查询词典 silica

By means of X-ray diffraction, nitrogen adsorption, UV-Vis diffuse reflectance, a successful isomorphous substitution of titanium in the silica framework of SBA-15 samples with Si/Ti = 50, 25, 20 has been proved, the substitution of Ti for Si does not change the highly ordered two-dimensional hexagonal mesostructure of SBA-15. Titanium is totally tetrahedral and highly dispersed.

通过X射线衍射、N2气吸附脱附、紫外—可见漫反射等表征手段，证明在Si/Ti＝50，25，20时，钛原子成功地取代了SBA-15中的硅原子而没有改变SBA-15高度有序的介孔二维六角结构，其中钛全部以四配位状态存在，而且高度分散。

By controlling the process of sol gel, the charge storage stability of porous silica thin film electret based on silicon substrate were investigated by measurements of IR spectra, isothermal surface potential decay and current spectra of open circuit Thermally Stimulated Discharge.

通过控制溶胶凝胶工艺条件，利用相应条件下样品的红外光谱，等温表面电位衰减，开路热刺激放电电流谱等，考察了Si基多孔SiO2 薄膜驻极体体内沉积的空间电荷的储存稳定性，分析了各种工艺参数与薄膜驻极体性质之间的联系。

Analysis of the isothermal crystallization showed that the phenomenon is characterized by faster rates as the amount of silica is increased.

分析表明，等温结晶现象的特点是速度利率的数额二氧化硅是增加了。

Vegetarian alternatives include bentonite, kieselguhr, kaolin and silica gel.

素食替代品包括膨润土，矽藻土，高岭土和矽胶。

The catalysts were prepared by impregnation and precipitation method, and the active carbon,γ-Al2O3, silica and kieselguhr were selected as the carriers of catalyst. the effects of reaction conditions, such as reaction temperature, types of solvents, and types of hydrogen donors were investigated, It was found that the Pd/C catalyst was the best one, and its proper reaction conditions were also obtained as follow: sodium formate as hydrogen donor, water as solvent, reaction temperature of 70℃ and reaction time of 2.5h.

以活性炭、γ-Al2O3、硅胶和硅藻土等为载体，分别采用浸渍法和沉淀法制备了催化剂，对于反应温度、溶剂及氢供体的种类等反应条件的影响进行了研究，发现以沉淀法制备的Pd/C催化剂是对转移加氢最有效的催化剂，初步确定了适宜的反应条件为以甲酸钠作氢供体、水作溶剂及70℃反应2.5h等。

It was found that Pd-Co/active carbon catalyst was the optimal catalyst, and Pd-Co/γ-Al2O3 was also good, but silica and kieselguhr were not proper carriers for the object reaction, because of their stronger surface acidity, which could result in the formation of polymer, jammed the micro pores of catalyst, and then resulted in its deactivation. Addition of Bi, Ce and Cu promoters could not improve the activity of catalyst, but La and Ba promoter could enhance the activity of catalyst apparently, and the Co was the best promoter, especially Co was impregnate in advance. It was attributed to that the pre-impregnated Co may occupy the micro pores of active carbon, and cover some bad functional groups on the surface of catalyst, so that the active and selectivity of catalyst could be enhanced obviously.

研究结果表明，Pd-Co/活性炭催化剂是目标转移加氢反应的最适宜催化剂，Pd-Co/γ-Al203效果也较好，而硅胶和硅藻土由于表面酸性较强，容易造成生成聚合物而堵塞催化剂微孔、使催化剂迅速失活；此外，添加Bi、Ce、Cu等助剂时对活性并无改善作用，而添加La和Ba助剂时可使Pd的催化活性有所提高，效果最好的是Co助剂，尤其是先浸渍Co的Pd-Co/C催化剂，原因是Co占据了活性炭的微孔、覆盖了某些对目标反应不利的官能团，使其活性和选择性都有较大幅度的提高。

"Dynamite By mixing the nitroglycerin with kieselguhr, a porous silica-containing earth, in proportion s that left an essentially dry and granular material, Nobel produced a solid that was resistant to shock but readily explodable by heat or sudden impact."

诺贝尔将硝化甘油和硅藻土按照能形成基本干燥颗粒的比例混合，制成不怕振动、但受热或撞击后易于引爆的固体。

Eat : Lack of silica may result in lank hair, dull skin, and sores and receding of the gums.

吃： 缺乏硅酸将会导致头发稀少、皮肤粗糙和牙龈脆弱。

Methods: The cyclodextrin, concentration, pH, organic solvent were studied, and the results indicated that the enantiomer of ephedrin and ephedrine levorotatory were baseline separated under the following experimental conditions: uncoated fused silica capillary (75 μm× 68 cm), 25 mmol/L Tris, 2% HP-β-CD and 1% SBE-β-CD, pH was adjusted at 3.0 by phosphoric acid, and 15 kV separation voltage.

以SBE-β-CD和HP-β-CD二元环糊精为手性添加剂，探讨了环糊精种类及浓度、pH、有机溶剂种类等因素对麻黄碱及伪麻黄碱对映体拆分的影响，结果表明：毛细管：未涂渍熔融石英毛细管75μm×68 cm（有效长度60 cm）。分离用缓冲液为25 mmol/L的Tris缓冲液，含2.0% HP-β-CD和1.0% SBE-β-CD，用磷酸调节pH至3.0。

The suitable process parameters with high ratio of limonite were put forward through studying optimization of ore blending, different basicity, silica and MgO content of sinter, different size of limestone.

通过对烧结配矿优选试验，不同R、SiO2和MgO含量试验，不同的石灰石粉粒度试验结果的研究分析，提出了在高配比褐铁矿条件下适宜的配矿方案及合理的工艺参数。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。