共查询到20条相似文献,搜索用时 15 毫秒
1.
To obtain kaolinite at low temperature and pressure from the system Si(OH)(4)-Al(3+)-H(2)O, the sixfold coordination of aluminum is a necessary prerequisite. Kaolinite was synthesized at pH values from 2 to 9 and with a ratio of SiO(2) to Al(2)O(3) in solution from 1 to 10 by means of the complexation of Al(3+) and fulvic acid. 相似文献
2.
Lee KC Sprague MR Sussman BJ Nunn J Langford NK Jin XM Champion T Michelberger P Reim KF England D Jaksch D Walmsley IA 《Science (New York, N.Y.)》2011,334(6060):1253-1256
Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature. By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions. 相似文献
3.
A bulk nanocrystalline (nc) pure copper with high purity and high density was synthesized by electrodeposition. An extreme extensibility (elongation exceeds 5000%) without a strain hardening effect was observed when the nc copper specimen was rolled at room temperature. Microstructure analysis suggests that the superplastic extensibility of the nc copper originates from a deformation mechanism dominated by grain boundary activities rather than lattice dislocation, which is also supported by tensile creep studies at room temperature. This behavior demonstrates new possibilities for scientific and technological advancements with nc materials. 相似文献
4.
Super plastic bulk metallic glasses at room temperature 总被引:1,自引:0,他引:1
In contrast to the poor plasticity that is usually observed in bulk metallic glasses, super plasticity is achieved at room temperature in ZrCuNiAl synthesized through the appropriate choice of its composition by controlling elastic moduli. Microstructures analysis indicates that the super plastic bulk metallic glasses are composed of hard regions surrounded by soft regions, which enable the glasses to undergo true strain of more than 160%. This finding is suggestive of a solution to the problem of brittleness in, and has implications for understanding the deformation mechanism of, metallic glasses. 相似文献
5.
6.
In a ferromagnet, an applied electric field E invariably produces an anomalous Hall current JH that flows perpendicular to the plane defined by E and M (the magnetization). For decades, the question of whether JH is dissipationless (independent of the scattering rate) has been debated without experimental resolution. In the ferromagnetic spinel CuCr2Se4-xBrx, the resistivity rho (at low temperature) may be increased by several decades by varying x (Br) without degrading M. We show that JH/E (normalized per carrier, at 5 kelvin) remains unchanged throughout. In addition to confirming the dissipationless nature of JH, our finding has implications for the generation and study of spin-Hall currents in bulk samples. 相似文献
7.
Helium has been solidified at room temperature. The melting pressure at 24 degrees C is 115 kilobars, in complete agreement with the Simon equation. An original apparatus was developed for this experiment, which allows loading of the cell at room temperature. Applications to various areas of research are suggested. 相似文献
8.
Many salts of polynuclear carboxylic acids, phenols, amines, and sulfonic acids adsorbed on paper, silica, alumina, and other substrates exhibit strong triplet phosphorescence at room temperature, with no evidence of quenching by oxygen. No phosphorescence has been observed with nonionic materials. The spectra are similar to those of frozen solutions at -196 degrees C, and the technique provides a simple means of demonstrating phosphorescence phenomena, identifying unknown materials, and investigating the spectra of triplet states. 相似文献
9.
Yamada Y Ueno K Fukumura T Yuan HT Shimotani H Iwasa Y Gu L Tsukimoto S Ikuhara Y Kawasaki M 《Science (New York, N.Y.)》2011,332(6033):1065-1067
The electric field effect in ferromagnetic semiconductors enables switching of the magnetization, which is a key technology for spintronic applications. We demonstrated electric field-induced ferromagnetism at room temperature in a magnetic oxide semiconductor, (Ti,Co)O(2), by means of electric double-layer gating with high-density electron accumulation (>10(14) per square centimeter). By applying a gate voltage of a few volts, a low-carrier paramagnetic state was transformed into a high-carrier ferromagnetic state, thereby revealing the considerable role of electron carriers in high-temperature ferromagnetism and demonstrating a route to room-temperature semiconductor spintronics. 相似文献
10.
Venkataramani S Jana U Dommaschk M Sönnichsen FD Tuczek F Herges R 《Science (New York, N.Y.)》2011,331(6016):445-448
Magnetic bistability, as manifested in the magnetization of ferromagnetic materials or spin crossover in transition metal complexes, has essentially been restricted to either bulk materials or to very low temperatures. We now present a molecular spin switch that is bistable at room temperature in homogeneous solution. Irradiation of a carefully designed nickel complex with blue-green light (500 nanometers) induces coordination of a tethered pyridine ligand and concomitant electronic rearrangement from a diamagnetic to a paramagnetic state in up to 75% of the ensemble. The process is fully reversible on irradiation with violet-blue light (435 nanometers). No fatigue or degradation is observed after several thousand cycles at room temperature under air. Preliminary data show promise for applications in magnetic resonance imaging. 相似文献
11.
