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An evolutionary adaptive neuro-fuzzy inference system for estimating field penetration index of tunnel boring machine in rock mass 被引量:3
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作者 Maryam Parsajoo Ahmed Salih Mohammed +2 位作者 Saffet Yagiz Danial Jahed Armaghani Manoj Khandelwal 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2021年第6期1290-1299,共10页
Field penetration index(FPI) is one of the representative key parameters to examine the tunnel boring machine(TBM) performance.Lack of accurate FPI prediction can be responsible for numerous disastrous incidents assoc... Field penetration index(FPI) is one of the representative key parameters to examine the tunnel boring machine(TBM) performance.Lack of accurate FPI prediction can be responsible for numerous disastrous incidents associated with rock mechanics and engineering.This study aims to predict TBM performance(i.e.FPI) by an efficient and improved adaptive neuro-fuzzy inference system(ANFIS) model.This was done using an evolutionary algorithm,i.e.artificial bee colony(ABC) algorithm mixed with the ANFIS model.The role of ABC algorithm in this system is to find the optimum membership functions(MFs) of ANFIS model to achieve a higher degree of accuracy.The procedure and modeling were conducted on a tunnelling database comprising of more than 150 data samples where brittleness index(BI),fracture spacing,α angle between the plane of weakness and the TBM driven direction,and field single cutter load were assigned as model inputs to approximate FPI values.According to the results obtained by performance indices,the proposed ANFISABC model was able to receive the highest accuracy level in predicting FPI values compared with ANFIS model.In terms of coefficient of determination(R^(2)),the values of 0.951 and 0.901 were obtained for training and testing stages of the proposed ANFISABC model,respectively,which confirm its power and capability in solving TBM performance problem.The proposed model can be used in the other areas of rock mechanics and underground space technologies with similar conditions. 展开更多
关键词 Tunnel boring machine(TBM) field penetration index(FPI) Neuro-fuzzy technique Evolutionary computation Artificial bee colony(ABC)
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Some Index Classes of Singularity of Vector Fields on Manifolds with Boundary
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作者 Xu Xu, Liu Heng-xing School of Mathematics and Statistics, Wuhan University, Wuhan 430072, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2002年第4期388-390,共3页
V. I. Arnold defined some particular classes of index for singularities of adapted fields. We generalize these index classes for general fields on manifolds with boundary and get some relations of these index classes.
关键词 adapted fields SINGULARITY index
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Influence of Coordinate Field Index on Upconversion Luminescence in Er ^(3+) Doped Tellurite Glasses
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作者 苏方宁 邓再德 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第S1期30-32,共3页
The upconversion luminescence in Er 3+ doped tellurite glasses (MKT: TeO_2-MgO-K_2O) were performed. Two green emission bands at 521 and 550 nm, corresponding to the 2H_ 11/2→4I_ 15/2 and 4S_ 3/2→4I_ 15/2 transition... The upconversion luminescence in Er 3+ doped tellurite glasses (MKT: TeO_2-MgO-K_2O) were performed. Two green emission bands at 521 and 550 nm, corresponding to the 2H_ 11/2→4I_ 15/2 and 4S_ 3/2→4I_ 15/2 transitions, respectively, were observed. Coordinate field index, which was proposed by deducing from Pauling′s rules on the basis of Zachariasen′s random network theory, can be used to rationalize the remarkable variation in the intensity of upconversion luminescence. 展开更多
关键词 coordinate field index pauling′s rules Zachariasen′s random network theory upconversion luminescence tellurite glasses rare earths
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Indexes of Indoor Thermal Environment with Asymmetrical Radiant Field
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作者 钟珂 刘加平 亢燕铭 《Journal of Donghua University(English Edition)》 EI CAS 2004年第1期63-67,共5页
