http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Xiaohong Zheng (검색결과 10 건)
- 무료
- 기관 내 무료
- 유료
-
-
Weijia Zheng,Runquan Huang,Meijin Lin,Fang Guo,YangQuan Chen,Xiaohong Wang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4
A fractional order sliding mode control (FOSMC) method is developed in this paper to deal with the control problem of permanent magnet synchronous motor (PMSM) speed servo system subject to multiple disturbances including model uncertainties, unknown constant disturbances and harmonic disturbances. The lumped exogenous disturbances and uncertainties of the PMSM speed servo are estimated by an improved disturbance observer (DO) and an extended state observer (ESO), respectively. Then, a novel FOSMC law is developed by incorporating the feedforward compensation and a fractional order switching law. The stability of the closed-loop system is established based on Lyapunov stability approach. Under the FOSMC scheme, the tracking performance and robustness of the PMSM servo system are improved simultaneously in the presence of mismatched disturbance torques and measurement noise. The effectiveness and advantages of the proposed method are demonstrated by the PMSM speed regulation experiments and the comparisons with some existing methods.
-
Synthesis of aminated calcium lignosulfonate and its adsorption properties for azo dyes
Yingying Wang,Linli Zhu,Xiaohong Wang,Wanru Zheng,Chen Hao,Chenglong Jiang,Jingbo Wu 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.61 No.-
A low-cost adsorbent, aminated calcium lignosulfonate (ACLS) was prepared and successfully applied to the adsorption of Congo red and the Titan yellow dyes. The adsorbent was characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), elemental mapping images (EMIs) and Brunauer–Emmett–Teller (BET) analysis. And the efficiency of ACLS for the removal of Congo red and the Titan yellow dyes was evaluated by several factors, such as temperature, pH, adsorbent dose, contact time and initial concentration of dyes solution. And the test ranges of temperature, pH, adsorbent dose, contact time and initial concentration of dye solution were 25–45 °C, 2–12, 0.005–0.05 g, 1–48 h, 10–200 mg L−1, respectively. The adsorption results demonstrated a good ability to remove dye with the removal rates of 97% and 91% for 30 mg L−1 Congo red and 40 mg L−1 Titan yellow, respectively. The adsorption kinetic and adsorption isotherms can be well described by the pseudo second order kinetic and the Langmuir isotherm model for the both dyes, respectively. Moreover, the maximum adsorption capacity of Congo red and Titan yellow reached 258.4 mg g−1 and 190.1 mg g−1 in the study of the Langmuir adsorption isotherm, respectively. Thermodynamic studies show that the adsorption of the two dyes is a spontaneous endothermic process. The results indicate that the ACLS has the potential to be used in the treatment of dye wastewater.
-
Ning Jia,Bin Yang,Xiaohong Wang,Shishuang Cui,Peng Chen,Ru Xia,Zhengzhi Zheng,Jiasheng Qian,Yuchao Ke,Yang Pan 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-
In this study, graphene nanoplatelets (GNP) and nickel–cobalt (NiCo) alloy were adopted as reinforcingmaterials to prepare epoxy (EP) resin-based composites. NiCo particles were able to achieve uniformanchoring on GNPs’ surface under the electrostatic force due to the successful introduction of oxygendefects on GNPs. With the synergistic effect of adhesive PVDF and salt particles, the system with threedimensionally(3D) interconnected network was successfully constructed. Benefit from the formation ofmechanically stable and efficient heat conduction paths, the thermal conductivity (TC) of the EP/PVDF/NiCo@GNP composite reached 1.077 Wm1K1 at a filler volume fraction of 6.82 vol%, while the counterpart’sstoragemodulus (E’) was up to 3.22 GPa. In addition, a scaling formula was quantitatively proposed tocorrelate TC with E’, and the perfect agreement between the theoretical prediction and experimental dataclarified the underlying mechanism of the relationship between phonons transport and stress transferwithin a systemwith 3D ordered structures. The establishment of relationship between AHR (average heatingrate) and TC made it possible to further predict TC of composites based upon the infrared thermal imaging(ITI) data. The as-prepared GNP composites show good application prospects as thermal managementmaterials which need to experience thermally mechanical deformation.
