石湾陶业的火崇拜

“功昭日月,威耀星辰;恩泽五土,德荫陶人。”这是千百年来在石湾陶人中广泛流传的赞美火神的古诗。佛山石湾镇,南国著名陶都,早在四五千年前的新石器时代,先民们就用火创造出富有地方特色的印纹陶文化,其后经秦汉、唐宋,制陶业蒸蒸日上,至明清时期,已渐达到鼎盛,有“石湾瓦,甲天下”之誉。改革开放之后,陶人更利用其炉火纯青的技艺,把石湾建成中国最大的陶瓷基地之一,令古老的陶窑再焕生机。陶器是人类利用自然物为原料,通过高温化学反应制造出来的一种生活中最常用的物品。烧制陶瓷离不了火,一块普普通通的泥巴,经火煅烧…     

Material and Elastic Properties of Al‐Tobermorite in Ancient Roman Seawater Concrete

The material characteristics and elastic properties of aluminum‐substituted 11 Å tobermorite in the relict lime clasts of 2000‐year‐old Roman seawater harbor concrete are described with TG‐DSC and ²⁹Si MAS NMR studies, along with nanoscale tomography, X‐ray microdiffraction, and high‐pressure X‐ray diffraction synchrotron radiation applications. The crystals have aluminum substitution for silicon in tetrahedral bridging and branching sites and 11.49(3) Å interlayer (002) spacing. With prolonged heating to 350°C, the crystals exhibit normal behavior. The experimentally measured isothermal bulk modulus at zero pressure, K₀, 55 ±5 GPa, is less than ab initio and molecular dynamics models for ideal tobermorite with a double‐silicate chain structure. Even so, K₀, is substantially higher than calcium‐aluminum‐silicate‐hydrate binder (C–A–S–H) in slag concrete. Based on nanoscale tomographic study, the crystal clusters form a well connected solid, despite having about 52% porosity. In the pumiceous cementitious matrix, Al‐tobermorite with 11.27 Å interlayer spacing is locally associated with phillipsite, similar to geologic occurrences in basaltic tephra. The ancient concretes provide a sustainable prototype for producing Al‐tobermorite in high‐performance concretes with natural volcanic pozzolans.     

Far‐Red‐Emitting BiOCl:Eu3+ Phosphor with Excellent Broadband NUV‐Excitation for White‐Light‐Emitting Diodes

Rare‐earth ion‐doped semiconducting phosphor has attracted extensive attention due to the ability to achieve efficient luminescence through the host sensitization. Here, we present a new type red‐emitting Eu³⁺ ‐doped BiOCl phosphors possessing a broad excitation band in the near‐ultraviolet (NUV) region. Experimental measurements and theoretical calculations confirm that Eu³⁺ ion dopants result in forming impurity energy level near valence band, and the excellent broadband NUV‐exciting ability of Eu³⁺ ion is due to the electronic transitions of BiOCl band gap. Moreover, the highest emission intensity of the phosphors is from the ⁵D₀ → ⁷F₄ transition of Eu³⁺ around 699 nm (far‐red) through whether host excitation or direct Eu³⁺ ions excitation, which lie in the particular structure of BiOCl crystals. Our results indicate that the Eu³⁺ ‐doped BiOCl crystals show great potential as red phosphors for white‐light‐emitting diodes.     

彩陶文化的多重装饰艺术法则——以马家窑彩陶为例

彩陶这种古老的艺术样式，其图案组织和表现手法都是一种卓绝的创造。其中我们看到了许多元素之间的组织与表现方式，并从其大量的图形样式及结构中，归纳出它们所构成的形式美的一些基本手法及规则，例如：对比与和谐、比例与视觉重心、均衡与秩序、填充与空白、双关与多效法等。     

古代陶器测温的模拟实验研究

热膨胀法是目前比较流行的古陶瓷烧成温度的测试方法,虽然已有近半个世纪的应用历史,而对其理论和实验依据却鲜有探索,以至于开始有人怀疑该方法的可行性。本文是对古代陶器测温方法的一次探索。通过模拟制备不同烧成温度的陶器,再利用热膨胀仪重烧以获取其重烧时的热膨胀性能曲线(DIL曲线),总结规律,讨论该方法的可行性以及烧成温度判定标准等关键问题,以期为进一步的研究提供实验数据。     

宜兴紫砂泥料性能研究

我国紫砂陶土种类众多,分布广泛,其矿产主要集中在江南地区,然而各产区的矿物类型和化学组成不同,表现出不同的物理、化学性质.本文主要研究宜兴紫砂泥料的特征,借助显微观察、X荧光分析、热分析等测试手段,通过与福建、江西等地紫砂泥料相比较,以及宜兴当地不同种类紫砂泥料之间的成分对比,探究宜兴地区紫砂泥料的独特性,阐明不同种类...     

