限；云、冷杉林与环境因子——海拔之间呈明显的负相关；在高海拔区云、冷彬林十分脆弱，一旦原有种群结构的郁闭度低于0.3，森林的稳定性将被破坏，即使在完全封禁的条件下，25年生的疏林要恢复到有林地状态，需要40年的时间。

The following exciting results are revealed: 1 When considering the influence of some nonlinear elements such as hard-limit of exciters, the effects of some devices such as Power System Stabilizer and Static Var Compensator which can introduce positive damping in power system, the reasonability of system parameter values in simulation, the SNB surface and HB surface on the boundary of SSSR will turn close to each other and even coalesce together; 2 Under some conditions, coupling between slow exciters and shunt capacitors will bring negative damping in power system dynamics, which increases the possibility of oscillatory instability. So the power system with mass shunt compensators is easily subjected to the oscillatory instability. In recent years, chaotic phenomena of power system have been reported many times. Some simulation studies even found chaos existing inside the power system SSSR. In this dissertation, chaotic phenomena in power systems are thoroughly studied in order to make clear the relation of chaos and SSSR. The following results are derived: 1 Based on Li-Yorke Theorem and their definition on the chaos, the existence of chaos in power system is verified; 2 Three possible routes of causing chaos in power system are found and deeply investigated. They are route of cascading period doubling, route of directly initial energizing and route of torus bifurcation (or quasi-periodicity). The latter two routes are investigated for the first time in power system stability studies; 3 When the stability conditions of chaos are broken, it is found they can lead to voltage collapse, angle divergence, or voltage collapse with angle divergence simultaneously.

针对在电力系统小扰动稳定区域内可能存在混沌吸引域的有关报道，本文深入研究了电力系统混沌现象的出现途径和与系统失稳模式之间的关系：1利用Li-Yorke定理和Li-Yorke的混沌定义，从理论上证明了电力系统混沌现象的存在性；2发现了电力系统中导致混沌出现的三种可能途径：倍周期分岔导致混沌、初始能量直接激发混沌和经由环面分岔导致混沌，并对后两种新发现的途径进行了较为细致的研究；3发现了混沌极限环破裂导致电压崩溃、角度失稳以及电压崩溃和角度失稳同时出现的现象，其中混沌极限环破裂导致系统角度失稳和电压崩溃及角度失稳同时出现的现象均属首次报道；4证明由微分-代数方程描述的系统模型，其小扰动稳定域的边界只包含HB、SNB和SIB三种分岔界面，在SSSR的内部和边界上，均不可能存在会导致混沌的点，从而将混沌现象排除在小扰动稳定域的研究之外，简化了后者的研究工作。

At first,the various fractals of different levels in astronomy and cosmology are introduced.

在引入天文学和宇宙论中不同层次的分形后，把它推广到任意直线型的泛分形理论和一般化的分形天文学。

The implementation of on-line monitoring of oil-dissolved gas for transformer tap changing switch contributes to correctly judge the faulty condition and extending trend of tap changing switch, to reduce the maintenance cost of tap changing switch as well as to improve the operational security and reliability of transformer.

对变压器分接开关实施油中溶解气体的在线监测，有助于正确判断分接开关的故障状态和发展趋势，降低分接开关的维护成本，并提高变压器运行的安全性和可靠性。

The thesis mainly concerns the following aspects: the relay protection and its trip-close circuit of two circuits transmission-lines are stand alone. The device has the ability of phase-trip that is owns transmission line single phase , 2 or 3phases fault only fault phase tripped.so as to making the power system contact as close as possible. The function of reclosing distribute into relay protection of line and breaker, so it is easy to get no-serious fault information of line protection and realize self-adapted multi pole reclosing. The breaker reclosing depend on the state of owns breaker andthe adjacent breaker. The criterion of serious fault and the sequence reclosing is simple and useful.

本项目具有如下特点：两回线的保护装置及跳、合闸回路完全独立；装置具有分相跳闸功能，即本线单相、两相、三相故障时均只跳故障相，使得故障时系统联系尽可能紧密；重合闸功能合理分配在线路保护和断路器保护中，充分利用了线路保护的信息实现无严重故障判别和分相顺序重合策略的自适应重合功能，由断路器保护根据断路器本身的工作状态和相邻断路器的配合关系实现重合出口；判断严重故障的判据及分相顺序重合闸原理简单合理，具有实用意义，降低了重合于永久故障对系统的冲击。

Inflorescence branching or unbranched, branches bearing terminal umbels; bracts usually absent; rays 4–40, unequal, erect to ascending in flower, spreading widely and lengthening in fruit; bracteoles 1–4, linear-lanceolate, unequal; umbellules very few flowered, 2–3(–5)-flowered; pedicels extremely unequal.

花序分枝或者不分枝，分枝生顶生伞形花序；苞片通常无；伞辐4-40，不等长，直立到上升的在花中，平展的宽和变长的在果期；小苞片1-4，线状披针形，不相等；小伞形花序的非常少的花，2-3(-5)花；花梗极其不相等。

Cases of AL were classified by morphologic and immunologic typings.

为了评价免疫分型在急性白血病分型中的科学意义，应用形态学分型、直接免疫荧光标记流式细胞仪检测免疫分型对68例AL进行了分析。

AbstractTo evaluate the significance of immunologic classification for typing of acute leukemia. 68 cases of AL were classified by morphologic and immunologic typings.

为了评价免疫分型在急性白血病分型中的科学意义，应用形态学分型、直接免疫荧光标记流式细胞仪检测免疫分型对68例AL进行了分析。

Moreover,in this dissertation,a method ispresented to control safe basin with the fractal erosion,that is by the application ofthe weak parameter periodic perturbation with an optimal frequency to control thefractal erosion basin,and the analytical study shows that the essence of the methodis that the parameter periodic perturbation can be used to delay the occurrence ofhomoclinic tangencies.

并且在本文提出了一种对分形侵蚀安全域进行控制的方法，那就是应用具有最优频率的参数周期扰动对于已受到分形侵蚀的安全域加以控制，在理论分析中得到这种控制分形侵蚀安全域的方法实质上延缓了鞍点同宿相切的发生，同时考虑了外加噪声对控制后安全域的影响，得到这种控制方法具有很好的鲁棒性。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