4,838 research outputs found
Phenological response of vegetation to upstream river flow in the Heihe Rive basin by time series analysis of MODIS data
Liquid and solid precipitation is abundant in the high elevation, upper reach of the Heihe River basin in northwestern China. The development of modern irrigation schemes in the middle reach of the basin is taking up an increasing share of fresh water resources, endangering the oasis and traditional irrigation systems in the lower reach. In this study, the response of vegetation in the Ejina Oasis in the lower reach of the Heihe River to the water yield of the upper catchment was analyzed by time series analysis of monthly observations of precipitation in the upper and lower catchment, river streamflow downstream of the modern irrigation schemes and satellite observations of vegetation index. Firstly, remotely sensed NDVI data acquired by Terra-MODIS are used to monitor the vegetation dynamic for a seven years period between 2000 and 2006. Due to cloud-contamination, atmospheric influence and different solar and viewing angles, however, the quality and consistence of time series of remotely sensed NDVI data are degraded. A Fourier Transform method – the Harmonic Analysis of Time Series (HANTS) algorithm – is used to reconstruct cloud- and noise-free NDVI time series data from the Terra-MODIS NDVI dataset. Modification is made on HANTS by adding additional parameters to deal with large data gaps in yearly time series in combination with a Temporal-Similarity-Statistics (TSS) method developed in this study to seek for initial values for the large gap periods. Secondly, the same Fourier Transform method is used to model time series of the vegetation phenology. The reconstructed cloud-free NDVI time series data are used to study the relationship between the water availability (i.e. the local precipitation and upstream water yield) and the evolution of vegetation conditions in Ejina Oasis from 2000 to 2006. Anomalies in precipitation, streamflow, and vegetation index are detected by comparing each year with the average year. The results showed that: the previous year total runoff had a significant relationship with the vegetation growth in Ejina Oasis and that anomalies in the spring monthly runoff of the Heihe River influenced the phenology of vegetation in the entire oasis. Warmer climate expressed by the degree-days showed positive influence on the vegetation phenology in particular during drier years. The time of maximum green-up is uniform throughout the oasis during wetter years, but showed a clear S-N gradient (downstream) during drier years
3-Nitro-4-(propylamino)benzonitrile
In the title compound, C10H11N3O2, the nitro group is essentially coplanar with the aromatic ring [dihedral angle = 1.3 (3)°] and forms an intramolecular amine–nitro N—H⋯O hydrogen bond. In the crystal, weak intermolecular aromatic C—H⋯Onitro hydrogen bonds link the molecules. Weak aromatic ring π–π interactions [minimum ring centroid separation = 3.7744 (13) Å] are also present
Understanding College Student’ Acceptance Of Online Credit Offering Services In China
With the rapid economic growth in China, peoples’ consumption behavior is constantly changing. The online credit offering service is playing a more and more important role in China. In this paper, we aim to understand college students’ acceptance of online credit offering services in China. A research model based on technology acceptance model (TAM) with six research hypotheses is proposed. And an empirical study with 239 subjects was conducted to test this model. According to the results, 4 of 6 hypotheses were supported. The results indicated that both perceived usefulness and subjective norm directly affected college students’ behavior intention to use online credit offering services significantly
Development and Strategies of E-commerce Patents
Internet and information technologies break the transaction barriers, and the permission of the patentable subject matter for business methods and software acts as the moving power for enterprises entering into the knowledge competition age. Computer software can be a patentable subject matter is the inevitable consequence of the development of technology and law, while the patentability of business methods reflects that the advantages of industry competitiveness have shifted from labor to knowledge and innovation. This study analyzes the quantity and trends of e-commerce related patents, and clarify the concepts of patentable subject matter regarding business methods. Since United States is the leading country in the e-commerce and the patent system, decisions and patent statistics of United States are considered as the references in this study. In addition, a set of innovation and patent strategies for enterprises is also proposed to deal with the patent barriers established by technology leaders
A Model for Understanding the Market Orientation Effects of CRM on the Organizational Process
To build an understanding of the impacts of Customer Relationship Management (CRM) on organizational behaviors and processes this study strives to develop a model of CRM effects on work practice, value-creation processes and organizational performance. Moderating factors that affect the transition results are also studied. The model is developed by iterative steps of content analysis. The objectives of building this model are: 1) to establish a framework with propositions about the chained effects of CRM on organizational performance and the influential management activities and 2) to develop a measurement instrument of the CRM effects on market-oriented behaviors and performance. Although the model testing and enhancement are in progress, the preliminary findings reveal that behavioral changes towards market-orientation can be reflected in two levels of work practice: coordinated intelligence management in the team work and proactive attitude with individuals. With such a market-oriented focus, CRM user organizations are more likely to develop positive market performance as well as process performance, and indirectly bring up financial performance
Dependence of quantum correlations of twin beams on pump finesse of optical parametric oscillator
The dependence of quantum correlation of twin beams on the pump finesse of an
optical parametric oscillator is studied with a semi-classical analysis. It is
found that the phase-sum correlation of the output signal and idler beams from
an optical parametric oscillator operating above threshold depends on the
finesse of the pump field when the spurious pump phase noise generated inside
the optical cavity and the excess noise of the input pump field are involved in
the Langevin equations. The theoretical calculations can explain the previously
experimental results, quantitatively.Comment: 27 pages, 8 figure
Reflective liquid crystal hybrid beam-steerer
We report on efficient optical beam-steering using a hot-embossed reflective blazed grating in combination with liquid crystal. A numerical simulation of the electrical switching characteristics of the liquid crystal is performed and the results are used in an FDTD optical simulator to analyze the beam deflection. The corresponding experiment on the realized device is performed and is found to be in good agreement. Beam deflection angles of 4.4° upon perpendicular incidence are found with low applied voltages of 3.4V. By tilting the device with respect to the incoming optical beam it can be electronically switched such that the beam undergoes either total internal reflection or reflection with a tunable angle
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