环

The annulus model captures the key features of rotating convection in full spherical geometry and has been widely employed to study convection, magnetoconvection and dynamos in planetary systems, usually in connection with the small-gap approximation neglecting the effect of azimuthal curvature of the annulus.

圆环模型被广泛用来研究行星系统的对流，磁对流和发电机。通常在这些研究中用到了小间隙的近似，忽略了圆环的环向曲率效应。我们这一工作用数值模拟方法解完全的非线性对流方程组来研究有限间隙的旋转圆环中的非线性对流。

Our company specializes in manufacturing various stainless steel products, hardware accessories, marine hardware and other products, main products are as follows: Shackle (Bow type, Straight type, insurance, Japanese, Continental, American, reversing, rotary, fixed), chuck (Japanese, Continental, Americanê, German, American Forge, Din741), flower-lan (Japanese, American, Korean, closed), rotating ring (style, eye-eye , fork-eye), rings (Continental, Italian, Japanese-style), Pulley, Circle, D-rings, spring hooks, cargo hook, marine hardware (sleeve, slip cap, Smooth hinge base, side and base hinge, through-hole seat, single seat, etc.).

我公司专业生产加工各种不锈钢制品、五金配件、船用五金等产品，主要产品如下：卸扣（弓型，直型，保险，日式，欧式，美式，扭转，旋转式，固定式）、卡头（日式，欧式，美式玛钢，德式，美式锻打，Din741）、花兰（日式，美式，韩式，封闭）、旋转环（叉叉式，眼眼式，叉眼式）、套环、滑轮、圆环、D型环、弹簧钩、货钩、船用五金（滑套，滑帽，平滑底座绞链，侧而底座绞链，通孔座，单孔座等）。

Then can weld starting the resistance directly on the rotor winding, and cancel collecting the electric ring and electric brush.

将定子一种极数的磁场感应于转子绕组中的电流，通过集电环和电刷，但由另一种极数的磁场感应的电流，却自动流经另一闭合回路，而不通过集电环和电刷：于是，如果后一种极数是电动机的工作基波磁场，而把前一种极数作为用以起动的谐波磁场，则可以把起动电阻直接焊接在转子绕组上，而把集电环和电刷取消，从而出现了转子电路上无集电环、无电刷、无触点的谐波起动绕线型感应电动机。

Tricholoma may be a paraphyletic genus two. The collections identified as T. caligatum is a mixture. Some parts of them from France are members of T. matsutake, the other parts from North America are closed to T. bakamatsutake and T. fulvocastaneum. Tricholoma robustum and T. focale form a clade which is obviously a sister group of the stirp Subannulate. The stirp Caligata was defined as a group mainly on the basis of the predominant veil. But from the result of molecular systematic analysis, the presence of veil is not a stable character in the matsutake group. Species having symbiosis with conifers and broad leaf tree are all transformed from those whose host specificity is not strict. The phylogenetic tree based on ITS sequences resembled the tree of NJ algorithm based on cladistic coding. In the phylogenetic tree based on morphylogical characters, T. zangii and T. bakamatsutake form a clade, but it is the result of convergent evolution as suggested by molecular analyses. The distribution area of the matsutake group can be divided into six regions: middle and northern Europe region, Mediterranean region, Hengduan Mount.— Southeastern Tibet region, Northeastern China—Japan—Far-east Russia region, the Atlantic—North America region and the Rocky Mountain region. The abundance center of the matsutake group are Hengduan Mount.—Southeastern Tibet region and the Rocky Mountain region. Hengduan Mount.

松口蘑群的分子系统学研究得出的结果有：由于粗壮口蘑和羽衣口蘑明显和亚环族(Tricholoma，section subannulate)的种类是来自同一个谱系，和其它松口蘑群的种不具有最近共同祖先，因此松口蘑群是一个多系群；松口蘑群和口蘑属其他种类的亲缘关系比和蜜环菌属更接近；梭柄松苞菇和松口蘑群的差距明显小于油黄口蘑(T.flavovirens)和棕灰口蘑；口蘑属是一个多系群；鉴定为欧洲口蘑的标本明显不是一个单系群，其中一部分是松口蘑，另一部分和黄褐口蘑及傻松口蘑(T.bakamatsutake)比较接近；划分松口蘑群的标准是菌环的存在，但从分子系统学的结果来看，菌环的存在与否并非是一个很稳定的性状；和针叶树专性共生及和阔叶树专性共生均由寄主专化性不强的种类转化而来；在形态学系统发育树上青冈口蘑和傻松口蘑被聚为一个分枝，分子系统学的研究结果表明，这是趋同进化的结果；用支序方法编码作出的NJ树的结果更接近ITS序列的结果。

