奇人杨根连

磨玉如磨人——杨根连磨出来的不仅是玉雕绝技,磨出的更是自己的人品。4月的京城,风依然大。在一间不起眼的地下室里,杨根连正气定神闲地做着手里的活儿。灯光下,金丝楠木做的工作台闪烁着大气而高贵的光泽。杨根连经营着一家业内有名的玉器行,然而让他誉满京城的,却是其身怀6项独门宫廷玉雕绝技,而且还恢复了曾两度失传的＂金镶玉＂工艺。因而,他做的薄胎玉器和金镶玉被称为＂中国玉雕界的劳期莱斯＂。     

扬州·玉作缘

品牌档累品牌名称：扬州玉器厂创办时间：1956年创办人：8位扬州玉雕老艺人经营内容：玉器、雕塑工艺品传承人：顾水俊、江春源、高毅进、薛春梅＂红风车,转一转吧,福来我家。＂提到扬州,便想起这首古装片里的童谣,朗朗上口,配合纯白皎洁的琼花,随风飘扬,寄托着无限美好和希望。     

金银错满西域情

他是金银和玉石再次完美交融的推手,同时也用几十年的不懈努力,开创了当代新疆玉雕的独特风格。在众多玉雕大师新作中,有一种玉雕,在玉器表面镶嵌金银纹饰以及珍贵宝石,造型独特,华贵雍容,充满西域风情。不用说,这些作品定然来自新疆,出自＂马爷＂之手。     

金银错满西域情

他是金银和玉石再次完美交融的推手,同时也用几十年的不懈努力,开创了当代新疆玉雕的独特风格。在众多玉雕大师新作中,有一种玉雕,在玉器表面镶嵌金银纹饰以及珍贵宝石,造型独特,华贵雍容,充满西域风情。不用说,这些作品定然来自新疆,出自＂马爷＂之手。     

当裸女成为玉雕

我们必须承认,在这个开放的年代,我们的眼睛时常在色情与艺术之间左顾右盼。裸体,在今天已然成为一个众所周知,却又秘而不宣的暧昧词语。尤其当它落到代表传统美德的美玉之上,更成为赚人眼球的热点。是色情还是艺术?是创新还是亵渎?无论你是见仁还是见智,终归不能否认,这次创新已经备受瞩目。     

玉满荆襄袁嘉骐

玉器创作是琢玉人寄情于作品的过程,一件好的玉器作品是无韵之诗、无声之歌。大师简介:袁嘉骐,湖北人,1954年7月出生,中国工艺美术大师。现任湖北省工艺美术研究所玉雕研究室主任,国家一级美术师,创建了个人玉雕艺术馆。     

浅谈玉雕

古人云:"玉具有美质,在于石间,不值良工琢磨,与瓦砾不别。"意思说,石中之玉具有美得本质,但不经过精雕细琢,与破瓦乱石没有区别,可见美玉来自人为,美玉来自创造。雕琢美就是玉器创作的艺术美,只有将璞玉雕琢成包含民族智慧的玉器,才能使玉石的美感得到充分显现,使人们感到玉的美好,在感叹大自然的造化和玉人鬼斧神     

扬州·玉作缘

品牌档累品牌名称:扬州玉器厂创办时间:1956年创办人:8位扬州玉雕老艺人经营内容:玉器、雕塑工艺品传承人:顾水俊、江春源、高毅进、薛春梅"红风车,转一转吧,福来我家。"提到扬州,便想起这首古装片里的童谣,朗朗上口,配合纯白皎洁的琼花,随风飘扬,寄托着无限美好和希望。都说"烟花三月下扬州",此番南行,却是错过了三月,也错过了琼花。盛夏的扬州,走在街头几乎听不到什么声响,杨柳依依,荷叶轻摆,古朴     

漆膜光泽测定技术及其应用

叙述了漆膜光泽测定的技术基础与方法标准，介绍了漆膜多角度光泽计国内外开发现状及典型仪器特征，并对影响漆膜光泽的因素作了粗浅地探讨。     

宝理塑料服务大众

作为工程塑料的专业生产厂家,宝理塑料有限公司成功开发出众多高性能的材料,为工程塑料的发展做出了重大贡献。为更多地了解宝理塑料在中国的进一步发展规划、《塑料工业》记者有幸对宝理塑料（香港）有限公司技术及开发部高级经理黎振鹏先生（以下简称黎）进行了专访。     

Dihydrogen Catalysis: A Remarkable Avenue in the Reactivity of Molecular Hydrogen

Molecular hydrogen is the simplest and most abundant compound in the universe and is involved in numerous industrial chemical processes. In conventional chemistry, dihydrogen typically plays the role of a reductant and a reagent for homogeneous and heterogeneous hydrogenation processes such as the industrial and enzymatic ammonia formation, reduction of metallic ores and hydrogenation of unsaturated fats and oils. However, there are also processes in which molecular hydrogen participates as promoter, and even as catalyst. The catalytic role of the dihydrogen in free-valence migration in irradiated polymers and the interstellar isomerization of the formyl cation (protonated carbon monoxide) are well-documented examples of such processes. Recently, this issue has received new attention. Dihydrogen has been shown to play the role of a dehydrogenation catalyst (involving particularly metallocomplexes and inorganic materials), a relay (pass-on) transfer molecular agent and a transporter of protons.