Bio‐Oil as a Potential Biomass‐Derived Renewable Raw Material for Bio‐Phenol Production

A route for directional conversion of bio‐oil into phenol by means of coupling the catalytic cracking of the bio‐oil with the hydroxylation of the bio‐oil‐based benzene‐rich aromatics is proposed. High selectivity for phenol in the resulting organic liquid was achieved, with an almost complete conversion of the bio‐oil. Co‐cracking of the bio‐oil with methanol over a Zn‐modified zeolite significantly enhanced the yields of aromatics and decreased the deactivation of the catalyst during the catalytic cracking of the bio‐oil. The phenol yield depended on the metal oxide catalysts, the temperature, and the reaction time during hydroxylation of the benzene‐rich aromatics. The reaction pathway of converting bio‐oil into phenol was elucidated based on the products identified and the characterization of the catalysts.     

Removal of direct Red‐31 and direct Orange‐26 by low cost rice husk: Influence of immobilisation and pretreatments

The aim of the present study is to investigate the influence of free, carboxymethyl cellulose (CMC) immobilised, PVA–alginate immobilised, and HCl treated rice husk on the removal of Direct Red‐31 and Direct Orange‐26 dyes. The biosorption capacity of the rice husk increased with HCl treatment (67.39 and 45.34 mg/g) and decreased with PVA–alginate immobilisation (9.73 and 10.03 mg/g) as compared to the free biomass (65.56 and 45.58 mg/g) at 200 mg/L dye concentration for Direct Red‐31 and Direct Orange‐26, respectively. Equilibrium data were best described by Langmuir Type 1 for Direct Red‐31 and Direct Orange‐26 (free, CMC immobilised, PVA–alginate immobilised, and HCl treated). Best correlation coefficients for Direct Red‐31 and Direct Orange‐26 using free, CMC immobilised, PVA–alginate immobilised, and HCl treated rice husk were obtained for pseudo‐second order and Elovich kinetic models. Values of Gibbs free energy (ΔG°) and enthalpy change (ΔH°) indicated that reaction was spontaneous and endothermic in nature at the studied temperatures. FT‐IR studies showed the involvement of carbonyl, carboxyl, and amide groups in the biosorption process. SEM exhibited the morphological changes on the biosorbent surface and BET analysis to determine the surface area is also carried out.     

Empirical Evidence for A‐Site Order in Perovskites

Models for composition–structure relationships are useful in both the lab and industry, yet few exist for perovskites‐containing extrinsic defects or cation ordering. In this work, an empirical model is used to predict the existence of A‐site cation ordering. Specifically, four compositions in the Na_(1?3x)/2La_(1+x)/2TiO₃ system (x = 0.0, 0.0533, 0.1733 and 0.225) were synthesized using a conventional solid‐state mixed‐oxide method. The structure of the x = 0 end‐member (Na_0.5La_0.5TiO₃) has been reported in various space groups, but always with a random distribution of Na⁺ and La³⁺ on the A site; however, empirical modeling suggests that it is not only ordered but also that a small volume increase accompanies the ordering process. While no evidence of long‐range A‐site ordering is observed in this composition via X‐ray or neutron diffraction, electron‐diffraction data indicate short‐range ordering of Na⁺ and La³⁺ ions, with the degree of cation ordering decreasing (but the scale of ordered domains and degree of vacancy ordering generally increasing) with increasing x. First‐principles calculations via density functional theory support both conclusions that short‐range ordering in Na_0.5La_0.5TiO₃ is stable and that it results in a volume increase with respect to the disordered analog. A similar analysis has been conducted for the Li_(1?3x)/2La_(1+x)/2TiO₃ and Na_(1?3x)/2La_(1+x)/2(Mg_0.5W_0.5)O₃ solid solutions. These systems provide additional validation of the accuracy and versatility of the empirical modeling method used.     

