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- 伞之过 2010-12-28 00:00:00
- From size, it usually generate significant changes in chemical and physical properties of small particle size in 0.1 microns (note 1 m = 100 centimeters, 1 centimeter = 10,000 microns, 1 micron = 10 nanometers, 1 nano = 10 ella), namely below 100 nanometers. Therefore, particle size in 1 ~ 100 nanometer particles called ultra fime grain materials, is also a kind of nanometer materials. Nano metal material is the middle of 1980s, then the successful development of field contains nano semiconducting film, nano ceramic, nano CiXing materials and nano biomedical materials. Nanoscale structure material referred to as the nanometer material (nano material), is to show its structure unit size between 1 nano ~ 100 nanometer range between. Because of its size is close to electronic coherence length, and its nature because strong coherent brings the self-organization makes properties change greatly. And, its scale has come close to the wavelength of light, plus its surface with large special effect, thus its display properties, such as melting point, magnetic, optical, heat conductivity, conductive properties etc, often is different from the substance in overall state behavior of nature. Nanoparticles material called utrasmall particle materials from the nanoparticles (nano distinguish) composition. Nanoparticles also called utrasmall particle size, generally means within 1 ~ 100nm between particles, is in atom clusters and macro objects at the junction of the transition region, from the macro and micro usually on the viewpoint, this system not only atypical microscopic system also atypical macroscopic systems, is a kind of typical mesoscopic system, has the surface effect, small size effect and the macroscopic quantum tunneling effect. When people put the macro object subdivided into utrasmall particle (nanometer level), it will display a lot of exotic characteristics, namely its optical, heat, electricity, magnetic, mechanical and chemical properties of solid and bulky than when there will be significant different.Nanotechnology generalized range including nano materials technology and nano machining technology, nano measurement technology, nano application technology, etc. One nanometer material technology focuses on nano functional material production (superfine powder, coating, nano modified materials etc), performance testing technology (chemical composition, microstructure and surface morphology and geophysical, geochemical and electric, magnetic and optical properties, such as heat and). Nano machining technology contains precision machining technology (energy beam machining, etc) and scanning probe techniques. Nanomaterials has certain uniqueness, when matter scale small to certain degree, then have to switch to quantum mechanics to replace traditional mechanical view to describe its behavior, when powder particles size by 10 micron drop to 10 nano, its size is changed for 1,000 times, but converted volume is ten nine 4k times the giant, so both behavior will generate obvious difference. Nanoparticles are different from large physical reason is in the surface area of the relative increase, namely utrasmall particle surface was full of ladder shape structure, the structure with high surface can represent the unrest atoms. This kind of atomic extremely easily with foreign atomic adsorption of bonding, at the same time because narrow particle size and provides large surface activity of atoms. It is melting point, nano powder due to each particle constituent atoms less, surface atomic in instability, make its surface lattice vibration amplitude of the bigger, so has the high surface energy, causing utrasmall particle unique thermal property, also is caused by melting down, as nano powder will than traditional powder easy in low temperature sintering and become good sintering promote materials 从尺寸大小来说,通常产生物理化学性质显著变化的细小微粒的尺寸在0.1微米以下(注1米=100厘米,1厘米=10000微米,1微米=1000纳米,1纳米=10埃),即100纳米以下。因此,颗粒尺寸在1~100纳米的微粒称为超微粒材料,也是一种纳米材料。 纳米金属材料是20世纪80年代中期研制成功的,后来相继问世的有纳米半导体薄膜、纳米陶瓷、纳米瓷性材料和纳米生物医学材料等。 纳米级结构材料简称为纳米材料(nano material),是指其结构单元的尺寸介于1纳米~100纳米范围之间。由于它的尺寸已经接近电子的相干长度,它的性质因为强相干所带来的自组织使得性质发生很大变化。并且,其尺度已接近光的波长,加上其具有大表面的特殊效应,因此其所表现的特性,例如熔点、磁性、光学、导热、导电特性等等,往往不同于该物质在整体状态时所表现的性质。 纳米颗粒材料又称为超微颗粒材料,由纳米粒子(nano particle)组成。纳米粒子也叫超微颗粒,一般是指尺寸在1~100nm间的粒子,是处在原子簇和宏观物体交界的过渡区域,从通常的关于微观和宏观的观点看,这样的系统既非典型的微观系统亦非典型的宏观系统,是一种典型的介观系统,它具有表面效应、小尺寸效应和宏观量子隧道效应。