资源类型

期刊论文 799

会议视频 32

年份

2024 1

2023 48

2022 94

2021 64

2020 57

2019 47

2018 41

2017 58

2016 30

2015 36

2014 36

2013 30

2012 28

2011 27

2010 24

2009 36

2008 34

2007 50

2006 23

2005 14

展开 ︾

关键词

仿真 7

农业科学 6

质量控制 6

控制 5

智能控制 4

能源 4

主动控制 3

模糊控制 3

环境 3

神经网络 3

自适应控制 3

解耦控制 3

风险控制 3

2021全球十大工程成就 2

2022全球工程前沿 2

三峡升船机 2

三峡工程 2

不确定性 2

中药 2

展开 ︾

检索范围：

排序： 展示方式：

Precision control system of two-DOF stage with linear ultrasonic motor

ZHANG Hanlei, SHI Yunlai, ZHAO Chunsheng

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 421-425 doi: 10.1007/s11465-008-0063-9

摘要： Using an appropriate control method, linear ultrasonic motors can be used in applications requiring high position accuracy. In this paper, a closed loop PI control system is designed to achieve high position accuracy during the control of a two-DOF stage driven by linear ultrasonic motors. Two ultrasonic motors are mounted on the stage to generate motion in two orthogonal directions. The PI control algorithm is used to increase the stability and accuracy of position control. The -axis mover covers 30 mm forward and backward in less than 0.3 s settling time and the -axis mover in less than 0.4 s. Experimental results denote that the control strategy proposed in this paper appears to have high efficiency, quick response, and high accuracy.

关键词： settling     position accuracy     PI control     control algorithm     orthogonal    

HTML PDF 收藏

Performance of PI controller for control of active and reactive power in DFIG operating in a grid-connected

Azzouz TAMAARAT,Abdelhamid BENAKCHA

《能源前沿（英文）》 2014年 第8卷 第3期   页码 371-378 doi: 10.1007/s11708-014-0318-6

摘要： Due to several factors, wind energy becomes an essential type of electricity generation. The share of this type of energy in the network is becoming increasingly important. The objective of this work is to present the modeling and control strategy of a grid connected wind power generation scheme using a doubly fed induction generator (DFIG) driven by the rotor. This paper is to present the complete modeling and simulation of a wind turbine driven DFIG in the second mode of operating (the wind turbine pitch control is deactivated). It will introduce the vector control, which makes it possible to control independently the active and reactive power exchanged between the stator of the generator and the grid, based on vector control concept (with stator flux or voltage orientation) with classical PI controllers. Various simulation tests are conducted to observe the system behavior and evaluate the performance of the control for some optimization criteria (energy efficiency and the robustness of the control). It is also interesting to play on the quality of electric power by controlling the reactive power exchanged with the grid, which will facilitate making a local correction of power factor.

关键词： wind power     doubly fed induction generator (DFIG)     vector control     active power     reactive power     maximum power point tracking (MPPT)    

HTML PDF 收藏

纳卫星微型百叶窗热控技术研究及仿真

杨娟,李运泽,王浚

《中国工程科学》 2008年 第10卷 第7期   页码 169-172

摘要： 在球状纳卫星动态特性模型的基础上，提出了一种模 糊PI 混合控制方法。分别在舱内仪器散热增加和减少的工况下进行控制仿真。

关键词： 纳卫星     微型百叶窗     模糊PI 控制器     仿真    

HTML PDF 收藏

Modeling and control of a permanent magnet synchronous generator dedicated to standalone wind energy

Louar FATEH,Ouari AHMED,Omeiri AMAR,Djellad ABDELHAK,Bouras LAKHDAR

《能源前沿（英文）》 2016年 第10卷 第2期   页码 155-163 doi: 10.1007/s11708-016-0410-1

摘要： The interest for the use of renewable energies has increased, because of the increasing concerns of the environmental problems. Among renewable energies, wind energy is now widely used. Wind turbines based on an asynchronous generator with a wound rotor present the inconvenience of requiring a system of rings and brooms and a multiplier, inferring significant costs of maintenance. To limit these inconveniences, certain manufacturers developed wind turbines based on synchronous machines with large number of pairs of poles coupled directly with the turbine, avoiding using the multiplier. If the generator is equipped with permanent magnets, the system of rings and brooms is eliminated. The control of the permanent magnet synchronous generator (PMSG) can be affected with the implementation of various techniques of control. This paper presented a new approach mainly based on the control strategy of power production system based on the PMSG. In fact, a mathematical model that simulates the Matlab chain was established with the introduction of control techniques, such as direct control of the torque (DTC) to control the load side converter (LSC), the control of the speed of the turbine and the DC-bus voltage ensured by PI regulators. To show the performance of the correctors used, some simulation results of the system were presented and analyzed.

