A new preparation process combining melt spinning and hot pressing has been developed for the (AgxSbTex/2+1.5)(15)(GeTe)(85) (TAGS-85) system. Compared with samples prepared by the traditional air-quenching and hot-pr...
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A new preparation process combining melt spinning and hot pressing has been developed for the (AgxSbTex/2+1.5)(15)(GeTe)(85) (TAGS-85) system. Compared with samples prepared by the traditional air-quenching and hot-pressing method, electrical conductivity and thermal conductivity are lowered. The thermoelectric performance of the TAGS-85 samples varied with changing Ag content and reached the highest ZT of 1.48 when x was 0.8 for the melt-spun sample, compared with the maximum ZT of 1.36 for the air-quenched sample. The Seebeck coefficient of the melt-spun TAGS-85 alloys was improved, while both the electrical conductivity and thermal conductivity were decreased. The net result of this process is to effectively enlarge the temperature span of ZT > 1, which will benefit industrial application.
high-quality, monodisperse, and size-controlled Fe3O4, Ag, and bifunctional Fe3O4/Ag heterodimer nanocrystals (NCs) have been synthesized successfully. In the synthesis of Fe3O4 NCs, dodecanol was chosen as the substi...
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high-quality, monodisperse, and size-controlled Fe3O4, Ag, and bifunctional Fe3O4/Ag heterodimer nanocrystals (NCs) have been synthesized successfully. In the synthesis of Fe3O4 NCs, dodecanol was chosen as the substitute of 1,2-hexadecanediol and "size control" was achieved by simply adjusting the proportion among the ligands instead of utilizing seed-mediated growth. In the synthesis of Ag NCs, organometallic silver acetylacetonate (Agacac) was used as precursors and tunable particle size could be easily obtained by adjusting the reaction temperatures. By using different sized Fe3O4 NCs as seeds, Fe3O4/Ag heterodimer NCs with particle sizes tuned from 5 to 16 nm for Fe3O4 and 4 to 8 nm for Ag were successfully synthesized and superparamagnetism were maintained. We found that the size of Ag attached on the Fe3O4 NCs relied on the size of Fe3O4 seed. UV-vis absorption spectra and TEM investigations revealed that the bigger the Fe3O4 NCs seed used, the bigger the Ag NCs that were obtained from the heterodimer NCs. In addition, we demonstrated that all of these NCs were successfully transferred into water by surface modification with biocompatible carboxylic acid groups, which made them meet the basic requirement for biolabeling and biomedical applications.
Oligochitosan induce plant resistance against plant virus via different signal transduction pathways. Here, the Ca2+ signaling pathway was investigated by which oligochitosan elicited defense responses to tobacco mosa...
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Oligochitosan induce plant resistance against plant virus via different signal transduction pathways. Here, the Ca2+ signaling pathway was investigated by which oligochitosan elicited defense responses to tobacco mosaic virus (TMV) in tobacco (Nicotiana tabacum cv. Huangmiaoyu nn) plants. The results showed that the multiplication and movement of TMV in tobacco plants were inhibited by oligochitosan. Oligochitosan also increased cytosolic free calcium ions and regulated the expression of calreticulin. Furthermore, the inhibitory effect on TMV and the regulation effect on calreticulin were depressed when blocking the Ca2+ signaling pathway by EGTA. These results indicated that oligochitosan induced tobacco resistance to TMV through Ca2+ signaling pathway. (C) 2010 Elsevier Ltd. All rights reserved.
Effective intelligent transportation system depends on the abundance of timely road information. This paper first presents the role of road information by taking dynamic route guidance system as an example;and then ex...
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ISBN:
(纸本)9781424473021
Effective intelligent transportation system depends on the abundance of timely road information. This paper first presents the role of road information by taking dynamic route guidance system as an example;and then explains the necessary of importing wireless sensor networks as road information providers. We illustrate the principle of using magnetic sensors to detect vehicles and how the road information is achieved by in-network aggregation. We also provide several scenarios of making use of the real time road information.
The IEEE802.15.4 is a low-bit-rate wireless communicate standard that enables global inter-connectivity and inter-operability amongst Wireless Personal Area Network (WPAN) transceivers from different manufacturers. It...
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ISBN:
(纸本)9781424481293
The IEEE802.15.4 is a low-bit-rate wireless communicate standard that enables global inter-connectivity and inter-operability amongst Wireless Personal Area Network (WPAN) transceivers from different manufacturers. It is also considered as the PHY and MAC technology for Wireless Sensor Networks, which can be widely used for sensing, gathering and operating information in future smart cities. In Jan. 2009, the 802.15.4c amendment was approved to address the Chinese regulatory changes which have opened new bands for Wireless PAN using within china. However, the urban environments' impacts over its performance in the new band are still not clear. We demonstrate the viability of using IEEE 802.15.4c in urban scenarios by a series of real field experiments and result analysis. Results show that at 4dBm transmission power over 780MHz channel and with typical antenna setups, the effective transmission range is 200 meters in open scenario, 60 and 40 meters in light and heavy traffic scenarios respectively. We also show that the performance is not affected evidently by the mobility of transceivers up to the speed of 80 km/h. The most important performance factors are the availability of line-of-sight between sender and receiver in urban scenarios. We also use the famous Rappaport channel model for field experimental data fitting, and show that the model is valid even with moving massive reflectors. The empirical data and model fitting will benefit upper layer protocol design based on 802.15.4c in china in the future.
