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关键词

N∶P比值 1

低剂量CT；CT成像；全变分；稀疏字典学习 1

光合产物 1

关键影响因素 1

冬小麦 1

分配指数 1

变化 1

可溶性糖 1

地下水位变化 1

地球卫星遥感监测 1

宏观静摩擦系数 1

局部最大小波系数；可靠特征点分配；目标跟踪；跟踪-学习-检测（TLD）；卡尔曼滤波器 1

干旱和复水 1

平衡 1

影响因素 1

微分静摩擦系数 1

微牛纳牛静摩擦系数 1

数值模型 1

时钟数据恢复；数字滤波器；相位插值器 1

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CHARACTERISTICS OF SOIL QUALITY ATTRIBUTES UNDER DIFFERENT AGROECOSYSTEMS AND ITS IMPLICATIONS FOR AGRICULTURE IN THE CHOKE MOUNTAIN WATERSHED IN ETHIOPIA

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023502

摘要：

● Soil properties varied within coefficients of variation ranging from 7% to 169%.

关键词： agroecosystem     Choke Mountain watershed     coefficients of variation     Ethiopia     soil quality indicator    

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Experimental study of aerodynamic interference effects on aerostatic coefficients of twin deck bridges

Zhiwen LIU , Zhengqing CHEN , Gao LIU , Xinpeng SHAO ,

《结构与土木工程前沿（英文）》 2009年 第3卷 第3期   页码 292-298 doi: 10.1007/s11709-009-0048-8

摘要： The aerodynamic interference effects on aerostatic coefficients of twin deck bridges with large span were investigated in detail by means of wind tunnel test. The distances between the twin decks and wind attack angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of twin decks. The research results have shown that the drag coefficients of the leeward deck are much smaller than that of a single leeward deck. The drag coefficients of a windward deck decrease slightly compared with that of a single deck. The lift and torque coefficients of windward and leeward decks are also affected slightly by the aerodynamic interference of twin decks. And the aerodynamic interference effects on lift and torque coefficients of twin decks can be neglected.

关键词： twin decks     aerodynamic interference effects     aerostatic coefficients     wind tunnel test    

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Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2014年 第8卷 第1期   页码 41-48 doi: 10.1007/s11708-013-0292-4

摘要： Narrow-band transmissivities in the spectral range of 150 to 9300 cm and at a uniform resolution of 25 cm were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO -H O-N mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO , H O, CO, and CH in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model.

关键词： transimissity     HITEMP     HITRAN     Planck mean absorption coefficients    

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微分和表观静摩擦系数的表式

王渭源

《中国工程科学》 2001年 第3卷 第8期   页码 29-32

摘要：

当前，工程师和科学家都对微牛和纳牛量级载荷静摩擦系数（以下简称微牛纳牛静摩擦系数）很感兴趣。但文献中至今没有详细讨论过微牛纳牛静摩擦系数与载荷的关系，而且发表的实验结果都不相互讨论。从微分静摩擦系数的定义出发，导出几种典型模型下微分静摩擦系数和表观静摩擦系数的表式，并据此广泛讨论这些文献中的实验结果。

关键词： 微分静摩擦系数     微牛纳牛静摩擦系数     表观静摩擦系数     宏观静摩擦系数    

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Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

《化学科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 190-194 doi: 10.1007/s11705-007-0035-3