This review article, combined with original results, is focused on the mechanisms of the chemical processes where dihydrogen demonstrates catalytic behavior. We will call these processes (with somewhat broader meaning of the term) “dihydrogen catalysis” (DHC) which also includes the reactions mediated by transition metal dihydrides. Dihydrides are tentatively considered as pre-activated dihydrogen, coordinated to a metal center or implanted into a solid surface/support.

DHC reactions are classified into five major reaction types: (i) dihydrogen-assisted relay transport of H-atoms (H2-RT); (ii) dihydrogen-assisted stepwise relay transport of H-atoms or of a free valence (sH2-RT); (iii) dihydrogen-assisted proton transport (H2-PT); (iv) dihydrogen-assisted dehydrogenation (H2-DeH); and (v) pre-activated dehydrogenation (PA-DeH). The classification of these mechanisms is based on a detailed analysis of numerous potential energy surfaces studied by DFT and ab initio methods in conjunction with available experimental data. The H2-RT, H2-DeH, and PA-DeH processes occur via cyclic transition states. The relay H2-RT transport involves the H-H-H triad linked to both H-donor and H-acceptor centers, whereas the transition state ring in the H2-DeH dehydrogenation processes involves a H-H-H-H tetrad with the dihydrogen catalyst located in the middle. The H2-PT mechanism provides the transport of a proton mediated by dihydrogen combined in a triangular (H₃⁺)-carrier unit.

There are also practically important processes stimulated by dihydrogen such as the hydrogen spillover and hydrogen build-up in electronics, in which the catalytic role of dihydrogen is ambiguous, either because of the uncertainties in mechanisms, or prevailing traditional views. Some examples are briefly discussed in the framework of the concept of dihydrogen catalysis, some being provided with theoretical support (in part calculated by us), and others being merely hypothesized to provide suggestions to an interested reader.     

Small and Simple,yet Sturdy: Conformationally Constrained Peptides with Remarkable Properties

The sheer size and vast chemical space (i.e., diverse repertoire and spatial distribution of functional groups) underlie peptides’ ability to engage in specific interactions with targets of various structures. However, the inherent flexibility of the peptide chain negatively affects binding affinity and metabolic stability, thereby severely limiting the use of peptides as medicines. Imposing conformational constraints to the peptide chain offers to solve these problems but typically requires laborious structure optimization. Alternatively, libraries of constrained peptides with randomized modules can be screened for specific functions. Here, we present the properties of conformationally constrained peptides and review rigidification chemistries/strategies, as well as synthetic and enzymatic methods of producing macrocyclic peptides. Furthermore, we discuss the in vitro molecular evolution methods for the development of constrained peptides with pre-defined functions. Finally, we briefly present applications of selected constrained peptides to illustrate their exceptional properties as drug candidates, molecular recognition probes, and minimalist catalysts.     

香包秀庆阳

庆阳香包,粗犷如歌,浪漫如诗。它的源流同端午节一样悠长,它的意蕴和黄土地一样深厚。它以其独特的文化艺术魅力,逐渐发展成为颇具示范效应与经济规模的民俗文化产业。     

香包秀庆阳

庆阳香包,粗犷如歌,浪漫如诗。它的源流同端午节一样悠长,它的意蕴和黄土地一样深厚。它以其独特的文化艺术魅力,逐渐发展成为颇具示范效应与经济规模的民俗文化产业。     

进口电器设备的"克星"——记全国"五一"劳动奖章获得者杨辉

益阳橡胶塑料机械集团有限公司大件车间青年电工杨辉,凭借自己对设备维护的执著追求,娴熟掌握了公司精、大、稀进口数控设备的电器维修技术,打破了进口设备电器故障靠外国专家修理的神话,     

Remarkable hexagonal carbon tubes transformed from zinc tetrapyridylporphine

Herein, a simple template-free method to the preparation of hexagonal carbon microtubes by pyrolysis of zinc tetrapyridylporphine (ZnTPyP) was reported. With cetyltrimethyl ammonium bromide as the auxiliary agent, ZnTPyP molecules assemble into hexagonal microtubes. Corresponding ZnTPyP microtubes and microrods can be selectively fabricated by changing the concentration of tetrapyridylporphine (TPyP) and zinc ions. Through the pyrolysis of ZnTPyP precursors, remarkable carbon microtubes with hexagonal cross-section are prepared. The formation of carbon microtubes are evidenced by X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy.     

Isoprenoids: Remarkable diversity of form and function

The isoprenoid biosynthetic pathway is the source of a wide array of products. The pathway has been highly conserved throughout evolution, and isoprenoids are some of the most ancient biomolecules ever identified, playing key roles in many life forms. In this review we focus on C-10 mono-, C-15 sesqui-, and C-20 diterpenes. Evidence for interconversion between the pathway intermediates farnesyl pyrophosphate and geranylgeranly pyrophosphate and their respective metabolites is examined. The diverse functions of these molecules are discussed in detail, including their ability to regulate expression of the β-HMG-CoA reductase and Ras-related proteins. Additional topics include the mechanisms underlying the apoptotic effects of select isoprenoids, antiulcer activities, and the disposition and degradation of isoprenoids in the environment. Finally, the significance of pharmacological manipulation of the isoprenoid pathway and clinical correlations are discussed.