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One was HF/pyridine diazotization reaction at the 4-position of fluorene ring, and the other was Grignard reaction on the 9-position with Grignard reagent of pentafluorochlorobenzene.

使用HF/吡啶法在芴环的4位引入了氟原子，使用五氟氯苯格氏试剂在芴环的9位引入了全氟苯，合成了五个氟取代三联(9，9-二苯基)芴化合物。

It is well known that the acetonitrile (CH_3CN) can form stable complex compound with boron halide (BF_3). The sample was complexed in a platinum crucible by acetonenitrile and dissolved by HF: HNO_3 (3:1) solution in a pressure sample dissolver at proper temperature.

基于硼的卤化物(BF_3)能与乙腈(CH_3CN)形成稳定的络合物，将试样置于铂金坩埚内加入乙晴作为络合剂，用HF+HNO_3(3：1)在压力溶样器内加温溶解。

Different escharotic decide the different speed of reaction, thus to cause the great effect on stone carving speed, carving effect, for example, marble whose mainly component is carbonate, so it is better to choose escharotic made from HCI, while for granite , whose mainly component is silicate, it is better to choose escharotic made from HF

腐蚀剂类型的不同又决定了反应速度的差异，进而对雕刻速度、雕刻效果都会生产比较大的影响，例如，以碳酸盐为主要成分的大理石类石材，选择由HCl配制的腐蚀剂比较适宜；而以硅酸盐为主要成分的花岗石类石材，选择由HF配制的腐蚀剂比较适宜。

HF communication generally depends on the reflection of signals from the higher F layer and such signals must travel through the D layer at least twice.

HF 通信一般取决于信号的反射从更高的F 层数并且这样信号必须游遍D 层数至少两次。

Lanthanides belong to the sixth cycle of the periodic table Ⅲ B family, are all solid metal, they are La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, holmium, erbium, thulium, ytterbium, and lutetium were 15 kinds of metals and their periphery are two layers of electronic 5d16s2, while the peripheral third layer f orbital but never zero to 14, so the external electronic structure of 4f0-145d16s2, and therefore these elements in oxidation number are to 3, very close chemical properties, extraction, when it is difficult to separate them they are mostly multi-element mineral mix, more difficult to increase refining, and their atomic number of 57-71, one by one to increase the number of protons the nucleus, and thus extranuclear electron of gravity is also growing, so that atomic radius decreases with increasing atomic number Z, which makes lanthanides contraction, ionic radius is also reduced, which also makes Zr, Hf, Nb and Ta, Mo and W, the atom and ionic radius very close to each other they also determine a similar nature, resulting in difficult separation, also the tribe Ⅷ of the fifth cycle, ruthenium, rhodium, palladium, and the sixth cycle, osmium, iridium, platinum is very similar in nature, thus The six elements, said platinum group elements.

镧系元素属于周期表第六周期中ⅢB族，全部是固体金属，它们是镧、铈、镨、钕、钷、钐、铕、钆、铽、镝、钬、铒、铥、镱和镥共十五种金属元素，它们的外围两层的电子均是5d16s2，而外围第三层的f轨道电子却从零增加到14个，所以外围电子结构为4f0－145d16s2，而使这些元素氧化数均为＋3，化学性质极为接近，提炼时很难分开，它们的矿石又大多是多种元素混在一起的，更增加提纯难度，它们的原子序数为57－71，核内质子数逐个增加，因而对核外电子引力也不断增强，使原子半径随原子序数Z增加而减小，这就使镧系元素收缩、离子半径也缩小，这也使得Zr和Hf，Nb和Ta、Mo和W等原子和离子半径都很接近、也决定了它们彼此性质类似，以致难以分离、也使第Ⅷ族中第五周期的钌、铑、钯和第六周期的锇、铱、铂在性质上极为相似，因而称这六个元素为铂系元素。

To further explore the origin of the blue shift for C-H bond not directly participating in H-bond formation, we present a theoretical investigation on the complexes formed by formamide and small molecules such as HF et al.

为了进一步研究不直接参与氢键形成的C-H键蓝移的起因，我们对甲酰胺和HF等小分子形成的氢键复合物进行了理论计算研究。

Fluoride treatment included both excised leaves cultured in nutrient solutions and leaves from plants fumigated with HF.

氟化物处理既包括培养在营养溶液中的切离叶片和HF熏气的植株上来的叶片。

The structures of furan-〓 and the vibrational frequency of O-H were investigated by use of HF and DFT methods.

用HF和B3LYP方法对呋喃-水团簇的结构和团簇中水分子的O-H振动光谱进行了研究。

Applying atomic many-body theory to analyse the Goldston diagrams of effective Hamiltonian and wave operator about electron-electron correlation for open shell atoms, we use a simple method to evaluate the effective Hamiltonian and calculate the correlation effectes of Corbon with HFS model as a zeroth order approximation. Making contrasts with the experiment and the calculation based on HF model we get pleased results.

应用原子多体理论对开壳层原子中电子关联效应的有效哈密顿量及波算符的Goldston图进行了分析，在此基础上得到了计算有效哈密顿量的简单方法；以HFS模型为零级近似对中性碳原子基态的关联效应进行了计算并通过与实验结果及其他文献基于HF模型进行的计算相比较，得到了令人满意的结论。

Chapter 5 covered the quantum chemistry study of the model molecule (410 atoms) of HupA- Acetylcolinesterase complex at HF/4-31G level with point charge model (1929 point charges) to simulate the environment effect on complex active site.

第五章：用HF/4-31G量子化学方法对单分子状态石杉碱甲、活化状态的石杉碱甲以及石杉碱甲-乙酰胆碱酯酶复合物的模型体系（410原子，1929个点电荷）进行了从头计算研究，指认了对于形成稳定复合物贡献最大的石杉碱甲分子的基团和酶的氨基酸残基，揭示了活性位点中水分子的重要作用。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。