The main features of top-flcor rooms with natural ventilation are identified by investigating indoor thermal environment in summer season. One is high indoor air temperature, for this reason the indoor climate is far ... The main features of top-flcor rooms with natural ventilation are identified by investigating indoor thermal environment in summer season. One is high indoor air temperature, for this reason the indoor climate is far beyond the thermal comfort standard; the other is the inhomogeneons temperature distribution of the inner wall surfaces, and high temperature of the inner surface of the roof causes much scorching to the head of occupant. This is the characteristic of such rooms. Both features mentioned above should be considered comprehensively for the evaluation of indoor thermal environment of the top-floor rooms with asymmetric radiant field. In order to characterize the indoor thermal environment of the rooms, the heat stress index, HSI and radiant heat flux reaching human head, Q_R should be introduced simultaneously as thermal indexes for the indoor climate evaluation. The application of the indexes to a topfloor room is presented and analyzed. 展开更多
关键词 thermal index asymmetrical radiant field top-floor room natural ventilation
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Characterization of Orchard Fields Based on Soil Fertility Index (SOFIX)
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作者 Pitchayapa Pholkaw Quoc Thinh Tran +4 位作者 Takamitsu Kai Taiki Kawagoe Kenzo Kubota Kiwako S. Araki Motoki Kubo 《Journal of Agricultural Chemistry and Environment》 2020年第3期159-176,共18页
Soil samples from 139 agricultural orchard fields (apple, grape, tea, and others) w</span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> an... Soil samples from 139 agricultural orchard fields (apple, grape, tea, and others) w</span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> analyzed using the soil fertility index. From these samples, an orchard field database was constructed and the soil properties between orchard, upland, and paddy fields </span><span style="font-family:Verdana;">were </span><span style="font-family:""><span style="font-family:Verdana;">compared. The average value of bacterial biomass in the orchard fields was 7.4 × 10</span><sup><span style="font-family:Verdana;">8</span></sup><span style="font-family:Verdana;"> cells/g-soil, ranging from not detected (lower than 6.6 × 10</span><sup><span style="font-family:Verdana;">6</span></sup><span style="font-family:Verdana;"> cells/g-soil) to 7.7 × 10</span><sup><span style="font-family:Verdana;">9</span></sup><span style="font-family:Verdana;"> cells/g-soil. The average values of total carbon (TC), total nitrogen (TN), total phosphorus (TP), and total potassium (TK), were 24,000 mg/kg (2670 to 128,100 mg/kg), 1460 mg/kg (133 to 6400 mg/kg), 1030 mg/kg (142 to 5362 mg/kg), and 5370 mg/kg (1214 to 18,155 mg/kg), respectively. The C/N and C/P ratios were 19 (3 to 85) and 27 (2 to 101), respectively. Soil properties of the orchard fields were compared with those of the upland and the paddy fields. The average value of bacterial biomass in the orchard fields was almost the same as that in the upland fields (8.0 × 10</span><sup><span style="font-family:Verdana;">8</span></sup><span style="font-family:Verdana;"> cells/g-soil), but the number was lower than that in the paddy fields (12.9 × 10</span><sup><span style="font-family:Verdana;">8</span></sup><span style="font-family:Verdana;"> cells/g-soil). The average values of TC and TN in the orchard fields fell between those in the upland fields (TC: 33,120 mg/kg, TN: 2010 mg/kg) and the paddy fields (TC: 15,420 mg/kg, TN: 1080</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">mg/kg). The relationship between the bacterial biomass and TC in the orchard fields resembled that in the upland fields. A suitable soil condition for the orchard fields was determined as TC: ≥25,000 mg/kg, TN: ≥1500 mg/kg, TP: ≥900 mg/kg and TK: 2500 - 10,000 mg/kg.</span><span style="font-family:""> </span><span style="font-family:Verdana;">These recommended values will be effective for the improvement of the soil quality in the orchard fields by enhancing the number and activities of microorganisms. 展开更多