关键词： wind turbine     permanent magnet synchronous generator (PMSG)     converter     proportional-integral (PI)     control     direct control of the torque (DTC)     regulation    

HTML PDF 收藏

4Pi荧光超分辨显微术综述 Review

郝翔, 李依明, 傅爽, 李旸晖, 许迎科, 匡翠方, 刘旭

《工程（英文）》 2022年 第11卷 第4期   页码 146-153 doi: 10.1016/j.eng.2020.07.028

摘要： 回顾这些历程，一个重要的里程碑是基于两个对置物镜的4Pi 显微架构及其超分辨版本的出现。鉴于此，本文综述了4Pi 超分辨显微术的近期进展。总体上，4Pi 超分辨显微镜为透明样品观测提供了一
种能够突破衍射极限、非侵入、各向同性的三维分辨率的技术手段。具体而言，本文针对目标开关和随机开关两个主要4Pi 超分辨显微术版本，讨论了它们的架构、原理、应用和未来发展趋势。

关键词： 荧光超分辨显微术     超分辨成像     4Pi超分辨显微术     isoSTED     4Pi-SMLM    

HTML PDF 收藏

RGS16 regulated by let-7c-5p promotes glioma progression by activating PI3K-AKT pathway

《医学前沿（英文）》 2023年 第17卷 第1期   页码 143-155 doi: 10.1007/s11684-022-0929-y

摘要： Gliomas are the most common central nervous system tumours; they are highly aggressive and have a poor prognosis. RGS16 belongs to the regulator of G-protein signalling (RGS) protein family, which plays an important role in promoting various cancers, such as breast cancer, pancreatic cancer, and colorectal cancer. Moreover, previous studies confirmed that let-7c-5p, a well-known microRNA, can act as a tumour suppressor to regulate the progression of various tumours by inhibiting the expression of its target genes. However, whether RGS16 can promote the progression of glioma and whether it is regulated by miR let-7c-5p are still unknown. Here, we confirmed that RGS16 is upregulated in glioma tissues and that high expression of RGS16 is associated with poor survival. Ectopic deletion of RGS16 significantly suppressed glioma cell proliferation and migration both in vitro and in vivo. Moreover, RGS16 was validated as a direct target gene of miR let-7c-5p. The overexpression of miR let-7c-5p obviously downregulated the expression of RGS16, and knocking down miR let-7c-5p had the opposite effect. Thus, we suggest that the suppression of RGS16 by miR let-7c-5p can promote glioma progression and may serve as a potential prognostic biomarker and therapeutic target in glioma.

关键词： RGS16     let-7c-5p     glioma     proliferation     migration    

HTML PDF 收藏

THD reduction with reactive power compensation for fuzzy logic DVR based solar PV grid connected system

Akhil GUPTA,Saurabh CHANANA,Tilak THAKUR

《能源前沿（英文）》 2014年 第8卷 第4期   页码 464-479 doi: 10.1007/s11708-014-0307-9

摘要： Dynamic voltage restorer (DVR) is used to protect sensitive loads from voltage disturbances of the distribution generation (DG) system. In this paper, a new control approach for the 200 kW solar photovoltaic grid connected system with perturb and observe maximum power point tracking (MPPT) technique is implemented. Power quality improvement with comparison is conducted during fault with proportional integral (PI) and artificial intelligence-based fuzzy logic controlled DVR. MPPT tracks the actual variable DC link voltage while deriving the maximum power from a photovoltaic array and maintains DC link voltage constant by changing modulation index of the converter. Simulation results during fault show that the fuzzy logic based DVR scheme demonstrates simultaneous exchange of active and reactive power with less total harmonic distortion (THD) present in voltage source converter (VSC) current and grid current with fast tracking of optimum operating point at unity power factor. Standards (IEEE-519/1547), stipulates that the current with THD greater than 5% cannot be injected into the grid by any distributed generation source. Simulation results and validations of MPPT technique and operation of fuzzy logic controlled DVR demonstrate the effectiveness of the proposed control schemes.

