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41.
针对传统的差压密度计和压力式液位计分别存在可靠性不高、不适用于介质密度经常变化的场合的问题,设计了一种基于Freescale MC9S08AW60微控制器的智能力敏传感器,详细介绍了该传感器主要电路的设计。该智能传感器实现了数据采集、信号处理、数据通信和电流环输出式数模转换功能。实际应用表明,在-20~+80℃的工作温度范围内,密度测量精度可达±5kg/m3,液位测量不受悬浮液回流和液位波动的影响,很好地满足了工业现场的应用。 相似文献
42.
In recent years, there has been a considerable growth of application of group technology in cellular manufacturing. This has led to investigation of the primary cell formation problem (CFP), both in classical and soft-computing domain. Compared to more well-known and analytical techniques like mathematical programming which have been used rigorously to solve CFPs, heuristic approaches have yet gained the same level of acceptance. In the last decade we have seen some fruitful attempts to use evolutionary techniques like genetic algorithm (GA) and Ant Colony Optimization to find solutions of the CFP. The primary aim of this study is to investigate the applicability of a fine grain variant of the predator-prey GA (PPGA) in CFPs. The algorithm has been adapted to emphasize local selection strategy and to maintain a reasonable balance between prey and predator population, while avoiding premature convergence. The results show that the algorithm is competitive in identifying machine-part clusters from the initial CFP matrix with significantly less number of iterations. The algorithm scaled efficiently for large size problems with competitive performance. Optimal cluster identification is then followed by removal of the bottleneck elements to give a final solution with minimum inter-cluster transition cost. The results give considerable impetus to study similar NP-complete combinatorial problems using fine-grain GAs in future. 相似文献
43.
D. L. Wakefield 《International Journal of Thermophysics》1988,9(3):365-381
This paper is the final in a series of three viscosity and density studies of pure n-alkanes and selected binary and quaternary mixtures. A standard U-tube viscometer was used for viscosity measurements, and a Pyrex flask-type pycnometer was used for density determinations. Results are given here for pure alkane and selected binary mixtures of n-tetradecane + n-octane, for selected quaternary mixtures of n-hexadecane + n-dodecane + n-decane + n-hexane, and for pure and selected quaternary mixtures of n-hexadecane + n-dodecane + n-nonane + n-heptane at 303.16 and 308.16 K. The principle of congruence was tested, as was the Grunberg and Nissan equation, as they have been shown to be useful as prediction techniques for other n-alkane binary mixtures. Comparisons were made between the two groups of quaternary alkane mixtures and the binary n-tetradecane + n-octane mixtures of the same pseudo composition to understand better the dependence of mixture viscosities on the composition parameter. 相似文献
44.
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
45.
46.
47.
目前离子膜电解槽的发展方向为复极、自然循环、高电流密度、低电耗,伍德诺拉公司BM2.7-Ⅲ型槽、美国西方化学公司ExL^B-65槽、日本氯工程公司BiTAC-858槽即具有这些先进性能。对这3种槽进行了介绍与对比。 相似文献
48.
全国48家化肥催化剂制造厂总能力为57Kt/a,产量近30kt/a,设备利用率不到50%。平均万吨氨耗催化剂10.36t,高于国外5.60t水平。现生产31个品种203个型号的催化剂中有103种经部级鉴定,但经常使用的约50种。目前化肥催化剂工业水平与国外相比还存在四方面差距。 相似文献
49.
50.
哈萨克斯拉夫图像文本经过行切分和列切分后,存在水平方向接触和垂直方向重叠的粘连字符。为提高字符识别率,依据字符连通域的最小外接矩形切分开垂直方向重叠的粘连字符图像块;利用判决条件:字符宽度概率密度分布图、字符图像块垂直投影的波峰数目和字符图像块垂直投影波峰的对称性,分离初始粘连字符图像块中正确的单个字符图像块和实际接触的粘连字符图像块;在允许的字符宽度范围内,寻找粘连字符图像垂直投影图的极小值点,以切分实际接触的粘连字符。实验结果表明,该方法泛化能力较好且识别率有明显提高。 相似文献