二重的

If lecture classes were restricted to juniors and seniors, who are less in need of scholarly nurturing and more able to prepare work on their own, they would be far less destructive of students' interests and enthusiasms than the present system.

讲课这一方式不会完全从大学消失。一是因为讲课似乎从经济上是必需的，二是讲课起源于悠久的传统，而且人们又把传统本身看得很重。

Amino-5-acety laminobenzenesulfonic acid has been synthesized from 2, 5-diaminobenzene sulfonic acid and Acid Red BG (CI Acid Red 37) has been synthesized by coupling the diazonium salt of 2-amino-5-acetylaminobenzenesulfonic acid with racid.

利用2，5-二氨基苯磺酸为原料合成2-氨基-5-乙酰氨基苯磺酸，并进一步经2-氨基-5-乙酰氨基苯磺酸重氮盐与γ酸的偶合反应合成了酸性红BG（CIAcidRed37），并对影响反应的因素进行了讨论

The effects of larium salt, cerium salt and praseodymium salt on thermal stability of PVC were studied, the synergistic effects of rare earth stabilizers with PDOP,β- diketone and ESO were also investigated by heat aging test, witheness test, conductivity test and TG analysis.

通过热老化测试、白度测试、电导率测试和热重分析，研究了镧、铈、镨盐对PVC热稳定性能的影响，同时考察了辅助热稳定剂亚磷酸酯、β-二酮和环氧大豆油与稀土类稳定剂的协同效应。

The domains Ca2 and Ca3 are responsible for the dimerization of a-heay chains in immunoglobulin A molecules under natural conditions.

在天然状态下，IgA分子的Ca2和Ca3结构域负责重链的二聚体化。

Despite the tragedy of their origins in slavery, the Gullah have survived and revived to produce a

尽管来自奴隶的不幸出身，古拉人仍在二十一世纪的科技奇绩中浴火重火

The photosynthetic pigment contents, chlorophyll a/b rate, free proline, soluble sugar and malondialdehyde contents in the leaves of Hemerocallis fulva var. florepleno which was under different light intensities during their growth were studied.

对重瓣大花萱草进行不同程度遮荫处理，研究了其生长过程中叶片中的光合色素含量、叶绿素a/b值、游离脯氨酸、可溶性糖及丙二醛含量的变化及其生理特性。

The photochemical graft copolymerization of isoprene on the surface of tetrafluoroethylene-propylene copolymer was effected by external magnetic field.

我们已经报道了异戊二烯在四氟乙烯一丙烯共聚物的光化学接枝反应，并且证实了该反应是按三重态机理进行的〔l。

Two coordination polymers [Pb6(H2O)24]·3H2O(1)(H3cit=citric acid)and Pb(H2O)2(2)(tar=tartaric acid)were synthesized under hydrothermal conditions and characterized via IR,TG-DTA,C,H,N elemental analysis,XRD and single crystal X-ray diffraction analysis.

在水热条件下，合成了2个含柔性配体柠檬酸和酒石酸的二价铅配位聚合物[Pb6(H2O)24]。3H2O(1)(H3cit=citricacid)及Pb(H2O)2(2)(tar=tartaricacid)。用红外光谱、差热-热重、元素分析、粉末X射线衍射及单晶X射线衍射等手段对化合物进行了表征。化合物1属三斜晶系，P1空间群，a=0.97053(19)nm，b=0.9764(2)nm，c=1.0955(2)nm，α=109.016(3)°，β=98.380(3)°，γ=92.136(3)°，V=0.9671(3)nm3，Z=2，R1=0.0420，wR2=0.1049，GOF=1.064。

Density functional calculations predicted that both the ZrO3 and HfO3 molecules possess a closed-shell singlet ground state with a non-planar Cs geometry, in which the side-on coordinated O2 falls into the peroxide category.

结果表明ZrO3和HfO3都具有单重电子基态以及非平面的Cs构型，可以看作金属一氧化物二价正离子与过氧配体形成的络合物。

The purified IgY was reduced with dithiothreitol , and heavy chains and light chains were obtained.

纯化的IgY经二硫苏糖醇还原，得到重链和轻链。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。