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991.
针对非结构化的海量文档获取困难的问题,设计和开发了基于云存储的网络文档共享系统。该系统采用了Hadoop和Lucene以及Mahout来实现对文档存储、全文检索和推荐。通过测试证明,网络文档共享系统可以使用户更快速高效地获取文档。  相似文献   
992.
An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AGC) is proposed. This approach judges the signal power according to the AGC control voltage and switches the working modes correspondingly and adaptively. Non-coherent accumulation times and the detection threshold are reconfigured according to the working mode. Theoretical derivation and verification by simulation in typical situations are provided, and the algorithm is shown to be superior in terms of the mean acquisition time, especially in strong signal scenarios compared with the conventional algorithm.  相似文献   
993.
In this paper, the effects of different CdCl2 annealing methods, including vapor annealing and dip-coating annealing, on the performance of CdS/CdTe polycrystalline thin-film solar cells are studied. After annealing, the samples are lightly etched with 1% bromine in methanol to remove surface oxides. Both annealing methods give CdTe polycrystalline thin films with good crystallinity and complete structure. For solar cells containing the annealed CdTe films, cell efficiency first increases and then decreases as the concentration of CdCl2 solution used for dip-coating annealing increases, and the optimized CdCl2 concentration is 12%. The uniformity of the performance of all cells is analyzed by calculating the relative standard deviation for each parameter. The uniformity of cell performance can be improved dramatically by dip-coating annealing instead of vapor annealing. Most notably, an appropriate concentration of CdCl2 (12%) acts as a protective layer that is conducive to realizing uniform high-performance CdS/CdTe solar cells. According to the location of depletion regions, the CdTe films treated by dip-coating annealing show a relatively low doping concentration, except for the sample treated with a CdCl2 concentration of 6%, which is consistent with the changes of short-circuit current density of the cells. It is believed that these results can be applied to the large-scale production of CdTe polycrystalline thin-film solar cells.  相似文献   
994.
Two kinds of CACs with different monocalcium aluminate(CA) contents were used in the PC/CAC(PAC) mixtures. Effects of CA and CACs on the properties of PAC were analyzed by setting times and the compressive strength tests, and also by means of calorimetry, XRD, DTA-TG and ESEM. The experimental results show that the compressive strength of the PAC mortars decreases with increasing content of CAC while it declines sharply with a higher content of CA in CAC. Compared with neat PC paste, the content of calcium hydroxide in hydrates of PAC paste decreases significantly, and the hydration time of PC is prominently prolonged. Additionally, the higher the content of CA in CAC, the more obviously the hydration of PC is delayed, confi rming that the CA phase in CAC plays an important role in the delay of PC hydration.  相似文献   
995.
In order to investigate the anti-leaching capability of pyrochlore Gd2Zr2O7 immobilized An3+, trivalent neodymium was used as the simulacrums for radioactive wastes with trivalence, Gd2-xNdxZr2O7(0.0x 2.0) series samples were successfully synthesized by high temperature solid reaction and using Gd2O3, Zr O2 powders as starting materials. The experiments of long-term chemical stability were conducted in synthetic seawater at 40 and 70 ℃. The XRD diffractive data and extraction ratio of as-received samples were collected with the help of X-ray diffraction(XRD) instrument and inductively coupled plasma mass spectrometry(ICPMass). The results indicate that the phases of as-received compounds keep the single phase of pyrochlore. The extraction ratio of Gd3+, Zr4+ and Nd3+ in waste forms is increasing with the increase of immersion time in synthetic seawater. The extraction ratio of waste forms at 70 ℃ is higher than at 40 ℃. The highest extraction ratio of Gd3+, Zr4+ and Nd3+ after 42 days is near 0.025 8, 0.003 8 and 0.045 2 μg·m L-1, respectively.  相似文献   
996.
Baskakov型算子是研究函数逼近问题的一种很重要的工具。该文基于Gupta所提出的q-Baskakov算子,介绍了一类修正的q-Baskakov算子,给出了该类算子的一些基本性质,并且得到了该类算子的一致收敛定理,从而进一步推广了q-Baskakov算子的一些结论。  相似文献   
997.
该文介绍了基于地图Mashup的水质实时监测系统的设计,实现了对监测站点各项数据的查询和报表输出,与现场视频信号动态连接进行直观监测,并且能够对监测站信息进行设置,同时系统设计兼顾了良好的用户界面交互性。  相似文献   
998.
A hybrid remotely operated underwater vehicle (HROV) capable of working to the full ocean depth has been developed. In order for the vehicle to achieve a certain survivability level, a self-repairing control system (SRCS) has been designed. It consists of two basic technologies, fault diagnosis and isolation (FDI) and reconfigurable control. For F'DI, a model-based hierarchical fault diagnosis system is designed for the HROV. Then, control strategies which reconfigure the control system at intervals according to information from the FDI system are presented. Combining the two technologies, it can obtain the fundamental frame of SRCS for the HROV. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, an assessment of the HROV' s survivability is vitally needed before it enters operational service. This paper presents a new definition of survivability for underwater vehicles and develops a simple survivability model for the SRCS. As a result of survivability assessment for the SRCS, we are able to figure out the survivability of SRCS and make further optimization about it. The methodology developed herein is also applicable to other types of underwater vehicles.  相似文献   
999.
近几年,在政府大力扶持之下,安徽中小企业快速发展,已成为推动经济持续、健康发展的重要力量,但在发展过程中也存在一些不容忽视的问题。本文从企业总量、地区分布、企业产值、所有制类型等方面对安徽中小企业进行调查,在此基础上分析安徽中小企业在发展过程中存在的问题,并提出相应的建议和对策,对丰富中小企业发展理论、制定安徽中小企业发展政策具有一定的意义。  相似文献   
1000.
现实生活中,已经有多款用于擦洗玻璃的装置面市,但因这些产品或制造成本比较高昂,或使用范围有限,甚至效果不好,使其局限性比较大,难以得到推广。针对这些问题,本设计采用51单片机来控制自动擦窗器的电机及喷水装备以达到擦洗玻璃的目的,其效果明显,装置简单,成本较低,利用价值大,有着广阔的市场前景。  相似文献   
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