摘要： The separations of olefin/paraffin, aromatic/aliphatic hydrocarbons or olefin isomers using ionic liquids instead of volatile solvents have interested many researchers. Activity coefficients γ at infinite dilution of a solute in ionic liquid are generally used in the selection of solvents for extraction or extractive distillation. In fact, the measurement of γ by gas-liquid chromatography is a speedy and cost-saving method. Activity coefficients at infinite dilution of hydrocarbon solutes, such as alkanes, hexenes, alkylbenzenes, styrene, in 1-allyl-3-methylimidazolium tetrafluoroborate ([AMIM][BF]) and 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ([MPMIM][BF]) and [MPMIM][BF]-AgBF have been determined by gas-liquid chromatography using ionic liquids as stationary phase. The measurements were carried out at different temperatures from 298 to 318 K. The separating effects of these ionic liquids for alkanes/hexane, aliphatic hydrocarbons/benzene and hexene isomers have been discussed. The hydrophobic parameter, dipole element, frontier molecular orbital energy gap and hydration energy of these hydrocarbons were calculated with the PM3 semi-empirical quantum chemistry method. The quantitative relations among the computed structure parameters and activity coefficients at infinite dilution were also developed. The experimental activity coefficient data are consistent with the correlated and predicted results using QSPR models.

关键词： cost-saving     consistent     coefficient     measurement     separating    

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Effect of friction coefficients on the dynamic response of gear systems

Lingli JIANG, Zhenyong DENG, Fengshou GU, Andrew D. BALL, Xuejun LI

《机械工程前沿（英文）》 2017年 第12卷 第3期   页码 397-405 doi: 10.1007/s11465-017-0415-4

摘要：

The inevitable deterioration of the lubrication conditions in a gearbox in service can change the tribological properties of the meshing teeth. In turn, such changes can significantly affect the dynamic responses and running status of gear systems. This paper investigates such an effect by utilizing virtual prototype technology to model and simulate the dynamics of a wind turbine gearbox system. The change in the lubrication conditions is modeled by the changes in the friction coefficients, thereby indicating that poor lubrication causes not only increased frictional losses but also significant changes in the dynamic responses. These results are further demonstrated by the mean and root mean square values calculated by the simulated responses under different friction coefficients. In addition, the spectrum exhibits significant changes in the first, second, and third harmonics of the meshing components. The findings and simulation method of this study provide theoretical bases for the development of accurate diagnostic techniques.

关键词： dynamic response     friction coefficient     wind loads     wind turbine gearbox    

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Temperature variation of concrete box girder bridge

Jian WANG, Zhi FANG,

《结构与土木工程前沿（英文）》 2009年 第3卷 第4期   页码 407-413 doi: 10.1007/s11709-009-0053-y

摘要： On the basis of theoretical analysis and measurement on site, the temperature gradients and its variation on concrete box girder bridges resulting from ambient temperature, solar radiation, and structural temperature fields were discussed. With the help of the heat transfer theory and finite element method (FEM), the heat flux of the surface of concrete box girder was carried out, and all the heat fluxes were described as the convection. The results were compared with that from field measurements, and a good correlation was found. It was revealed that the methods, the parameters, the boundary condition used in this paper were reasonable. Last, some conclusions were obtained, which could provide the basis for box girder design under solar radiation.

关键词： temperature     transfer     correlation     radiation     variation    

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Assessment of liver volume variation to evaluate liver function

null

《医学前沿（英文）》 2012年 第6卷 第4期   页码 421-427 doi: 10.1007/s11684-012-0223-5

摘要：

In order to assess the value of liver volumetry in cirrhosis and acute liver failure (ALF) patients, we explored the correlation between hepatic volume and severity of the hepatic diseases. The clinical data of 48 cirrhosis patients with 60 normal controls and 39 ALF patients were collected. Computed tomography-derived liver volume (CTLV) and body surface area (BSA) of normal controls were calculated to get a regression formula for standard liver volume (SLV) and BSA. Then CTLV and SLV of all patients were calculated and grouped by Child-Turcotte-Pugh classification for cirrhosis patients and assigned according to prognosis of ALF patients for further comparison. It turned out that the mean liver volume of the control group was 1 058±337 cm3. SLV was correlated with BSA according to the regression formula. The hepatic volume of cirrhosis patients in Child A, B level was not reduced, but in Child C level it was significantly reduced with the lowest liver volume index (CTLV/SLV). Likewise, in the death group of ALF patients, the volume index was significantly lower than that of the survival group. Based on volumetric study, we proposed an ROC (receiver operating characteristic) analysis to predict the prognosis of ALF patients that CTLV/SLV<83.9% indicates a poor prognosis. In conclusion, the CTLV/SLV ratio, which reflects liver volume variations, correlates well with the liver function and progression of cirrhosis and ALF. It is also a very useful marker for predicting the prognosis of ALF.

