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Adsorption and desorption of acetylene on HZSM-5 and NaZSM-5 zeolites were investigated in the presence of trace water.

在80℃下，NaZSM-5上乙炔的饱和吸附量约为HZSM-5上的5倍。

The energy of excited state depended on the nature of different cations. 3. 4-(4-tolyl)-6-phenyl-2, 2'-bipyridine platinum acetylide complex containing a monoazazcrown moiety in the acetylide ligand could signal Mg〓 specifically and displayed large changes both in color and in luminescence intensity upon complexation with Mg〓. The most striking result was that it could signal Mg〓 specifically even in the presence of alkali and alkaline earth metal ions in high concentrations.

对位带有氮杂-15-冠-5冠醚的苯乙炔为辅助配体的4-（4-甲基苯基）-6-苯基-2，2'-联吡啶Pt络合物AC，不仅在碱金属和碱土金属的存在下吸收光谱明显改变，更有意义的是，它只有在Mg〓离子存在时能够发光，因此可以通过发射光谱选择性的识别Mg〓，尤其可以在高浓度的其它金属离子存在下选择性的检出Mg〓离子。

Nucleophilic opening of the terminalepoxide 57 by a lithium acetylide from 27 in the presence of BF3·EtO furnishedcompound 58, which had the skeleton of target molecule, subsequent conversionsinvolved the introduction of γlactone gave Annonacin.

然后以三氟化硼参与的炔负离子开环氧反应建立分子骨架，得到化合物58。随后经氢化，引入α，β不饱和丁内酯环、去保护等几步反应，就得到Annonacin。

Analogous complexes 3a" and 4a"= CpRu(PPh32, Ar = para-C6H4OMe containing methoxy group at the para-position of gem-diphenyl group were similarly obtained from protonation of the corresponding acetylide complexes via formation of vinylidene intermediate. But only complex 3a'= CpRu(PPh32, Ar2 = fluorenyl is stable in solution, and decomposed to unidentified complex when heated to reflux in THF. Deprotonation of complex 4a in the presence of base gives neutral acetylide complex 6a.

在两个相邻位置的苯基对位位置上接有一甲氧基的衍生物3a"和4a"也可利用类似的质子化反应合成，唯有错合物3a'= CpRu(PPh32， Ar2 = fluorenyl 可以稳定於溶液中，不会进行上述反应，如将其溶於四氢呋喃溶液加热至沸腾则会分解产生无法鉴定的化合物。

Test for acid content; test for the presence of an antibody.

对酸含量进行测试；对抗体的存在进行化验

In the presence of these other disorders, the assessment of a gap metabolic acidosis can be cloud ed.

但如果这些其它的紊乱存在的话，代酸间隙的分析就比较困难。

In the presence of these other disorders, the assessment of a gap metabolic acidosis can be clouded.

但如果这些其它的紊乱存在的话，代酸间隙的分析就比较困难。

In the presence of these other disorder s, the assessment of a gap metabolic acidosis can be clouded.

但如果这些其它的紊乱存在的话，代酸间隙的分析就比较困难。

It may mean no more than an acknowledgement of your presence .

它可能仅仅意味着对你出现的认可而已。

Science: Any natural force acting upon matter, any substance the presence of which produces phenomena, whether physical as electricity, chemical as actinism, oxygen, medicinal as chloroform, etc.

指在近代科学中，任何作用于物质的自然力，其出现会产生现象的任何实体，这现象可以是像电那样的物理现象，像光化作用那样的化学现象，……等等

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。