查询词典 birch

Birch Reduction, one of the most powerful synthetic methodologies available to organic chemists, provides a bridge between aromatic and aliphatic compounds and makes a huge arsenal of aromatic derivatives readily available for construction of alicyclic molecules, which are possibly converted into various natural products.

Birch还原是联接芳香族和脂肪族化合物的桥梁，它使许多芳香族衍生物成为合成脂肪族化合物，尤其六元脂环天然产物的起始原料，因此Birch还原是有机合成中很有用的方法。

Next, based on the analysis of deficiency of BIRCH algorithm, we propose a new clustering algorithm based on sampling.

随后，在分析BIRCH算法不足的基础上，提出了一种基于抽样的聚类算法。

A fragrance introduced by the sensuality of birch wood, bergamot and bitter orange; juniper wood and artemisia mingle with cardamom, underlined by cold spices for the middle note; the base note finally emerges, sensually, releasing oak, cedarwood and vetiver, as an echo of the birch wood.

前香味以桦木、柠檬和苦柑橘为主，洋溢著感性的芬芳；中段以刺柏木、艾与小豆蔻为主调，搭配温凉的辛香；后段则由橡木、松与岩兰草所组成，逐渐散发出感性的馥郁，回应前段的桦木香。

Instead of calling on some scholar, I paid many a visit to particular trees, of kinds which are rare in this neighborhood, standing far away in the middle of some pasture, or in the depths of a wood or swamp, or on a hilltop; such as the black birch, of which we have some handsome specimens two feet in diameter; its cousin, the yellow birch, with its loose golden vest, perfumed like the first; the beech, which has so neat a bole and beautifully lichen-painted, perfect in all its details, of which, excepting scattered specimens, I know but one small grove of sizable trees left in the township, supposed by some to have been planted by the pigeons that were once baited with beechnuts near by; it is worth the while to see the silver grain sparkle when you split this wood; the bass; the hornbeam; the Celtis occidentalis, or false elm, of which we have but one well-grown;some taller mast of a pine, a shingle tree, or a more perfect hemlock than usual, standing like a pagoda in the midst of the woods; and many others I could mention.

我并没有去访问哪个学者，我访问了一棵棵树，访问了在附近一带也是稀有的林木，它们或远远地耸立在牧场的中央，或长在森林、沼泽的深处，或在小山的顶上；譬如黑桦木，我就看到一些好标本，直径有两英尺：还有它们的表亲黄桦木，宽弛地穿着金袍，像前述的那种一样地散发香味，又如山毛榉，有这样清洁的树干，美丽地绘着苔藓之色，处处美妙呵，除了一些散在各地的样本，在这乡镇一带，我只知道有一个这样的小小的林子，树身已相当大了，据说还是一些被附近山毛榉的果实吸引来的鸽子播下的种子；当你劈开树木的时候，银色的细粒网闪发光，真值得鉴赏；还有，椴树，角树；还有学名为Celtis occidenta lis的假榆树，那就只有一棵是长得好的；还有，可以作挺拔的桅杆用的高高的松树，以及作木瓦用的树；还有比一般松树更美妙的我们的铁杉，像一座宝塔一样矗立在森林中；还有我能提出的许多别的树。

Birch of western United States resembling the paper birch but having brownish bark.

美国西部的一种桦树，类似于纸皮桦，但是树皮棕色。

This paper took the insect-resistant transgenic birch grown in greenhouse for four years as study materials. The genomic DNA and RNA of leaves were extracted and the integration and the expression characteristic of the extraneous genes in the insect-resistant transgenic birch were analysed by methods of multiplex PCR, reverse primer PCR, inverse PCR, RT-PCR, and insect-feeding experiment of the transgenic plants respectively.

本文以温室四年生转抗虫基因白桦为研究材料，提取叶片的基因组DNA和RNA，运用多重PCR，反向引物PCR，反向PCR和RT-PCR等方法，并结合转基因白桦的喂虫实验，分别对转基因白桦外源基因的整合特性和表达特性进行分析，所得结果如下： 1。

The main reason why quarter-sawn board of Birch had smaller dry compressing shear strength than flat-sawn board of Birch in normal conditions was that Birch had different shear strength to the grain between quarter-sawn board and flat-sawn board. Meanwhile xylary rays in flat-sawn board were transversely cut and left a lot of pores in the flat-sawn board, so adhesive can enter these pores and turn into adhesive nail. While these pores provided a kind of tunnel for water, so cause this phenomenon that wet compressing shear strength of flat-sawn board of Birch was smaller than that of quarter-sawn board of Birch. The possible reason why quarter-sawn board of Oak had greater dry compressing shear strength than flat-sawn board of Oak in normal conditions was that ratio of springwood on quarter-sawn board and flat-sawn board was different.