关键词： liver volume variation     cirrhosis     acute liver failure (ALF)    

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arsenic trioxide on proliferation and apoptosis of U266 cells and its relationship with the expression variation

ZHAN Rong, YU Qinghong, HUANG Haobo

《医学前沿（英文）》 2008年 第2卷 第4期   页码 356-360 doi: 10.1007/s11684-008-0068-0

摘要： The aim of this article is to explore the effect of arsenic trioxide (AsO) on the proliferation and apoptosis of myeloma cell line U266 and its relationship with the expression variation of vascular endothelial growth factor (VEGF). The viability and apoptosis of U266 cells were observed by methylthiazolyl- tetrazolium (MTT) assay and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The effect of AsO on the VEGF expression of U266 cells were tested by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR) analysis. We found that AsO could significantly inhibit the growth of U266 cells, and the concentration for 50% growth inhibition (IC) was 2 ?mol/L. After treatment with 2, 5, 10 ?mol/L AsO for 36 hours, dose-dependent apoptosis of U266 cells was observed. After treatment with 2, 5, 10 ?mol/L AsO for 72 hours, a dose-dependent reduction of VEGF in the supernatant of U266 cells culture was found. As far as single cells are concerned, nevertheless, the expression of VEGF mRNA did not vary. So we draw the conclusion that AsO could induce the apoptosis of U266 cells and inhibit their proliferation, decrease the tumor load, and lead to the reduction of VEGF in the culture supernatant, but not change the expression of VEGF in single U266 cells.

关键词： VEGF expression     expression variation     culture supernatant     labeling     concentration    

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Temporal variation of heavy metal pollution in urban stormwater runoff

Wen LI, Zhenyao SHEN, Tian TIAN, Ruimin LIU, Jiali QIU

《环境科学与工程前沿（英文）》 2012年 第6卷 第5期   页码 692-700 doi: 10.1007/s11783-012-0444-5

摘要： Stormwater runoff from three types of urban surfaces, a parking lot, a street, and a building roof, was monitored during four rainfall events that occurred in the one-year period from June 2009 to June 2010. The event mean concentrations (EMC) of dissolved copper (Cu), lead (Pb), zinc (Zn), manganese (Mn), and iron (Fe) exceeded China’s National Water Quality Standards for Surface Water. The degree of heavy metal contamination was related to the type of underlying surfaces. Additionally, the concentration of dissolved heavy metals peaked shortly after the runoff began and then declined sharply as a result of adequate flushing. First flush effects of varying degrees were also observed during all of the monitored rainfall events based on the first flush ratio ( ). Redundancy analysis revealed that four environmental variables (rainfall depth, intensity, antecedent dry weather period and type of underlying surface) had significant effects on the strengths of the first flush effects, accounting for 72.9% of the variation in the . Dissolved metals presented varying first flush effects on different underlying surfaces that occurred in the following relative order: parking lot>roof>road for low intensity and high runoff volume rainfall events; parking lot>road>roof for high intensity and low runoff volume events. The relative strength of the first flush for dissolved heavy metals was Fe, Mn>Cu, Zn>Pb.

关键词： urban stormwater     heavy metal pollution     temporal variation     event mean concentration     first flush effect     redundancy analysis    

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RESPONSE OF WHEAT COMPOSITE CROSS POPULATIONS TO DISEASE AND CLIMATE VARIATION OVER 13 GENERATIONS