关键词 Orchard field Soil Fertility index (SOFIX) Bacterial Biomass
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3D Slicing of Weighted Index for Reservoir Quality of Lower Miocene Rocks, Belayim Marine Oil Field, Gulf of Suez, Egypt
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作者 Ibrahim Mohammad Al-Alfy Ali Mohammad El-Hawary +2 位作者 Hassan Badr El-Dein Mohammad Mohammad Ahmed Shaheen Muhammad Nabih 《Journal of Geoscience and Environment Protection》 2022年第8期55-65,共11页
This study aims to have a single coefficient resulting from the integration of all the reservoir parameters through which a decision can be taken to determine the best quality places in the reservoir. The conventional... This study aims to have a single coefficient resulting from the integration of all the reservoir parameters through which a decision can be taken to determine the best quality places in the reservoir. The conventional well logging data in nine wells were used to determine the reservoir parameters in the study area. Seven different parameters were calculated, five of them were directly proportional to the quality of the reservoir, while the remaining two parameters which represent shale volume and water saturation were inversely proportional to the reservoir quality. The index of each parameter was calculated. A new value was created from the integration of the seven different parameter indexes called the weighted index for the reservoir quality. The reservoir quality values were sliced in the three dimensions depending on the effect of all reservoir parameters and not on any single parameter. It is clear from the results of this study that horizontal and vertical slicing, as well as cut-off values, illustrates that the middle and upper parts are the best places for the reservoir to explore hydrocarbons, where the values of the weighted index of the reservoir quality range from 0.65 to 0.9. Meanwhile, the quality of the reservoir decreases in its lower parts. 展开更多
关键词 3D Slicing Weighted index Reservoir Parameters Belayim Marine Oil field
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Improvement in refractive-index change in LiNbO3:Ce:Cu by applying an external electric field
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作者 戴翠霞 刘立人 +3 位作者 刘德安 周煜 柴志方 栾竹 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第12期2491-2495,共5页
By jointly solving two-centre material equations with a nonzero external electric field and coupled-wave equations, we have numerically studied the dependence of the non-volatile holographic recording in LiNbO3:Ce:C... By jointly solving two-centre material equations with a nonzero external electric field and coupled-wave equations, we have numerically studied the dependence of the non-volatile holographic recording in LiNbO3:Ce:Cu crystals on the external electric field. The dominative photovoltaic effect of the non-volatile holographic recording in doubly doped LiNbO3 crystals is directly verified. And an external electric field that is applied in the positive direction along the c-axis (or a large one in the negative direction of the c-axis) in the recording phase and another one that is applied in the negative direction of the c-axis in the fixing phase are both proved to benefit strong photorefractive performances. Experimental verifications are given with a small electric field applied externally. 展开更多
关键词 non-volatile holographic recording external electric field refractive-index change LiNbO3:Ce:Cu crystals
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Space-Energy Duality Generalized 4-Index Einstein Field Equation
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作者 Mahgoub A. Salih 《International Journal of Astronomy and Astrophysics》 2023年第4期281-297,共17页