-
( Qiang Li ),( Tao Qin ),( Xiaohong Guan ),( Qinghua Zheng ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.4
With the exhaustion of global IPv4 addresses, IPv6 technologies have attracted increasing attentions, and have been deployed widely. Meanwhile, new applications running over IPv6 networks will change the traditional traffic characteristics obtained from IPv4 networks. Traditional models obtained from IPv4 cannot be used for IPv6 network monitoring directly and there is a need to investigate those changes. In this paper, we explore the flow features of IPv6 traffic and compare its difference with that of IPv4 traffic from flow level. Firstly, we analyze the differences of the general flow statistical characteristics and users` behavior between IPv4 and IPv6 networks. We find that there are more elephant flows in IPv6, which is critical for traffic engineering. Secondly, we find that there exist many one-way flows both in the IPv4 and IPv6 traffic, which are important information sources for abnormal behavior detection. Finally, in light of the challenges of analyzing massive data of large-scale network monitoring, we propose a group flow model which can greatly reduce the number of flows while capturing the primary traffic features, and perform a comparative measurement analysis of group users` behavior dynamic characteristics. We find there are less sharp changes caused by abnormity compared with IPv4, which shows there are less large-scale malicious activities in IPv6 currently. All the evaluation experiments are carried out based on the traffic traces collected from the Northwest Regional Center of CERNET (China Education and Research Network), and the results reveal the detailed flow characteristics of IPv6, which are useful for traffic management and anomaly detection in IPv6.
-
Yan, Lin,Li, Tongling,Zhang, Rongqin,Xu, Xiaohong,Zheng, Pengcheng The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.6
A simple HPLC method using UV detection was developed and validated for the determination of levodropropizine (LDP) In dog plasma. The sample was prepared for injection using a liquid-liquid extraction method with 1-phenypiperazine as the internal standard. The mobile phase was methanol - diethylamine solution (0.05 M) (20:80, v/v, pH adjusted to 3.0 with $H_3PO_4$) with a detection wavelength of 240 nm. The limit of quantitation (LOQ) of LDP in a biological matrix was determined to be 25.25 ng/mL. The calibration curve was linear across the concentration range of 25.25 to 2020 ng/mL. The intra-day and inter-day precision values (CV%) were within 7% and accuracy (R.E. %) was within 6% of the nominal values for medium (252.5 ng/mL) and high (2020 ng/mL) LDP concentrations. For the LDP concentration at the LOQ, the intra-day and inter-day precision and accuracy were within 20% and 10%, respectively. The average absolute recovery for LDP was 70.28%. This method was successfully used to analyze plasma samples in a steady-state bioavailability study of a newly developed sustained-release LDP tablets (SR) using immediate-release tablets (IR) as the reference. The relative bioavailability of the SR was determined to be $106.3\;{\pm}\;12.8%$ (n=6). The $C_{max}$ of the SR was significantly lower (p<0.05), and the $t_{max}$ was significantly longer than that of the IR (p<0.05). The results of ANOVA and two one-sided tests indicated that the SR exhibited acceptable sustained release properties and was bioequivalent to the IR.
-
Fen-Qiang Li,Juehao Ding,Miao Zheng,Jianlin Xu,Xiaohong Ge,Hui Li,Jun Zhao 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.7
A combination of multi-physics numerical simulation and experiment was conducted to study the magnetic pulse compaction technology driven by two aluminum tubes of tungsten copper powder. Then, the effects of different process parameters on the density and uniformity of the compact were studied by tuning the thickness of the pack and driver tubes and the gap between them. Results show that the density of compact is the highest when the thickness of the driver tube is 1.0 mm. More energy is consumed for force conduction as the thickness of the pack tube increases. Thus, the density of the compact is the highest when the thickness of the packer tube is 0.8 mm. The speed of the driver tube impacting the pack tube also increases with the rise in the gap. Accordingly, the compaction density with the gap of 1.5 mm is the highest under the same other parameters.
-
Lin Yan,Tongling Li,Rongqin Zhang,Xiaohong Xu,Pengcheng Zheng 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.6
A simple HPLC method using UV detection was developed and validated for the determination of levodropropizine (LDP) in dog plasma. The sample was prepared for injection using a liquid-liquid extraction method with 1-phenypiperazine as the internal standard. The mobile phase was methanol - diethylamine solution (0.05 M) (20:80, v/v, pH adjusted to 3.0 with H3PO4) with a detection wavelength of 240 nm. The limit of quantitation (LOQ) of LDP in a biological matrix was determined to be 25.25 ng/mL. The calibration curve was linear across the concentration range of 25.25 to 2020 ng/mL. The intra-day and inter-day precision values (CV %) were within 7% and accuracy (R.E. %) was within 6% of the nominal values for medium (252.5 ng/mL) and high (2020 ng/mL) LDP concentrations. For the LDP concentration at the LOQ, the intra-day and inter-day precision and accuracy were within 20% and 10%, respectively. The average absolute recovery for LDP was 70.28%. This method was successfully used to analyze plasma samples in a steady-state bioavailability study of a newly developed sustained-release LDP tablets (SR) using immediate-release tablets (IR) as the reference. The relative bioavailability of the SR was determined to be 106.3 ± 12.8% (n=6). The Cmax of the SR was significantly lower (P<0.05), and the tmax was significantly longer than that of the IR (P<0.05). The results of ANOVA and two one-sided tests indicated that the SR exhibited acceptable sustained release properties and was bioequivalent to the IR.
