基于IPRAN接入层设备成环率相关问题研究

针对4G(第四代移动通信技术)网络建设初期IPRAN(IP Radio Access Network,无线接入网IP化)接入层设备成环率低的问题,论文首先从基站发展现状出发,结合基站建设运转状况,采取实地调查、数据收集、风暴分析等多种方法,对IPRAN接入层设备成环率进行总结分析,然后结合图表分析方法对造成光缆线路和建维问题的各种原因采用末端原因分析方法进行深入研究,最后对巩固期IPRAN接入层设备成环率效果进行了验证。

C网基站成环改造常见故障分析

网络优化的目的是提升资源的利用率、增强网络安全稳定性并提高维护效率,而基站成环是网络优化的一个重要手段,网络成环改造可能产生的一些隐形故障若不能及时处理也将对严重影响网络质量。本文针对C网组网建环时,容易出现光纤熔接错纤、东西向尾纤错连等几种常见故障进行了分析。

溶液法合成烯丙基苯并噁嗪中间体与其固化性能的研究

以 2 烯丙基苯酚为原料 ,采用多种溶剂通过溶液法合成一种高成环率的 3 苯基 3,4 二氢 8 烯丙基 2H 1,3 苯并嗪 (简称为烯丙基苯并嗪 ) ,利用1H NMR、FT IR、MS、元素分析和DSC对其结构和固化行为进行了研究。结果表明 ,该中间体的成环率和溶剂的极性有关 ,溶剂的极性越强 ,成环率越低。

聚苯并噁嗪预聚体的结构与固化行为的研究

采用以甲苯为溶剂的溶液法合成了一种成环率高的聚苯并嗪预聚体即聚双 (3,4 二氢 3 苯基 1 ,3 苯并嗪 )预聚体 ,通过1 H NMR、FT IR、GPC和DSC对预聚体的结构和固化行为进行了研究。结果表明 ,该预聚体的成环率与溶剂的极性有关 ,溶剂极性越强 ,成环率越低 ;成环率对预聚体的固化温度和Tg 有一定的影响 ,成环率越低 ,预聚体的固化温度越低 ,其固化产物的Tg 越低。

饲用酶制剂对布列塔尼亚兔红细胞免疫吸附性能的影响

62只28日龄断奶布列塔尼亚兔用按窝配对法分为3组,试1组日粮中添加0 75%饲用复合酶制剂,试 2 组日粮中添加0 1%饲用复合酶制剂,结果表明试2组的红细胞浓度显著高于对照组(P<0 05),试 1 组与对照组差异不显著(P>0 05);红细胞吸附酵母的成环数试2组也显著高于对照组(P<0 05),试1组与对照组相比有下降趋势,差异不显著(P>0 05);各组成环率差异均不显著(P>0 05)。

浅析药品依诺肝素钠的生产工艺

这项生产工艺是本课题大量实验的相关成果,借鉴法国公司依诺肝素钠生产情况,采用一种原材料,经过科学、严谨的生产过程,所研制的依诺肝素钠样品符合欧洲药典标准。根据实验情况,文章总结了生产过程中需要重视的环节,使这种药品国产化成为可能。

A Novel High-Voltage Detector Integrated into SPIC by Using FFLR

A novel high voltage detector that can be integrated into SPIC (Smart Power IC) is proposed.The structure is designed on the basis of normal junction terminal technique of FFLR (Floating Field Limiting Rings) system.The field limiting ring as a voltage divider,is used to optimize the surface field.The voltage of main junction increases from 0 to a high value,while the utmost ring is designed to vary within a small range,which can be handled by using low voltage logic circuits.An example of 400V rings system is analyzed and simulated for this structure.The results prove that the high voltage detector can detect high voltage in SPIC.The structure can be integrated into SPIC.Besides,it is compatible with CMOS or BCD(Bipolar CMOS Dmos) technology,without any additional processes required.

Electrochemical behavior of Li incorporation in Al in LiTFSI/KTf molten salt electrolyte

The electrochemical behavior of lithium incorporated in aluminum electrode in LiTFSI/KTf （lithium bis （trifluoromethylsulfonyl） amide/CF3SO3K） molten salt electrolyte was studied by a variety of electrochemical techniques including cyclic voltammetry, chronopotentiometry and chronoamperometry. The reduction reaction is found involving a nucleation process on the aluminum electrode. The results of chronopotentiometry indicate that the process of lithium incorporation in aluminum is smooth and uniform. The galvanostatic cycle experiments show that the coulombic efficiency is very low in the first cycle, which is mainly due to the ＂retention capacity＂ of Li-Al alloys. This characteristic is testified by the results of XRD and SEM. The results of chronoamperometry indicate that the incorporation of lithium into aluminum for the formation of a-phase Li-Al alloy is limited by its diffusion rate, with a measured diffusion coefficient of 1.8× 10^-10 cm2/s.