The introduction of a new concept of space-energy duality serves to extend the applicability of the Einstein field equation in the context of a 4-index framework. The utilization of the Weyl tensor enables the derivat... The introduction of a new concept of space-energy duality serves to extend the applicability of the Einstein field equation in the context of a 4-index framework. The utilization of the Weyl tensor enables the derivation of Einstein’s equations in the 4-index format. Additionally, a two-index field equation is presented, comprising a conventional Einstein field equation and a trace-free Einstein equation. Notably, the cosmological constant is associated with a novel concept that facilitates the encoding of space and energy information, thereby enabling the recognition of mutual interactions between space and energy in the presence of gravitational forces, as dictated by Einstein’s field equations (EFE) and Trace-Free Einstein Equation (TFE). 展开更多
关键词 Einstein field Equation Trace-Free Einstein Equation 4-index Cosmological Constant
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Soil Carbon Pool Management Index under Different Straw Retention Regimes 被引量:5
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作者 曾研华 吴建富 +4 位作者 何虎 潘晓华 石庆华 吴自明 邓伟明 《Agricultural Science & Technology》 CAS 2012年第4期818-822,共5页
[Objective] To clarify the effects of different straw retention regimes on soil fertility in double cropping paddy field. [Method] The effects of different straw reten- tion regimes on total organic carbon (CToc), a... [Objective] To clarify the effects of different straw retention regimes on soil fertility in double cropping paddy field. [Method] The effects of different straw reten- tion regimes on total organic carbon (CToc), active carbon (CA) and mineralized carbon (CM) were analyzed, and carbon pool active (A), carbon pool active index (A/), carbon pool index (CPI) and carbon pool management index (CPMi) for each treat- ment were calculated. [Result] Compared with the unfertilized treatment (CK), CToc, CA, CM and the available ratio of soil carbon were increased in the treatment of re- turning early season and late season rice straws to field. With the same nutrient application, CToc, CA and the available ratio of soil carbon in the field with straw re- turned to field were higher than that of straw incineration and no straw returning, and the change in soil CA content was more significant. The difference in CPMI be- tween different treatments reached significant or very significant level, and the value was in the order of straw directly returned to field 〉 straw returned to field after in- cineration 〉 no straw returned to field. [Conclusion] This study provided theoretical bases for the increase of soil CA content and soil fertility in double rice fields. 展开更多
关键词 Double-cropping paddy field Different straw retention regimes Total or- ganic carbon Active carbon Mineralized carbon Carbon pool management index
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Physiological and Biochemical Response of Artificial Wetland Plant under Electric Field 被引量:6
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作者 卢守波 宋新山 +2 位作者 张涛 王道源 严登华 《Agricultural Science & Technology》 CAS 2010年第5期121-124,共4页
By measuring wetland plants chlorophyll content,malondialdehyde(MDA) content and superoxide dismutase(SOD) enzyme activity,the changes of wetland plant physiological characeristics under different power strength were ... By measuring wetland plants chlorophyll content,malondialdehyde(MDA) content and superoxide dismutase(SOD) enzyme activity,the changes of wetland plant physiological characeristics under different power strength were studied,and the mechanism of electric field on plant physiological characteristics was analyzed to provide a theoretical basis for the pollutant removal ability strengthening of artificial wetland under electricfield.The results showed that compared with the control plants,low-intensity-voltage(1 V and 3 V) had no significant effect on the normal physiological and biochemical indexes of the plants,and the growth trend was better than the control group;with the voltage increasing,plant chlorophyll content,MDA content and SOD activity were greatly affected,indicating that plants were under strong oxidative stress,and the growth was damaged.Therefore,a suitable electric field could enhance the sewage treatment effect of constructed wetland. 展开更多
关键词 Electric field Artificial wetland plant Physiological and biochemical indexes Response
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2021年漾濞M_(S)6.4地震前重力段差指标量分析及场源特征反演
