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Now showing items 1 - 16 of 41


    Provided in an embodiment of the present invention are a virtual network function (VNF) network elements management method, device and system, the method comprising: a VNF resource pool management device receives a VNF network element request message transmitted by a VNF resource pool user (PU), the VNF network element request message comprising the attribute information and position strategy of a VNF network element to be requested; according to the VNF network element request message and the position information of the VNF network element in a VNF resource pool, the VNF resource pool management device determines a first VNF network element conforming to the attribute information and the position strategy from the VNF resource pool, the first VNF network element comprising at least one VNF network element; and the VNF resource pool management device transmits to the VNF resource PU a VNF network element response message comprising the identifier information of the first VNF network element, thus avoiding the risk of abnormal operation of a functional group constituted of the VNF network elements.
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  • Nitrogen Critical Loads for an Alpine Meadow Ecosystem on the Tibetan Plateau

    Zong, Ning   Shi, Peili   Song, Minghua   Zhang, Xianzhou   Jiang, Jing   Chai, Xi  

    Increasing atmospheric nitrogen (N) deposition has the potential to alter plant diversity and thus the function and stability of terrestrial ecosystems. N-limited alpine ecosystems are expected to be particularly susceptible to increasing N deposition. However, little is known about the critical loads and saturation thresholds of ecosystem responses to increasing N deposition on the Tibetan Plateau, despite its importance to ecosystem management. To evaluate the N critical loads and N saturation thresholds in an alpine ecosystem, in 2010, we treated an alpine meadow with five levels of N addition (0, 10, 20, 40, and 80 kg N ha−1 year−1) and characterized plant and soil responses. The results showed that plant species richness and diversity index did not statistically vary with N addition treatments, but they both changed with years. N addition affected plant cover and aboveground productivity, especially for grasses, and soil chemical features. The N critical loads and saturation thresholds, in terms of plant cover and biomass change at the community level, were 8.8–12.7 and 50 kg N ha−1 year−1 (including the ambient N deposition rate), respectively. However, pronounced changes in soil inorganic N and net N mineralization occurred under the 20 and 40 kg N ha−1 year−1 treatments. Our results indicate that plant community cover and biomass are more sensitive than soil to increasing N inputs. The plant community composition in alpine ecosystems on the Qinghai-Tibetan Plateau may change under increasing N deposition in the future.
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    A method, a system and a multicast network for improving multicast reliability in the multicast technology field are provided. The method includes that an intermediate node receives a retransmission window notification message sent by the first upstream node, updates the retransmission window notification message and sends the updated retransmission window notification message to a downstream node of the intermediate node. The first upstream node is the upstream node of the intermediate node. The system includes a receiving module and an update module. The multicast network includes the first upstream node, the intermediate node and the downstream node of the intermediate node. Updating retransmission window notification message enables receiver sides to know more retransmission data that can be provided. Consequently multicast reliability is improved.
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  • Effects of Roughness Strip and Acoustic Sensor Height on Subsonic Boundary Layer by Experiment

    Zong, Ning   Yang, Guang Jun   Sun, Jing  

    According to the measurement requirements of acoustic fatigue load on aft fuselage structure and the external installation restriction of the acoustic sensor on aircraft surface, an acoustic sensor is installed on the silencing jet test plate with reference to body type of the real aircraft. A dynamic test and analysis system combined hot wire wind speed measurement and acoustic spectrum measurement is built up for the combined experiments with different acoustic sensor height and various boundary layer flow structure at subsonic flow condition. Turbulence development of different boundary layer is analyzed. The test result can be coordinated with the local measurement to aircraft flow structure so as to estimate the effect of acoustic sensor on the flow field.
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  • Using Soil Survey Database to Assess Soil Quality in the Heterogeneous Taihang Mountains, North China

    Geng, Shoubao   Shi, Peili   Zong, Ning   Zhu, Wanrui  

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  • Experimental Research on Aerodynamic Characteristics of Large Aspect Ratio Wing in Unfolding Process