常熟叫花鸡常温保鲜技术的研究 总被引:1,自引:0,他引:1
通过单因素试验,筛选出最佳防腐效果的防腐剂,再通过正交试验,将乳酸链球菌素、乳酸钠、山梨酸钾混合加入到常熟叫花鸡的腹腔填料中,通过对常温下不同贮藏时间的常熟叫花鸡腹腔填料中菌落总数测定和感官分析,研究复合型防腐剂对常熟叫花鸡填料的防腐作用,以探讨常熟叫花鸡常温下的保鲜技术.结果表明: 常熟叫花鸡填料中乳酸链球菌素、山梨酸钾、乳酸钠添加量分别为0.15、0.18、0.10 g·kg-1时,常温下保质期由原来的2 d延长至5 d.以乳酸链球菌素为主的复合型防腐剂联合其他防腐剂的抑菌效果明显大于单一抑菌效果. 相似文献
12.
采用杂交育种技术,初步育成了可采用常温水进行缫丝的家蚕新品种LBM43×LBM。在25℃水温条件下,LBM43的450 m解舒率55.8%,纤度为4.39 D,粒茧索绪平均时间为6.8 min;LBM的450 m解舒率10.0%,纤度为2.58 D,粒茧索绪平均时间为3.0 min,粒茧缫丝平均时间为2.0 min;一代杂交种LBM43×LBM解舒率88.9%,纤度为2.83 D,粒茧索绪平均时间为3.0 min,粒茧缫丝平均时间为2.7 min。杂交一代的万头蚕收茧量为18 kg,是原种LBM43的1.84倍,是原种LBM的2.02倍。 相似文献
13.
Small solid precipitates (bubbles) of xenon in an aluminum matrix have been formed by ion implantation. Lattice images of this room-temperature inert gas solid were obtained using high-resolution phase-contrast electron microscopy. Many bubbles showed a high degree of crystalline perfection, but regions of defective crystallinity were observed in several cases. 相似文献
14.
【目的】建立一种室温均相改性农林废弃物的方法.【方法】选用甘蔗渣为原料,在室温下,将其溶解在二甲基亚砜/1-甲基咪唑溶剂体系中,利用异丁酸酐为改性剂,对甘蔗渣进行了均相改性研究.【结果和结论】保持反应时间为180 min,将酸酐与甘蔗渣质量比从1∶1提高到6∶1时,甘蔗渣均相衍生化的反应得率由10.3%增加到49.2%;保持酸酐与甘蔗渣质量比为3∶1,将反应时间由15 min提高到45 min,反应得率由25.1%增加到27.4%,但进一步延长反应时间,反应得率略有下降,反应时间240 min时,反应得率降低至24.7%.利用FT-IR和CP/MAS13C-NMR分析发现,甘蔗渣与异丁酸酐发生了酯化反应,在甘蔗渣中引入了带有烷基的酯键基团.甘蔗渣中的碳水化合物和木质素分子均参与了化学反应. 相似文献
15.
Shape control of inorganic nanocrystals is important for understanding basic size- and shape-dependent scaling laws and is useful in a wide range of applications. With minor modifications in the chemical environment, it is possible to control the reaction and diffusion processes at room temperature, opening up a synthetic route for the production of polymetallic hollow nanoparticles with very different morphology and composition, obtained by the simultaneous or sequential action of galvanic replacement and the Kirkendall effect. 相似文献
16.
17.
18.
The combination of a defined medium with single-pass perfusion has made possible long-term maintenance of beating rat hearts at 22 degrees C in vitro. The 6- to 9-day survival period appears to be the longest so far reported for hearts. This method provides a stable system which should be useful for investigating the role of single factors in myocardial preservation and evaluating the effects of exposure to pharmacological and toxicological agents. 相似文献
19.
Atomic hydrogen has been stably encapsulated in both solution and crystal at room temperature. Upon gamma-ray irradiation of [(CH(3))(3)Si](8)Si(8)O(20), which is the trimethylsilylated derivative of the silicate anion with a double four-ring (D4R) cage, electron spin resonance (ESR) spectra revealed that a single hydrogen atom is encapsulated in the center of the D4R cage and is stable for periods of many months. Attack by chemically reactive species such as oxygen was prevented by the D4R cage, but the ESR signal of the hydrogen atom was sensitive to the magnetic interaction caused by the presence of the O(2) molecule near the cage. 相似文献
20.
针对生物质常温闭式成型机的不足,本文引入了开式成型的概念,并在原有闭式成型机液压驱动设备的基础上,改进了成型腔.通过对生物质原料的力学分析,设计了开式成型的变径成型锥头.并使用小刨花、锯末等材料进行验证,探讨了对生物质常温变径成型机成型效果的影响因素,同时确定了较高成型质量时成型腔的压缩比范围. 相似文献