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排序方式: 共有8007条查询结果,搜索用时 31 毫秒
1.
利用工作面高抽巷施工掩护顺槽掘进工作面下向穿层条带预抽钻孔,通过对钻场底板深、浅孔注浆封堵围岩裂隙解决了孔内返水不畅难题;采取了"两堵一注"封孔方式确保封孔严密不漏气;孔内全程下吹水管,实现了单孔、分组、定时吹水工作目标,提高了下向消突钻孔抽采效果,形成了一套高效、快速的下向穿层钻孔消突管理模式,实现了高地压严重突出区域煤层高效消突以及技术经济一体化目标,安全经济效益显著。  相似文献   
2.
This paper introduces a 9-bit time-based capacitance-to-digital converter (T-CDC). This T-CDC adopts a new design methodology for parasitic cancellation with a simple calibration technique. In T-CDCs, the input sensor capacitance is first converted into a delay pulse using a capacitance-to-time converter (CTC) circuit; then this delay signal is converted into a digital code through a time-to-digital converter (TDC) circuit. A prototype of the proposed T-CDC is implemented in UMC 0.13 μm CMOS technology. This T-CDC consumes 8.42 μW and achieves a maximum SNR of 45.14 dB with a conversion time of 1 μs that corresponds to a figure of merit (FoM) of 16.4 fJ/Conv.  相似文献   
3.
在高性能计算领域,数据流是一类重要的计算结构,也在很多实际场景表现出很好的性能和适用性。在数据流计算模式中,程序是以数据流图来表示的,数据流计算中一个关键的问题是如何将数据流图映射到多个执行单元上。通过分析现有数据流结构的指令映射方法及其不足,提出了基于数据流结构的新型指令映射优化方法。主要是根据多地址共享数据包的特性对指令映射方法进行优化,延迟多地址共享数据路由包的拆分,减少网络拥堵。  相似文献   
4.
针对电子商务顾客购物人工系统的计算实验研究,提出一种基于状态类比假说的人工情绪模型,给出了情绪的产生、增强、衰落和消失过程的描述方法,研究了外部刺激、情感强度和内部驱动力的计算方法,并进行了模拟分析。基于此人工情绪模型,构建了电商顾客购物的情绪-行为影响关系模型;将其应用于电商顾客购物的计算实验分析。结果表明,该人工情绪模型能较好地应用于电商复杂人工系统顾客购物的计算实验。  相似文献   
5.
In this work, gallium doped copper sulfide (Ga-doped CuS) nanocrystals were prepared using a solvothermal method. The effects of Ga doping on the crystal structures, chemical composition, morphology, optical properties and thermal performance of copper sulfide (CuS) were investigated. The Ga-doped CuS nanocrystals had a hexagonal structure comparable to that of pure CuS. The Cu+/Cu2+ ratio first decreased and then increased with increasing Ga3+ doping. Both CuS and Ga-doped CuS exhibited nanoplate and nanorod morphologies. The visible transmittance of the Ga-doped CuS films was in the range of 61–77.1%. Importantly, the near-infrared (NIR) shielding performance of the films can be tuned by adjusting the concentration of the Ga dopant. The NIR shielding value of the optimal Ga-doped CuS film was 72.4%, which was approximately 1.5 times as high as that of the pure CuS film. This can be ascribed to the enhanced plasmonic NIR absorption that resulted from an increase in the hole concentration after doping with Ga3+ ions. In the thermal performance test, the Ga-doped CuS film lowered the interior temperature of the heat box by 9.1 °C. Therefore, the integration of good visible transmittance and high NIR shielding performance make the Ga-doped CuS nanocrystals a promising candidate for energy-efficient window coatings.  相似文献   
6.
In this work we propose an optimal back plane biasing (OBB) scheme to be used in a UTBB FD SOI technology that minimizes the energy per operation consumption of sub threshold digital CMOS circuits. By using this OBB scheme, simulations show that more than 30% energy savings can be obtained with low threshold voltage (LVT) devices in comparison with classic symmetric back plane biasing (SBB) schemes. Additionally, this OBB scheme allows to adjust the performance of the circuit with very small energy penalties. A very simple and intuitive model, for sub threshold digital CMOS circuits, was developed to justify the benefits obtained by OBB. The results predicted by the model are confirmed with extensive simulation results. We show that the OBB approach can be applied easily to a given circuit just based on the information provided by a logic simulation of the circuit (or even an analysis of its structure) and simple electrical simulations of the pMOS and nMOS transistors. Finally, we show that the variability in the energy consumption is improved by using OBB and suggests that new sizing methodologies must be studied to fully benefit from the wide back plane voltage range available in UTBB FD SOI technology for the design of robust energy efficient digital circuits.  相似文献   
7.
Greenhouses in northern climates require a large amount of supplemental heating for growing crops in winter seasons, so energy‐efficient design of greenhouses based on local climate is important to minimize the heating demand. In this study, greenhouse design parameters including shape, orientation, the angle of the roof, and width of the span have been studied for the conceptual design of conventional greenhouses for Canadian Prairies using a heating simulation model. Five different shapes of greenhouses including even‐span, uneven‐span, modified arch, vinery, and quonset shape have been selected for the study. The simulation results proved that the uneven‐span gable roof shape receives the highest solar radiation, whereas the quonset shape receives the lowest solar radiation. However, the quonset shape greenhouse requires about 7.6% less annual heating as compared to the gable roof greenhouse, but the quonset would not be adopted as multispan greenhouses. Therefore, the gable roof greenhouse is considered as energy efficient for the multispan gutter connected greenhouses whereas quonset shape as a free‐standing single‐span greenhouses. In high northern latitudes, the greenhouse with east‐west orientation is more energy efficient from heating and cooling point of view when the length‐width ratio of the greenhouse is more than 1. The heating energy saving potential of the large span width in single‐span greenhouses is relatively higher as compared to the multispan greenhouses.  相似文献   
8.
In dense traffic railway networks, trains may often slow down or stop between stations owing to previous train delays. If preceding train trajectory can be predicted, energy‐efficient driving can be achieved by suppressing unnecessary speed changes. In this paper, we propose an algorithm to find energy‐efficient driving considering fixed‐block signaling (FBS) system by using dynamic programming (DP). DP is suitable for use because it can optimize the control inputs with discrete and state constraints. In this paper, we discuss energy‐efficient driving by considering a FBS system using some case studies of simulation. In the simulation, we examine a technique to drive an express train in an energy‐efficient way when the preceding local train is running toward the station with passing loops. The results show that the proposed method can derive complex speed profiles for energy‐efficient driving and the train can be operated with a maximum reduced energy consumption of 8.3%.  相似文献   
9.
中低品位磷矿高效清洁综合利用是中国基础磷化工产业发展中遇到的共性瓶颈问题。以中低品位磷矿磷-钙-镁一体化综合利用中试成果为基础,通过创新集成技术对中低品位磷矿直接进行处理,获得高品质磷精矿[w(P2O5)≥36%、w(MgO)≤0.5%]可用于任何湿法磷酸及热法黄磷生产工艺,同时回收高附加值的氢氧化镁和轻质碳酸钙。该工艺磷全部回收、无尾矿产生、实现了废水近零排放,项目的实施对推动中国磷化工产业可持续发展及从源头解决“三磷”问题具有重要意义。  相似文献   
10.
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