《农业科学与工程前沿（英文）》 2021年 第8卷 第3期   页码 400-415 doi: 10.15302/J-FASE-2021394

摘要：

Since the F5 (2005), three winter wheat composite cross populations (CCPs) based on germplasm specifically suitable for low-input conditions were subjected to natural selection under organic and conventional management. In the F6, each CCP was divided into two parallel populations (12 CCPs in total) and maintained continuously until 2018. Commonly used modern cultivars with different disease susceptibilities were grown alongside to assess the agronomic performance of the CCPs. The organically managed CCPs were comparable in yield and foliar disease resistance to two continuously used reference cultivars, Achat and Capo. In contrast, under conventional management the cv. Capo outyielded the CCPs (Achat was not tested), highlighting the importance of parental cultivar choice for specific management systems. The CCPs were found to be moderately resistant to brown rust and even to the newly emerged stripe rust races prevalent in Europe since 2011. Differences between the CCPs were mainly due to parental genetic background and were significant in the first five generations, but were no longer so in the last five generations. In addition, these differences tended to vary depending on the experimental year and the environmental stresses present. In conclusion, the CCPs despite being derived from older cultivars are able to compete with more recently released reference cultivars under organic farming practices and represent a dynamic germplasm resource.

 

关键词： evolutionary breeding     heterogeneous crop population     management system    

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Erratum to: Meter-scale variation within a single transect demands attention to taxon accumulation curves

《环境科学与工程前沿（英文）》 2022年 第16卷 第6期 doi: 10.1007/s11783-022-1560-5

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Short-term effect of temperature variation on the competition between PAOs and GAOs during acclimation

Nanqi REN, Han KANG, Xiuheng WANG, Nan LI

《环境科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 277-282 doi: 10.1007/s11783-010-0226-x

摘要： Sequencing batch reactor (SBR) for enhanced biological phosphorus removal (EBPR) processes was used to investigate the impact of the temperature shock on the competition between phosphorus-accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) in start-up stage. During the 34 days operation, SBR was set with temperature variation(0–5 d, 22±1°C; 6–13 d, 29±1°C; 14–34 d, 14±1°C). PAOs and GAOs were analyzed by fluorescent in situ hybridization (FISH), and intracellular polyphosphate granules were stained by Neisser-stain. The results showed that the influence of temperature shock on PAOs’ abundance was more serious than that on GAOs in the enriching process. Under sudden and substantially temperature variation, from 22±1°C to 29±1°C and then to 14±1°C, the domination of PAOs was deteriorated. After temperature shock, PAOs’ competitive advantages at low temperature that concluded in other study did not appear in our study. As mesophilic, GAOs (indicated by and ) were more temperature adaptive and better grew and took the domination at 14±1°C in the end. In the competition process, organisms of tetrad forming organisms (TFOs)-like shape which were considered as typical GAOs, were observed. With the evidence of poly-P granules containing by Neisser-straining and result of FISH, these organisms of TFOs-like shape were better to be assumed as adaption state or a special self-protecting shape of PAOs.

关键词： fluorescent in situ hybridization (FISH)     tetrad forming organisms (TFOs)     temperature variation     enhanced biological phosphorus removal (EBPR)    

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Multi-stage dual replica bit-line delay technique for process-variation-robust timing of lowvoltageSRAMsense

Shou-biao TAN,Wen-juan LU,Chun-yu PENG,Zheng-ping LI,You-wu TAO,Jun-ning CHEN

《信息与电子工程前沿（英文）》 2015年 第16卷 第8期   页码 700-706 doi: 10.1631/FITEE.1400439

摘要： A multi-stage dual replica bit-line delay (MDRBD) technique is proposed for reducing access time by suppressing the sense-amplifier enable (SAE) timing variation of low voltage static random-access memory (SRAM) applications. Compared with the traditional technique, this strategy, using statistical theory, reduces the timing variation by using multi-stage ideas, meanwhile doubling the replica bit-line (RBL) capacitance and discharge path simultaneously in each stage. At a supply voltage of 0.6 V, the simulation results show that the standard deviations of the SAE timing and cycle time with the proposed technique are 69.2% and 47.2%, respectively, smaller than that with a conventional RBL delay technique in TSMC 65 nm CMOS technology (Taiwan Semiconductor Manufacturing Company, Taiwan).

