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耒电#3、#4机组SVEDALA双进双出磨煤机差压料位测量装置改造后,测量准确性差、故障率高,通过分析问题、持续改进后,对取样管路和测量探针以及控制方案进行改造.改造完成后,新的测量系统测量准确,无测量管路堵塞和测量失真等现象,达到提高磨煤机运行安全性和节能降耗的目的. 相似文献
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温差电材料热导率的激光脉冲测试法 总被引：2，自引：0，他引：2
简要地介绍了热导率激光脉冲法的测量原理和实际装置,着重对该方法在半导体温差电材料热导率测试中的问题和解决途径进行了详细的讨论。 相似文献
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针对光纤布喇格光栅(FBG)发生弯曲应变实现压力(应力)传感检测的实际情况,对FBG与衬底材料全粘附和两点粘附耦合对压力传感特性影响进行了对比实验研究。结果表明,全粘附耦合会对传感器输入与输出响应特性产生较大的非线性影响,这种非线性影响主要来源于应力双折射、应力梯度等引起的谱展宽干扰。由实验结果得出,在压力为0～4N测量范围内,采用全粘附耦合引起的FBG反射光谱的展宽约为0．28nm;采用两点粘附耦合后,谱宽不随压力而变,而线性度较之全粘贴耦合时提高了1．89％。 相似文献
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Lessa Kay Grunenfelder Enrique Escobar de Obaldia Qianqian Wang Dongsheng Li Brian Weden Christopher Salinas Richard Wuhrer Pablo Zavattieri David Kisailus 《Advanced functional materials》2014,24(39):6093-6104
Chiton are marine mollusks who use heavily mineralized and ultrahard teeth to feed on epilithic and endolithic algae on intertidal rocks. To fulfill this function, chiton teeth must be tough and wear‐resistant. Impressive mechanical properties are achieved in the chiton tooth through a hierarchically arranged composite structure consisting of a hard shell of organic‐encased and highly oriented nanostructured magnetite rods that surround a soft core of organic‐rich iron phosphate. Microscopic and spectroscopic analyses combined with finite element simulations are used to probe the ultrastructural features and uncover structure–mechanical property relationships in the fully mineralized teeth of the gumboot chiton Cryptochiton stelleri. By understanding the effects of the nanostructured architecture within the chiton tooth, abrasion‐resistant materials can be developed for tooling and machining applications, as well as coatings for equipment and medical implants. 相似文献
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Biomineralization: Stress and Damage Mitigation from Oriented Nanostructures within the Radular Teeth of Cryptochiton stelleri (Adv. Funct. Mater. 39/2014) 
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下载免费PDF全文 Lessa Kay Grunenfelder Enrique Escobar de Obaldia Qianqian Wang Dongsheng Li Brian Weden Christopher Salinas Richard Wuhrer Pablo Zavattieri David Kisailus 《Advanced functional materials》2014,24(39):6085-6085
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Lise T. de Jonge Sander C. G. Leeuwenburgh Jeroen J. J. P. van den Beucken Joop G. C. Wolke John A. Jansen 《Advanced functional materials》2009,19(5):755-762
The biological performance of orthopedic and oral implants can be significantly improved by functionalizing the non‐physiological metallic implant surface through the application of biologically active coatings. In this paper, a cost‐effective alternative to traditional biomedical coatings for bone substitution through exploitation of the specific advantages of the electrospray deposition technique for the immobilization of the enzyme alkaline phosphatase (ALP) onto the implant surface is presented. Since ALP increases the local inorganic phosphate concentration required for physiological mineralization of hard tissues, ALP coatings will enable enzyme‐mediated mineralization onto titanium surfaces. To evaluate the bone‐bioactive capacity of the ALP‐coated titanium surface, soaking experiments are performed. Although the purely inorganic so‐called simulated body fluid is the standard in vitro procedure for predictive studies on potential bone bonding in vivo, an alternative testing solution is proposed that also contains organic phosphates (cell culture medium supplemented with the organic β‐b;‐glycerophosphate (β‐b;‐GP) and serum proteins), thereby resembling the in vivo conditions more closely. Under these physiological conditions, the electrosprayed ALP coatings accelerated mineralization onto the titanium surface as compared to noncoated implant material by means of enzymatic pathways. Therefore, this novel approach toward implant fixation holds significant promise. 相似文献
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Emily Asenath‐Smith Hanying Li Ellen C. Keene Zhi Wei Seh Lara A. Estroff 《Advanced functional materials》2012,22(14):2890-2890
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Emily Asenath‐Smith Hanying Li Ellen C. Keene Zhi Wei Seh Lara A. Estroff 《Advanced functional materials》2012,22(14):2891-2914
In recent years, the prevalence of hydrogel‐like organic matrices in biomineralization has gained attention as a route to synthesizing a diverse range of crystalline structures. Here, examples of hydrogels in biological, as well as synthetic, bio‐inspired systems are discussed. Particular attention is given to understanding the physical versus chemical effects of a broad range of hydrogel matrices and their role in directing polymorph selectivity and morphological control in the calcium carbonate system. Finally, recent data regarding hydrogel‐matrix incorporation into the growing crystals is discussed and a mechanism for the formation of these single‐crystal composite materials is presented. 相似文献
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激光冲击是一种以高功率脉冲激光辐照金属材料的新型表面改性处理技术。课题组通过对铝、钛和不锈钢这三种典型的金属结构材料,在有水约束层和记号笔涂层作保护层的情况下,进行激光冲击对比试验,获得强激光冲击作用下金属结构材料的损伤特性,并定量分析了激光冲击次数与金属材料表面凹坑深度的关系,结果表明凹坑深度与冲击次数呈线性关系且斜率与金属材料的屈服强度成反比。为了探究激光冲击光斑形貌对于金属材料损伤的影响,我们还对比了方斑和圆斑的冲击情况。 相似文献
