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The potential therapeutic benefit of adjuvant radiotherapy for patients with stage I uterine sarcoma has not been clear. In this study, we aimed to develop a risk scoring model to select the subgroup of patients with stage I uterine sarcoma who might benefit from adjuvant radiotherapy.Patients with stage I uterine sarcoma from the Surveillance, Epidemiology, and End Results program from 2010 to 2014 were retrospectively included in this analysis. Cox proportional hazards models were performed to identify risk factors.A total of 947 stage I uterine sarcoma patients were included. The 5-year disease-specific survival (DSS) of the overall cohort was 75.81%. Multivariate analysis identified stage (p = 0.013), tumor grade (p 0.001) and histology (p = 0.043) as independent prognostic factors for DSS, and these factors were used to generate the risk scoring model. The low-risk group presented a better DSS than the high-risk group (95.51% vs. 49.88%, p 0.001). The addition of radiotherapy to surgery significantly increased the DSS in the high-risk group compared with surgery alone (78.06% vs. 46.88%, p = 0.022), but no significant survival benefit was observed in the low-risk group (98.36% vs. 100%, p = 0.766).Our risk scoring model based on stage, tumor grade, and histology predicted the outcome of patients with stage I uterine sarcoma cancer. This system may help to select stage I uterine sarcoma cancer patients who might benefit from adjuvant radiotherapy.

In intercropping systems, high-positioned crops often exert shading stress on low-positioned crops, thus affecting the agronomic characteristics of the low-positioned crops. This study determined the mechanisms of photosynthetic, physiological and yield variations among peanut cultivars under shading stress. Four peanut cultivars, S60, C4, P12, and YS151, were grown in the field and subjected to shading stress for 77 days during reproductive stages. S60 and P12 showed lower yield and reduced biomass accumulation than C4 and YS151 under shading stress. Shading stress induced higher antioxidant enzyme activities in S60 and P12, relative to C4 and YS151. Under shading stress, S60 and P12 showed a higher light-trapping capability than C4 and YS151, which was associated with changes in chlorophyll (Chl) a and b contents, and Chl a/b ratio. The net photosynthetic rate, stomatal conductance and transpiration rates of C4 and YS151 were decreased, but the intercellular CO2 concentration increased under shading stress. The results demonstrated that non-stomatal limiting factors decreased the photosynthetic capacity of peanut under shading stress. The maximum photochemical efficiency of PSII (Fv/Fm) and non-photochemical quenching (NPQ) were higher in S60 and P12 than in C4 and YS151 under shading stress. These results suggest that S60 and P12 could absorb more light energy from weak light environments for photosynthesis than C4 and YS151 and dissipate the excess energy in the form of heat to improve their light protection ability. This study explains the inter-variety differences in shading stress tolerance in peanut and provides physiological parameters for guiding the selection of shade-tolerant cultivars.

To explore the surgical safety of patients with comorbid non-small cell lung cancer (NSCLC) and pneumoconiosis.In this study, the clinical data of 165 NSCLC patients treated at West China Fourth Hospital, Sichuan University from August 2019 to May 2021 were collected. Among them, 21 patients with comorbid pneumoconiosis were included in the pneumoconiosis group, and the remaining 144 patients were included in the general group. Radical resection for lung cancer was performed in both groups. The perioperative clinical data, including preoperative, intraoperative and postoperative indicators, of the two groups were compared and analyzed.There was no perioperative death in either group. The proportions of male patients and patients with smoking history in the pneumoconiosis group were significantly higher than those in the general group (NSCLC patients with comorbid pneumoconiosis face relatively greater risks during the perioperative period when they undergo radical resection for lung cancer. Therefore, the close attention of surgeons and the nursing staff should be raised accordingly.

