前顶极群落

Asian (47.4%) and temperate genera mainly constituted by North temperate (50%) and E. Asian (50%). So that the geographical elements are discomplex. In the 25 species of arborous layer, 76% is the middle subtropical zonal type, 16% south subtropical zonal type and 8% north subtropical zonal type, of which the first 6 positions of important value index were all middle subtropical zonal type. This showed that the community was subtropical characteristic. There are 59.5% evergreen and 40.5% deblade of 79 known species in which the mid-phaenerophytes is the first position of all, accounting for 27.8%, and the evergreen broad-leaved species constituted the majority of meso-phaenerophytes which accounts for 15.2%.

乔木层多数优势种为稳定型种群，所以乔木层优势区系成分相当稳定，表明该群落为一种顶极群落。59个种子植物属只有10个分布区类型和4个变型，地理成分不复杂，其中热带分布27属占46.6%，温带分布31属占53.4%；热带分布以泛热带和热带亚洲分布为主，分别占52.6%和47.4%，温带分布为北温带和东亚分布各占50%。25个乔木层树种中，中亚热带地理分布类型的占76%，南亚热带地理分布类型的占16%，北亚热带地理分布类型占8%，重要值指数排列前6名的均为中亚热带地理分布类型，所以该群落为亚热带性质。

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