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A numerical study of non-Darcy flow in EGS heat reservoirs during heat extraction

Wenjiong CAO, Wenbo HUANG, Guoling WEI, Yunlong JIN, Fangming JIANG

《能源前沿(英文)》 2019年 第13卷 第3期   页码 439-449 doi: 10.1007/s11708-019-0612-4

摘要: Underground non-Darcy fluid flow has been observed and investigated for decades in the petroleum industry. It is deduced by analogy that the fluid flow in enhanced geothermal system (EGS) heat reservoirs may also be in the non-Darcy regime under some conditions. In this paper, a transient 3D model was presented, taking into consideration the non-Darcy fluid flow in EGS heat reservoirs, to simulate the EGS long-term heat extraction process. Then, the non-Darcy flow behavior in water- and supercritical CO (SCCO )-based EGSs was simulated and discussed. It is found that non-Darcy effects decrease the mass flow rate of the fluid injected and reduce the heat extraction rate of EGS as a flow resistance in addition to the Darcy resistance which is imposed to the seepage flow in EGS heat reservoirs. Compared with the water-EGS, the SCCO -EGS are more prone to experiencing much stronger non-Darcy flow due to the much larger mobility of the SCCO . The non-Darcy flow in SCCO - EGSs may thus greatly reduce their heat extraction performance. Further, a criterion was analyzed and proposed to judge the onset of the non-Darcy flow in EGS heat reservoirs. The fluid flow rate and the initial thermal state of the reservoir were taken and the characteristic Forchheimer number of an EGS was calculated. If the calculated Forchheimer number is larger than 0.2, the fluid flow in EGS heat reservoirs experiences non-negligible non-Darcy flow characteristic.

关键词: enhanced geothermal system     non-Darcy flow     heat extraction     Reynolds number     Forchheimer number    

Estimating the number of Chinese cancer patients eligible for and benefit from immune checkpoint inhibitors

《医学前沿(英文)》 2022年 第16卷 第5期   页码 773-783 doi: 10.1007/s11684-021-0902-1

摘要: The total number of cancer patients who are eligible for and will benefit from immune checkpoint inhibitors (ICIs) in China has not been quantified. This cross-sectional study was conducted to estimate the number of Chinese cancer patients with eligibility and response to ICIs based on the 2015 Chinese cancer statistics and the immune checkpoint inhibitor clinical practice guideline of the Chinese Society of Clinical Oncology. A total of 11 ICIs were recommended for 17 cancer types. The estimated number of eligible patients annually was 1 290 156 (55.18%), which included 888 738 males (60.05%) and 400 468 females (46.67%). The estimated number of responders annually was 448 972 (19.20%), which included 309 023 males (20.88%) and 139 764 females (16.29%). Gastric cancer (n=291 000, 12.45%), non-small-cell lung cancer (n=289 629, 12.39%), and hepatocellular carcinoma (n=277 100, 11.85%) were the top three cancer types with the highest number of eligible patients. Non-small-cell lung cancer (n=180 022, 7.70%), hepatocellular carcinoma (n=75 648, 3.24%), and small-cell lung cancer (n=64 362, 2.75%) were the top three cancer types with the highest number of responders. In conclusion, ICIs provide considerable benefit in Chinese cancer patients under optimal estimation.

关键词: benefit     China     eligibility     immune checkpoint inhibitor     public health    

Identification of structural parameters and boundary conditions using a minimum number of measurement

Ali KARIMPOUR, Salam RAHMATALLA

《结构与土木工程前沿(英文)》 2020年 第14卷 第6期   页码 1331-1348 doi: 10.1007/s11709-020-0686-4

摘要: This article proposes a novel methodology that uses mathematical and numerical models of a structure to build a data set and determine crucial nodes that possess the highest sensitivity. Regression surfaces between the structural parameters and structural output features, represented by the natural frequencies of the structure and local transmissibility, are built using the numerical data set. A description of a possible experimental application is provided, where sensors are mounted at crucial nodes, and the natural frequencies and local transmissibility at each natural frequency are determined from the power spectral density and the power spectral density ratios of the sensor responses, respectively. An inverse iterative process is then applied to identify the structural parameters by matching the experimental features with the available parameters in the myriad numerical data set. Three examples are presented to demonstrate the feasibility and efficacy of the proposed methodology. The results reveal that the method was able to accurately identify the boundary coefficients and physical parameters of the Euler-Bernoulli beam as well as a highway bridge model with elastic foundations using only two measurement points. It is expected that the proposed method will have practical applications in the identification and analysis of restored structural systems with unknown parameters and boundary coefficients.