Starch is the most important component in endosperm of sorghum grain. Usually, two types of starch are present: amylose (AM) and amylopectin (AP). The levels of AM and AP contents play a significant role in the appearance, structure, and quality of sorghum grains and in marketing applications. In the present study, a panel of 634 sorghum (Sorghum bicolor (L.) Moench) accessions were evaluated for starch, AM, and AP contents of grain, which included a mini core collection of 242 accessions from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in India, and 252 landraces and 140 cultivars from China. The average starch content was 67.64% and the average AM and AP contents were 20.19 and 79.81%, respectively. We developed a total of 260 000 high-confidence single nucleotide polymorphism (SNP) markers in the panel of 634 accessions of S. bicolor using specific locus amplified fragment sequencing (SLAF-seq). We performed genome-wide association studies (GWAS) of starch, AM, and AM/AP of grain and SNP markers based on a mixed linear model (MLM). In total, 70 significant association signals were detected for starch, AM, and AM/AP ratio of grain with P

Cigarette smoke- (CS-) induced oxidative stress and inflammation in the lung are serious health problems. Primary and reprocessed tea products contain multiple antioxidants that have been reported to protect the lung against CS-induced injury. However, the beneficial effects of Eurotium cristatum fermented loose dark tea (ECT) and Eurotium cristatum particle metabolites (ECP) on CS-induced lung injury and its potential hepatic metabolic detoxification are still unclear. Therefore, sixty mice were randomly divided into six equal groups. CS-exposed mice were prevented or treated with ECP or ECT infusions for 12 or 8 weeks to determine the antioxidative stress, anti-inflammatory and potential metabolic detoxification of ECT and ECP. Thirty-six mice were randomly divided into six equal groups to observe the effects on hepatic metabolic detoxification by replacing daily drinking water with ECT. Results showed that CS significantly decreased the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) and upregulated the expressions of malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-8, and IL-1β in serum. These adverse effects were modulated by ECP and ECT. In addition, ECT upregulated the mRNA expression of pregnane X receptor (PXR) and cytochrome P450 (CYP450) in the liver on daily free drinking ECT mice group. Western blot analysis further revealed that in CS-exposed mice, ECP and ECT significantly decreased the phosphorylation of mitogen-activated protein kinase (MAPK) in the lung but upregulated the protein expressions of PXR and aryl hydrocarbon receptor (AhR) in the liver. Overall, our findings demonstrated that ECT and ECP protected against lung injury induced by CS via MAPK pathway and enhanced hepatic metabolic detoxification via PXR and AhR pathways. Therefore, daily intake of ECT and ECP can potentially protect against CS-induced oxidative and inflammatory injuries.

Some enterprises of the Pearl River Delta had invested in Hunan province, and they played significant roles in Hunan’s economic development. However, the contribution to economic growth in general was not obvious in Hunan. According to the quantitative analysis that Hunan undertook an obstacle to the shift of the Pearl River Delta Industry. It could be found: The actual utilization of foreign investment in Hunan, Hunan road length, the balance of rural and urban residents in Hunan, Hunan consumption level and years of commodity market turnover, these five variables are the key barriers that Hunan could not take over the transfer successfully in Internet era. Five variables representing the Government's institutional arrangements for attracting foreign investment, transport infrastructure, subject to cultural constraints on investment entrepreneurial spirit, the regional market factors in Hunan that be decided from the regional market size and level of development. Therefore, to speed up the transfer of industries in Hunan docking the Pearl River Delta, it must be focused on several aspects of the above and then do the reform and innovation.

Cervical cancer is one of the most common female malignancies worldwide. Liquiritin (LT), a major constituent of Glycyrrhiza Radix, possesses a variety of pharmacological activities, including anti-cancer, anti-oxidative, anti-inflammatory and neuro-protective effects. However, its role in human cervical cancer remains to be elusive. In our study, we found that LT suppressed cervical cancer cell migration, invasion and cloning ability with little cytotoxicity to human normal cells. In addition, apoptosis was induced by LT in cervical cancer cells through activation of Caspase-3 and poly ADP-ribose polymerase (PARP) cleavage. LT-triggered apoptosis was dependent on extrinsic and intrinsic pathways, which were relied on Fas-associated protein with death domain (FADD)- and Bcl-2/Bax-regulated pathways, leading to Caspase-8 and Caspase-9 cleavage, respectively. LT was found to increase FADD expression, while reduce Bcl-2 expression, contributing to Caspase-3 cleavage. And tumor suppressors, p21 and p53, were enhanced after LT treatment, inhibiting the growth of cervical cancer cells in vitro. Significantly, in vivo study suggested that tumor growth was impeded by LT in a dose-dependent manner through enhancing apoptosis. Together, the data here revealed that LT was an effective and promising candidate for preventing human cervical cancer progression via apoptosis enhancement.