当人们将宏观物体细分成超微颗粒(纳米级)后,它将显示出许多奇异的特性,即它的光学、热学、电学、磁学、力学以及化学方面的性质和大块固体时相比将会有显著的不同。 纳米技术的广义范围可包括纳米材料技术及纳米加工技术、纳米测量技术、纳米应用技术等方面。其中纳米材料技术着重于纳米功能性材料的生产(超微粉、镀膜、纳米改性材料等),性能检测技术(化学组成、微结构、表面形态、物、化、电、磁、热及光学等性能)。纳米加工技术包含精密加工技术(能量束加工等)及扫描探针技术。 纳米材料具有一定的独特性,当物质尺度小到一定程度时,则必须改用量子力学取代传统力学的观点来描述它的行为,当粉末粒子尺寸由10微米降至10纳米时,其粒径虽改变为1000倍,但换算成体积时则将有10的9次方倍之巨,所以二者行为上将产生明显的差异。 纳米粒子异于大块物质的理由是在其表面积相对增大,也就是超微粒子的表面布满了阶梯状结构,此结构代表具有高表面能的不安定原子。这类原子极易与外来原子吸附键结,同时因粒径缩小而提供了大表面的活性原子。 就熔点来说,纳米粉末中由于每一粒子组成原子少,表面原子处于不安定状态,使其表面晶格震动的振幅较大,所以具有较高的表面能量,造成超微粒子特有的热性质,也就是造成熔点下降,同时纳米粉末将比传统粉末容易在较低温度烧结,而成为良好的烧结促进材料。 一般常见的磁性物质均属多磁区之集合体,当粒子尺寸小至无法区分出其磁区时,即形成单磁区之磁性物质。因此磁性材料制作成超微粒子或薄膜时,将成为优异的磁性材料。 纳米粒子的粒径(10纳米~100纳米)小于光波的长,因此将与入射光产生复杂的交互作用。金属在适当的蒸发沉积条件下,可得到易吸收光的黑色金属超微粒子,称为金属黑,这与金属在真空镀膜形成高反射率光泽面成强烈对比。纳米材料因其光吸收率大的特色,可应用于红外线感测器材料。 纳米技术在世界各国尚处于萌芽阶段,美、日、德等少数国家,虽然已经初具基础,但是尚在研究之中,新理论和技术的出现仍然方兴未艾。我国已努力赶上先进国家水平,研究队伍也在日渐壮大。
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- 谁发个纳米材料英文文章和翻译啊
2010-12-27 22:11:25
339
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- 纳米材料英文文献加翻译
2013-06-26 12:47:02
467
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- 纳米材料翻译(8)
- Symposium Spotlights the State of the Science Nanotechnology research may still be in its infancy, but indications are good that the field will be growing up fast in the coming years. This promising trend was evident at the second Interna... Symposium Spotlights the State of the Science Nanotechnology research may still be in its infancy, but indications are good that the field will be growing up fast in the coming years. This promising trend was evident at the second International Symposium on Nanotechnology and Occupational Health, which was held in Minneapolis in early October 2005. Sponsored by NIOSH, the Office of the Vice President for Research at the University of Minnesota and the Center for Biological and Environmental Nanotechnology at Rice University, the symposium showcased not only the progress that has been made in the study of nanotechnology’s workplace issues, but also the depth and breadth of questions that remain. Patrick O’Shaughnessy of the University of Iowa, Iowa City, considered the meeting “very productive. It brought together most of the players from health and safety. It was good to see the variety of academic, government and business people interested in ensuring that the health and safety topics and concerns are addressed as soon as possible. No one wants another asbestos problem to emerge.”He notes that several talks and poster sessions on toxicology showed data implying that nanoparticles tested may not be as reactive as first suspected. In addition, there was a general consensus that typical mass-based measurements will not be adequate when evaluating a workplace because of nanoparticles’ small size and low mass. “Interestingly, devices that measure particle surface area may be very useful because the particles have an extremely large surface-to-volume ratio, and therefore, a greater potential to react with lung tissue,” O’Shaughnessy says. Other topics of interest, adds Mark Hoover of NIOSH, Morgantown, W. Va., included how to organize health and safety programs and resources to manage nanoparticles effectively and safely, personal protective equipment and filtration, as well as whether existing information about micrometer particles can be extrapolated to the nanometer range. “The evidence is still developing,” Hoover says, “but many people will do investigations with multiple metrics so we can be sure.”Hoover was also impressed with the symposium’s international flavor. “You had a lot of networking going on between U.S. scientists and their colleagues from the Pacific Rim, the European Union, Australia and New Zealand,” he says. “Everybody is eager to get up to speed with their colleagues’ research.” 展开
2006-10-18 03:35:51
392
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- 纳米材料翻译(3)
