选择性的

This protocol could also be used for the selective reduction of the endocyclic double bond of the 3-electron withdrawing group substituted coumarins. This method is clean, mild, and efficient.2 ZrCl_4 / HEH was found to be a selective and efficient reagent combination for the direct reductive amination of electron rich aldehydes and ketones with weakly basic amines after scanning various catalysts such as InCl_3, BiCl_3, CF_3COOH and so on.

图一 1。我们用汉斯酯作为有机还原剂，乙醇为溶剂，实现了4-甲叉基噁嗯唑酮和吡唑酮环外双键的高选择性还原；此外，我们还将这一还原体系用于3-吸电子集团取代-3，4-二氢香豆素环内双键的选择性还原。

To improve the selectivity, the Co/Mn/Br catalyst system with ethanal as an additive was studied and the reaction conditions were also optimized, which were as follows:the amount of ethanal 10%(mole ration base on the substrate), reaction temperature 100℃,reaction time 30min,the oxygen pressure 0.2MPa, the amount of the composite catalyst Co/Mn/Br 7%,the mass ration of different ingredients 2:2:1. Under these conditions, the yield comes to 24.10% and the selectivity reaches 75.03%.

为了提高反应的选择性，论文初步研究了以乙醛作为添加剂条件下各工艺参数的影响，并进行正交优化，得出最佳条件为：乙醛加入量1：10，反应温度100℃，反应时间30min，氧气压力0.2MPa， Co/Mn/Br混合催化剂加入量7%，质量比2：2：1，在此条件下，反应产率为24.10%，选择性可达75.03%。

In the forth part, in the presence of chiral phosphoric acid, highly enantio-enriched (up to 98% ee)α-aryl glycine derivatives could be synthesized via asymmetric transfer hydrogenation of the α-aryl imino esters using Hantzsch ester as the hydrogen source.

第四部分工作中，利用Hantzsch酯作为氢源，高对映选择性地实现了手性磷酸催化芳基酮酸酯亚胺的不对称仿生氢化反应，以最高98％的对映选择性得到苯甘氨酸衍生物。

The regioselectivity observed experimentally is predicted correctly by theoretical calculation and is determined kinetically.

计算结果不仅正确预测了实验所发现的完全的区城选择性，而且表明这种选择性由动力学因素所决定。

Structure preferences of megalopae and first juveniles decreased consequently among grassy type, cavity type, knuckling type shelters and also decreased with increasing sizes (5, 7, 10 mm).

其中，对草丛型、洞穴型和折角型隐蔽物的选择性依次降低，对5.7和10mm隐蔽物的选择性也依次降低。

Results Compared with percutaneous coronary angiography,the sensitivity of sixteen slice sparil CT in diagnosing moderate and severe coronary stenosis was 83.33%,and the specificness,positive predictive value,negative predictive value and degree of accuracy was 91.40%,85.59%,89.95% and 83.33% respectively.

对16层螺旋CT显示冠状动脉狭窄和经皮选择性冠状动脉造影显示冠状动脉狭窄进行定量评价。以经皮选择性冠状动脉造影结果作为诊断的金标准。计算出16层螺旋CT冠状动脉成像对冠状动脉狭窄的诊断准确性指标。

The former was underlain by both attention-based rehearsal and attentional biased competition, while the latter was only the consequence of attention-based rehearsal.

选择性注意和客体工作记忆，与选择性注意和空间工作记忆两种交互关系的实质是不同的。

The methods for controlling bottom water coning in horizontal well of offshore oilfield are presented.

对南海涠洲11-4油田C4水平井底水脊进的原因进行了分析，提出利用选择性堵剂和选择性注入及过顶替的方法来控制底水脊进。

The female weevils oviposited on mung beans as well as adzuki beans in no-choice test, while they preferred adzuki bean over mung bean in choice test. To study the relationship between oviposition behaviour and host preference, three treatments (A: pure adzuki beans; M: pure mung beans; Mixed: mixed adzuki beans with mung beans) were provided to the female.

过去的研究报告指出，雌豆象成虫利用相对法则检视寄主品质，以决定是否产卵於寄主豆上；而且在非选择性试验中，雌虫产於绿豆或红豆的卵数相等；但在红、绿豆选择性试验中，雌虫则偏好产卵於红豆。

Objective To evaluate clinical applications of Roberts uterine catheterand to discuss techniques of selective catheterization of uterine arteries.Methods 469patients underwent selective uterine artery cathe terization and further intervenioen therapy,time needed for selective catheterization and catheter-related comˉplications were recorded.

目的 评价罗伯特子宫动脉导管的临床应用价值并探讨子宫动脉选择性插管技术方法使用罗伯特子宫动脉导管对469例患者进行选择性子宫动脉造影和介入治疗，统计插管所需时间及与导管操作相关的并发症。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