从火药的发展看北宋时期儒法斗争对科技发展的影响

劳动人民推动了火药的发明火药是我国古代的四大发明(指南针、造纸、印刷术和火药)之一。伟大领袖毛主席在《中国革命和中国共产党》一文中曾经指出:“在很早的时候,中国就有了指南针的发明。还在一千八百年前,已经发明了造纸法。在一千三百年前,已经发明了刻版印刷。在八百年前,更发明了活字印刷。火药的应用也在欧洲人之前。所以,中国是世界文明发达最早的国家之一”。我国发明的火药属“黑色火药”。主要成份是硫磺、硝石和木炭。在古典文献上可查到的关于火药的代表性配方有以下两个:一是郑思远撰的《真元妙道要略》中有这样一段记载:“有以硫磺、雄黄合硝石并蜜烧之,焰起、烧手面及烬屋舍者。”蜜加热分解成炭,再加上硫磺与硝石就是黑色火药,烧起来以后,火势十分猛烈,能把房子都烧掉。     

对“在高中有机化学中加入我国化学史料的建议”一文的一点意见

编辑同志: 本年1月号黄兰孙同志写的:“在高中有机化学中加入我国化学史料的建议”一文,其中谈到的几点,在今后讲课以及编写课本当中,都是值得注意的,不过在第九点,谈到我国的四大发明之一——火药的时候,文中说:“至於火药的成分是由最初用硝石、硫磺和木炭,到后来加入种种化合物和各种有机物质成为各种各样的火药料的。”从字面上看来好像是今天国防上所用的火药都是在黑火药中加入各种物质而配制成的。据我所知不是这样,一般人所说的火药就是黑火药,它仍然是由硝石、硫磺和木炭配成的,大量用在矿山的爆炸上,而国防     

儒法斗争与我国古代火药的发展

火药是我国古代劳动人民在长期的生产斗争中的一项伟大发明。现在已知的最早关于火药配方的记载见于隋末唐初著名医学家孙思邈的《丹经》。这说明,火药与炼丹术和医药学有一定的联系。在火药发展的漫长历史中,儒法两条路线起到了截然相反的作用。炼丹术起于战国时期,主要目的是企图通过某种神奇的超自然力使某些物质变成可以使人“长生不老”的“仙丹”,这是唯心主义在人们社会生活中的一种表现,带有浓厚的神秘主义色彩。但是,随着生产的发展和人们对于自然界的认识的不断深化,有些人在炼丹实践中,借助于对物质性质变化的探索,自觉或不自觉     

补谈中国古代硫磺提纯法——介绍363年前的一篇文章

不论是天然硫或从硫铁矿制得的硫,均不免含有杂质。但是关于几百年前,或更久远一些,古人如何提纯硫磺的记载,难得被人发现。1984年赵匡华及郭正谊同志撰文介绍了郁永河先生的《采硫日记》(公元1697年),认为台湾地区“以油炼硫,在我国历史上,其他地区清代以前从未有过。”,“是中华民族科技史上重要的     

我国利用硫铁矿制硫史初步考证

一、前言至迟在公元前二世纪初,我国的道家已以硫磺和水银为主要原料进行着炼丹的试验。他们记录了硫磺的许多物化性质,例如熔化、化合、燃烧、升华等。硫磺作为一个药物,在公元初的《神农本草经》中已记录下来。唐朝已发明了火药,硫磺便是其中重要配料。但当时的硫磺是怎样来的?炼硫技术又是怎样逐步提高的?这些问题尚未有人加以澄清。作者为此作了一番考证工作。     

洋葱状富勒烯的提纯研究

以石墨粉为碳源, Al为催化剂, 采用真空热处理法制备了平均粒径为15～35 nm的洋葱状富勒烯(OLFs).并用CS₂分离和空气氧化法对得到的OLFs初产品进行了提纯处理.高分辨透射电镜(HRTEM)、X射线衍射(XRD)、热重分析(TGA)对提纯前后样品的分析表明, CS₂分离处理可有效去除初产品中裸露的金属催化剂微粒,然后在空气中610 ℃焙烧200 min,可基本去除无定型碳,并大量去除了石墨状碎片等碳杂质, OLFs的纯度在50％(体积分数)以上.     