Stable Isotopes of Carbon and Oxygen as a Possible New Tool for Estimating Firing Temperatures of Ancient Pottery

The ratios of the stable isotopes of carbon (¹³C/¹²C) and oxygen (¹⁸O/¹⁶O) in calcite in clays that contain carbonate and that were fired at temperatures between 500 and 700 °C displayed a good correlation with the firing temperature for both isotopes. The isotopic composition indicated that the original carbonate was either completely decomposed or that it exchanged with environmental CO₂ to obliterate the original isotopic signature. The isotopic effects seem to be kinetically controlled. The isotope thermometer is used to compare refiring temperatures of pottery which was fired under controlled conditions. The differences between calculated and actual temperatures did not exceed 132 °C and in most cases was about 50 °C or less. Isotopic analysis of pottery from Tel Miqne-Ekron and Deir el Balah, dated to the 13th–12th centuries BC, gave an average ancient firing temperature of about 600 °C. If shown to be of general validity, then perhaps this technique can be used also for estimating preparation temperatures of ancient mortar, especially when preserved in dry climates where later changes would be minimized.     

A Sponge‐Like 3D‐PPy Monolithic Material for Reversible Adsorption of Radioactive Iodine

3D polypyrrole (3D‐PPy) monolith is prepared by a simple chemical oxidation of pyrrole monomer using FeCl₃ as an oxidant. The as‐prepared PPy monolith exhibits an abundant porosity and with a mesopore size of about 9.1 nm in diameter. Taking advantage of its mesoprous feature as well as the unique chemical composition, the 3D‐PPy is employed as the porous medium for adsorption and removal of radioactive iodine from environment. A high iodine adsorption capacity of 1.6 g g⁻¹ for 3D‐PPy is obtained which is competing with that of those reported porous organic polymers. Besides, the adsorption kinetics and adsorption thermodynamic experiments show that the adsorption is dominated by the pseudosecond‐order kinetics and Langmuir models. Considering its simple and low cost‐effective preparing method, unique monolithic porous as well as π–π conjugated chemical structure, the resulted 3D‐PPy may be found useful applications for removal of radioactive iodine to address environmental issues.     

Material characterization of a high‐dielectric‐constant polymer–ceramic composite for embedded capacitor for RF applications

Embedded capacitor technology can improve electrical performance and reduce assembly cost compared with traditional discrete capacitor technology. Polymer–ceramic composites have been of great interest as embedded capacitor materials because they combine the processability of polymers with the desired electrical properties of ceramics. We have developed a novel nanostructure polymer–ceramic composite with a very high dielectric constant (ε_r ≈ 150, a new record for the highest reported ε_r value of a nanocomposite) in a previous work. RF applications of embedded capacitors require that the insulating material have a high ε_r at a high frequency (in the gigahertz range), low leakage current, high breakdown voltage, and high reliability. A set of electrical tests were conducted in this study to characterize the electrical properties of the novel high‐ε_r polymer–ceramic nanocomposite developed in‐ house. The results show that this material had a fairly high ε_r in the RF range, low electrical leakage, and high breakdown voltage. An 85°C/85% thermal humidity aging test was been performed, and it showed that this novel high‐K material had good reliability. An embedded capacitor prototype with a capacitance density of 35 nF/cm² was manufactured with this nanocomposite with spin‐coating technology. This novel nanocomposite can be used for the integral capacitors for RF applications. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2228–2231, 2004     

Evidence for the Formation of a Radical‐Mediated Flavin‐N5 Covalent Intermediate

The redox‐neutral reaction catalyzed by 2‐haloacrylate hydratase (2‐HAH) leads to the conversion of 2‐chloroacrylate to pyruvate. Previous mechanistic studies demonstrated the formation of a flavin‐iminium ion as an important intermediate in the 2‐HAH catalytic cycle. Time‐resolved flavin absorbance studies were performed in this study, and the data showed that the enzyme is capable of stabilizing both anionic and neutral flavin semiquinone species. The presence of a radical scavenger decreases the activity in a concentration‐dependent manner. These data are consistent with the flavin iminium intermediate occurring by radical recombination.     

