还原

Mehods Commercially available glycine ethyl ester hydrochloride was used as starting material to give the target compound via addition, protection with BOC, Dieckmann cyclation, reduction with NaBH4 and LiAlH4, protection, oxidation, oximation and deprotection.

以甘氨酸乙酯盐酸盐为原料，依次经加成、BOC保护氨基、Dieckmann环化、NaBH4还原羰基、LiAlH4还原氰基、BOC保护氨甲基、氧化、肟化、脱BOC保护等9步反应制得目标化合物。

Self-made tungsten trioxide (WO_3) by calcining ammonium paratungstate was selected as the raw material to produce ultrafme and homogenous tungsten powder by oxidation-reduction method.

通过研究，得到如下结论：(1)本研究选取的三氧化钨原料，通过氧化—还原法(4次氧化5次还原)是可以制备出超细钨粉的；所得金属钨粉的平均粒度约为0.38μm。

The results of asymmetric reduction of latent chiral ketones by carbonyl reductase showed that the enzyme had a high specificity for pentanone in aliphatic ketones and for the acetophenone derivates that contained a withdrawing group at α-position.

利用羰基还原酶不对称催化还原潜手性酮类化合物发现，对于芳香酮类化合物，酶对α位为强电负性基团的底物专一性较强；对于脂肪酮类化合物，酶对五碳脂肪酮的专性较高。

Methods Male New Zealand white rabbits were exposed to pentavalent arsenate and trivalent arsenite 5 mg/L for 18 weeks, respectively. Levels of thioredoxin, protein and non-protein sulfhydryl and the activity of thioredoxin reductase and glutathione reductase in liver, and the levels of inorganic arsenic, monomethylarsonic acid and dimethylarsinic acid in blood, urine, and hair were measured after that.

家兔以自由饮水方式慢性暴露于无机3价砷及5价砷，18周后，测定肝脏组织中蛋白巯基、非蛋白巯基、硫氧还蛋白水平，以及硫氧还蛋白还原酶、谷胱甘肽还原酶活性，同时检测血、尿及毛发中无机砷及其代谢产物甲基砷和二甲基砷。

While in photoreduction of Cr , the titania-modified MCM-41 photocatalysts were more photoactive than the titania-silica composite (25％ TiO〓).

在光催化降解苯酚中氧化钛修饰MCM-41的光催化活性虽然不及结晶的锐钛矿相纳米氧化钛，但是仍具有较高的催化活性；在光催化还原Cr到Cr反应中氧化钛修饰MCM-41的光催化还原性明显高于部分结晶的TiO〓-SiO〓（25wt％TiO〓）复合氧化物。

The photoreductive reactions prove that the natural sphalerite sample exhibits a high photoactivity on reducing methyl orange under visible light irradiation, which is consistent with its specific characterization.

与其特殊的物理化学性质相符，天然闪锌矿光催化还原降解甲基橙的实验证明了其较高的可见光催化还原活性。

The aluminium powder has been used to reduce titanium tetrachloride to generate the low valent titanium reagent which can induce the reductive coupling of aldehydes and ketones to form the corresponding pinacol s.

以价廉易得的铝粉还原四氯化钛制得低价钛，将其用于醛酮还原偶联，合成了6种片呐醇，其中对称片呐醇4种，不对称片呐醇2种。

The feature of the shaft furnace-iron bath smelter charging carbon-bearing pellets is that partial off-gas of shaft furnace is mixed with gas from smelter and then put into shaft for preheating and pre-reduction. The optimum operational parameter is at the point of prereduction degree of 52% and post-combustion degree of 32% where the coal consumption is 750kg/tone-hot metal and oxygen consumption is 420Nm〓/tone-hot metal.(5) The systematic simulation of rotary hearth furnace-iron bath smeter is firstly formulated.

4本文建立的含碳球团竖炉—铁浴工艺流程模型的特点之一是竖炉炉顶出口煤气的一部分与铁浴煤气混合后，重新进入竖炉，本文报道的对系统部分出口物流返回反应器的非序贯式流程进行的系统模拟，为今后类似问题的模拟提供了参考，本工艺的最低消耗点的操作条件是：预还原度52％，二次燃烧率32％，这时的最低煤耗为750kg／tFe（中挥发份煤VM=19％），氧耗约420Nm〓／tFe，对应于预还原度30～70％的优化组合的二次燃烧率为32～13％。

Thirdly, selective catalytic reduction of NO with propene over Cu ion-exchanged Al-MCM-41 has been studied.

在氮氧化物催化还原的活性评价实验中，考察了铜离子交换的Al-MCM-41对丙烯选择还原一氧化氮的催化活性。

Because the temperature of coal volatile pyrogenation differs from the temperature of reduction of iron oxide by H2, H2 releases at the initial stages of reduction, and the reduction efficiency of hydrogen is very low.

由于煤中挥发分的热解析出温度与氢还原铁氧化物的还原温度不一致，氢在还原初期迅速放出，导致氢的还原作用率低；提高温度和加热速度可提高煤中氢的还原作用率和挥发分的利用率。

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。