福州电信建维协作提升IPRAN设备性能的实践

早期由于基站大建设,为适应基站业务的快速发展,IPRAN网络大量铺设,网络的健全性较弱、设备空置率高且信息不完整,影响用户感知。为提升IPRAN设备的健壮性,充分盘活可利用资源,节约投资建设成本,福州分公司建维协作,针对全区A设备进行充分分析,开发系统报表及检测工具,通过数据支撑网络优化。通过同沟同缆整治,IPRAN成环率有了很大的提升。不同沟率从32.08%提升到83.32%,不同缆率从75.83%提升到94.87%。同时拆除空置A设备用于网络调度,盘活空置的A设备用于现网建设或网络调整,预计可节省投资64.75万元,节省空间141U,节省功耗16750 W。

The Jitter Performance Comparison Between DLL and PLL-Based RF CMOS Oscillators

By jitter performance comparison between PLL (Phase Locked Loop) and DLL (Delay Locked Loop),a helpful equation is derived for the structure choice between DLL and PLL based synthesizers fabricated in CMOS processes to get an optimum jitter performance and power consumption.For a frequency synthesizer,a large multiple factor prefers PLL based configuration which consumes less power,while a small one needs DLL based topology which produces a better jitter performance.

Multiple Cropping Intensity in China Derived from Agro-meteorological Observations and MODIS Data

Double-and triple-cropping in a year have played a very important role in meeting the rising need for food in China.However,the intensified agricultural practices have significantly altered biogeochemical cycles and soil quality.Understanding and mapping cropping intensity in China′s agricultural systems are therefore necessary to better estimate carbon,nitrogen and water fluxes within agro-ecosystems on the national scale.In this study,we investigated the spatial pattern of crop calendar and multiple cropping rotations in China using phenological records from 394 agro-meteorological stations(AMSs)across China.The results from the analysis of in situ field observations were used to develop a new algorithm that identifies the spatial distribution of multiple cropping in China from moderate resolution imaging spectroradiometer(MODIS)time series data with a 500 m spatial resolution and an 8-day temporal resolution.According to the MODIS-derived multiple cropping distribution in 2002,the proportion of cropland cultivated with multiple crops reached 34%in China.Double-cropping accounted for approximately 94.6%and triple-cropping for 5.4%.The results demonstrat that MODIS EVI(Enhanced Vegetation Index)time series data have the capability and potential to delineate the dynamics of double-and triple-cropping practices.The resultant multiple cropping map could be used to evaluate the impacts of agricultural intensification on biogeochemical cycles.

Assessment of total suspended sediment concentrations in Poyang Lake using HJ-1A/1B CCD imagery

We explored the potential of the environment and disaster monitoring and forecasting small satellite constellations (HJ-1A/1B satellites) charge-coupled device (CCD) imagery (spatial resolution of 30 m, revisit time of 2 days) in the monitoring of total suspended sediment (TSS) concentrations in dynamic water bodies using Poyang Lake, the largest freshwater lake in China, as an example. Field surveys conducted during October 17-26, 2009 showed a wide range of TSS concentration (3-524 mg/L). Atmospheric correction was implemented using the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) module in ENVI with the aid of aerosol information retrieved from concurrent Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) surveys, which worked well at the CCD bands with relatively high reflectance. A practical exponential retrieval algorithm was created between satellite remote sensing reflectance and in-situ measured TSS concentration. The retrieved results for the whole water area matched the in-situ data well at most stations. The retrieval errors may be related to the problem of scale matching and mixed pixel. In three selected subregions of Poyang Lake, the distribution trend of retrieved TSS was consistent with that of the field investigation. It was shown that HJ-1A/1B CCD imagery can be used to estimate TSS concentrations in Poyang Lake over synoptic scales after applying an appropriate atmospheric correction method and retrieval algorithm.

A Viable Megawatt-Class Space Power Plant under Rankine Cycle

The aim of the article concerns to the achieved research results regarding the viability of a megawatt-class space power plant based on the Rankine cycle for which the main objectives are to highlight the key issues responsible for improving the Rankine cycle efficiency. Two working fluids are studied （water and ammonia） on the basis of its well known characteristics. Cycles operating under top and bottom temperatures approaching the state of the art technology associated to cooling fluid reservoirs are key to improve the efficiency. With such strategy, the achieved thermal efficiency increases more than 20% with respect to conventional power plants. Mentioned benefits associated to the strategy based on the reduction of the required payload capacity, the condenser radiation surface and the power plant mass represent the main advantages of the proposed innovation techniques.

Environmental change and its effects on inter-decadal variations of diatom production, species composition and frustule dissolution in a coastal marginal sea

The implications of climate change during the second half of the 20th century have been reported throughout the world. Although marginal seas are sensitive to climate change and anthropogenic impacts, relatively little attention has been given to the South East Asian marginal seas. Thus, to bridge this gap in knowledge, a sediment core was collected from the coastal areas of the Leizhou Peninsula in the South China Sea （SCS） to study the inter-decadal climate change and its consequences using diatom species composition as a proxy record. Diatom absolute abundance varied from 2 300 to 68 000 and averaged 16 000 valves per gram of dry weight （v/gdw）. The fractional dissolution index （F~） was usually below 0.5, which indicates low to moderate preservation of diatom valves at coastal area of the SCS. At the inter-decadal time scale, total diatom abundance was high for the period after 1972, which coincided with 1） increased percentage of planktonic diatom abundance and F~; 2） emergence and dominance of high productivity indicative cosmopolitan species such as Thalassionema nitzschioides and Paralia sulcata （their relative abundance increased from 〈1.5% to 〉7% for the period before and after 1972, respectively）; 3） decreased relative abundance of the small-sized eutrophication indicative species, Cyclotella striata, from 70% to 40%. This study reveals that variations in the abundance of diatoms preserved in the sediment was a function of both production and dissolution/preservation of diatom valves, which in turn was intimately connected to the prevailing environmental/climatic conditions. In conclusion, these data reveal the existence of substantial changes in the coastal SCS in response to the 1970s climate shift that was recorded in different parts of the world.