Graphene‐Supported Ce–SnS2 Nanocomposite as Anode Material for Lithium‐Ion Batteries

A graphene‐supported Ce–SnS₂ (Ce–SnS₂/graphene) nanocomposite has been synthesized via a hydrothermal route. Structure, morphology, and electrochemical properties of the composites were studied by means of XRD, SEM, TEM, Raman, XPS, TGA, and electrochemical measurements. The Ce–SnS₂ crystal particles with a flower‐like structure were distributed on the graphene sheets (GNS). The particle sizes of each petal are in the range 50–100 nm with clear lattice fringes. The atomic ratio of Sn, S, Ce, C, and O is estimated to be 1:2:0.05:3.11:0.64 and the content of Ce–SnS₂ composite is 80 wt.% in the as‐synthesized sample. The Ce–SnS₂/graphene composite exhibits high initial discharge capacity (1638.3 mAh/g at 0.5 C), high capacity retention (707 mAh/g at 0.5 C after 50 cycles), and good rate capability due to the synergy effect between Ce–SnS₂ nanoparticles and graphene nanosheets. The superior performance is ascribed to the presence of graphene keeping the structure stable.     

Reactive‐Injecting Follow‐Through Shaped Charges from Sequent‐Material Conical Liners

Shaped charges using reactive‐metal liners have the potential for beyond‐penetration effects, e.g. thermodynamic events that increase pressure in a volume adjacent to the penetration. Shaped charge liners made from a copper penetrating‐ and an aluminum reactive‐component in a sequent‐material configuration were compared in tests to baseline homogeneous copper liners. Copper lined shaped charges had greater mild steel penetration performance, but lacked beyond‐penetration pressurization effects exhibited by the sequent‐material lined units. Jet capture experiments, beyond‐penetration constant‐volume tests, and thermochemical equilibrium calculations provide evidence supporting the aluminum slug comminution into unoxidized reactive fuel, augmenting beyond‐penetration effects.     

5‐Amino‐3,4‐dinitropyrazole as a Promising Energetic Material

The nitrogen‐rich energetic compound 5‐amino‐3,4‐dinitropyrazole (5‐ADP) was investigated using complementary experimental techniques. X‐ray diffraction indicates the strong intermolecular hydrogen bonding in 5‐ADP crystals. Compound exhibits low impact sensitivity (23 J) and insensitivity to friction. The activation energy of thermolysis determined to be 230±5 kJ mol⁻¹ from DSC measurements. Accelerating rate calorimetry indicates the lower thermal stability (173 °C) of 5‐ADP than that of RDX, which is probably the main concern about using this compound. 5‐ADP also exhibits good compatibility with common energetic materials (viz. TNT, RDX, ammonium perchlorate), including an active binder. The burning rate of 5‐ADP monopropellant is higher than that of benchmark HMX, while the pressure exponent 0.51±0.04 is surprisingly low. Addition of ammonium perchlorate does not affect the pressure exponent of 5‐ADP, while the burning rate increases. The 5‐amino‐3,4‐dinitropyrazole exhibits a notable combination of combustion performance, low sensitivity, and good compatibility, which renders it as a promising energetic material.     

Promising CL‐20‐Based Energetic Material by Cocrystallization

A novel cocrystal (NEX‐1) of CL‐20 and MDNT is presented herein. The CL‐20: MDNT cocrystal, obtained in high yield by resonant acoustic mixing, shows new properties versus the discrete components. This is the first example of cocrystallization of CL‐20 where the new material is less sensitive to friction than CL‐20 itself, while demonstrating similar impact and ESD sensitivity. The CL‐20: MDNT cocrystal shows promise in the production of new energetic materials of interest by the cocrystallization of well‐characterized components.     

Gold‐Catalyzed Synthesis of Dibenzopentalenes – Evidence for Gold Vinylidenes

A series of easily accessible arene‐1,2‐diynes, bearing one aryl substituent on one of the alkynyl groups, is readily converted to dibenzopentalenes in good yields by gold(I) catalysts. The participation of gold acetylides could be proven by the direct conversion to the corresponding gem‐diaurated dibenzopentalenes with a gold catalyst. From an experiment with a gold acetylide complex and stoichiometric amounts of the gold “catalyst” the corresponding gem‐diaurated complex of a dibenzopentalene could be obtained and characterized by X‐ray crystal structure analysis. Labelling studies with deuterated alkynes show the expected deuteration of the two remaining positions of the pentalene core. All this provides evidence for a dual activation mode of the reaction and gold(I) vinylidene complexes as intermediates of the catalytic cycle.