    Zong, Ning   Yang, Guang Jun   Lv, Sheng Li  

    For an unmanned aerial vehicle, in order to study the aerodynamic characteristics of the large aspect ratio wing during the deployment process with variable sweep angles, the scaled model was tested in the wind tunnel at different angles of attack with various sweep angles of wing. Experimental results indicate that the aerodynamic configuration satisfies the cruise design requirements, providing favorable longitudinal and lateral-directional stability. Fuselage of multi-plane combination brings beneficial effect for lift. Analysis have been made on the cases including wing flow separation which lead to the step of lift curve, and the existence of longitudinal unstable range during wing unfolding, which make the foundation for next optimum of configuration. The work described in this paper can be applied in the design of unmanned aerial vehicles, missiles and other research areas.
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    Disclosed are a transmission control method, apparatus and system so as to effectively utilize network link resources. The method of the present invention comprises: obtaining link status information about a network; determining a parameter recommended value for TCP transmission according to the link status information; and performing TCP transmission according to the determined parameter recommended value. The present invention can enable TCP transmission status to reflect network congestion status more real, prevent a congestion misjudgment from occurring, and improve the utilization rate of link resources in a network.
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  • Purification and some properties of an .ALPHA.-D-xylosidase from Bacillus sp. No. 693-1.

    ZONG, Ning   YASUI, Tsuneo  

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  • Spatial–Temporal Variation of ANPP and Rain-Use Efficiency Along a Precipitation Gradient on Changtang Plateau, Tibet

    Zhao, Guangshuai   Liu, Min   Shi, Peili   Zong, Ning   Wang, Jingsheng   Wu, Jianshuang   Zhang, Xianzhou  

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  • Nitrogen addition stimulated compensatory growth responses to clipping defoliation in a Northern Tibetan alpine meadow

    Zong, Ning   Shi, Peili  

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  • Effects of Warming and Nitrogen Addition on Plant Photosynthate Partitioning in an Alpine Meadow on the Tibetan Plateau

    Zong, Ning   Chai, Xi   Shi, Pei-Li   Yang, Xiao-Cheng  

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  • Substrate specificity of Bacillus .ALPHA.-D-xylosidase.

    ZONG, Ning   KAMIYAMA, Yoshi   YASUI, Tsuneo  

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  • Responses of ecosystem respiration to nitrogen enrichment and clipping mediated by soil acidification in an alpine meadow

    Zong, Ning   Shi, Pei-li   Chai, Xi   Jiang, Jing   Zhang, Xian-zhou   Song, Ming-hua  

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  • Effects of warming and nitrogen addition on nutrient resorption efficiency in an alpine meadow on the northern Tibetan Plateau

    Zong, Ning   Shi, Peili   Chai, Xi  

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  • Timing patterns of nitrogen application alter plant production and CO2 efflux in an alpine meadow on the Tibetan Plateau, China

    Zong, Ning   Song, Minghua   Shi, Peili   Jiang, Jing   Zhang, Xianzhou   Shen, Zhenxi  

    Nitrogen (N) availability is an important factor that determines ecosystem productivity and respiration, especially in N-limited alpine ecosystems. However, the magnitude of this response depends on the timing and amounts of N input. Moreover, we have only a limited understanding of the potential effects of the timing of N fertilization on ecosystem carbon (C) and N processes, and activities of the soil microbes. A nitrogen fertilization experiment was conducted in an alpine meadow on the Tibetan Plateau to determine how plant productivity and ecosystem respiration (RE) respond to the timing and amount of N application. In this study, half of the N was added either in the early spring (ES), before the growing season, or in the late fall (LF), after the growing season. All treatments received the other half of the N in mid-July. Three N levels (10, 20, 40 kg N hm(-2) yr(-1)) were used for each of two N treatments, with no N addition used as a control. Plant aboveground biomass, ecosystem respiration (RE) and soil respiration (RS) were measured for the 2011 and 2012 growing seasons. The LF treatment enhanced ecosystem CO2 efflux compared with the ES treatment at high N addition levels, resulting from an increase of soil dissolved organic C (DOC) and soil microbial activity. The ES treatment resulted in increased plant aboveground biomass when compared with LF during both growing seasons, although this increase accounted for little variation in ecosystem and soil respiration. Overall, the ES treatment is likely to increase the ecosystem C pool, while the LF treatment could accelerate ecosystem C cycling, especially for the high N treatment. Our results suggest that supplying N during the early stage of the growing season benefits both forage production and soil C sequestration in this alpine ecosystem. (C) 2014 Elsevier GmbH. All rights reserved.
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  • Isolation and characterization of bacteria which produce .ALPHA.-xylosidase and cultural conditions for enzyme production.

    ZONG, Ning   NAKANISHI, Kotoyoshi   YASUI, Tsuneo   YAMASATO, Kazue  

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