关键词： fuzzy logic     maximum power point tracking (MPPT)     proportional integral (PI)     control     voltage restorer    

HTML PDF 收藏

Xiao Ke Qing improves glycometabolism and ameliorates insulin resistance by regulating the PI3K/Akt pathway

Xiaoqing Li, Xinxin Li, Genbei Wang, Yan Xu, Yuanyuan Wang, Ruijia Hao, Xiaohui Ma

《医学前沿（英文）》 2018年 第12卷 第6期   页码 688-696 doi: 10.1007/s11684-018-0662-8

摘要：

Xiao Ke Qing (XKQ) granule has been clinically used to treat type 2 diabetes mellitus (T2DM) for 10 years in Chinese traditional medication. However, its mechanisms against hyperglycemia remain poorly understood. This study aims to investigate XKQ mechanisms on diabetes and diabetic liver disease by using the KKAy mice model. Our results indicate that XKQ can significantly reduce food and water intake. XKQ treatment also remarkably decreases both the fasting blood glucose and blood glucose in the oral glucose tolerance test. Additionally, XKQ can significantly decrease the serum alanine aminotransferase level and liver index and can alleviate the fat degeneration in liver tissues. Moreover, XKQ can ameliorate insulin resistance and upregulate the expression of IRS-1, PI3K (p85), p-Akt, and GLUT4 in the skeletal muscle of KKAy mice. XKQ is an effective drug for T2DM by ameliorating insulin resistance and regulating the PI3K/Akt signaling pathway in the skeletal muscle.

关键词： XKQ     type 2 diabetes mellitus     KKAy mice     PI3K/Akt pathway     diabetic liver disease    

HTML PDF 收藏

Ultraviolet-B induced expression of hypoxia-inducible factor 1α, transferrin receptor through EGFR/PI3K

LI Yanhua, BI Zhigang

《医学前沿（英文）》 2007年 第1卷 第1期   页码 79-86 doi: 10.1007/s11684-007-0016-4

摘要： The aim of this research was to explore the effects and signaling pathway of ultraviolet-B (UVB) irradiation on the expression of hypoxia-inducible factor 1α (HIF-1α) and transferrin receptor (TfR). HIF-1α protein was measured by Western blot method. Expressions of epidermal growth factor receptor (EGFR), phosphor-EGF-R and TfR after UVB irradiation were determined with flow cytometry. After UVB irradiation, mRNA levels of HIF-1α and TfR were detected by real time-PCR. Results showed that compared with control groups, UVB was able to induce HIF1α and TfR protein expression in a dose- and time-dependent manner in HaCat cells (<0.05). TfR mRNA was expressed in a dose-dependent manner and reached a peak at the 8th hour in HaCat cells (<0.05) whereas HIF-1α mRNA expression was not affected by UVB treatment (>0.05). The EGFR/PI3K/AKT signaling pathway was required for the induction of HIF-1α and TfR expression induced by UVB. UVB induced activation of EGFR in HaCat cells and EGFR regulated expression of TfR and HIF-1α. EGFR (-/-) MEF did not increase the HIF1 expression following UVB irradiation (>0.05). In contrast, EGFR (+/+) MEF strongly enhanced HIF1α expression after UVB irradiation (<0.05). PD153035, a selective inhibitor of EGFR tyrosine kinase, inhibited the TfR protein expression in UVB-treated cells in a dose-dependent manner (P<0.05). PI3K inhibitors, LY294002 and wortmannin, inhibited HIF-1? and TfR expressions induced by UVB (P<0.05). The DEC1 (-/-) Ha-Cat cells did not increase their TfR and HIF-1α expressions following UVB irradiation (>0.05). In contrast, DEC1 (+/+) HaCat cells strongly enhanced TfR and HIF-1? protein expression after UVB irradiation (P<0.05). We conclude that UVB induces TfR and HIF-1αexpressions via EGFR/PI3K/AKT/DEC1 signaling pathway.
HTML PDF 收藏

Enhanced photoelectrochemical water splitting with a donor-acceptor polyimide

《能源前沿（英文）》 doi: 10.1007/s11708-023-0910-8

摘要： Polyimide (PI) has emerged as a promising organic photocatalyst owing to its distinct advantages of high visible-light response, facile synthesis, molecularly tunable donor-acceptor structure, and excellent physicochemical stability. However, the synthesis of high-quality PI photoelectrode remains a challenge, and photoelectrochemical (PEC) water splitting for PI has been less studied. Herein, the synthesis of uniform PI photoelectrode films via a simple spin-coating method was reported, and their PEC properties were investigated using melamine as donor and various anhydrides as acceptors. The influence of the conjugate size of aromatic unit (phenyl, biphenyl, naphthalene, perylene) of electron acceptor on PEC performance were studied, where naphthalene-based PI photoelectrode exhibited the highest photocurrent response. This is resulted from the unification of wide-range light absorption, efficient charge separation and transport, and strong photooxidation capacity. This paper expands the material library of polymer films for PEC applications and contributes to the rational design of efficient polymer photoelectrodes.