Starch content is a key factor affecting sorghum grain quality. The research of sorghum grain starch accumulation and the related synthesis enzyme activities has great significance for understanding the mechanisms of starch metabolisms. The differences between a high and a low starch content sorghum hybrids (Tieza 17 and Liaoza 11, respectively) in grain starch accumulation and the related synthesis enzyme activities were assessed following imposition of water stress during flowering stage. The total starch, amylase and amylopectin accumulation all decreased at the mid-late stage of grain filling under drought stress during flowering stage. The maximum and mean accumulation rates also decreased. During grain filling, soluble starch synthase (SSS), granule-bound starch synthase (GBSS), starch branching enzyme (SBE), and starch debranching enzymes (DBE) activities were all affected, though differently. Drought stress reduced starch accumulation in a larger extent for Tieza 17 than Liaoza 11. Drought stress during flowing stage reduced starch synthesis enzyme activities, thus reducing starch accumulation in grains, and the differences between starch components were also demonstrated under drought stress.

Doped carbon materials have been recognized as a promising non-Pt cathode catalyst for oxygen reduction reaction (ORR). We prepared a new Fe-N codoped carbon meterial by the carbonization of Polyaniline-Prussian blue composite (PANI-PB). PANI-PB was first prepared by doping polyaniline with ferrous ion and ferricyanide ion in turn. The composite was then carbonized in a nitrogen atmosphere at a heating rate of 10°C min−1 up to a maximum temperature of 800°C, forming a Fe-N doped carbon meterial (Fe-N/C). The product demonstrates a unique graphitized structure and has a relatively high Fe-N doping amount. The cyclic voltammetry curves (CV) show that the composite can catalyze the ORR much more efficiently than either of the single materials containing only carbonized PANI or carbonized PB in alkaline media.

Based on the theoretical analysis and the simulation results of the ion implantation process and the floating Junction structure, a 4H-SiC SBD with floating junction (FJ_SBD) is fabricated. Compared with the on-resistance 5.13 mΩ·cm2 of conventional SBD fabricated at the same time, the on-resistance of FJ_SBD with 3μm P+ buried box is only 6.29 mΩ·cm2. The breakdown voltage of the FJ_SBD reaches 950V which is much higher than the 430V of conventional SBD. According to the presented results, The BFOM of the FJ_SBD is 3 times higher than the value of the conventional SBD. It is proved that FJ-SBD has greater prospects for development.

Semi-supervised clustering is a method which can improve clustering performance by introducing partial supervised information. This paper mainly studies the semi-supervised fuzzy clustering which introduces Mahalanobis distance and Gaussian Kernel. And we obtain a new semi-supervised fuzzy clustering objective function. By solving the optimization problem, we propose a semi-supervised fuzzy clustering algorithm F-SCAPC which includes F(M)-SCAPC and F(K)-SCAPC. And we do experimental research for proposed algorithm F-SCAPC using the selected standard data set and the artificial data set. Besides, we compare performance of presented algorithm F-SCAPC with AFFC, KFCM-F and SCAPC algorithms. From the results, we can see that F-SCAPC is effective in the convergence speed and the accuracy.

The thrust rod is the key load-bearing part of the balanced suspension on heavy commercial vehicle. In order to optimize the structure and study the durability of it, we carried out the force and simulation analysis. In this paper, the model of thrust rod and guide mechanism was simplified. Under all driving conditions, force analysis was done for fully-loaded vehicle and force calculation formulae of thrust rods in different directions were derived. Multi-body dynamics model of the vehicle was established with ADAMS and we compared the differences of the two algorithms. Then the results of the two algorithms were compared with the load spectrum test results. We find the calculated results are in good agreement with engineering requirements.