- The preparation of ultrafine powder of bismuth sulfide The synthesis of binary metal sulfides has been the focus of attention because of their important physical and chemical properties [1, 2], good commercial applications in semiconductor... The preparation of ultrafine powder of bismuth sulfide The synthesis of binary metal sulfides has been the focus of attention because of their important physical and chemical properties [1, 2], good commercial applications in semiconductors, pigments, luminescence devices, solar cells, IR detectors and optical fiber, communications, modern thermoelectric coolers [3]. Bismuth sulfide (Bi2S3) is a direct band gap material with Eg of 1.3 eV [4] and useful for photodiode arrays of photovoltaics [5]. Usually, busmuth sulfide can be prepared by direct reaction of bismuth and sulfur vapor in a quartz vessel at high temperature [6]. The chemical deposition method was applied to prepare bismuth sulfide through reaction of bismuth salt complexed by triethanolamine or EDTA with an aqueous solution containing a sulfur sourse such as thioacetamide, thiourea, sodium thiosulphate, geseous H2S. However, the powders obtained through this route are mostly amorphous or poorly crystallized [7–10]. The thermal decomposition preparation of bismuth sulfide was also reported by thermal decomposition of bismuth dithiocarbamate complexes [11], metal ethylxanthate [12], Bi-thiourea complex [13]. However, all these methods required high temperature or else the final poducts contain some impurites. Some researches use nonagueous solutions for depostion of bismuth sulfide thin films, but they have got amorphous products [14, 15]. Yu and Qian reported thermal synthesis of Bi2S3 through a reaction of BiCl3 and thiourea in ethanol at 140 °C [16]. 展开
2006-10-18 03:54:51
327
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- 纳米材料翻译(6)
- Such interest is well founded.Touted as the impetus for a 21st century industrial revolution, manufactured nanoscale materials (less than 100 nanometers) are being studied intensely by a variety of industries. Worldwide, governments are alr... Such interest is well founded.Touted as the impetus for a 21st century industrial revolution, manufactured nanoscale materials (less than 100 nanometers) are being studied intensely by a variety of industries. Worldwide, governments are already investing billions of dollars in nanotechnology; that figure almost certainly will surpass $1 trillion in the next 10 years. Perhaps the only thing that approaches nanotechnology's technological potential is the uncertainty surrounding its occupational health risks. Relatively little is known about the exposure patterns and toxicity levels of ultrafine materials. But with hundreds of thousands of workers expected to join an industry that likely will redefine nearly every aspect of manufacturing and processing in the coming years, it’s essential that IHs learn as much as they can about potential workplace safety issues related to nanotechnology. “This is an opportunity for IHs to be at the forefront of solving problems before they arise,” says Mark Hoover, a senior research scientist at NIOSH in Morgantown, W.Va.“It is certainly a better approach than having to react to a problem or perform a cleanup on short notice.” 展开
2006-10-18 04:39:25
484
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- 纳米材料翻译(4)
- In this study the preparation of ultrafine powder of Bi2S3 by a reaction between bismuth octanoate and sulfur in organic solvent such as high boiling alcanes is reported. The first step was the preparation of bismuth octanoate. Bi(NO3)3Y... In this study the preparation of ultrafine powder of Bi2S3 by a reaction between bismuth octanoate and sulfur in organic solvent such as high boiling alcanes is reported. The first step was the preparation of bismuth octanoate. Bi(NO3)3⋅5H2O and octanic acid were used as the starting materials. The acid was reagent and solvent at the same time and was added in twice excess. After boiling the mixture of starting materials during 1 hour, the product was salted out by ethylacetate. The precipitate was filtered and dried in exxicator at room temperature.The second step was the synthesis of bismuth sulfide by boiling of bismuth octanoate and sulfur in decane during 2.5 hours. The dark grey precipitate was filtered and washed with hexane several times to remove the impurites. The product was dried in exxicator at room temperature. 展开
2006-10-18 10:56:47
427
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- 翻译以下英文:
- The standard error of the mean (SEM) is a measure of how far your sample mean is likely to be from the true population mean. The SEM is calculated by this equation:SEM=SD/N. With large samples, the SEM is always small. By itself, the SEM i... The standard error of the mean (SEM) is a measure of how far your sample mean is likely to be from the true population mean. The SEM is calculated by this equation:SEM=SD/N. With large samples, the SEM is always small. By itself, the SEM is difficult to interpret. It is easier to interpret the 95% confidence interval, which is calculated from the SEM. 展开