关键词: structural model validation     eigenvalue problem     response surface     inverse problems    

Influence of cetane number improver on performance and emissions of a common-rail diesel engine fueled

Wu YU, Gen CHEN, Zuohua HUANG

《能源前沿(英文)》 2011年 第5卷 第4期   页码 412-418 doi: 10.1007/s11708-011-0163-9

摘要: In this paper, the effect of cetane number (CN) improver on performance and emissions, including particulate number concentration and size distribution, of a turbocharged, common-rail diesel engine fueled with biodiesel-methanol were studied. Two volume fractions (0.3% and 0.6%) of CN improver were added to BM30 (30% of methanol in the biodiesel-methanol blend) in the experiment. The results show that, compared with those of biodiesel-methanol blend, the peak value of cylinder pressure increases, the second peak of heat release rate decreases, the start of second heat release are advanced, and the fuel economy and thermal efficiency are improved when CN improver is added to biodiesel-methanol blend. Besides, CO and HC emissions decrease, NO emission varies little and smoke emissions increase slightly. Moreover, exhaust particles of BM30 mainly distribute in nano-size range. Furthermore, particle number concentration decreases and peak of size distribution profile shifts toward large size direction.

关键词: biodiesel     methanol     common-rail (CR) diesel engine     cetane number (CN) improver    

Forecast method for used number of parts and components based on complex network

LIU Fu-yun, QI Guo-ning, YANG Qing-hai

《机械工程前沿(英文)》 2006年 第1卷 第4期   页码 479-484 doi: 10.1007/s11465-006-0064-5

摘要: Applying directed complex network to model the main structure of a product family, according to in-degree bi-logarithmic coordinate distribution curve and distribution rule of nodes of the network, in-degree evolving rule of nodes of the network is presented and analytic expression of in-degree probability density of nodes is derived. Through the analysis of the relation between existing kinds of components and existing product numbers, an expression of the relation between kinds of components and product numbers is derived. A forecast method for the increment of component numbers and parts based on the increment of products is presented. As an example, the component numbers of an industrial steam turbine product family is forecasted, forecast result verified and forecast error analyzed.

关键词: complex network     industrial     component     analytic expression     forecast    

MPC-based interval number optimization for electric water heater scheduling in uncertain environments

Jidong WANG, Chenghao LI, Peng LI, Yanbo CHE, Yue ZHOU, Yinqi LI

《能源前沿(英文)》 2021年 第15卷 第1期   页码 186-200 doi: 10.1007/s11708-019-0644-9

摘要: In this paper, interval number optimization and model predictive control are proposed to handle the uncertain-but-bounded parameters in electric water heater load scheduling. First of all, interval numbers are used to describe uncertain parameters including hot water demand, ambient temperature, and real-time price of electricity. Moreover, the traditional thermal dynamic model of electric water heater is transformed into an interval number model, based on which, the day-ahead load scheduling problem with uncertain parameters is formulated, and solved by interval number optimization. Different tolerance degrees for constraint violation and temperature preferences are also discussed for giving consumers more choices. Furthermore, the model predictive control which incorporates both forecasts and newly updated information is utilized to make and execute electric water heater load schedules on a rolling basis throughout the day. Simulation results demonstrate that interval number optimization either in day-ahead optimization or model predictive control format is robust to the uncertain hot water demand, ambient temperature, and real-time price of electricity, enabling customers to flexibly adjust electric water heater control strategy.

关键词: electric water heater     load scheduling     interval number optimization     model predictive control     uncertainty    

involved in nitrogen cycling in wastewater treatment plants using DNA microarray and most probable number-PCR

Junqin PANG, Masami MATSUDA, Masashi KURODA, Daisuke INOUE, Kazunari SEI, Kei NISHIDA, Michihiko IKE