-
Interfacial mechanical behaviors of RC beams strengthened with FRP
Jiangdong Deng,Airong Liu,Peiyan Huang,Xiaohong Zheng 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.3
FRP-concrete interfacial mechanical properties determine the strengthening effect of RC beams strengthened with FRP. In this paper, the model experiments were carried out with eight specimens to study the failure modes and the strengthening effect of RC beams strengthened with FRP. Then a theoretical model based on interfacial performances was proposed and interfacial mechanical behaviors were studied. Finite element analysis confirmed the theoretical results. The results showed that RC beams strengthened with FRP had three loading stages and that the FRP strengthening effects were mainly exerted in the Stage III after the yielding of steel bars, including the improvement of the bearing capacity, the decreased ultimate deformation due to the sudden failure of FRP and the improvement of stiffness in this stage. The mechanical formulae of the interfacial shear stress and FRP stress were established and the key influence factors included FRP length, interfacial bond-slip parameter, FRP thickness, etc. According to the theoretical analysis and experimental data, the calculation methods of interfacial shear stress at FRP end and FRP strain at midspan were proposed. When FRP bonding length was shorter, interfacial shear stress at FRP end was larger that led to concrete cover peeling failure. When FRP was longer, FRP reached the ultimate strain and the fracture failure of FRP occurred. The theoretical results were well consistent with the experimental data.
-
Stratigraphic classification of the Quaternary North Hebei Plain using geophysical methods
Peng Dai,Kongyou Wu,Shengdong Wang,Sicong Zheng,Tianshe Cheng,Xiaohong Deng 한국지질과학협의회 2024 Geosciences Journal Vol.28 No.2
The North Hebei Plain is a typical example of a deep-covered area, with a thickness of more than 200 m Quaternary loose sediments. Previous studies have tried various stratigraphic classification methods but lack an effective combination of geophysical methods. Based on the analysis of rock strata and dating tests, combined with geophysical well-logging data, shallow seismic reflection, and paleomagnetic dating, the Quaternary strata of the deep-covered area in the Hebei Plain was divided into the Lower Pleistocene series, the Middle Pleistocene series, the Upper Pleistocene series, and the Holocene series. By observing the cores of the Quaternary borehole QHJ02, this paper focused on dividing its loose sediments into eight lithological sections, according to the lithology, sediment colour, sedimentary assemblage, and sedimentary environment. The geomagnetic polarity belt is divided according to the paleomagnetic inclination of the paleomagnetic sample in borehole QHJ02. The results of the paleomagnetic test show that the interval of 0–101.3 m is Brunhes normal polarity chron, the interval from 101.3 to 219.5 m is Matuyama reversed polarity chron, and the interval from 219.5 to 350 m is Gauss normal polarity chron. The amplitude of the geophysical logging curve shows a good correspondence with the lithology of the QHJ02 borehole. The lithology changes can be identified through the abrupt abnormal positions of logging curves such as gamma ray, resistivity, and magnetization to analyze the sedimentary environment combination and determine the formation boundary. According to the combination of paleomagnetic, shallow seismic reflection, and geophysical well logging methods, we can determine the bottom boundaries of the Quaternary and middle Pleistocene are 219.5 m and 101.3 m, respectively. According to the combination of geophysical well-logging, lithostratigraphic assessment, dating experiment of Accelerator Mass Spectrometry 14C (AMS 14C), and Optically Stimulated Luminescence (OSL), we can determine the bottom of the upper Pleistocene and the lower limit of Holocene to be at 45.4 m and 21.4 m, respectively. Based on a comprehensive analysis of rock stratigraphic characteristics and well-logging curves, this study investigated the paleoenvironmental characteristics of borehole QHJ02 at different ages. The Upper Neogene was characterized by branch channels and river floodplains, with localized occurrences of alluvial fans, avulsion fans, and inter-channel lowlands. During the Early Pleistocene, branch channels and inter-channel lowlands dominated, with localized river floodplains. The Middle Pleistocene witnessed alternating branch channels and river floodplains as the main paleoenvironments. In the Late Pleistocene, branch channels and inter-channel lowlands were prevalent. The Holocene saw a combination of natural levees and river floodplain environments. These findings enhance our understanding of the geological evolution and paleoenvironmental changes in the North Hebei Plain.
ScienceON연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