关于《天工开物》所记炼锌技术之管见

明代宋应星《天工开物》中有一段关于炼锌技术的记载,原料是炉甘石(菱锌矿,主要成分为碳酸锌ZnCO_3),燃料是煤饼,用泥罐外加热的方式进行冶炼,这是研究明代炼锌技术最重要、最基本的资料。但有的问题宋应星交代得不太清楚,因此引起现在人们对这一炼锌法工艺原理的意见分歧:有人认为是蒸馏法,也有人认为是迥流法。两说相同处是:都认为炉甘石受热后先分解成氧化锌(ZnO)和二氧化碳     

东晋道士发明火药新说

唐代道士最先发明火药的说法似乎已为学界所普遍接受.但是通过对东晋道教炼丹经诀<太上八景四蕊紫浆五珠降生神丹方经>的研究,发现还在东晋时,道士炼丹配方中所用的雄黄、雌黄、硝石和薰陆香等粉末状药物,事实上就已经包含了传统火药中"一硝、二黄、三木炭"的基本组成成份,而且为了防止爆炸的发生,道士们还有意采取了多种防范措施.这表明最初的火药雏形似可上溯至东晋甚至更早,从而有可能改写唐代火药发明说这一影响巨大的结论,并将火药的发明时间至少提前约550年.     

LiCl-KCl熔盐中纯氧氧化提纯单壁碳纳米管

以LiCl-KCl(wLiCl∶wKCl=55∶45)熔盐为反应介质,对在熔盐中纯氧氧化提纯单壁碳纳米管(SWCNT)进行了研究.发现可以通过控制熔盐温度和氧气流量来控制氧化反应温和地进行.将5gSWCNT粗产品分散在200g熔盐中,在470℃下用300mL?min-1氧气氧化2h可获得3.8%SWCNT收率.采用TEM,SEM,TGA和Raman谱对提纯前后SWCNT的形貌和组成进行了分析,发现提纯后SWCNT产品中无定形碳被有效去除,而SWCNT结构未发现明显变化.     

火炸药和化学北大核心CSCD

火药是中国古代四大发明之一,曾对世界格局和发展进程产生重要影响,然而明末清初之后火药火器在中国却日益衰落。火药随战争移步西方,变身黑火药,促进了近代化学科学的诞生和发展。而化学科学的发展对火炸药大家族意义非凡,二者之间彼此成就,缘分匪浅。中国现代火炸药王的辉煌成就重焕中国火药之荣光。论文回顾了火炸药的传奇发展历程和开天辟地的作用,讲述其特种化学能源的属性、丰富的种类和独特的工作原理,并努力追溯火药燃烧和爆炸的内在机制。旨在凸显科学思维方式及化学学科的发展对火炸药研究的重要性,从而不断丰富化学专业学生的知识内涵,激发学生的创新思维热忱,增强化学人的专业自信、文化自信和民族自信,弘扬科学家精神。     

Generation and detection of levuglandins and isolevuglandins in vitro and in vivo

Levuglandins (LGs) and isolevuglandins (isoLGs), formed by rearrangement of endoperoxide intermediates generated through the cyclooxygenase and free radical induced oxidation of polyunsaturated fatty acids (PUFAs), are extraordinarily reactive, forming covalent adducts incorporating protein lysyl ε-amino groups. Because they accumulate, these adducts provide a dosimeter of oxidative injury. This review provides an updated and comprehensive overview of the generation of LG/isoLG in vitro and in vivo and the detection methods for the adducts of LG/isoLG and biological molecules in vivo.     

钙与人体及临床

钙是宏量元素，是人体中含量较高的元素之一，体内99％的钙构成骨骼和牙齿以及维持骨骼结构，1％的钙调节人体重要生理功能。钙的含量过高或过低都与许多疾病有关，只有保持一种平衡状态，才能使机体处于正常环境。     

Coassembly of Nanorods and Nanospheres in Suspensions and in Stratified Films

The entropically driven coassembly of nanorods (cellulose nanocrystals, CNCs) and nanospheres (dye‐labeled spherical latex nanoparticles, NPs) was studied in aqueous suspensions and in solid films. In mixed CNC‐latex suspensions, phase separation into an isotropic latex‐NP‐rich and a chiral nematic CNC‐rich phase took place; the latter contained a significant amount of latex NPs. Drying the mixed suspension resulted in CNC‐latex films with planar disordered layers of latex NPs, which alternated with chiral nematic CNC‐rich regions. In addition, fluorescent latex NPs were embedded in the chiral nematic domains. The stratified morphology of the films, together with a random distribution of latex NPs in the anisotropic phase, led to the films having close‐to‐uniform fluorescence, birefringence, and circular dichroism properties.     