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0846-x

摘要: Nitrogen-cycling microbial communities in municipal WWTPs were characterized. Numbers of , and genes were quantified by MPN-PCR. Diversity of whole nitrogen-cycling communities was analyzed with DNA microarray. CAS process retained diverse nitrogen cycling populations. Specific, limited populations may be dominated in nitrogen removal processes. To improve nitrogen removal performance of wastewater treatment plants (WWTPs), it is essential to understand the behavior of nitrogen cycling communities, which comprise various microorganisms. This study characterized the quantity and diversity of nitrogen cycling genes in various processes of municipal WWTPs by employing two molecular-based methods:most probable number-polymerase chain reaction (MPN-PCR) and DNA microarray. MPN-PCR analysis revealed that gene quantities were not statistically different among processes, suggesting that conventional activated sludge processes (CAS) are similar to nitrogen removal processes in their ability to retain an adequate population of nitrogen cycling microorganisms. Furthermore, most processes in the WWTPs that were researched shared a pattern:the and the bacterial genes were more abundant than the and archaeal genes, respectively. DNA microarray analysis revealed that several kinds of nitrification and denitrification genes were detected in both CAS and anaerobic-oxic processes (AO), whereas limited genes were detected in nitrogen removal processes. Results of this study suggest that CAS maintains a diverse community of nitrogen cycling microorganisms; moreover, the microbial communities in nitrogen removal processes may be specific.

关键词: DNA microarray analysis     Nitrogen cycling functional genes     Most probable number-polymerase chain reaction (MPN-PCR)     Wastewater treatment plants (WWTPs)    

灰数灰度的一种公理化定义

刘思峰,林益

《中国工程科学》 2004年 第6卷 第8期   页码 91-94

摘要:

基于对已有的几种灰数灰度定义的讨论,建立了灰数灰度定义的公理系统;以灰数灰度定义公理为准绳,由灰数产生的背景或论域及灰数取数域的测度构造出一种新的灰数灰度定义式。新定义克服了原有定义中存在的问题,较为科学地描述了灰数的不确定程度。

关键词: 灰色系统     灰数灰度     测度     公理化定义    

基于区间数的多指标灰靶决策模型的研究

党耀国,刘思峰,刘斌

《中国工程科学》 2005年 第7卷 第8期   页码 31-35

摘要:

现实生活中遇到的许多问题都具有不确定性,使得在对系统进行决策评估时,指标值难以精确化。在此情形下,人们常常对指标值给出一个区间,到目前为止, 尚未有人研究区间数灰靶决策。首先定义了区间数、m维区间数的距离及其距离性质,并证明了当区间数为实数时,区间数距离就是实数距离的推广;提出了区间数规范化方法,在此基础上, 建立了基于区间数的灰靶决策模型,从而把灰靶决策模型由实数序列拓展到区间数序列,使灰靶决策理论得到发展,同时为扩大灰靶决策的应用领域提供了理论根据。最后以实例验证了该模型的有效性与实用性。

关键词: 区间数     灰靶决策     模型     应用    

Relationship between the number of tapping-induced secondary laticifer lines and rubber yield among

Yueyi CHEN,Xinsheng GAO,Xiaofei ZHANG,Weimin TIAN

《农业科学与工程前沿(英文)》 2016年 第3卷 第4期   页码 363-367 doi: 10.15302/J-FASE-2016122

摘要: The lack of suitable early selection parameters means that traditional rubber breeding for yield is time-consuming and inefficient. Laticifer is a tissue specific for natural rubber biosynthesis and storage in rubber tree. The number of the secondary laticifers in the trunk bark tissues is positively correlated with rubber yield in the matured rubber trees that are regularly tapped. In the present study, the rubber yield from 280 of 4–5 year-old virgin trees from 7 cross combinations was compared with the number of newly differentiated secondary laticifers caused by tapping. Results showed that the number of tapping-induced lines of secondary laticifers varied in different germplasm and was positively related to the rubber yield, indicating this could be used as a suitable parameter for early evaluation of yield potential of rubber trees.

关键词: Hevea brasiliensis     rubber yield breeding     early evaluation     tapping     secondary laticifer differentiation    

基于Z数的TODIM与TOPSIS方法 None

Renato A. KROHLING, André G. C. PACHECO, Guilherme A. dos SANTOS

《信息与电子工程前沿(英文)》 2019年 第20卷 第2期   页码 283-291 doi: 10.1631/FITEE.1700434

摘要: 提出一种针对多标准决策问题处理Z数的方法。使用模糊数A和B的有序对Z=(A, B)定义Z数,其中A是兴趣变量的语言值,B是A的概率测度语言值。人类通过自然语言进行交流,使用这样的句子如“从家到大学大约需要半小时”。将Z数转化为模糊数,Z-TODIM和Z-TOPSIS分别是模糊TODIM和模糊TOPSIS的直接扩展。将提出的方法应用于两个案例并与使用精确数的标准方法比较,结果证明其可行。

