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141.
分析了UART核的结构和智能卡的传输协议,提出一种基于UART核的智能卡接口IP核的设计。该设计以成熟的UART核为基础,无需编写异步串口的时序与接口逻辑,仪在串口核中增加收发缓冲器和协议处理等模块,减少了工作量并缩短了开发周期。最后对所设计的IP核进行仿真和实际测试,结果表明该IP核设计正确,运行稳定,适合在多卡系统中应用。 相似文献
142.
对于集成电路设计、生产过程中的多目标、多约束统计优化问题,本文提出了“合格率足够高”的优化宗旨,并从概率论的基本原理出发,结合集成电路的特点,导出了一种合格率的近似表述方法,提出的变权重Monte Carlo法编程简便,效率高。采用这些优化策略设计的集成电路合格率优化系统取得了比较好的结果。 相似文献
143.
High-field designs could reduce the cost and complexity of tokamak reactors. Moreover, the certainty of achieving required plasma performance could be increased. Strong Ohmic heating could eliminate or significantly decrease auxiliary heating power requirements and high values of nE could be obtained in modest-size plasmas. Other potential advantages are reactor operation at modest values of , capability of higher power density and wall loading, and possibility of operation with advanced fuel mixtures. Present experimental results and basic scaling relations imply that the parameterB
2a, where B is the magnetic field and a is the minor radius, may be of special importance. A superhigh-field compact ignition experiment with very high values ofB
2a (e.g.,B
2a=150 T2 m) has the potential of Ohmically heating to ignition. This short-pulse device would use inertially cooled copper plate magnets. Compact engineering test reactor and/or experimental hybrid reactor designs would use steady-state, water-cooled copper magnets and provide long-pulse operation. Design concepts are also described for demonstration/commercial reactors. These devices could use high-field superconducting magnets with 7–10 T at the plasma axis. 相似文献
144.
Conceptual fusion reactor studies over the past 10–15 yr have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points toward smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion reactors. The results of a number of recent conceptual designs of reversed-field pinch, spheromak, and tokamak fusion reactors are summarized as examples of more compact approaches. While a focus has been placed on increasing the fusion-power-core mass power density beyond the minimum economic threshold of 100–200 kWe/tonne, other means by which the overall attractiveness of fusion as a long-term energy source are also addressed.Nomenclature
a
Plasma minor radius at outboard equatorial plane (m)
-
A
Plasma aspect ratioR
T
/a
-
AC
Annual charges ($/yr)
-
b
Plasma minor radius in vertical direction (m)
-
B
Magentic field at plasma or blanket (T)
-
B
c
Magnetic field at the coil (T)
-
B
Toroidal magnetic field (T)
-
B
Poloidal magnetic field (T)
- BOP
Balance of plant
-
C
Coil
-
COE
Cost of electricity (mills/kWeh)
- CRFPR
Compact RFP reactor
- CT
Compact torus (FRC or spheromak)
-
c
FPC
Unit cost of fusion power core ($/kg)
-
DC
Direct cost ($)
- DZP
Dense Z-pinch
-
E
Escalation rate (1/yr)
-
EDC
Escalation during construction ($)
- ET
Elongated tokamak
-
F
Annual fuel charges ($/yr)
-
FC
Component of UDC not strongly dependent or FPC size ($/kWe)
- FW
First wall
-
FPC
Fusion power core
-
f
Aux
Fraction of gross electric power recirculated to BOP
-
f
1
(IC+IDC+EDC)/DC
-
f
2
(O&M + SCR + F)/AC
-
IC
Indirect cost ($)
-
IDC
Interest during construction ($)
-
I
w
Neutron first-wall loading (MW/m2)
-
i
Toroidal plasma current (MA)
-
j
Plasma current density, I/a2
-
k
B
Boltzmann constant, 1.602(10)–16 (J/keV)
- LWR
Light-water (fission) reactor
-
MPD
Mass power density 1000PE/MFPC (kWe/tonne)
-
M
N
Blanket energy multiplication of 14.1-MeV neutron energy
-
M
FPC
Mass of fusion power core (tonne)
-
n
Plasma density (m–3) or toroidal MHD mode number
-
O&M
Annual operating and maintenance cost ($/yr)
-
p
f
Plant availability factor
- PFD
Poloidal field dominated (CTs, RFP, DZP)
-
P
Construction time (yr)
- PTH
Thermal power (MWt)
-
P
E
Net electric power (1-)P
ET
(MWe)
- PET
Total gross electric power (MWe)
- pf
Fusion power (MW)
-
q
Tokamak safety factor (B
/B
gq
)(a/R
T
)
-
q
e
EngineeringQ value, 1/e
-
R
T
Major toroidal radius (m)
- RFP
Reversed-field pinch
- RPE
Reactor plant equipment (Account 22)
- S
Shield
-
SCR
Annual spare component cost ($/yr)
- SSR
Second stability region for the tokamak
- S/T/H
Stellarator/torsatron/heliotron
- ST
Spherical tokamak or spherical torus
-
T
Plasma temperature (keV)
-
TDC
Total direct cost ($)
-
TOC
Total overnight cost ($)
-
UDC
Unit direct cost,TDC/10
3
P
E
($/kWe)
-
V
p
Plasma volume (m3)
-
W
p
Plasma energy (GJ)
-
W
B
Magnetic field energy (GJ)
-
Magnetic utilization efficiency, 2nkBT/(B
2/20)
-
0
Permeability of free space, 4(10)–7 H/m
-
XE
Plasma confinement efficiency, a2/4E
-
e
Plasma energy confinement time
-
p
Overall plant efficiency, TH(1-)
-
TH
Thermal conversion efficiency
-
FPC
AverageFPC mass density (tonne/m3)
-
Plasma vertical elongation factor,b/a
-
Thickness of allFPC engineering structure surround plasma (m)
-
Total recirculating power fraction, (P
ET-P
E)/P
ET, or inverse aspect ratioa/R
T
This work was performed under the auspices of USDOE, Office of Fusion Energy. 相似文献
145.