关键词： polyimide (PI) film     photoelectrochemistry     band structure engineering     aromatic unit    

HTML PDF 收藏

Effects of mulching for water conservation on soil carbon, nitrogen and biological properties

Xiaomin PI, Tongxun ZHANG, Benhua SUN, Quanhong CUI, Yun GUO, Mingxia GAO, Hao FENG, David W.

《农业科学与工程前沿（英文）》 2017年 第4卷 第2期   页码 146-154 doi: 10.15302/J-FASE-2017136

摘要： The effect of mulching with straw, white plastic film and black plastic film for improving soil water storage and on the soil properties was examined in a wheat-maize rotation system on Loess soil in northwestern China. All the mulches improved the water storage to some extent and led to warmer soils. However, the organic C and total N contents of the soils declined significantly under the mulches, particularly the plastic film mulches, and this could have long-term detrimental effects on soil quality and the sustainability of the some mulching practices.

关键词： biomass     carbon     mulch     nitrogen     plastic films     soil     straw     water storage    

HTML PDF 收藏

A 3D porous WP2 nanosheets@carbon cloth flexible electrode for efficient electrocatalytic hydrogen evolution

Mingyu Pi, Xiaodeng Wang, Dingke Zhang, Shuxia Wang, Shijian Chen

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 425-432 doi: 10.1007/s11705-018-1726-7

摘要：

Self-standing porous WP2 nanosheet arrays on carbon fiber cloth (WP2 NSs/CC) were synthesized and used as a 3D flexible hydrogen evolution electrode. Because of its 3D porous nanoarray structure, the WP2 NSs/CC exhibits a remarkable catalytic activity and a high stability. By using the experimental measurements and first-principle calculations, the underlying reasons for the excellent catalytic activity were further explored. Our work makes the present WP2 NSs as a promising electrocatalyst for hydrogen evolution and provides a way to design and fabricate efficient hydrogen evolution electrodes through 3D porous nano-arrays architecture.

关键词： WP2     nanosheet arrays     hydrogen evolution electrocatalyst     flexible electrode    

HTML PDF 收藏

Agent的PASS-BDI模型

樊玮,陈增强,袁著祉

《中国工程科学》 2004年 第6卷 第6期   页码 43-49

摘要： 将Das等人提出的计划—注意—同时性加工—继时性加工认知过程模型引入Agent的理论研究中，建立了Agent的PASS-BDI模型，利用多价&pi;-演算从心智状态，

关键词： 主体     π-演算     认知过程     心智状态    

HTML PDF 收藏

Structural parameter design method for a fast-steering mirror based on a closed-loop bandwidth

Guozhen CHEN, Pinkuan LIU, Han DING

《机械工程前沿（英文）》 2020年 第15卷 第1期   页码 55-65 doi: 10.1007/s11465-019-0545-y

摘要： When a fast-steering mirror (FSM) system is designed, satisfying the performance requirements before fabrication and assembly is vital. This study proposes a structural parameter design approach for an FSM system based on the quantitative analysis of the required closed-loop bandwidth. First, the open-loop transfer function of the FSM system is derived. In accordance with the transfer function, the notch filter and proportional-integral (PI) feedback controller are designed as a closed-loop controller. The gains of the PI controller are determined by maximizing the closed-loop bandwidth while ensuring the robustness of the system. Then, the two unknown variables of rotational radius and stiffness in the open-loop transfer function are optimized, considering the bandwidth as a constraint condition. Finally, the structural parameters of the stage are determined on the basis of the optimized results of rotational radius and stiffness. Simulations are conducted to verify the theoretical analysis. A prototype of the FSM system is fabricated, and corresponding experimental tests are conducted. Experimental results indicate that the bandwidth of the proposed FSM system is 117.6 Hz, which satisfies the minimum bandwidth requirement of 100 Hz.