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Hermann Ehrlich Mykhailo Motylenko Alexander Ereskovsky Izabela Zgłobicka Teresa Noga Tomasz Płociński Mikhail V. Tsurkan Elżbieta Wyroba Szymon Suski Henryk Bilski Marcin Wysokowski Hartmut Stöcker Anna Makarova Denis Vyalikh Juliane Walter Serguei L. Molodtsov Vasilii V. Bazhenov Iaroslav Petrenko Enrico Langer Andreas Richter Elke Niederschlag Marcin Pisarek Armin Springer Michael Gelinsky David Rafaja Andrzej Witkowski Dirk C. Meyer Teofil Jesionowski Krzysztof J. Kurzydłowski 《Advanced functional materials》2016,26(15):2503-2510
Diatoms are considered unicellular eukaryotic organisms exclusively depositing biogenic silica. Heretofore there has been no report of calcification by these algae. Here it is shown that calcium carbonate within the stalks of Didymosphenia geminata, a nuisance species that has prolifically colonized streams and rivers globally, is biogenic in origin and occurs as a network of calcite nanofibers. The nanofibrous framework in the mineralized polysaccharide matrix imparts mechanical support to the stalks, providing stability in variable flow conditions. The results demonstrate that D. geminata possesses cellular and periplasmic carbonic‐anhydrases that contribute to carbon fixation and biomineralization, respectively. The activity of external carbonic‐anhydrase was more than 50% of the total activity, which points to its role in anchoring this bioeroding diatom on hard surfaces. The first evidence of multiphase biomineralization by diatoms that deposit both biogenic silica and crystalline biogenic calcite which are imparting distinct functional advantage to the organism is provided. 相似文献
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Hermann Ehrlich Eike Brunner Paul Simon Vasily V. Bazhenov Joseph P. Botting Kontantin R. Tabachnick Armin Springer Kurt Kummer Denis V. Vyalikh Serguei L. Molodtsov Denis Kurek Martin Kammer René Born Alexander Kovalev Stanislav N. Gorb Petros G. Koutsoukos Adam Summers 《Advanced functional materials》2011,21(18):3473-3481
The hierarchically structured glass sponge Caulophacus species uses the first known example of a silica and calcite biocomposite to join the spicules of its skeleton together. In the stalk and body skeleton of this poorly known deep‐sea glass sponge siliceous spicules are modified by the addition of conical calcite seeds, which then form the basis for further silica secretion to form a spinose region. Spinose regions on adjacent spicules are then joined by siliceous crosslinks, leading to unusually strong cross‐spicule linkages. In addition to the biomaterials implications it is now clear, from this first record of a biomineral other than silica, that the hexactinellid sponges are capable of synthesizing calcite, the ancestral skeletal material. We propose that, while the low concentrations of calcium in deep sea waters drove the evolution of silica skeletons, the brittleness of silica has led to retention of the more resilient calcite in very low concentrations at the skeletal joints. 相似文献
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As an analogue of the main protein contained in naturally formed nacre, reconstituted silk fibroin (SF) from the Bombyx mori silkworm silk shows a strong preference for the formation of the aragonite form of CaCO3 crystals and allows fine control over their size and morphology. The aragonite phase could be generated via two different routes: direct growth or dissolution and recrystallization, depending on the concentration of Ca2+ and SF. Generally, lower concentrations of Ca2+ and SF favor the formation of aragonite needles and their aggregates, of which the lattice structure of the precursor is similar to that of the organic matrix in natural shell. Higher concentrations lead to the formation of aragonite aggregates via a dissolution and recrystallization process through intermediates of lens‐like vaterite. Molecular modeling shows that the β‐strand conformers of silk fibroin molecules has an excellent match with the ionic spacing in the aragonite (010) plane, which can promote growth along the (001) long axis of aragonite crystals. This synergy between silk fibroin and the aragonite phase may help our understanding of the function of organic matrices involved in the biomineralization process, and facilitate the fabrication of synthetic materials with the potential for high performance mechanical properties. 相似文献
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Heather A. Currie Olivier Deschaume Rajesh R. Naik Carole C. Perry David L. Kaplan 《Advanced functional materials》2011,21(15):2889-2895