146.
CVD反应器传输过程的三维数学模型 总被引:1,自引:0,他引:1
提出了一个同时表示CVD过程的气体流动、温度分布和物质传输的三维数学模型。应用这个模型预报了在含有SiCl_4的氢气流中沉积出Si的锥台式反应器中的速度场、温度场和浓度场。所得的结果有助于增进对这类反应器中的传输过程的认识,模型亦可用于设计参数的最优化,诸如入口流量,锥台倾角等。 相似文献
147.
148.
为了研究金属氢化物储氢反应器放氢过程的热质传递特性,本文建立了金属氢化物反应器的二维轴对称数学模型。此反应器内装填了Ti0.95Zr0.05Mn1.55V0.45Fe0.09储氢合金和膨胀石墨组成的复合压块。通过与文献中实验数据的对比验证了所建立模型的有效性。论文考察了换热流体温度、流体平均流速和氢气排出压力变化对金属氢化物反应器放氢过程的影响,比较了优化操作参数和基准操作参数下的放氢性能。并对优化操作参数下放氢反应过程特征进行了分析。模拟结果表明:换热管附近床层区域的换热效果更好,放氢反应进行得更快。当换热流体温度从313.15K升高到353.15K时,放氢时间从17100s降低到了6700s。虽然提高换热流体平均流速可以缩短反应器的放氢反应时间,但其强化效果是很有限的。当换热流体流速超过3m/s时,氢化物床与换热管壁之间的接触热阻成为整个传热过程的主要热阻,增加流速的强化效果已不明显。优化后的操作参数为:氢气排出压力为0.3MPa、换热流体温度为353.15K、换热流体平均流速为3m/s。与基准操作参数相比,放氢反应时间缩短了约56%,对操作参数的优化能够显著地提高反应器的放氢速率。Ti0.95Zr0.05Mn1.55V0.45Fe0.09合金的放氢反应过程仅仅在前4s内主要受氢气压力的控制,而随后的反应过程主要是受传热过程控制。 相似文献
149.
比较曝气头曝气以及膜曝气两种曝气方式支持的菌藻共生系统在不同的运行条件下对污染物的去除效能,探讨去除机理。结果表明,以膜曝气为基础的MABAR对氨氮、总氮、磷、化学需氧量(COD)的去除负荷相对于以曝气头曝气为基础的HABAR,最高分别提升1.44、21.22、3.08、52.09 kg/m2/m3。藻类积累方面,MABAR在5个阶段的积累量都高于HABAR,最高提升15.17 mg/cm2。这不但归因于膜曝气良好的无吹脱和高效的碳化能力为自养藻类提供了充足的无机碳,而且膜曝气为一些十分有利于藻类生长的细菌,例如Acidovorax、Rhodobacter和Acinetobacter,提供了良好的生存环境。MABAR不但能够提升去除效能,还能够促使光生物膜反应器抵抗冲击,维持稳定,这对未来光生物反应器的实际应用提供了一种新的运行方式。 相似文献
150.
Chemical looping gasification (CLG) of Ningdong coal by using Fe2O3 as the oxygen carriers (OCs) was studied, and the gasification characteristics were obtained. A computation fluid dynamics (CFD) model based on Eulerian‐-Lagrangian multiphase framework was established, and a numerical simulation the coal chemical looping gasification processes in fuel reactor (FR) was investigated. In addition, the heterogeneous reactions, homogeneous reactions and Fe2O3 oxygen carriers' reduction reactions were considered in the gasification process. The characteristics of gas flow and gasification in the FR were analyzed and it was found that the experiment results were consistent with the simulation values. The results show that when the O/C mole rate was 0.5:1, the gasification temperature was 900 ℃ and the water vapor volume flow rate was 2.2 ml·min-1, the mole fraction of syngas reached a maximum value of the experimental result and simulation value were 71.5% and 70.2%, respectively. When the O/C mole rate was 0.5:1, the gasification temperature was 900 ℃, and the water vapor volume flow was 1.8 ml·min-1; the gasification efficiency reached the maximum value was 62.2%, and the maximum carbon conversion rate was 84.0%. 相似文献