交换

Anion exchange and solvent extraction are used to separate and purify Re.

Re的分离方法仍然是离子交换和溶剂萃取法。

The yield of the 3, 4-dihydropyrimidine-2(1H)-one was up to 95.4% under mole ratio of anisaldehyde, methyl acetoactate and urea is 1:2:5, ion-exchange membrane is 3 g, ethyl alcohol as solvent and refluxing for 2 h.

当对羟基苯甲醛、乙酰乙酸甲酯与脲的摩尔比为1：2：5，乙醇作溶剂，3 g离子交换膜，回流2 h，产物收率达95.4%。

Methoxycarbonyl-4-(4-methoxyphenyl )-6-methyl-3, 4-dihydropyrimidine-2(1H)-one was synthesized from anisaldehyde, methyl acetoactate and urea in presence of HF-1O1 strong acidic ion-exchange membrane.

在HF-101强酸性离子交换膜的存在下，由对羟基苯甲醛、乙酰乙酸甲酯与脲一步合成了5－甲氧羰基－4－（4－甲氧苯基）－6－甲基－3，4－二氢嘧啶－2(1H)－酮。

By analyzing the differences between acidic and basic catalytic action in this transesterificatios, it is considered that the main cause of yielding an anisole by-product is due to the basic catalysis, a Lewis acidic catalyst is helpful for the selective DPC formation.

通过分析酸碱催化作用在酯交换反应中的差异，认为碱催化是副产物苯甲醚生成的主要原因，Lewis酸性的催化剂有利于碳酸二苯酯的高选择性。

When metal oxides were supported on γ-Al〓O〓, higher conversions of phenol were obtained, but the selectivties to anisole, a by-product, were also higher.

在使用负载型催化剂催化苯酚与DMC的酯交换反应中，γ-Al〓O〓作载体时的催化性能比SiO〓作载体时好，但产物中苯甲醚的选择性也相对较高。

With this standard method, simultaneous quantification of DMC, MPC, DPC, phenol and anisole can be achieved accurately, which provide the standard methods for evaluation of different catalysts and control of the reaction process. The microwave-aided catalytic technique was applied in the transesterification of DMC and phenol.

分别以苯甲酸乙酯和丙酮为内标物，实现了对酯交换反应塔釜产品和塔顶馏分的同时定量，为评价催化剂活性的高低和工艺条件的优劣提供了标准化分析方法。

But the concentration of Li2CO3 remains nearly consistent and a new component, CH3OLi, is found in SEI. It can be concluded from these results that anisole reacts with the reduction product of EC and DEC, RCO3Li, in the first process of Li＋ intercalating into the carbon electrode. The obtained CH3OLi is helpful in building up a more effective and stable SEI of the carbon electrode, reducing the cointercalation of solvent molecular. All these contribute to the improvement of the cycle performance of lithium-ion battery.

根据以上分析结果，提出了苯甲醚对锂离子电池循环性能的影响机理：在Li＋嵌入石墨电极的初次过程中，苯甲醚和EC、DEC的还原分解产物RCO3Li发生基团交换反应，生成CH3OLi，该产物能有效提高石墨电极表面SEI的稳定性，减少锂离子嵌入石墨过程中引起的溶剂分子共嵌入，从而改善电池的循环性能。

To understand the thermodynamic process of the transesterification, the thermodynamic properties (△r H o,△r S o,△r G o, K p ) of the reaction for production of DPC and anisole from 373 K to 473 K was calculated by using Material Studio and ChemCAD software as well as Benson and Joback group contribution methods.

DMC与苯酚酯交换合成DPC反应热力学方面的研究报道很少，散见于一些工艺设计专利中，且都未对数据来源做详细介绍，很难对数据的可靠性进行验证。

After staving off sleep during the rituals of his official anointment by the Roman priests, Mark Antony finds Pompey and his men, greeting them irreverently before offering Caesar's terms: to avoid bloodshed, he wishes to command a single legion provence, in exchange for immunity from a Senate war tribunal.

强忍着睡意，Mark Antony参加完了由罗马教父主持的官方任命仪式，然后他Pompey和他的支持者们，傲慢的向他们打了个招呼，然后转达了Caesar的条件：为了避免流血，他希望交出一部分兵权，只指挥普罗旺斯军团，做为交换，元老院不对他的进行战争罪的指控。

Under the conditions of stir speeds 400 r·min~(-1) and distance between anode and cathode 1 mm, by using the orthogonal design, the optimum technological conditions were found that the current density was 0.3 A·cm~(-2), initial NaOH concentration in catholyte was 50 g·L~(-1), reaction times of two steps were all theoretical electrochemical reaction times. In the first electrosynthesis, initial Na_2CrO_4 concentration in anolyte was 650 g·L~(-1), and reaction temperature was 80℃. In the second electrosynthesis, initial Na_2Cr_2O_7 concentration in anolyte was 700 g·L~(-1), and reaction temperature was 85℃.

324全氟磺酸增强复合阳离子交换膜、阴阳极液中搅拌速度均为400r·min~(-1)条件下，通过正交实验得到优化工艺条件为：电流密度0.3A·cm~(-2)，阴极液氢氧化钠初始浓度50g·L~(-1)，两步反应时间均为理论电催化反应时间，第一步阳极液铬酸钠初始浓度650g·L~(-1)，反应温度80℃，第二步阳极液重铬酸钠初始浓度700g·L~(-1)，反应温度85℃。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。