Structure Formation and Molecular Mobility in Water and in Aqueous Solutions

The study of the structure of water and of aqueous solutions has recently received new impetus from the efforts at commercial desalineation of sea water and from developments in molecular biology. The current view that, apart from single molecules, water contains only one type of structural element, namely “flickering” network structures with tetrahedrally hydrogen-bonded water molecules (two-states model) is proving inadequate in the interpretation of new experimental data and in the calculation of thermodynamic functions. After a critical discussion of the basis of this model and of the concept of hydrogen bonds, a second kind of structural element, i.e. a third state, is suggested: small aggregates of molecules containing mainly non-tetrahedral hydrogen bonds as well as some tetrahedral ones, and packed more densely than allowed by the lattice-like structure. These aggregates – dimers to hexamers – can be regarded as the primary products of disruption of the network structures, and displace the latter as structural components in water with increasing temperature or concentration of solutes. This “combined” model allows a consistent interpretation of the properties of water and of the various effects of dissolved substances.     

Advances in amperometric and conductometric detection in capillary and chip-based electrophoresis

Amperometric and conductometric detection are currently the two major electrochemical detection modes in capillary and chip electrophoresis. The ease of miniaturization and integration of electrochemical detection elements offers a high potential for the development of portable analytical devices based on electromigrative separations. The challenges and basic concepts of both detection principles in the context of capillary/chip electrophoresis are shortly introduced and milestones of the methodical developments are summarized from a historical perspective. Recent advances and applications are discussed with more detail. Particular attention is paid to new trends in this area of research such as measurements in short capillaries and the enormous progress and increased popularity of contactless conductivity detection. Correspondence: Frank-Michael Matysik, Institute of Analytical Chemistry, University of Leipzig, Linnéstr. 3, D-04103 Leipzig, Germany     

Femtosecond electron-transfer reactions in mono- and polynucleotides and in DNA

Quenching of redox active, intercalating dyes by guanine bases in DNA can occur on a femtosecond time scale both in DNA and in nucleotide complexes. Notwithstanding the ultrafast rate coefficients, we find that a classical, nonadiabatic Marcus model for electron transfer explains the experimental observations, which allows us to estimate the electronic coupling (330 cm(-1)) and reorganization (8070 cm(-1)) energies involved for thionine-[poly(dG-dC)](2) complexes. Making the simplifying assumption that other charged, pi-stacked DNA intercalators also have approximately these same values, the electron-transfer rate coefficients as a function of the driving force, DeltaG, are derived for similar molecules. The rate of electron transfer is found to be independent of the speed of molecular reorientation. Electron transfer to the thionine singlet excited state from DNA obtained from calf thymus, salmon testes, and the bacterium, micrococcus luteus (lysodeikticus) containing different fractions of G-C pairs, has also been studied. Using a Monte Carlo model for electron transfer in DNA and allowing for reaction of the dye with the nearest 10 bases in the chain, the distance dependence scaling parameter, beta, is found to be 0.8 +/- 0.1 A(-1). The model also predicts the redox potential for guanine dimers, and we find this to be close to the value for isolated guanine bases. Additionally, we find that the pyrimidine bases are barriers to efficient electron transfer within the superexchange limit, and we also infer from this model that the electrons do not cross between strands on the picosecond time scale; that is, the electronic coupling occurs predominantly through the pi-stack and is not increased substantially by the presence of hydrogen bonding within the duplex. We conclude that long-range electron transfer in DNA is not exceptionally fast as would be expected if DNA behaved as a "molecular wire" but nor is it as slow as is seen in proteins, which do not benefit from pi-stacking.     

Carbon chains and rings in the laboratory and in space

Seventy-seven reactive organic molecules of astrophysical interest have been identified in a supersonic molecular beam, 73 in the radio band by Fourier-transform microwave spectroscopy, four in the optical by laser cavity ringdown spectroscopy. Most are linear carbon chains, but six consist of carbon chains attached to the compact, highly polar C3 ring, and two are rhomboidal cyclic configurations of SiC3. The laboratory astrophysics of the radio molecules is complete for the time being, in the sense that essentially all the rotational transitions of current interest to radio astronomy (including hyperfine structure when present) can now be calculated to a small fraction of 1 km s(-1) in equivalent radial velocity; six of the radio molecules have already been detected in space on the basis of the present data. The FTM spectrometer employed in this work is far from fundamental limits of sensitivity, so many more molecules can probably be found by refinements of present techniques. The density of reactive molecules in our supersonic beam is generally high by the standards of laser spectroscopy, and many of the radio molecules probably have detectable optical transitions which we are attempting to find, largely motivated by the long-standing problem of the diffuse interstellar bands. Our most interesting result to date is the detection of a fairly strong molecular band at 443 nm in a benzene discharge, in exact coincidence with the strongest and best known interstellar band. Isotopic shifts measured with partially and totally deuterated benzene suggest that the carrier of the laboratory band is a hydrocarbon molecule with the elemental formula CnH5, with n most likely in the range 3-6.