关键词: 多标准决策;TODIM;TOPSIS;模糊数;Z数    

通过一个等价雷诺数揭示层流到湍流的转捩区域 Article

陈晓东

《工程(英文)》 2019年 第5卷 第3期   页码 576-579 doi: 10.1016/j.eng.2018.09.013

摘要:

Flow transition from laminar to turbulent mode (and vice versa)—that is, the initiation of turbulence—is one of the most important research subjects in the history of engineering. Even for pipe flow, predicting the onset of turbulence requires sophisticated instrumentation and/or direct numerical simulation, based on observing the instantaneous flow structure formation and evolution. In this work, a local Reynolds number equivalence γ (ratio of local inertia effect to viscous effect) is seen to conform to the Universal Law of the Wall, where γ = 1 represents a quantitative balance between the abovementioned two effects. This coincides with the wall layer thickness (y+ = 1, where y+ is the dimensionless distance from the wall surface defined in the Universal Law of the Wall). It is found that the characteristic of how the local derivative of γ against the local velocity changes with increasing velocity determines the onset of turbulence. For pipe flow, γ  25, and for plate flow, γ 151.5. These findings suggest that a certain combination of γ and velocity (nonlinearity) can qualify the source of turbulence (i.e., generate turbulent energy). Similarly, a re-evaluation of the previous findings reveals that only the geometrically narrow domain can act locally as the source of turbulence, with the rest of the flow field largely being left for transporting and dissipating. This understanding will have an impact on the future large-scale modeling of turbulence.

关键词: 局部等价雷诺数     转捩     壁面律     管流     平板流动     建模    

Genome-wide search for candidate genes determining vertebrae number in pigs

Longchao ZHANG, Jingwei YUE, Xin LIU, Jing LIANG, Kebin ZHAO, Hua YAN, Na LI, Lei PU, Yuebo ZHANG, Huibi SHI, Ligang WANG, Lixian WANG

《农业科学与工程前沿(英文)》 2017年 第4卷 第3期   页码 327-334 doi: 10.15302/J-FASE-2017163

摘要: Longer porcine carcasses may be expected to have more vertebrae. Therefore, vertebrae number in pigs is an economically important trait. To examine the genetic basis of this trait, we genotyped 578 F Large White × Minzhu pigs using the Porcine SNP60K BeadChip. A genome-wide association study (GWAS) identified 36 significant single nucleotide polymorphisms (SNPs) on the chromosomes SSC1 (294.28–300.32 Mb) and SSC7 (102.22–109.39 Mb). A 6.04-Mb region that contained all 13 significant SNPs on SSC1 also contained the gene , previously reported to influence the number of vertebrae in pigs. However, the reported putative casual mutation of c.748C>T showed no genome-wide significant association with the trait, suggesting it was not a causal mutation in our population. The remaining 23 significant SNPs on SSC7 were concentrated in a 7.17-Mb region, which was within a quantitative trait locus interval for number of vertebrae. was the closest gene to the most significant SNP and might be a candidate. Haplotype sharing and block analysis refined the QTL to an interval of about 3 Mb containing 29 candidate genes. Of these 29 genes, the previously reported possible casual mutation of g.19034A>C was not found to be a causal mutation in our population. Exploration of these genes via additional genetic and functional studies in mammals revealed that could be a good candidate on SSC7. A mutation of c.1749G>A was detected by GWAS and could be proposed as a candidate causal mutation, or as closely linked to a causal mutation, for the number of vertebrae in pigs.

关键词: genome-wide association study     number of vertebrae     pig     SSC7     TGFβ3    

Thermodynamic performance experiment and cooling number calculation of a counter-flow spray humidifier

WANG Yuzhang, LI Yixing, WENG Shilie, WANG Yonghong

《能源前沿(英文)》 2008年 第2卷 第1期   页码 43-47 doi: 10.1007/s11708-008-0005-6

摘要: An experimental investigation of the thermodynamic performance of a counter-flow spray humidifier was conducted on the basis of theoretical analysis of the heat and mass transfer mechanism inside the humidifier. Critical parameters such as the temperature and relative humidity of air and the temperature of water at the inlet and outlet were measured. The influence of every measured parameter on the thermal performance of the humidifier was obtained under different experimental conditions. The cooling number, whose variation was also obtained, was calculated according to the measured data. The experimental results show that both the temperature and the temperature increment of outlet humid air and the temperature of outlet water increase with an increase of the water-gas ratio, whereas the cooling number decreases. Under all experimental conditions, the outlet humid air reaches or is close to the saturation level. The lower cooling number is favorable for the system, but it has an optimal value for a certain humidifier.