关键词： fast-steering mirror     structural parameter     PI controller     bandwidth     notch filter    

HTML PDF 收藏

流感与COVID-19患者的免疫球蛋白G糖基化差异 Article

Marina Kljaković-Gašpić Batinjan, Tea Petrović, Frano Vučković, Irzal Hadžibegović, Barbara Radovani,

《工程（英文）》 2023年 第26卷 第7期   页码 54-62 doi: 10.1016/j.eng.2022.08.007

摘要：

The essential role of immunoglobulin G (IgG) in immune system regulation and combatting infectious diseases cannot be fully recognized without an understanding of the changes in its N-glycans attached to the asparagine 297 of the Fc domain that occur under such circumstances. These glycans impact the antibody stability, half-life, secretion, immunogenicity, and effector functions. Therefore, in this study, we analyzed and compared the total IgG glycome—at the level of individual glycan structures and derived glycosylation traits (sialylation, galactosylation, fucosylation, and bisecting N-acetylglucosamine (GlcNAc))—of 64 patients with influenza, 77 patients with coronavirus disease 2019 (COVID-19), and 56 healthy controls. Our study revealed a significant decrease in IgG galactosylation, sialylation, and bisecting GlcNAc (where the latter shows the most significant decrease) in deceased COVID-19 patients, whereas IgG fucosylation was increased. On the other hand, IgG galactosylation remained stable in influenza patients and COVID-19 survivors. IgG glycosylation in influenza patients was more time-dependent: In the first seven days of the disease, sialylation increased and fucosylation and bisecting GlcNAc decreased; in the next 21 days, sialylation decreased and fucosylation increased (while bisecting GlcNAc remained stable). The similarity of IgG glycosylation changes in COVID-19 survivors and influenza patients may be the consequence of an adequate immune response to enveloped viruses, while the observed changes in deceased COVID-19 patients may indicate its deviation.

关键词： 流行性感冒     COVID-19     病毒感染     糖基化     免疫球蛋白G     肺炎    

HTML PDF 收藏

标题 作者 时间 类型 操作

Precision control system of two-DOF stage with linear ultrasonic motor

ZHANG Hanlei, SHI Yunlai, ZHAO Chunsheng

期刊论文

Performance of PI controller for control of active and reactive power in DFIG operating in a grid-connected

Azzouz TAMAARAT,Abdelhamid BENAKCHA

期刊论文

纳卫星微型百叶窗热控技术研究及仿真

杨娟,李运泽,王浚

期刊论文

Modeling and control of a permanent magnet synchronous generator dedicated to standalone wind energy

Louar FATEH,Ouari AHMED,Omeiri AMAR,Djellad ABDELHAK,Bouras LAKHDAR

期刊论文

4Pi荧光超分辨显微术综述

郝翔, 李依明, 傅爽, 李旸晖, 许迎科, 匡翠方, 刘旭

期刊论文

RGS16 regulated by let-7c-5p promotes glioma progression by activating PI3K-AKT pathway

期刊论文

THD reduction with reactive power compensation for fuzzy logic DVR based solar PV grid connected system

Akhil GUPTA,Saurabh CHANANA,Tilak THAKUR

期刊论文

Xiao Ke Qing improves glycometabolism and ameliorates insulin resistance by regulating the PI3K/Akt pathway

Xiaoqing Li, Xinxin Li, Genbei Wang, Yan Xu, Yuanyuan Wang, Ruijia Hao, Xiaohui Ma

期刊论文

Ultraviolet-B induced expression of hypoxia-inducible factor 1α, transferrin receptor through EGFR/PI3K

LI Yanhua, BI Zhigang

期刊论文

Enhanced photoelectrochemical water splitting with a donor-acceptor polyimide

期刊论文

Effects of mulching for water conservation on soil carbon, nitrogen and biological properties

Xiaomin PI, Tongxun ZHANG, Benhua SUN, Quanhong CUI, Yun GUO, Mingxia GAO, Hao FENG, David W.

期刊论文

A 3D porous WP2 nanosheets@carbon cloth flexible electrode for efficient electrocatalytic hydrogen evolution

Mingyu Pi, Xiaodeng Wang, Dingke Zhang, Shuxia Wang, Shijian Chen

期刊论文

Agent的PASS-BDI模型

樊玮,陈增强,袁著祉

期刊论文

Structural parameter design method for a fast-steering mirror based on a closed-loop bandwidth

Guozhen CHEN, Pinkuan LIU, Han DING

期刊论文

流感与COVID-19患者的免疫球蛋白G糖基化差异

Marina Kljaković-Gašpić Batinjan, Tea Petrović, Frano Vučković, Irzal Hadžibegović, Barbara Radovani,

期刊论文