关键词： Process-variation-robust     Sense amplifier (SA)     Replica bit-line (RBL) delay     Timing variation    

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SPATIOTEMPORAL VARIATION OF WATER QUALITY AND ALGAL BIOMASS IN ERHAI LAKE AND ITS ENVIRONMENTAL MANAGEMENT

《农业科学与工程前沿（英文）》 2023年 第10卷 第4期   页码 566-578 doi: 10.15302/J-FASE-2023520

摘要：

Elucidating the spatiotemporal pattern of water quality and algal biomass is crucial for accurately tracing pollution sources and reducing the risk of algal blooms in lake systems. This study analyzed the spatiotemporal variability of water quality and algal biomass in Erhai Lake from 1994 to 2021 using water quality index (WQI), Mann-Kendall test and Sen’s slope combined methods. The potential causes of water quality deterioration and algal biomass dynamics were also elucidated. The results showed that the historical changes in the water environment of Erhai Lake mainly had three stages: satisfactory (1994‒2001), deteriorating (2002‒2010) and improving (2011‒2021). The changes in water quality and algal biomass were primarily affected by total nitrogen, total phosphorus and chemical oxygen demand in different stages. The water environment of Erhai Lake is currently improving significantly, starting in the southern area that is furthest from the sources of agricultural pollution, especially in summer and autumn. This is attributed to the implementation of control measures resulting in lower pollutant loads at particular times and places. Therefore, it is necessary to continue to promote standardized livestock farming, to strengthen rural wastewater collection and to investigate measures such as the interruption of the endogenous cycle.

关键词： Erhai Lake     control measures     water environment     water quality index (WQI)    

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标题 作者 时间 类型 操作

CHARACTERISTICS OF SOIL QUALITY ATTRIBUTES UNDER DIFFERENT AGROECOSYSTEMS AND ITS IMPLICATIONS FOR AGRICULTURE IN THE CHOKE MOUNTAIN WATERSHED IN ETHIOPIA

期刊论文

Experimental study of aerodynamic interference effects on aerostatic coefficients of twin deck bridges

Zhiwen LIU , Zhengqing CHEN , Gao LIU , Xinpeng SHAO ,

期刊论文

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

期刊论文

微分和表观静摩擦系数的表式

王渭源

期刊论文

Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

期刊论文

Effect of friction coefficients on the dynamic response of gear systems

Lingli JIANG, Zhenyong DENG, Fengshou GU, Andrew D. BALL, Xuejun LI

期刊论文

Temperature variation of concrete box girder bridge

Jian WANG, Zhi FANG,

期刊论文

Assessment of liver volume variation to evaluate liver function

null

期刊论文

arsenic trioxide on proliferation and apoptosis of U266 cells and its relationship with the expression variation

ZHAN Rong, YU Qinghong, HUANG Haobo

期刊论文

Temporal variation of heavy metal pollution in urban stormwater runoff

Wen LI, Zhenyao SHEN, Tian TIAN, Ruimin LIU, Jiali QIU

期刊论文

RESPONSE OF WHEAT COMPOSITE CROSS POPULATIONS TO DISEASE AND CLIMATE VARIATION OVER 13 GENERATIONS

期刊论文

Erratum to: Meter-scale variation within a single transect demands attention to taxon accumulation curves

期刊论文

Short-term effect of temperature variation on the competition between PAOs and GAOs during acclimation

Nanqi REN, Han KANG, Xiuheng WANG, Nan LI

期刊论文

Multi-stage dual replica bit-line delay technique for process-variation-robust timing of lowvoltageSRAMsense

Shou-biao TAN,Wen-juan LU,Chun-yu PENG,Zheng-ping LI,You-wu TAO,Jun-ning CHEN

期刊论文

SPATIOTEMPORAL VARIATION OF WATER QUALITY AND ALGAL BIOMASS IN ERHAI LAKE AND ITS ENVIRONMENTAL MANAGEMENT

期刊论文