2007-11-15 02:56:39
523
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- 谁能帮我翻译一下这段英文文献啊
- Fig. 1 shows that diamond particles are dispersed in the copper matrix. Since the diamond particles are easy to be stripped off during mechanical polishing, small pits are left on the surface of samples. When the samples were analyzed b... Fig. 1 shows that diamond particles are dispersed in the copper matrix. Since the diamond particles are easy to be stripped off during mechanical polishing, small pits are left on the surface of samples. When the samples were analyzed by electron probe for carbon, the particles displayed high carbon peaks, as shown in Fig. 2. Fig. 3 exhibits the analyzed result for extracted product of the copper–diamond composite by X-ray diffraction (XRD) analysis. It is shown that three dif- fraction peaks exist, shown as A, B and C, respectively. The interplanar distances corresponding to the three peaks and standard ones for diamond are compared in Table 1. The measured values of the interplanar distances are in good agreement with the standard ones, demon- strating that the extracted product should be the carbon in diamond state. Fig. 4(a) gives a TEM micrograph showing distribution and morphology of diamond particles (indicated as A, B, and C) in the copper–diamond composite. The calibration of interplanar distance for diffraction rings in Fig. 4(b) was given in Table 2. Compared to Table 1, it is also demon- strated that the calibrated interplanar distances for the diffraction rings conform to the standard ones of diamond. Therefore, it is believed that the graphitization of diamond particles hardly occurs after sintering at 1150–1220 K in the copper–diamond composite. Although diamond is a metastable allotropic modifica- tion of carbon, the graphitization of diamond particles in the copper–diamond composite did not occur, or the degree of graphitization was too small to be found. It is believed that the beginning temperature of graphi- tization would be associated with the purity of diamond powders. The impurities such as some metallic elements reduce the beginning temperature of diamond graphitiza- tion. When diamond is fabricated by the static synthesis method, Fe and Ni are often used as catalysts and are present in diamond as impurities to decrease the beginning temperature of graphitization [6]. It is understandable that both for the graphitization and its reverse reactions, their activation energies can be decreased by catalytic agents. Compared with the diamond fabricated by static synthesis, the diamond powders prepared by explosion method do not contain metallic impurities, thus leading to an obvious increase in the beginning temperature of graphitization. Hence, the detonation synthetic diamond might be more resistant to graphitization and probably suitable for the electric contact materials. 展开
2011-03-22 08:43:56
427
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- 翻译纳米材料摘要(2)
- Moreover, the particle size of incorporated ZnO calculated from the effective mass model was close to the results obtained from HRTEM. The synthesis method developed in course of this work can be used for the fabrication of different polym... Moreover, the particle size of incorporated ZnO calculated from the effective mass model was close to the results obtained from HRTEM. The synthesis method developed in course of this work can be used for the fabrication of different polymer-inorganic transparent nanocomposites with other functionalities. In the second part of the thesis, we studied a method for the fabrication of micro-porous surface layer – made of copper nanoparticles – on the surface of copper plates (suitable for heat exchangers). The micro-porous surfaces were formed from dendritic network of copper nanoparticles obtained by electrodeposition from solution using dynamic bubble formation and removal as template. The surface layer engineered and its structures were optimized in order to enhance the boiling heat transfer coefficient. To further optimize the dendritic structure, additional annealing step was introduce and its effect on the surface layer structure and properties were investigated. The properties of the deposited surface structures were investigated and its effect on the enhancement of the heart transfer coefficient has been studied. The fabricated enhanced surface has shown an excellent performance in nucleate boiling. Pool boiling tests were performed on refrigerant fluids (R134a) to evaluate the boiling performance of the electrodeposited nanostructured micro-porous structures. At heat flux of 1 W/cm2, the heat transfer coefficient is enhanced over 15 times compared to a plain reference surface. A model has been presented to explain the enhancement based on the structure characteristics. 展开