关键词: temperature increment     counter-flow     experimental investigation     temperature     water-gas    

Time reversal method for guided wave inspection in pipes

DENG Fei, WU Bin, HE Cunfu

《机械工程前沿(英文)》 2008年 第3卷 第3期   页码 251-260 doi: 10.1007/s11465-008-0050-1

摘要: The application of the time reversal method in pipe-like structures based on finite element method (FEM) is investigated. A steel pipe model measuring 70 mm × 3.5 mm is used to analyze the reflection coefficient of the (0,2) mode with the time reversal process. Simulation results show that the time reversal array method is beneficial to the improvement of the signal-to-noise ratio of a guided wave inspection system. As the intercepting window is widened, more energy is included in re-emitted signals, which leads to a large reflection coefficient of the (0,2) mode. In parallel, a circumferential locating method based on the time reversal method is described. The time reversal process used for guided wave inspection leads to the temporal and spatial focusing. When the time reversal signals are re-emitted, the angular profile obtained at the axial location of the defect can be used to determine the circumferential location of the defect. Except for a pipe with one defect, the circumferential locating method has been verified on another pipe model with two defects. Meanwhile, the elements number of the time reversal array has been discussed for enhancing the discrimination of the defect circumferential location.

关键词: reversal process     beneficial     circumferential location     energy     number    

标题 作者 时间 类型 操作

A numerical study of non-Darcy flow in EGS heat reservoirs during heat extraction

Wenjiong CAO, Wenbo HUANG, Guoling WEI, Yunlong JIN, Fangming JIANG

期刊论文

Estimating the number of Chinese cancer patients eligible for and benefit from immune checkpoint inhibitors

期刊论文

Identification of structural parameters and boundary conditions using a minimum number of measurement

Ali KARIMPOUR, Salam RAHMATALLA

期刊论文

Influence of cetane number improver on performance and emissions of a common-rail diesel engine fueled

Wu YU, Gen CHEN, Zuohua HUANG

期刊论文

Forecast method for used number of parts and components based on complex network

LIU Fu-yun, QI Guo-ning, YANG Qing-hai

期刊论文

MPC-based interval number optimization for electric water heater scheduling in uncertain environments

Jidong WANG, Chenghao LI, Peng LI, Yanbo CHE, Yue ZHOU, Yinqi LI

期刊论文

involved in nitrogen cycling in wastewater treatment plants using DNA microarray and most probable number-PCR

Junqin PANG, Masami MATSUDA, Masashi KURODA, Daisuke INOUE, Kazunari SEI, Kei NISHIDA, Michihiko IKE

期刊论文

灰数灰度的一种公理化定义

刘思峰,林益

期刊论文

基于区间数的多指标灰靶决策模型的研究

党耀国,刘思峰,刘斌

期刊论文

Relationship between the number of tapping-induced secondary laticifer lines and rubber yield among

Yueyi CHEN,Xinsheng GAO,Xiaofei ZHANG,Weimin TIAN

期刊论文

基于Z数的TODIM与TOPSIS方法

Renato A. KROHLING, André G. C. PACHECO, Guilherme A. dos SANTOS

期刊论文

通过一个等价雷诺数揭示层流到湍流的转捩区域

陈晓东

期刊论文

Genome-wide search for candidate genes determining vertebrae number in pigs

Longchao ZHANG, Jingwei YUE, Xin LIU, Jing LIANG, Kebin ZHAO, Hua YAN, Na LI, Lei PU, Yuebo ZHANG, Huibi SHI, Ligang WANG, Lixian WANG

期刊论文

Thermodynamic performance experiment and cooling number calculation of a counter-flow spray humidifier

WANG Yuzhang, LI Yixing, WENG Shilie, WANG Yonghong

期刊论文

Time reversal method for guided wave inspection in pipes

DENG Fei, WU Bin, HE Cunfu

期刊论文