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作者 郑秋月 黄江培 +3 位作者 吴宇琴 陈政宇 刘东 王青华 《地震研究》 北大核心 2025年第1期22-31,共10页
基于2016-2021年云南地区流动重力重复观测资料,利用流动重力段差变化可视化方法及重力场变化显著性程度指标量G和C值研究了2021年漾濞M_(S)6.4地震前的重力变化,并反演了其与地震孕育相关的场源分布特征,开展了对研究区重力变化及场源... 基于2016-2021年云南地区流动重力重复观测资料,利用流动重力段差变化可视化方法及重力场变化显著性程度指标量G和C值研究了2021年漾濞M_(S)6.4地震前的重力变化,并反演了其与地震孕育相关的场源分布特征,开展了对研究区重力变化及场源特征的定性和定量研究。结果表明:①段差表示法的大小和方向对地下物质的运移方向有一定的指示意义,震前重力指标量呈显著上升,震后又迅速回落,重力变化指标量G和C值可作为评价测网区域重力变化显著性程度的定量依据;②反演得到的重力变化场源位置主要集中在红河断裂带北段至滇西北一带,且表现出与维西-乔后断裂及红河断裂带走向较为一致的分布特征,这可能与地震前中上地壳的深部物质运移相关。 展开更多
关键词 重力段差 定量分析 重力变化指数 场源反演 漾濞M_(S)6.4地震
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Simulation of leaf area index and biomass at landscape scale 被引量:7
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作者 ZHANGNa YUGuirui +1 位作者 YUZhenliang ZHAOShidong 《Journal of Geographical Sciences》 SCIE CSCD 2003年第2期139-152,共14页
The method for simulating the temporal and spatial distribution patterns of leaf area index (LAI) and biomass at landscape scale using remote sensing images and surface data was discussed in this paper. The procedure... The method for simulating the temporal and spatial distribution patterns of leaf area index (LAI) and biomass at landscape scale using remote sensing images and surface data was discussed in this paper. The procedure was: (1) annual maximum normalized difference vegetation index (NDVI) over the landscape was calculated from TM images; (2) the relationship model between NDVI and LAI was built and annual maximum LAI over the landscape was simulated; (3) the relationship models between LAI and biomass were built and annual branch, stem, root and maximum leaf biomass over the landscape were simulated; (4) spatial distribution patterns of leaf biomass and LAI in different periods all the year round were obtained. The simulation was based on spatial analysis module GRID in ArcInfo software. The method is also a kind of scaling method from patch scale to landscape scale. A case study of Changbai Mountain Nature Reserve was dissertated. Analysis and primary validation were carried out to the simulated LAI and biomass for the major vegetation types in the Changbai Mountain in 1995. 展开更多
关键词 landscape scale leaf area index BIOMASS remote sensing field measurement CLC number:Q948.2 TP79
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V_r:A new index to represent the variation rate of geomagnetic activity 被引量:4
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作者 Dongmei Yang Yufei He +1 位作者 Chuanhua Chen Jiadong Qian 《Earthquake Science》 CSCD 2010年第4期343-348,共6页
By calculating the hourly standard deviation of the first-order differences of the horizontal geomagnetic com- ponent minute data, a new index Vr to represent the variation rate of the geomagnetic field was introduced... By calculating the hourly standard deviation of the first-order differences of the horizontal geomagnetic com- ponent minute data, a new index Vr to represent the variation rate of the geomagnetic field was introduced. Vr-indices show similar trends in the temporal change at different observatories and have simultaneous peak values at the observatories cov- ering a large span geographically, which reveals that the source of geomagnetic disturbances represented by Vr is in the mag- netosphere. Based on the comparison among Vr, Kp and ap, it is found that generally Vr changes linearly with Kp and ap, which means that the rapid changes of magnetic field usually exist together with magnetic disturbances. But there are excep- tions. As Vr can be easily produced by individual observatory in quasi real time and is more sensitive to the variation rate of geomagnetic field rather than the field itself, it can be expected to serve for monitoring or predicting the geomagnetic-induced event in a quick and intuitive way. 展开更多
关键词 Vr index first-order difference standard deviation variation rate of geomagnetic field geomagnetic-induced event
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Field Modeling Method for Identifying Urban Sphere of Influence:A Case Study on Central China 被引量:7
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作者 DENG Yu LIU Shenghe +2 位作者 WANG Li MA Hanqing WANG Jianghao 《Chinese Geographical Science》 SCIE CSCD 2010年第4期353-362,共10页
