A Sliding Mode Control Design based on the Reaching Law for Matrix Rectifiers

Zhiping Wang,Yunshou Mao,Zhanhu Hu,Yunxiang Xie 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.3

This paper presents a novel approach for achieving both a tight DC voltage regulation and a power factor control by applying the Reaching Law Sliding Mode Control (RL-SMC) and the conventional Sliding Mode Control (SMC). Applying these strategies on a matrix rectifier (MR) can achieve a unity grid side power factor when the DC load changes widely and it can provide a ripple-free output voltage that is easily affected by distortions of the three-phase ac voltage supply. Furthermore, by employing the reaching law on the SMC can solve the chatting problem of the sliding motion. Comparative Matlab simulations and experimental verifications for these strategies have been presented and discussed in this paper. The results show that by applying the SMC and RL-SMC on a MR can achieve a unity grid side power factor and a regulated ripple-free DC output.

Response of Water Tetramer to Intense Femtosecond Laser Pulses

Zhiping Wang,Xuefen Xu,Chaoyi Qian,Yanbiao Wang,Xu Wang 한국광학회 2017 Current Optics and Photonics Vol.1 No.4

We theoretically study the dynamics of water tetramer in intense femtosecond laser pulses with differentfrequencies. The simulations are carried out by incorporating the molecular dynamics method non-adiabaticallyinto the time-dependent local-density approximation (TDLDA-MD). Three typical scenarios of watertetramer including the normal vibration with enlarged OH bonds, free OH bonds breaking and the pureCoulomb explosion are presented by investigating the electronic and ionic dynamics. The result indicatesthat the ionization is enhanced and the corresponding fragmentation effect as well as the damping of thedipole moment are found more notably when increasing the laser frequency especially when the frequencyfalls in the resonant region of the absorption spectra. The study of the level depletion reveals that theratio of the emission amount from different levels can be controlled by changing the laser frequencyreferring to the Keldysh parameter.

A Sliding Mode Control Design based on the Reaching Law for Matrix Rectifiers

Wang, Zhiping,Mao, Yunshou,Hu, Zhanhu,Xie, Yunxiang The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.3

This paper presents a novel approach for achieving both a tight DC voltage regulation and a power factor control by applying the Reaching Law Sliding Mode Control (RL-SMC) and the conventional Sliding Mode Control (SMC). Applying these strategies on a matrix rectifier (MR) can achieve a unity grid side power factor when the DC load changes widely and it can provide a ripple-free output voltage that is easily affected by distortions of the three-phase ac voltage supply. Furthermore, by employing the reaching law on the SMC can solve the chatting problem of the sliding motion. Comparative Matlab simulations and experimental verifications for these strategies have been presented and discussed in this paper. The results show that by applying the SMC and RL-SMC on a MR can achieve a unity grid side power factor and a regulated ripple-free DC output.

High Performance Phthalonitrile Cure Reaction and Property Research with a Novel Adenine-containing Aromatic Amine

Zhiping Wang,Jianghuai Hu,Ke Zeng,Gang Yang 한국고분자학회 2017 폴리머 Vol.41 No.5

An adenine-containing curing agent, 9,10-bis(4-aminophenyl) adenine (p-APA) was designed to decrease the volatility of curing agent. The exact structure of p-APA was confirmed by proton nuclear magnetic resonance (1H NMR), infrared spectroscopy (IR) and elementary analyzer (EA). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were measured to compare volatility of p-APA with that of a traditional curing agent, 1,3-bis(4-aminophenoxy) benzene (4-APB), which indicated p-APA has better thermal stability and lower volatility. The thermal tests of different curing process of phthalonitriles showed good thermal and thermo-oxidative stabilities. The thermal property was improved along with increasing curing temperature and time and the glass-transition temperature (Tg) was not observed on DSC before 400℃. The Fourier transform infrared spectroscopy (FTIR) showed that triazine and phthalocyazine rings were the dominant reaction products of the cured phthalonitriles. The dynamic mechanical analysis (DMA) of post-cured phthalonitriles showed a storage modulus of 1.3 GPa at 40℃ and Tg about 500℃.

