查询词典 carbon

Using the basic principle of the color fading of Mn(Na2HP2O7)3, due to oxidizing by oxidizable organic matter at concentrated H2SO4 the effects of different concentrations of organic carbon compounds, colorimetric conditions (temperature, color developing time and colorimetric wave length) and some intervening ions on the colorimetric determination of dissolved organic carbon were systematically studied.

利用紫红色络合物Mn(Na2HP2O7)3在浓H2SO4存在时可氧化有机质使络合物颜色变浅的基本原理，系统研究了不同种类、不同浓度的有机碳化合物、比色测定的条件(温度、显色时间和比色波长)与一些干扰离子对水溶性有机碳比色测定的影响。

Monosaccharides are classified according to the umber of carbon atoms: a pentose has five carbon atoms and a bexose six.

根据碳原子数目可将单糖分类：一个戊糖有五个碳原子，一个己糖有六个。

We show that the combined oxygen and carbon isotope systematics are identical to those of well-understood Phanerozoic examples that lithified in coastal pore fluids, receiving a large groundwater influx of photosynthetic carbon from terrestrial phytomass.

他们得出一个引人注目的结论：这些氧和碳同位素的组合体系与我们非常了解的显生宙样品中的相同；显生宙样品岩化在了沿海的孔隙液中，接受着含有来自陆地植物质的光合作用碳的地下水流入。

We show that the combined oxygen and carbon isotope systematics are identical to those of well understood Phanerozoic examples that lithified in coastal pore fluids, receiving a large groundwater influx of photosynthetic carbon from terrestrial phytomass.

被广泛报道的新元古代碳酸盐中13C/12C 比例的下降并非是碳周期的波动，它们更容易通过与显生宙样品类比来理解。这个结果可能表明，在前寒武纪晚期，受由能够进行光合作用的藻类、苔藓和真菌构成的一层贴地覆盖物的影响，当时的地球正在发生"绿化"。

2 A kind of enzyme and mediator modified electrode is devised by immobilyzing both N-methyl phenazine sulfate and glucose oxidase on the surface of carbon glassy electrode (GOD-NMP-GC electrode), which successfully realizes the electron transfer process between glucose oxidase and carbon glassy electrode.

将NMP-GC电极与葡萄糖氧化酶结合，制作了GOD-NMP-GC电极，该电极可快速实现电极=NMP介体=GOD活性中心=葡萄糖之间的电子长程转移，并且用循环伏安法对酶催化反应进行了研究；用含丰富乳酸脱氢酶的乳酸杆菌与NMP-GC电极相结合，制作了介体微生物电极，并检测到GC电极=NMP=LDH活性中心=乳酸之间的非均相电子转移。

1 A mediator modified carbon glassy electrode (NMP-GC electrode) is made by immobilizing N-methyl phenazine sulfate as the mediator on the surfase of carbon glassy electrode, which successfully catalyzes the oxidation of NADH and reduce the over-potential of NADH almost 700mv.

采用N-甲基吩嗪硫酸酯作为氧化还原介体，制作了NMP修饰的玻碳电极，将该电极用于NADH的电催化，实现了NADH在NMP-GC上的可逆氧化还原，并且将NADH在电极上的过电位降低了700mv左右。

Therelationship of the amount of catalyst and the ee% of product was seen to be negative nonlin-ear. Catalyst 3 was used in the enantioselective addition of diethylzinc to aromatic aldehydesand gave good results. The configuration of products was determined by the configuration ofthe catalysts' chiral carbon linked with hydroxy group. Using β- amino alcohols bearing only one chiral center as catalysts for the enantiose-lective addition were studied. D-N, N-dialkyl-2-amino butanol gave poor catalytic effect be-cause of their structure. The configuration of the product is the same as the catalyst. Anotherkind of β- amino alcohols - phenylglycine derivatives and valine derivatives have chiralcenter on the carbon linked with amino group. Catalyzed by-phenylglycine derivatives 6,7, 9, 10, the reactions gave satisfied results. The optical yields exceeded 80%.

在探讨了含有两个手性中心的β-氨基醇之后，选择了只有一个手性中心的β-氨基醇，一是手性中心为连羟基的手性碳原子：D-N，N-二烷基-2-氨基丁醇；二是手性中心为连氨基的手性碳原子：D-苯基甘氨酸衍生物和L-缬氨酸衍生物。D-2-氨基丁醇的催化效果不太好，这与其结构的空间位阻较小有关系，反应产物与连羟基手性碳构型一致；由苯基甘氨酸和缬氨酸出发合成五种β-氨基醇6-10，研究了不同ee％的-6作用下的二乙基锌-苯甲醛加成反应，发现该催化剂具有不对称放大效应；-7，9，lO的催化效果也比较令人满意，光学产率80％以上，所得产物构型与催化剂构型一致。

The relative concentrations of oxygen and carbon dioxide in the surrounding air determine the balance of photosynthesis and photorespiration and thus the efficiency of carbon fixation .

环境中氧气和二氧化碳的相对含量决定了光合合成和光呼吸的反应平衡和二氧化碳固定的效率。

Pig iron is an alloy of iron and carbon with carbon content more than 2 percent.

生铁是一种铁碳合金，其含碳量在百分之二以上。

Pig iron is an alloy of iron and carbon with carbon content more than 2 per cent.

生铁是一种铁碳合金，其含碳量在百分之二以上。

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。