2006-10-18 01:46:56
395
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- 求翻译英文文献
- 2.2. Material Characterizations. A field emission scanning electron microscope (SEM, JEOL 6701F) was used to investigate the morphologies, particle sizes of the samples. Transmission electron microscopy and elemental compositions of the ... 2.2. Material Characterizations. A field emission scanning electron microscope (SEM, JEOL 6701F) was used to investigate the morphologies, particle sizes of the samples. Transmission electron microscopy and elemental compositions of the samples were determined by JEM-2100F (JEOL) coupled with an energy-dispersive X-ray spectroscopy (EDX, Phoenix) system. Wide-angle and low-angle X-ray powder diffraction (XRD) of the as-obtained samples were recorded on a Rigaku D/max-2500 with Cu Kα radiation (λ = 1.540 56 Å) operated at 40 kV and 200 mA. Raman measurements were performed using a DXR from Thermo Scientific with a laser wavelength of 532 nm. To calculate the pore size distribution and pore volumes, the nitrogen absorption and desorption isotherms were measured at 77.3 K with an Autosorb-1 specific surface area analyzer from Quantachrome. The content of N in N-doped porous carbon was determined by NHC elemental analysis using Flash EA 1112. Thermogravimetric (TG) analysis of S/C composite was performed on TG/DTA 6300 in an N2 flow to obtain the S content in the composite. A four-contact method was applied to measure the powder electronic conductivity of porous carbons. The powder sample was pressed to disk at 4 MPa with two stainless-steel plungers, whose resistance was measured by a Keithley 2400 digital multimeter in fourwire mode. The conductivity of the sample was calculated according to the resistance and the size of the disk. Information of the surface elements was obtained by X-ray photoelectron spectroscopy (XPS) performed on the Thermo Scientific ESCALab 250Xi using 200 W monochromatic Al Kα radiation. The 500 μm X-ray spot was used for XPS analysis. The base pressure in the analysis chamber was about 3 × 10−10 mbar. All reported data of XPS binding energy are calibrated based on the hydrocarbon C 1s line at 284.8 eV from adventitious carbon. Spectra were fitted with Lorentzian−Gaussian functions and smart background using Thermo Avantage software. 展开
2014-12-28 15:14:51
551
1
- 求助,英文文献翻译!
- 2. Experimental 2.1 Materials Nano-CaCO3 particles (D50: 30−70 nm by TEM (Fig. 1) and BET: ca.17m2·g-1) were supplied by Shanghai Zhuoyue Nanotech Corporation. Methyl methacrylate (MMA, Shanghai Lingfeng Chemicals) was purified ... 2. Experimental 2.1 Materials Nano-CaCO3 particles (D50: 30−70 nm by TEM (Fig. 1) and BET: ca.17m2·g-1) were supplied by Shanghai Zhuoyue Nanotech Corporation. Methyl methacrylate (MMA, Shanghai Lingfeng Chemicals) was purified by distillation under reduced pressure; potassium persulphate (K2S2O8, initiator, Shanghai Lingfeng Chemicals) was of chemical grade. Silane coupling agent A174 (γ-methacryloxypropyltrimethoxysilane) was purchased from Shanghai Yaohua Factory. Polyvinylchloride (PVC, WS-1000S) was supplied by Shanghai Chlor-Alkali Chemical Co., Ltd. Fig. 1 Morphology of untreated CaCO3 nanoparticles. Fig. 2 Morphology of PMMA-coated CaCO3 nanoparticles. 2.2 PMMA emulsion polymerization on CaCO3 nanoparticles 2.2.1 Surface silanation of nano-CaCO3 particles The nano-CaCO3 particles were homogeneously dispersed in ethanol (solid content 20%) by a sonication dispersion equipment. The slurry was then heated to 80°C with stirring, and the silane coupling agent A174 (5%, calculated based on the weight of nano-CaCO3 particles) was added into the slurry. After the slurry was stirred for 120 min at 80°C, it was filtered and the filter cake was then dried at 120°C in low vacuum for 120 min to obtain silanated CaCO3 powders. 展开
2011-05-16 00:26:36
445
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- 求助,英文文献翻译~