Uniform Side Illumination Generated from LEDs Arranged by an Annealing Algorithm

Xu Wang,Panling Lei,Chaoyi Qian,Zhiping Wang,Xuefen Xu,Zhouping Su 한국광학회 2022 Current Optics and Photonics Vol.6 No.3

Given a cubic space, it is easy to uniformly illuminate the floor with light sources placed on top. However, little has been reported about uniform illumination on walls with the same configuration of light sources. Here we present a luminaire consisting of nine light-emitting diodes (LEDs) with perfect Lambertian distribution, placed on the top as a 3 × 3 rectangular LED array. The distances between LEDs and tilt angles of each individual LED are adjustable and optimized by an annealing algorithm. After optimization, the array produces a rectangular illumination pattern on one wall with a uniformity of about 89%. Analysis shows that the tilt angles of individual LEDs are key parameters for uniform side illumination. In a scenario that is more practical, the tilt angles of all the LEDs are set to be the same, only decreasing the uniformity to 83%.

Polyglycerol modified polysiloxane surfactants: Their adsorption and aggregation behavior in aqueous solution

Guoyong Wang,Yanyan Zhu,Yunhui Zhai,Wanxu Wang,Zhiping Du,Jieqiong Qin 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.47 No.-

A simple process to synthesize polyglycerol modified polysiloxane surfactants has been carried outapplying a “grafting-to” approach. After formation of allyl polyglycerol ether (APGE) from diglycerol(DGY) and allyl glycidyl ether (AGE), polysiloxane modified by designed number of polyglycerol groups(PHMS-APGE) were obtained by connecting the APGE structure to different Si H functionalizedpolyhydromethyl siloxane (PHMS). The synthesized APGE-PHMS were characterized by IR and 1H NMR. Solubility measurements showed that the solubility of the as-prepared polymers increased in polarsolvents with the increasing of the amount of hydrophilic APGE groups. Furthermore, the surface activity,surface adsorption, aggregation and spreading behaviors of APGE-PHMS were investigated utilizingsurface tension measurements, dynamic light scattering (DLS), transmission electron microscopy (TEM)and contact angle measurements. The results showed that critical aggregation concentration (CAC) andthe time needed to reach adsorption equilibrium on water surface decrease systematically with theincrease in the number of APGE groups. These polymers in aqueous solutions could aggregate to formspherical assemblies. Moreover, the spreading behavior of these polymers on low energy surface wasfound to be influenced by the number of hydrophilic APGE groups.

Soybean GmAOC3 promotes plant resistance to the common cutworm by increasing the expression of genes involved in resistance and volatile substance emission in transgenic tobaccos

Qian Wu,Hui Wang,Juanjuan Wu,Dagang Wang,Yongli Wang,Lei Zhang,Zhiping Huang,Deyue Yu 한국식물학회 2015 Journal of Plant Biology Vol.58 No.4

The evaluation and use of endogenous soybean genes is an effective strategy to minimize the yield losses caused by insects. Allene oxide cyclase (AOC) catalyzes the most important step in the biosynthesis of jasmonate (JA), which plays a crucial role in plant defense against insects. In this study, the role of GmAOC3 in plant insect resistance was evaluated. Real-time PCR results indicate that GmAOC3 was uniquely and rapidly activated and attained peak expression in leaves after attack by the common cutworm (CCW). In insect bioassays, transgenic lines overexpressing GmAOC3 were significantly less damaged than wild-type plants, and the relative growth rate of CCW fed with leaves from transgenic lines was significantly lower than that of CCW fed with leaves from wild-type plants. Electron microscopy revealed that the density of leaf trichomes in transgenic lines overexpressing GmAOC3 was greater than that in wild-type tobacco. Several physiological and morphological indicators, including JA, phenolic content and the relative expression levels of the putrescine N-methyltransferase (PMT) and proteinase inhibitor (PI) genes, phenylalanine ammonia lyase (PAL) activity and volatile substances, increased in the transgenic plants overexpressing GmAOC3. Our findings indicate that GmAOC3 plays an important role in soybean resistance to CCW and can be used as a resource for plant breeding.