With rapid development of urbanization and regional interaction and interdependence, regional urban agglomeration planning becomes more and more important in China, in order to promote integrated development of variou... With rapid development of urbanization and regional interaction and interdependence, regional urban agglomeration planning becomes more and more important in China, in order to promote integrated development of various cities with close interrelationship. However, it is still arguable academically on how to define the boundary or which cities to be included for the urban agglomeration of a region. This paper aims to shed lights on how to identify urban spheres of influence scientifically by introducing field modeling method and by practicing a case study on 168 cities in Central China. In our field modeling method, the influence intensities of cities were measured by a compre-ensive index and urban spheres of influence were represented spatially by field intensity. Then, their classification and spatial distribution characteristics of study area in 2007 were identified and explored by using GIS and statistical methods. The result showed that: 1) Wuhan is the absolute dominant city in Central China; 2) the provincial capital cities dominate their own provinces and there are no other lower grade agglomeration centers; and 3) the basic types of organization form of urban sphere of influence are single-polar type, agglomeration type, close-related group type and loose-related group type. 展开更多
关键词 Central China urban sphere of influence urban influence index field intensity urban influence intensity
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Some Limit Theorems for Weighted Sums of Random Variable Fields 被引量:2
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作者 GAN Shixin CHEN Pingyan 《Wuhan University Journal of Natural Sciences》 CAS 2006年第2期323-327,共5页
Let{Xn^-,n^-∈N^d}be a field of Banach space valued random variables, 0 〈r〈p≤2 and{an^-,k^-, (n^-,k^-) ∈ N^d × N^d ,k^-≤n^-} a triangular array of real numhers, where N^d is the d-dimensional lattice (d... Let{Xn^-,n^-∈N^d}be a field of Banach space valued random variables, 0 〈r〈p≤2 and{an^-,k^-, (n^-,k^-) ∈ N^d × N^d ,k^-≤n^-} a triangular array of real numhers, where N^d is the d-dimensional lattice (d≥1 ). Under the minimal condition that {||Xn^-|| r,n^- ∈N^d} is {|an^-,k^-|^r,(n^-,k^-)} ∈ N^d ×N^d,k^-≤n^-}-uniformly integrable, we show that ∑(k^-≤n^-)an^-,k^-,Xk^-^(L^r(or a,s,)→0 as |n^-|→∞ In the above, if 0〈r〈1, the random variables are not needed to be independent. If 1≤r〈p≤2, and Banach space valued random variables are independent with mean zero we assume the Banaeh space is of type p. If 1≤r≤p≤2 and Banach space valued random variables are not independent we assume the Banach space is p-smoothable. 展开更多
关键词 Banaeh space of type p multidimensional index strong law of large numbers L" convergence weightedsums of random variable fields martingale difference array
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Near-Field Loop Antenna for the UHF RFID Reader 被引量:1
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作者 Peng Yang Yan Li +1 位作者 Li-Jun Jiang Feng Yang 《Journal of Electronic Science and Technology》 CAS 2011年第3期256-260,共5页
A loop antenna for near field readers is proposed. Through periodic interdigital capacitors, the phase of the current on the loop is compensated and kept in phase. Hence, a loop with a perimeter of one wavelength at 9... A loop antenna for near field readers is proposed. Through periodic interdigital capacitors, the phase of the current on the loop is compensated and kept in phase. Hence, a loop with a perimeter of one wavelength at 900 MHz achieves a uniform near magnetic field distribution inside the loop. A novel method is proposed to evaluate the performance of the coplanar waveguide (CPW) to coplanar stripline (CPS) transition, which is used as a balun for the feeding network in this paper. This loop antenna has a 70 MHz operating bandwidth and 12 cm maximum reading range when the output power is 24 dBm, which is suitable for most near field radio frequency identification (RFID) applications. 展开更多
关键词 index Terms--Loop antenna near field reader antenna radio frequency identification.