- PMMA has good compatibility with PVC due to specific interaction of a hydrogen bonding type between carbonyl groups (C=O) of PMMA and hydrogen from (CHCl) groups of PVC (Belhaneche-Bensemra et al., 2002; Ramesh et al., 2002). Zhou et al... PMMA has good compatibility with PVC due to specific interaction of a hydrogen bonding type between carbonyl groups (C=O) of PMMA and hydrogen from (CHCl) groups of PVC (Belhaneche-Bensemra et al., 2002; Ramesh et al., 2002). Zhou et al. (2001) studied the relationship between the coating thickness of PMMA on the surface of talc and mechanical properties of PMMA-g-talc/PVC composites, and found that there existed a critical thickness. Xie (2001) found that the PMMA coating on talc improved the dispersion of talc in the PVC matrix and enhanced the interfacial adhesion between talc and PVC. There appears to be a critical coating thickness of PMMA on the talc surface for optimum toughening. Quan et al. (2002) reported improved toughness and intension of the PVC composites filled with CaCO3/ACR core-shell complex particles prepared by in-situ emulsion polymerization of acrylic ester. In the present work, PMMA coated on the surface of CaCO3 nanoparticles by in-situ emulsion polymerization was characterized by FT-IR and 1H-NMR. The effects of PMMA thickness and particle fraction on the mechanical properties of PMMA-coated CaCO3 /PVC nanocomposites were also investigated. 展开
2011-05-16 04:20:15
503
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- 谁帮我翻译一下
- LabVIEWTM(LaboratoryVirtualInstrumentEngineeringWorkbench)isapowerfulinstrumentationandanalysisprogramminglanguageforPCsrunningMicrosoftWindows,SunSPARCstations,AppleMaci... LabVIEWTM (Laboratory Virtual Instrument Engineering Workbench) is a powerful instrumentation and analysis programming language for PCs running Microsoft Windows, Sun SPARCstations, Apple Macintosh computers, Concurrent PowerMax, and HP-UX workstations. LabVIEW departs from the sequential nature of traditional programming languages and features a graphical programming environment and all the tools needed for data acquisition, analysis, and presentation. With this graphical programming language, called “G,” you can program in a block diagram notation, the natural design notation of scientists and engineers. After you create a block diagram program, LabVIEW compiles it into machine code. LabVIEW integrates data acquisition, analysis, and presentation in one system. For acquiring data and controlling instruments, LabVIEW supports RS-232/422, IEEE 488 (GPIB), and VXI, including Virtual Instrument Software Architecture (VISA) functions, as well as plug-in data acquisition (DAQ) boards. An instrument library with drivers for hundreds of instruments simplifies instrument control applications. For analyzing data, the extensive Analysis library contains functions for signal generation, signal processing, filters, windows, statistics, regression, linear algebra, and array arithmetic. Because LabVIEW is graphical in nature, it is inherently a data presentation package. LabVIEW can generate charts, graphs, and customized, user-defined graphics. 尽量翻的好一点,谢谢 能不能对GOOGLE自动翻译过的稍加修改下 展开
2008-03-24 08:56:44
550
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- 纳米材料的摘要翻译(7)
- Drivers and Directions In the United States, the EPA and NIOSH are spearheading research into nanoparticles and their associated health risks through a variety of funded research projects and information exchange programs. NIOSH’s Web si... Drivers and Directions In the United States, the EPA and NIOSH are spearheading research into nanoparticles and their associated health risks through a variety of funded research projects and information exchange programs. NIOSH’s Web site also cites its participation in the multiagency National Nanotechnology Initiative and the Nanoscale Science, Engineering and Technology Subcommittee of the National Science and Technology Council’s Committee on Technology. But on the whole, the study of nanotechnology in the workplace is still in its infancy. Or as Keith Rickabaugh, technical director of materials and analytical services for RJ Lee Group, Monroeville, Pa., puts it, “what has been learned is that there is much more to learn.” Rickabaugh goes on to say that, “We need to learn how to economically/reasonably establish safe work practices and engineering controls to protect workers from an ‘unknown’ exposure risk. That includes performing studies to document the health risks of nanosized particles, and training workers to understand and be able to characterize those materials.” 展开
2006-10-18 01:02:26
593
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- 数据采集的英文怎么翻译?
