信息化教学在现代职业教学中的运用——评《职业教育信息化研究导论(第2版)》

介绍了化学热力学基础和葡萄糖体内氧化的3个阶段。葡萄糖体内外氧化符合化学热力学原理中的盖斯定律;酶参与和ATP的引入提高了反应活化分子数,实现了常温常压下的葡萄糖体内氧化;葡萄糖体内氧化的多步骤有助于获得最大非体积功,且多步反应可以有效调控能量在体内的释放速度;葡萄糖体内氧化的前2个阶段证明了葡萄糖可以适应不同条件为生物体提供能量,且不同阶段的中间产物也在生命活动起着重要作用。通过延伸讨论揭示了ATP在葡萄糖体内氧化的三重作用,作为能量形式提高反应活化分子数和存储能量,同时ATP还具有催化剂的特点。     

葡萄糖体内氧化中的化学热力学原理

介绍了化学热力学基础和葡萄糖体内氧化的3个阶段。葡萄糖体内外氧化符合化学热力学原理中的盖斯定律;酶参与和ATP的引入提高了反应活化分子数,实现了常温常压下的葡萄糖体内氧化;葡萄糖体内氧化的多步骤有助于获得最大非体积功,且多步反应可以有效调控能量在体内的释放速度;葡萄糖体内氧化的前2个阶段证明了葡萄糖可以适应不同条件为生物体提供能量,且不同阶段的中间产物也在生命活动起着重要作用。通过延伸讨论揭示了ATP在葡萄糖体内氧化的三重作用,作为能量形式提高反应活化分子数和存储能量,同时ATP还具有催化剂的特点。     

酶的化学(上)

Ⅰ绪言 1.生物体内的化学反应生物体其有—定的物质组成。在这具有一定物质组成的生物体内,一串互相联系的化学反应不断进行。例如,在消化过程中,分子构造比较复杂的食物水解成为分子构造比较简单的代谢物质;在生长过程中,分子构造比较简单的物质结合成为分子构造比较复杂的体内成分;在生物氧化过程中,代谢物质经过一系列化学反应,最后生成H_2O及CO_2。这种例子很多,不胜枚举。因有这些反应在体内进行,生物体才能与其周围环境进行物质交换。根据估计,人在其一生     

血红蛋白在纳米金修饰电极上的电化学研究

氧化还原蛋白在电极上的直接电化学研究不但能获得有关蛋白质和酶的热力学和动力学性质等重要信息,为开发新型生物传感器和生物反应器提供理论指导,而且对了解它们在生命体内的电子转移机理和生理作用机制具有重要意义。血红蛋白(Hb)是以血红素为辅基的蛋白质,在生物体中的主要     

生物体内的能量使者——ATP

众所周知,生物体中许多生命活动过程都需要消耗能量。那么,生物体内的能量都怎样产生、释放、转移、贮存和利用的呢?     

分子内激光选择化学及其发展

一、引言我们知道,在热力学上一个可以进行的化学反应,往往需要供给以能量才能以可观的速度(或在有限的时间内)进行或完成。凡研究以光的形式供给反应体系以能量使其反应进行者称为光化学。故研究以激光的形式供能给反应体系使反应进行者,则为激光化学。自然界的     

肌球蛋白中金属离子与ATP相互作用及其催化ATP水解的研究进展

生物体内细胞在氧化物质的过程中释放出的大量自由能,这些能量先形成高能磷酸化合物三磷酸腺苷（adenosine 5′-triphosphate,ATP）,当ATP水解为ADP（二磷酸腺苷,adenosine 5′-diphosphate）和无机磷酸时.     

肌球蛋白中金属离子与ATP相互作用及其催化ATP水解的研究进展

生物体内细胞在氧化物质的过程中释放出的大量自由能,这些能量先形成高能磷酸化合物三磷酸腺苷（adenosine 5′-triphosphate,ATP）,当ATP水解为ADP（二磷酸腺苷,adenosine 5′-diphosphate）和无机磷酸时.     

中学化学中常见的无机反应判据

在热力学和电化学中,通带以反应体系自由能变化(△G)和氧化还原反应电势差(ε)作为化学反应能否自发进行的判断,一般说来,(△G)0,化学反应可以向指定方向自发进行。     

细胞色素c在咔唑修饰的金电极上的直接电化学

在生物体内,细胞色素c是一种电子载体,它能进行可逆的氧化还原反应,但在金属电极上的电化学反应却不可逆。1977年,Hill研究组发现,在4,4′-联吡啶存在时,细胞色素c在金电极上能进行准可逆的电化学反应。4,4′-联吡啶在细胞色素c电化学反应的过程中不起氧化还原反应而被称为促进剂。Hill等对50多种有机化合物的促进作用进行评价后提出,能加速细胞色素c电化学反应速率的促进剂分子至少应具有两个功能团。表面增强拉曼光     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.