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Key technologies and practice for gas field storage facility construction of complex geological conditions in China 被引量:7
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作者 MA Xinhua ZHENG Dewen +3 位作者 SHEN Ruichen WANG Chunyan LUO Jinheng SUN Junchang 《Petroleum Exploration and Development》 2018年第3期507-520,共14页
In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storag... In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storage construction technologies were established, mainly including UGS site selection and evaluation, key index design, well drilling and completion, surface engineering and operational risk warning and assessment, etc. The effect of field application was discussed and summarized. Firstly, trap dynamic sealing capacity evaluation technology for conversion of UGS from the fault depleted or partially depleted gas reservoirs. A key index design method mainly based on the effective gas storage capacity design for water flooded heterogeneous gas reservoirs was proposed. To effectively guide the engineering construction of UGS, the safe well drilling, high quality cementing and high pressure and large flow surface injection and production engineering optimization suitable for long-term alternate loading condition and ultra-deep and ultra-low temperature formation were developed. The core surface equipment like high pressure gas injection compressor can be manufactured by our own. Last, the full-system operational risk warning and assessment technology for UGS was set up. The above 5 key technologies have been utilized in site selection, development scheme design, engineering construction and annual operations of 6 UGS groups, e.g. the Hutubi UGS in Xinjiang. To date, designed main indexes are highly consistent with actural performance, the 6 UGS groups have the load capacity of over 7.5 billion cubic meters of working gas volume and all the storage facilities have been running efficiently and safely. 展开更多
关键词 gas field STORAGE trap dynamic SEALING capacity key index design effective STORAGE volume drilling and COMPLETION in ultra-deep and ultra-low pressure formation ALTERNATING load surface engineering core equipment risk assessment and control
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Relationship analysis between September precipitation in western China and 700 hPa wind field in East Asia 被引量:1
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作者 ShaoYong Chen Quan Xia +1 位作者 JunTin Guo Shu Lin 《Research in Cold and Arid Regions》 2011年第5期419-425,共7页
The regional wind index influencing September precipitation in western China has been defined using the 700 hPa u and v components of NCAR/NCEP reanalysis data of 1961 to 2006. There are three regional wind field indi... The regional wind index influencing September precipitation in western China has been defined using the 700 hPa u and v components of NCAR/NCEP reanalysis data of 1961 to 2006. There are three regional wind field indices: southwest, southeast, and north, and these indices reflect the change of East Asian monsoon. The relationship between the indices was studied, and results show that they not only have a close relationship, but also have independence. Moreover, there is an obvious relationship between the wind indices and the autumn in particular the September precipitation in western China. The effect of wind indices on rain occurrence is most different: the influenced area of the southwest wind index is larger than that of the southeast wind index, and the southwest wind index is a controlling factor on autumn precipitation in western China. The weakening of southwest wind is the main cause resulting in reduction of autumn precipitation on the east side of the Tibetan Plateau. 展开更多
关键词 western China September precipitation 700 hPa wind field regional wind index
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New Topologies of High Torque Density Machine Based on Magnetic Field Modulation Principle 被引量:3
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作者 Yan Yue Shaofeng Jia Deliang Liang 《CES Transactions on Electrical Machines and Systems》 CSCD 2023年第1期1-10,共10页
With the increasing demand for high torque density in motors,more and more new topologies emerge.Furthermore,the magnetic field modulation principle is widely concerned and has evolved into an effective analysis metho... With the increasing demand for high torque density in motors,more and more new topologies emerge.Furthermore,the magnetic field modulation principle is widely concerned and has evolved into an effective analysis method for studying the new motor topology.This paper introduces the principle of magnetic field modulation.And the research on high torque density in recent years is reviewed from the perspective of magnetic field modulation,including permanent magnet vernier machine(PMVM),flux reverse machine(FRM),flux switching machine(FSM),dual permanent magnet(DPM)machine,and DC biased machine.The principle of magnetic field modulation makes it possible to propose higher torque density topologies in the future. 展开更多
关键词 index Terms-High torque density Magnetic field modulation Vernier machine Dual permanent magnet machine DC biased machine
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基于加权平均梯度方向场和改进Poincare Index的指纹奇异点检测算法
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作者 付佳 潘伟 郝重阳 《计算机应用》 CSCD 北大核心 2007年第10期2563-2565,共3页
针对指纹图像具有局部平行性和渐变性以及邻域的脊线方向相关性高的特点,提出了一种基于加权平均梯度的指纹方向场算法。改进了传统的PoincareIndex指纹奇异点检测算法。实验证明,在采用加权平均梯度算法获取的方向场上利用改进的Poinca... 针对指纹图像具有局部平行性和渐变性以及邻域的脊线方向相关性高的特点,提出了一种基于加权平均梯度的指纹方向场算法。改进了传统的PoincareIndex指纹奇异点检测算法。实验证明,在采用加权平均梯度算法获取的方向场上利用改进的PoincareIndex算法可实现对低质量指纹图像的奇异点的准确提取。 展开更多
关键词 指纹 奇异点 加权平均梯度方向场 POINCARE index
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