Design of remote ultrasonic signal generating system based on Kinetis60 and AD9951

A kind of remote ultrasonic generating system is designed in this paper.Microcontroller unit(MCU)Kinetis60and direct digital synthesizer(DDS)AD9951constitute the core section of this ultrasonic generating terminal in this system.A friendly and easy-operating host computer software is contrived to control the terminal to generate sinusoidal,rectangular and triangular waveform with variable frequency,amplitude and phase through ZigBee wireless transmission protocol.In order to enhance the practical driving ability,this system also includes power amplifier circuit and transformer matching design,which enable the ultrasonic generating terminal to output enough power for applying to different types of ultrasonic energy convertors.Through experimental verification,the host computer can precisely and swiftly control the ultrasonic generating terminal to generate the above three waveforms with variable wave elements.Oscilloscope is used to verify the terminal output performance of this remote system.

An Empirical Study of China＇s Energy- Intensive Industries＇ Growth Based on Environmental Total Factor Productivity

Using directional distance function and nonparametric data envelopment analys＆, th＆ paper estimates the environmental total factor productivity （ETFP） of energy-intensive industries in China from 1995 to 2010, and performs an empirical analysis on factors affecting ETFP growth after studying the differences of energy-intensive industries ＇ ETFP by industries and provinces. The findings include the following： energy-intensive industries ＇ETFP growth is mainly driven by technical progress; China, at its current development stage, still has the potential to raise the productivity of its energy- intensive industries. By estimating the provincial data, we find that the ETFP growth of different provinces converge at different levels. Further market liberalization, increased FDl flows and reductions in energy intensity will help to improve each province＇s ETFP growth. In addition, increasing investment in energy saving and emissions reduction and improving corporate environmental management capacity can help to reduce a company＇s short-term cost of complying with environmental regulations.

Low phase noise millimeter wave monolithic integrated phase locked-loop

A Monolithic integrated phase locked-loop （PLL） with a low phase noise is proposed in this paper. Several techniques are utilized to improve the performance of the PLL which works at the milli- meter-wave band. The on-chip high-Q eoplanar waveguides （CPWs） are utilized in the resonant tank and the differential current amplifier with a resonator is used to realize the VCO. In the output buffer circuit, several stages of cascaded source-followers connect and differential amplifiers are adopted to improve the driving capability of the PLL＇ s output signals. An improved analog multiplier topology is also used in the PD circuit to improve the gain of the PD. The proposed PLL is realized with a 0.2p, m GaAs pseudomorphie high electron mobility transistor （PHEMT） process. At 10 kHz offset from the center frequency, the measured output phase noise of the PLL output is only -88.83dBc/Hz. The circuit exhibits a low root mean sauare （RMS） litter of 1.68Ds.

Electricity Derived from Plants

The phenomenon of electrical potential differences along the plant apoplast has been reported for more than a century. Earlier works of harvesting energy from trees reported nW range of power with a few hundred-mV open circuit voltage and near uA range short circuit current. In this work, we show that if we cut a stem into pieces, each segment would maintain nearly the same open circuit voltage and short circuit current regardless of length. Using a pico-ampere meter, we also found that the living cells in the vascular cambial and secondary xylem and phloem tissues are the source of electricity. They provide a relatively constant voltage and current to external environment for reasons still under investigation. We demonstrate that by cascading separated stems we can accumulate up to 2 V of open circuit voltage. We also demonstrate by connecting them in parallel we can increase the short circuit current.

The Application of Automatic Welding in Mechanical Welding

With the development of science and technology, automation technology has begun to be applied to various fields. Automatic welding technology is increasingly used in the welding industry in the area. The introduction of automatic welding technology not only improve the quality and production efficiency, but also reduce production costs, the production environment in which the staff has also been improved. This paper discusses the current situation of automatic welding technology, mechanical industry, the demand for automatic welding, automatic welding technology advantages and development trends.

基于免疫算法的电力通信网线路规划方法

为了合理规划建设经济可靠的电力通信网络,提出了一种基于免疫算法的电力通信网线路规划方法,综合考虑了网络的经济性、可靠性和业务分布因素.基于站点成环率构造出网络可靠性函数,结合业务分布情况设计了电力通信网线路规划的问题模型,并利用免疫算法进行求解.该方法采用多目标优化模型,能在一定程度上提高规划方案的灵活性和全面性.仿真结果表明,在面对不同站点成环率约束的情况下,该方法均能提供有效的线路规划方案.