Forest fire identification by infrared thermal imager has beening a new research trend. However, currently the most algorithms of forest fire identification are usually designed based on the process designer’s experiences. Unfortunately, few researches on the efficiency of those algorithms have been developed when they were used to identify field forest fire. The response of inchoate forest fire identification algorithm by infrared thermal imager was investigated in this study according to different field testing times and scales. The results show that compare means appears more stability when using it to detect fire within it eliminates most interferences but also meets the requirement of long-space detecting, compared to other two methods.

Twenty-fivealkaline xylanase producing strains were isolated from Qinghai Lake side soil samples. Among these strains, QH14 produced 648.79 U/mLxylanase, and the enzymatic specific activity was 1148.56 U/mg after purification. This alkaline xylanase producing strain belongs to genus Bacillus based on16S rDNA sequencing analysis and then was designated as Bacillus sp. QH14. The alkalinexylanaseencoding gene, XynQH14, was cloned from Bacillus sp. QH14 and expressed in Escherichiacoli BL21 (DE3). The specific activity of the recombinant xylanase XynQH14 was 700.47 Umg-1 after purification by Ni-NTA affinity chromatography. The optimal temperature and pH of XynQH14 were 60℃ and pH9.2, respectively. Its activity was 50% of initial activity after incubation at 55 ℃ for 1h, 80% at pH7-11 at 37 ℃ for 24 h, and 31.02% at pH11 at 50℃ after 24 h, indicating that XynQH14 isthermostable and alkali-stable. These properties ofXynQH14 suggest its favorable potential applications in pulp and paper industries.

The paper provides a solution of tracking system on dual-DSP(ADSP-BF561, ADP-BF548), and gives the method of implementation and optimization. The system implements the complex tracking algorithm in real time on the high-performance dual-core ADSP -BF561. The multimedia processor ADSP-BF548，which has integrated a pixel composer and many interfaces internally, is used to control the entire operating of the system and complete the task of input and output flexibly. With the help of the code and decode chips ADV7181 and ADV7171, which have strong ability of adaption to varieties of video formats, the system has the features of easy- expansibility, strong adaption, stabilize, function, small size and low consumption.

This paper analyzes the working process of current-mode controlled Boost converter and finds that the system will produce the physical phenomenon of intermittency chaos when the converter works in the period windows of chaos zone and external noise reaches certain intensity. It can observe the phenomenon of noise-induced intermittent chaos and it also analyzes the relationship between noise intensity and induced intermittent chaos, the relationship between the noise intensity threshold and circuit parameters in resulting intermittent chaos from the perspective of numerical simulation. The research has an important theoretical and practical significance to nonlinear science and it can provide a reliable theoretical reference for the stable design of switching power converters.

This paper analysis the work principle of peak current mode H bridge converter. It can observe the system exhibits a kind of special nonlinear phenomenon: breathing phenomenon. When the disturbance signal frequency is not different with the switching frequency and there is a certain degree of disturbance signal intensity, it will produce breathing phenomenon through the modeling and numerical simulation to the system. We can know the theoretical analysis is same with the numerical simulation. At last, it discusses the change of circuit parameters Iref, E, L / T to impact degree of disturbance signal intensity to generate breathing. It can provide theoretical basis for stability design of H bridge converter.

This paper introduces the phenomenon of nonlinear chaos of the peak current mode to control H bridge converter that has been known to become chaos for wide parameter variations after simulating to the model of H bridge converter. The natural reason of nonlinear phenomena can be explained by theoretical analysis. According to the characteristics of H bridge converter, resonant parametric perturbation was provided to suppress chaotic behavior of the converter and made the system changing from chaos to stable period. It is an effective non-feedback method for controlling chaos and it is such a suitable control method for controlling chaos in non-autonomous systems. Selecting the best perturbation phase to achieve the best chaos control results can optimize the method of resonant parametric perturbation. The control method suppresses chaos with high efficiency and it can provide theoretical basis for stability design of H bridge converter.

