145 research outputs found
The study of lakes dynamic change based on RS and GIS –Take DaLiNuoEr Lake as an example
AbstractIn the study, TM images in eight periods was the data source, adopted RS and GIS technology, threshold value method, deference value and other methods,Statistics the water area of Dalinor from 1995 to 2009 in past 15 years. By establishing lake's Digital Elevation Model (DEM), it was analyzed dynamic change of Dalinor lakes volume in nearly 15 years. In this 15years, Dalinor lake's area narrowed from 246.7km2 in 1995 to 218 km2 in 2009, Lake area reduced 28.7km2, The average decrease speed was 2.05 km2 / a. The total volume narrowed from 4359821563.03 m3 in 1995 to 3889917491.37 m3 in 2009, the total volume reduced 469904071.66 m3, the average decrease speed was 33564576.55 m3 / a. Lake area and volume declined sharply
Influence of Low Load Truncation Level on Crack Growth for Al 2324-T39 and Al 7050-T7451
AbstractTests with middle-crack tension (M(T)) specimens made of Al 2324-T39 and Al 7050-T7451 are conducted to investigate the influence of low load truncation level on fatigue crack growth. The six different truncated spectra are obtained by removing the small cycles of which amplitudes are less than the specified percentages of the maximum amplitude in the basic flight-by-flight loading spectrum and the remainder of the spectrum is untouched. The tests indicate that the mean level of fatigue crack growth life (FCGL) increases as the load truncation level is enhanced. Considering both the time saving and the influence on FCGL, there is an applicable choice (i.e. spectrum S2 or spectrum S3 in this investigation) for full scale fatigue test. The scatter of FCGL becomes much larger than that under the basic spectrum when the load truncation level is increased to a specified high level, mainly due to the occurrence of crack slanting and branching under the high level truncated loading spectra
Evaluation Method for Green Ecological Airports in China Based on Combination Weighting
To scientifically and accurately evaluate the status of the development of green airports in China, evaluation methods of green, ecological airports are established in this paper. To address the shortcomings in subjective and objective weighting methods, we propose a combination weighting method based on Spearman’s rank correlation coefficient and evaluation grades based on interval approximation. At the same time, by taking into account resource conservation, environmental friendliness, operation efficiency, and people-oriented service, we propose an evaluation index system and an interval number for each index. Lastly, the theory is applied to five large airports in different regions of China. Analysis of the evaluation results shows that Shanghai Pudong International Airport (PVG) and Guangzhou Baiyun International Airport (CAN) have the highest scores for the resource conservation and environmental friendliness indexes, thus indicating that the development of a green ecological airport is closely related to its passenger transportation scale and economic strength. All considered airports showed the need for upgrading public service facilities and constructing intelligent equipment. The method proposed in this paper is reasonable and reliable; therefore, it can provide guidance for the evaluation and construction of green, ecological airports
Community-based Message Opportunistic Transmission
Mobile Social Networks (MSNs) is a kind of opportunistic networks, which is composed of a large number of mobile nodes with social characteristic. Up to now, the prevalent communitybased routing algorithms mostly select the most optimal social characteristic node to forward messages. But they almost don\u27t consider the effect of community distribution on mobile nodes and the time-varying characteristic of network. These algorithms usually result in high consumption of network resources and low successful delivery ratio if they are used directly in mobile social networks. We build a time-varying community-based network model, and propose a community-aware message opportunistic transmission algorithm (CMOT) in this paper. For inter-community messages transmission, the CMOT chooses an optimal community path by comparing the community transmission probability. For intra-community in local community, messages are forwarded according to the encounter probability between nodes. The simulation results show that the CMOT improves the message successful delivery ratio and reduces network overhead obviously, compared with classical routing algorithms, such as PRoPHET, MaxProp, Spray and Wait, and CMTS
Characterization of self-adjoint domains for regular even order C-symmetric differential operators
Let C be a skew-diagonal constant matrix satisfying C −1 = −C = C . We characterize the self-adjoint domains for regular even order C-symmetric differential operators with two-point boundary conditions. The previously known characterizations are a special case of this one
Characterization of self-adjoint domains for regular even order C-symmetric differential operators
Let be a skew-diagonal constant matrix satisfying . We characterize the self-adjoint domains for regular even order -symmetric differential operators with two-point boundary conditions. Thepreviously known characterizations are a special case of this one
mRNA/microRNA Profile at the Metamorphic Stage of Olive Flounder (Paralichthys olivaceus)
Flatfish is famous for the asymmetric transformation during metamorphosis. The molecular mechanism behind the asymmetric development has been speculated over a century and is still not well understood. To date, none of the metamorphosis-related genes has been identified in flatfish. As the first step to screen metamorphosis-related gene, we constructed a whole-body cDNA library and a whole-body miRNA library in this study and identified 1051 unique ESTs, 23 unique miRNAs, and 4 snoRNAs in premetamorphosing and prometamorphosing Paralichthys olivaceus. 1005 of the ESTs were novel, suggesting that there was a special gene expression profile at metamorphic stage. Four miRNAs (pol-miR-20c, pol-miR-23c, pol-miR-130d, and pol-miR-181e) were novel to P. olivaceus; they were characterized as highly preserved homologies of published miRNAs but with at least one nucleotide differed. Representative 24 mRNAs and 23 miRNAs were quantified during metamorphosis of P. olivaceus by using quantitative RT PCR or stem-loop qRT PCR. Our results showed that 20 of mRNAs might be associated with early metamorphic events, 10 of mRNAs might be related with later metamorphic events, and 16 of miRNAs might be involved in the regulation of metamorphosis. The data provided in this study would be helpful for further identifying metamorphosis-related gene in P. olivaceus
Macroscopic and Fluorescent Discrimination of Adenosine Triphosphate via Selective Metallo-hydrogel Formation: A Visual, Practical, and Reliable Rehearsal toward Cellular Imaging
- …