Electrochemical modification of the porosity and zeta potential of montmorillonitic soft rock

Wang, Dong,Kang, Tianhe,Han, Wenmei,Liu, Zhiping,Chai, Zhaoyun Techno-Press 2010 Geomechanics & engineering Vol.2 No.3

The porosity (including the specific surface area and pore volume-diameter distribution) of montmorillonitic soft rock (MSR) was studied experimentally with an electrochemical treatment, based on which the change in porosity was further analyzed from the perspective of its electrokinetic potential (${\zeta}$ potential) and the isoelectric point of the electric double layer on the surface of the soft rock particles. The variation between the ${\zeta}$ potential and porosity was summarized, and used to demonstrate that the properties of softening, degradation in water, swelling, and disintegration of MSR can be modified by electrochemical treatment. The following conclusions were drawn. The specific surface area and total pore volume decreased, whereas the average pore diameter increased after electrochemical modification. The reduction in the specific surface area indicates a reduction in the dispersibility and swelling-shrinking of the clay minerals. After modification, the ${\zeta}$ potential of the soft rock was positive in the anodic zone, there was no isoelectric point, and the rock had lost its properties of softening, degradation in water, swelling, and disintegration. The ${\zeta}$ potential increased in the intermediate and cathodic zones, the isoelectric point was reduced or unchanged, and the rock properties are reduced. When the ${\zeta}$ potential is increased, the specific surface area and the total pore volume were reduced according to the negative exponent law, and the average pore diameter increased according to the exponent law.

Synthesis, characterization and evaluation of Ni–Mo/Zr–Al2O3 catalyst for hydro-conversion of lignite-based heavy carbon resources

Zhiping Lei,Hengfu Shui,Lian Wu,Lijuan Gao,Muxin Liu,Zhicai Wang,Shibiao Ren 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.5

NaOH depolymerized products (SDP) of Shengli lignite was used as lignite-based heavy carbon resources in this study. Hydrotreatment of SDP over Ni–Mo/Al2O3 and Ni–Mo/Zr–Al2O3 catalysts was investigated. It was found that the incorporation of Zr to Ni–Mo/Al2O3 catalyst results in the easy reduction of metal oxides and the increase of the stacking degree and length of MoS2 slabs. Both of Ni–Mo/Al2O3 and Ni–Mo/Zr–Al2O3 catalysts show better performance for hydrogenation of SDP and can be used repeatedly. The incorporation of Zr to Ni–Mo/Al2O3 catalyst significantly inhibits the formation of tetrahydrofuran insolubles (THFI), promotes the formation of two-ring aromatics and increases HS yield compared to that over Ni–Mo/Al2O3 catalyst.

Compressive Mechanical Properties and Shock-Induced Reaction Behavior of a Ti–29Nb–13Ta–4.6Zr Alloy

Zhiping Guo,Ran Liu,Chuan Ting Wang,Yong He,Yuan He,Yue Ma,Xuebing Hu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.10

The compressive mechanical properties of a Ti–29Nb–13Ta–4.6Zr alloy were investigated at room temperature under variousstrain rates. The parameters of a modified Johnson–Cook constitutive equation were determined to describe the strainsoftening behavior under dynamic conditions. The testing results under compression show yield strength evidently increaseswith the increase of the strain rate. Moreover, it was found that the strain-rate effect of the yield strength upon dynamicdeformation is more significant than that upon quasi-static deformation. In order to characterize the impact-initiated reactionbehavior of Ti–29Nb–13Ta–4.6Zr alloy, the quasi-sealed test chamber was used to measure the pressure caused by energyreleased of fragments. It was obviously shown that the exothermic chemical reaction was more intense with the increase ofimpact velocity.