Although the climate change effects on plants have been a focus for more than two decades, such effects on aquatic species remain largely unknown. To evaluate the potential effects of elevated CO2 on growth and nutrient uptake of Eichhornia crassipe Solms (commonly known as water hyacinth, the world’s most significant invasive aquatic weed), plants were grown at two CO2 concentrations (380 and 800 ppm) combined with four nutrient levels (oligo-, meso-, eu-, and hypertrophic) for 2 months. Overall, elevated CO2 consistently enhanced plant growth at all nutrient levels, indicating more infestations of water hyacinth in future natural eutrophic waters. Moreover, the enhancement extent varied among nutrient availabilities, being more in eu- and hypertrophic levels and less in meso- and oligotrophic levels. Furthermore, the CO2 enrichment-deduced assimilation was allocated more to plant roots than shoots which would improve the nutrient absorption capacity and mostly transferred to offspring ramets rather than maintained at the mother ramet which would benefit the vegetative reproduction. Finally, under elevated CO2, although the nitrogen (N) and phosphorus (P) contents of E. crassipe slightly decreased which might mean increased difficulties in preventing its infestation by reducing N and/or P in eutrophic waters, the total N and P accumulation increased suggesting higher bioremediation efficiency of using water hyacinth for water eutrophication.

Issues of scale and aggregation become important when large range of space and time scales is considered in landscape models. However, identifying appropriate levels of aggregation to accurately represent the processes and components of ecological systems is challenging. A raster-based spatially explicit forest landscape model, LANDIS, was used to study the effects of spatial aggregation on simulated spatial pattern and ecological process in Youhao Forest Bureau of the Small Khingan Mountain in Northeastern China. The model was tested over 500 simulation years with systematically increased levels of spatial aggregation. The results show that spatial aggregation significantly influences the simulation of fire disturbance, species abundance, and spatial pattern. Simulated fire regime was relatively insensitive to grain size between 30.m and 270.m in the region. Spatial aggregation from 300.m to 480.m dramatically decreased fire return interval (FRI) and increased mean fire size. Generally, species abundance and its aggregation index (AI) remained higher level over simulation years at the fine-grained level of spatial aggregation than at coarser grains. In addition, the simulated forest dynamics was more realistic at finer grains. These results suggest that appropriate levels of spatial aggregation for the model should not be larger than 270.m.

Due to undesirable interference via unintended coupling paths, switching converters may exhibit complex intermittency, which appears as a form of bifurcation undergoing regular operation, subharmonics, and chaos orderly and repeatedly for a long period of time. Such intermittent operation, being an unwanted operating state, should normally be avoided in power converters. This paper expounds the mechanism and conditions for the emergence of intermittency in a common current-mode controlled Boost converter. It is found that interference at frequencies near the switching frequency or its rational multiples may induce intermittent operation. The strengths and frequencies of the interfering signals determine the type and period of intermittency. The problem is analyzed by transforming the time-bifurcation analysis to a conventional parameter-bifurcation analysis. Based on this transformation, intermittency can be investigated from the bifurcation control viewpoint. Furthermore, the critical circuit parameter conditions for the emergence of intermittency can be predicted and compared with those from circuit simulation.

This paper introduces a new memristor-based hyperchaotic complex Lu system (MHCLS) and investigates its adaptive complex generalized synchronization (ACGS). Firstly, the complex system is constructed based on a memristor-based hyperchaotic real Lu system, and its properties are analyzed theoretically. Secondly, its dynamical behaviors, including hyperchaos, chaos, transient phenomena, as well as periodic behaviors, are explored numerically by means of bifurcation diagrams, Lyapunov exponents, phase portraits, and time history diagrams. Thirdly, an adaptive controller and a parameter estimator are proposed to realize complex generalized synchronization and parameter identification of two identical MHCLSs with unknown parameters based on Lyapunov stability theory. Finally, the numerical simulation results of ACGS and its applications to secure communication are presented to verify the feasibility and effectiveness of the proposed method.