Composite or hybrid materials are commonly found in Nature, formed through the concentration and subsequent nucleation of ions upon organic templates that are most often protein based. Examples include the deposition of calcium containing salts in bone, teeth and the inner ear and iron oxide structures in magnetotactic bacteria. Biological organisms use a limited number of metal ions, the principal ones being calcium and iron, with lesser amounts of strontium, and barium. The ability to utilize other ions to generate composites offers the possibility of new material properties. New materials incorporating silver would be useful in the context of antimicrobial functions. Therefore, in the present study, a new route to such functionalized biomaterials is reported. Genetically engineered fusion proteins are created by the incorporation of nucleotides corresponding to short silver binding peptides identified by a combinatorial biopanning process into the consensus sequence of silk from the spider, Nephila clavipes. The resulting chimeric silk–silver binding proteins nucleated Ag ions from a solution of silver nitrate while the silk protein provided a stable template material which could be processed into films, fibers, and three‐dimensional scaffolds. The silk films inhibited microbial growth of both Gram‐positive and Gram‐negative microrganisms on agar plates and in liquid culture, thus highlighting the potential of these chimeric material systems as antimicrobial biomedical coatings. 相似文献
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Johannes Ihli Pieter Bots Alexander Kulak Liane G Benning Fiona C Meldrum 《Advanced functional materials》2013,23(15):1965-1973
Aggregation‐based crystal growth often gives rise to crystals with complex morphologies which cannot be generated via classical growth processes. Despite this, understanding of the mechanism is rather poor, particularly when organic additives or amorphous precursor phases are present. In this work, advantage is taken of the observation that aggregation‐based growth of calcium carbonate, and indeed many other minerals, is most often observed using diffusion‐based synthetic methods. By fully characterizing the widely used ammonia diffusion method (ADM)–which is currently used as a “black box”–the solution and supersaturation conditions which accompany CaCO3 precipitation using this method are identified and insight is gained into the nucleation and growth processes which generate calcite mesocrystals. This reveals that the distinguishing feature of the ADM is that the initial nucleation burst consumes only a small quantity of the available ions, and the supersaturation then remains relatively constant, and well above the solubility of amorphous calcium carbonate (ACC), until the reaction is almost complete. New material is thus generated over the entire course of the precipitation, a feature which appears to be fundamental to the formation of complex, aggregation‐based morphologies. Finally, the importance of this understanding is demonstrated using the identified carbonate and supersaturation profiles to perfectly replicate CaCO3 mesocrystals through slow addition of reagents to a bulk solution. This approach overcomes many of the inherent problems of the ADM by offering excellent reproducibility, enabling the synthesis of such CaCO3 structures in large‐scale and continuous‐flow systems, and ultimately facilitating in situ studies of assembly‐based crystallization mechanisms. 相似文献
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Kai Jiao Li‐Na Niu Chu‐Fan Ma Xue‐Qing Huang Dan‐Dan Pei Tao Luo Qi Huang Ji‐Hua Chen Franklin R. Tay 《Advanced functional materials》2016,26(38):6858-6875
Biomineralization in vertebrates is a ubiquitous and tightly regulated process which creates hierarchical structures for the skeleton. Because of the lack of understanding and applicability of cell‐based or biological systems to achieve intrafibrillar mineralization, scientists adopted various in vitro methods to elucidate the mechanism of intrafibrillar mineralization. In this article, biomimetic intrafibrillar mineralization of collagen in its wide ramifications is reviewed. It is intriguing how prevailing intrafibrillar mineralization mechanisms derived from two potentially discordant crystallization philosophies were equally adept, depending on the experimental context, at theorizing the formation of calcium phosphate within a fibrillar template. This complementarity is not unique to biomineralization and has precedence in other fundamental physical interpretations. A new intrafibrillar mineralization process based on the use of polycationic process‐directing agent added uncertainty to the use of existing mechanisms in accounting for the observations. 相似文献
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Yurong Ma Gerald Mehltretter Carsten Plüg Nadine Rademacher Martin U. Schmidt Helmut Cölfen 《Advanced functional materials》2009,19(13):2095-2101
Organic pigments are important crystalline substances, and their properties and applications rely on size and shape control. Pigment Yellow 181 (PY181) is an industrial azo pigment that is light and weatherfast and suitable for high temperature processing. One disadvantage is its needle‐like shape in the default β‐phase, which makes the pigment difficult to process in industry, e.g., in polymer melts, where a spherical structure would be ideal. Here, we show for the first time, that polymer‐induced liquid precursor structures can be formed even in association to a chemical reaction. Furthermore, it is demonstrated that biomineralization principles can be exploited for the generation of advanced functional materials, such as pigments with novel complex morphology and different properties. Stable PY181 microspheres of nanoplates in the β‐phase were obtained in mixed solvents of water and isopropanol by direct azo coupling under the directing influence of a designed copolymer additive aminobenzoylaminobenzamide‐acetoacetyl‐poly(ethylene imine)‐block‐poly(ethylene glycol) (ABABA‐acetoacetyl‐PEI‐b‐PEG). 相似文献