The thematic map is a major class of maps designed to demonstrate particular features or concepts,functioning as an indispensable tool in geographical *** process of thematic mapping is one into which geographical res...
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The thematic map is a major class of maps designed to demonstrate particular features or concepts,functioning as an indispensable tool in geographical *** process of thematic mapping is one into which geographical research goes deeply and *** key activity and course of thematic map production is the use of mathematical models to create thematic data ***,the selection and optimization of mathematical models is in the forefront of thematic map *** theoretical foundations,mechanisms and methods of mathematical model optimization are expounded in this paper,including two approaches,the phase by phase mode and the multi-aim scheme balance *** studies in eco-environment mapping and emergency mapping are described and analyzed,with a hierarchical analysis method being used in the model optimization for eco-environment fragility and sensitivity assessment mapping in Beibuwan (Guangxi) District,the dynamic system (DS) method being used in the model optimization for ecological security adjustment mapping in Xishuang Banna,Yunnan province,and the multi-phase mode being used in the models for forest fire and infectious diseases mapping.
The catalytic dehydration of ethanol into ethylene was studied over HZSM-5, phosphorous modified HZSM-5 and lanthanum-phosphorous modified HZSM-5 in the low temperature range from 473 K to 573 K. The experimental resu...
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The catalytic dehydration of ethanol into ethylene was studied over HZSM-5, phosphorous modified HZSM-5 and lanthanum-phosphorous modified HZSM-5 in the low temperature range from 473 K to 573 K. The experimental results demonstrated the lanthanum-phosphorous modified HZSM-5 offered the outstanding catalytic performance and the enhanced anti-coking ability markedly, especially for 0.5%La-2%PHZSM-5. Characterizations revealed that the improved catalytic performance and the excellent anti-coking ability of lanthanum-phosphorous modified HZSM-5 could be attributed to the harmonious acid sites and pore structure by the modification with lanthanum and phosphorous. (C) 2010 Elsevier B.V. All rights reserved.
The glial fibrillary acidic protein (GFAP) is an astrocyte-specific member of the class III intermediate filament proteins. It is generally used as a specific marker of astrocytes in the central nervous system (CNS). ...
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The glial fibrillary acidic protein (GFAP) is an astrocyte-specific member of the class III intermediate filament proteins. It is generally used as a specific marker of astrocytes in the central nervous system (CNS). We isolated a GFAP cDNA from the brain and spinal cord cDNA library of Gekko japonicus, and prepared polyclonal antibodies against gecko GFAP to provide useful tools for further immunochemistry studies. Both the real-time quantitative PCR and western blot results revealed that the expression of GFAP in the spinal cord after transection increased, reaching its maximum level after 3 days, and then gradually decreased over the rest of the 2 weeks of the experiment. Immunohistochemical analyses demonstrated that the increase in GFAP-positive labeling was restricted to the white matter rather than the gray matter. In particular, a slight increase in the number of GFAP positive star-shaped astrocytes was detected in the ventral and lateral regions of the white matter. Our results indicate that reactive astrogliosis in the gecko spinal cord took place primarily in the white matter during a short time interval, suggesting that the specific astrogliosis evaluated by GFAP expression might be advantageous in spinal cord regeneration.
This paper describes the design and implementation of a spatial data checking system based on quality rules. A relational expression of defining quality rules is presented and new quality rules can be extended by usin...
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ISBN:
(纸本)9781424473021
This paper describes the design and implementation of a spatial data checking system based on quality rules. A relational expression of defining quality rules is presented and new quality rules can be extended by using this structure. Methods of storing and parsing these quality rules for data checking are discussed. Based on this, a spatial data checking system is developed, in which extended data checking types can be defined and data checking tasks are made to execute automatic checking for spatial databases. The system has been applied to the construction of spatial databases in Jilin city and proved to be effective.
This paper describes a framework for multi-scale gray level analysis of images. It defines scales based on gray levels and organizes the basic "atoms" with a topographic map. The aim of this approach is to s...
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ISBN:
(纸本)9781424479948
This paper describes a framework for multi-scale gray level analysis of images. It defines scales based on gray levels and organizes the basic "atoms" with a topographic map. The aim of this approach is to separate a large number of pixels concentrating in a narrow range of gray values. The main advantage of the methodology is that it allows manipulating pixels according to gray levels and spatial relations simultaneously. We apply it to histogram modification of Synthetic Aperture Radar (SAR) images. The experiments on displaying and classification prove the superiority of the approach.
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