2010-07-05 09:53:28
395
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- 翻译英文~专业类的
- Whilegraphene,acarbon-basedtwo-dimensionalnanomaterials,hasreceivedanupsurgeofinterest,[1]self-assemblyofsmallorganicandorganometallicmoleculesinto2Dnanostructurescouldal... While graphene, a carbon-based two-dimensional nanomaterials, has received an upsurge of interest,[1] self-assembly of small organic and organometallic molecules into 2D nanostructures could also be harnessed to develop new classes of functional supramolecular nanomaterials.[2] In principle, quasi-2D lamellae or nanosheets are planar structures having a thickness less than 100 nm and lateral dimensions a few orders of magnitude greater than their thickness. Control over the bilateral intermolecular noncovalent interactions is anticipated to organize small molecules into regular 2D nanostructures, which has been a formidable challenge yet to be achieved. Recently, Shelnutt and co-workers obtained discrete porphyrin nanosheets reprecipitated from their solutions;[3] Sathish and co-workers constructed hexagonal C60 nanosheets using a liquid–liquid interfacial precipitation method;[4] the groups of Yao[5] and Hu[6] prepared singlecrystalline nanosheets of polycyclic aromatics using a surfactant- assisted reprecipitation and a physical vapor transporting method, respectively; and Zhang and co-workers suggested that molecules with intramolecular charge-transfer dipole moments could be grown into quasi-2D nanostructures.[7] Moreover, some amphiphiles and organogelators were found to self-organize into sheet-like nanostructures in contact with solvents.[8] Despite these advances, templateand surfactant-free synthesis of free-standing, crystalline, and optoelectronically active nanosheets from small molecules remains elusive. 展开
2010-03-06 01:33:12
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- “纳米材料” 用英文怎么说阿
2016-12-23 00:06:55
299
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- 十二烷基磺酸钠的MSDS中关于危害性的部分,谁给发个啊?
2011-11-01 21:58:27
351
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- 谁帮我翻译一下,谢谢
- ···until TLC analysis indicated the absence of dipolarophile.
2008-10-25 07:34:06
413
2
- 翻译一段纳米材料的摘要(1)
- Abstract Nanomaterials and nanotechnology have been hot issues during the recent decades. This thesis deals with the fabrication and engineering of novel nanomaterials with enhanced functionality, particularly nanocomposites and nanostruc... Abstract Nanomaterials and nanotechnology have been hot issues during the recent decades. This thesis deals with the fabrication and engineering of novel nanomaterials with enhanced functionality, particularly nanocomposites and nanostructured surfaces. The study includes two parts; in the first part, bulk transparent polymer-inorganic nanocomposites were produced by a novel synthesis method and its UV-absorption has been investigated. In the second part, nanostructured microporous surface layers, of copper, were fabricated by electrodeposition process and its effect on material’s performance for pool boiling has been investigated evaluated.In the first part of the thesis, bulk polymer-inorganic nanocomposites composed of poly(methylmethacrylate) (PMMA) and zinc compounds were prepared by an in situ sol-gel transition polymerization of zinc complex in PMMA matrix. The immiscibility of heterophases of solid organic and inorganic constituents was resolved by the in situ sol-gel transition polymerization of ZnO nanofillers within PMMA in the presence of dual functional agent, monoethanolamine, which provided strong secondary interfacial interactions for both complexing and crosslinking of constituents. Comprehensive characterization of the polymer-inorganic hybrid materials has been undertaken using a wide range of techniques; XRD, 1H NMR, FT-IR, TGA, DSC, UV-Vis, ED, SEM, TEM and HRTEM. The homogeneous PMMA-ZnO nanocomposites exhibited enhanced UV-sheltering effects in the entire UV range even at very low ZnO content of 0.02 wt%. 展开
2006-10-18 01:02:42
375
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