造成柞木径切板的常态压缩剪切强度比弦切板的常态压缩剪切强度大的主要原因是，在径切板和弦切板上早材胶接的比例不同，径切板的胶合强度试件上早材胶接的比例相对少，而弦切板的胶合强度试件上早材胶接的比例比径切板的胶合强度试件上早材胶接的比例相对大，由于早晚材胶接过程中强度决定于早材，这部分胶接强度比较低，这就使得柞木径切板的常态压缩剪切强度比弦切板的大；同时在柞木弦径面胶接过程中由于实际胶接面积的不同也能造成弦径面上API胶粘剂与之形成的化学键的数量不同，这也是造成柞木径切板的常态压缩剪切强度比弦切板的大的原因之一。

We have: Chinese South West White Birch, Alder, Chinese Mahogany, Chempaka,Chinese Northeast Birch, Basswood, Kashiwa Oak, Tulipwood, Chinese Ash, IPE, Tonkabean Cumaru, Macaranduba, Tauari, Walnut, Sapele, Maple, Red Oak, White Ask, Cherry, Cedar, Tata Juba Bubinga Sucupira ect including domestic and imported veneers and bamboo veneer.

工厂生产的木皮品种有：五角枫、白椿、国产黑胡桃、国产白元、铁杉、国产红樱桃、国产红檀、拐枣、香柏、西楠桦、白桦、白松、白木莲、铁椿、白胡桃、桃花芯、东北桦、椴木、柞木、楸木、水曲柳、紫檀、黄花梨、黑胡桃、红橡、白橡、樱桃、沙比利等各类国产及进口木皮。

Shuaiqi Company can supply the following products in large quantity throughout the year as:(1) Species of the Northeast:manchurian-tree wood, oak solid wood, birch, basswood, mongolian scotch pine, Korean pine, cembra pine, white beech, elm wood, and aspen wood, etc.(2) Species of Yuannan: Birch wood, white birch, rubber wood timber, gold teak veneered wood, etc.(3) Rotary species: peach, Okoume, basswood, birch wood, poplar, padauk wood, etc.(4) Imported species: red rubber, cherry, black Walnut, Thailand teak, sapelli, ayous, etc.

帅琦公司可以为您常年大量供货：（1）东北品种：水曲柳、柞木、桦木、椴木、樟子松、红松、节松、楸木、榆木、杨木等天然树种；（2）云南品种：西南桦、白木莲、白桦、橡胶木、金丝柚、黄云香、山香果树瘤等天然树种；（3）旋切品种：桃花芯、奥谷曼、柳桉、山桂花、大白木、黄云香、椴木、桦木、白杨木、花梨木等；（4）进口品种：红橡、樱桃、黑胡桃、沙贝利、泰柚、黑檀、花梨、铁刀、艳阳花等天然树种。

In measurements of a day,generallyspeaking,the photosynthesis of birch in mesophytic habitat is better than that in xerophytichabitat(peak values are 12.8,10.33μmolCO2m-2s-1 respectively);that of sexual birch inmesophytic habitat is better than that of clone birch(peak values are 9.87,6.71μmolCO2m-2s-1respectively);that of young tree is better than that of seedling(peak values are12.37,10.05μmolCO2m-2s-1 respectively).

在一天中的各个时刻，总体说来，中生生境生长的白桦光合作用超过旱生生境生长的白桦光合作用(净光合速率峰值分别为12.8、10.33μmolCO2m-2s-1)；白桦幼树的光合作用超过白桦幼苗(净光合速率峰值分别为12.37、10.05μmolCO2m-2s-1)；中生生境有性白桦的光合作用超过无性白桦的光合作用(净光合速率峰值分别为9.87μmolCO2m-2s-1、6.71μmolCO2m-2s-1)。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。