Cytochrome P450 BM-3 (CYP102) from Bacillus megaterium catalyzes the subterminal hydroxylation of long-chain fatty acids (C12 to C20) at the positions ω-1,ω-2,ω-3 and the epoxidation of unsaturated fatty acids. Artificial mutants of P450 BM-3 also hydroxylate substrates like short-chain fatty acids (C8 to C10), alkanes, cycloalkanes, heteroarenes and polycyclic aromatic hydrocarbons, which offers potential applications in the pharmaceutical industry, environmental measurement and bioremediation and chemical industry.

细胞色素P450BM-3来源于Bacillus megaterium，能催化长链脂肪酸C_(12-C_(20)的次末端(ω-1，ω-2，ω-3)羟化及不饱和脂肪酸的环氧化，其突变体催化的底物拓展到中链的脂肪酸C_8-C_(10、烷烃、环烷烃、杂环烃、多环芳烃等，因此在医药工业、环境检测和修复及化学工业具有广阔的前景。

CH3OH could attack the phosphor atom in 1,3,2-dioxaphopholane of compiound (1) to give O-methyl O-hydroxyethyl-O-phthalimidoethyl thiophosphate in 85% yield; in the presence of potassium hydroxide aryl selenol could attack the carbon atom in 1,3,2-diox-aphopholane of the cyclic phospholipid conjugate of N^1-(2-furanidyl)-N^3--5-fluorouracil to give the corresponding product of ring-opening in high yields.

在室温下，以异丙醇作溶剂，苯硒酚与化合物2不反应。在氢氧化钾存在下，以异丙醇／水作溶剂（体积比20：1，在室温下，硒酚可以有效地进攻中化合物2中1，3，2-二氧磷杂环戊烷中的碳原子生成相应的开环产物。按照这一反应条件，顺利实现了硒酚对N^1-（2-呋喃基）-N^3-羟烷基-5-氟脲嘧啶硫代环甘油磷脂缀合物的亲核开环，生成甘油骨架的端碳原子上带有芳硒基新颖的磷脂核苷缀合物。

Tolerance analysis aims to explore the effection of divided link on sum link, namely how to ascertain the assembled sum link"s tolerance if knowing all divided link"s dimension, tolerance and distribution parameter.

公差分析研究组成环对封闭环的影响，即已知各组成环的尺寸、公差及分布参数，确定最终装配后的封闭环公差。

In the second chapter, firstly, the definition of triangular matrix rings Γ, which is of order 3, is introduced.

在第二章中，我们首先引入了三级三角矩阵环Γ的定义，给出了三级三角矩阵环是左阿丁环、右阿丁环、阿丁R-代数的充分必要条件。

On the other hand, we also investigate the relation between the reduced left morphic rings and PS-rings, FS-rings and formal triangular matrix rings.

同时也讨论了约化的左morphic环与PS-环、FS-环以及形式三角矩阵环之间的关系。

A new method, step-search-diameter ,is presented to calculate the diameter of undirected double-loop networks G.

提出新的无向双环网络G的直径求解法———分步法；并得到一种新的直观图———螺旋环，研究了螺旋环的性质；给出了无向双环网络的直径d的显式公式；给出了N，s都固定的直径算法；在N固定，且2≤r

Shop assistant: Please check at the door.

店员：请您到门口柜台交费。

In the end, transportation of PAHs in the environmental matrix was preliminarily investigated and discussed according to PAHs data of soils and sediments from a certain region in Shanghai. The result indicated that there are two or more pathways on PAHs transportation in the environmental matrix.

最后，对上海特定地区内PAHs在环境介质中的迁移径途进行了分析讨论，结果表明上海市土壤和沉积物等环境介质中PAHs的迁移存在多种途径。