In view of reasonable explanation of intermittent subharmonics and chaos that can be gained from coupling filter between circuits, this paper discusses a method that maps time bifurcation with parameter bifurcation. Based on this mapping method, the general analysis method of characteristic multiplier, which is originally aimed at parameter bifurcation, can be used for the study of intermittency, i.e., time bifurcation. In this paper, all researches coming from characteristic multipliers, parameter-bifurcation diagrams, and the largest Lyapunov exponent indicate the same results as those produced by simulation and experiment. Thus, it is proved theoretically that the intermittency in switching power converter can be explained in terms of coupling of spurious interference.

With comprehensive consideration of generalized synchronization, combination synchronization and adaptive control, this paper investigates a novel adaptive generalized combination complex synchronization (AGCCS) scheme for different real and complex nonlinear systems with unknown parameters. On the basis of Lyapunov stability theory and adaptive control, an AGCCS controller and parameter update laws are derived to achieve synchronization and parameter identification of two real drive systems and a complex response system, as well as two complex drive systems and a real response system. Two simulation examples, namely, ACGCS for chaotic real Lorenz and Chen systems driving a hyperchaotic complex Lu system, and hyperchaotic complex Lorenz and Chen systems driving a real chaotic Lu system, are presented to verify the feasibility and effectiveness of the proposed scheme.

Twenty-fivealkaline xylanase producing strains were isolated from Qinghai Lake side soil samples. Among these strains, QH14 produced 648.79 U/mLxylanase, and the enzymatic specific activity was 1148.56 U/mg after purification. This alkaline xylanase producing strain belongs to genus Bacillus based on16S rDNA sequencing analysis and then was designated as Bacillus sp. QH14. The alkalinexylanaseencoding gene, XynQH14, was cloned from Bacillus sp. QH14 and expressed in Escherichiacoli BL21 (DE3). The specific activity of the recombinant xylanase XynQH14 was 700.47 Umg-1 after purification by Ni-NTA affinity chromatography. The optimal temperature and pH of XynQH14 were 60℃ and pH9.2, respectively. Its activity was 50% of initial activity after incubation at 55 ℃ for 1h, 80% at pH7-11 at 37 ℃ for 24 h, and 31.02% at pH11 at 50℃ after 24 h, indicating that XynQH14 isthermostable and alkali-stable. These properties ofXynQH14 suggest its favorable potential applications in pulp and paper industries.

The article studies on the parallel-connected buck converter under master-slave operation. Firstly, deduces the dynamical equations from the circuit structure, and gains the bifurcation and chaos diagram under the different parameters. Then, open out the reason of bifurcation and chaos by simple theoretical analysis. On basis of it, some chaos control method called phase-shift are putted forward, which are analysed with the mapping method that will map the time variable to some other parameter. The control results are validated by contrasting the power spectrum before and after the control method of phase-shift is adopted „

With spatially explicit landscape model (LANDIS), the dynamic change of forest landscape in Youhao Forest Bureau in Xiaoxinganling Mountains from 2001-2201 under 5 planting proportions of coniferous and broadleaved species, i.e., 100% broadleaved species, 70% broadleaved and 30% coniferous species, 50% broadleaved and 50% coniferous species, 30% broadleaved and 70% coniferous species, and 100% coniferous species, was studied, taking the forest under natural regeneration after harvesting as the control. The results showed that afforestation effectively promoted the recovery of forest resources, but single planting of coniferous species would lead to the area percent of broadleaved species lower than the control. When broadleaved species were planted only, the area percent of coniferous species was lower than the control. The area percent and aggregation index of Pinus koraiensis and Larix gmelini increased with increasing planting proportion of coniferous species, and those of Quercus mongolica increased with increasing planting proportion of broad-leaved species. Afforestation decreased the area percent of Betula phatyphylla, but had no significant effects on its aggregation index. Different afforestation strategies not only altered the species area percent, but also affected the species spatial pattern.

A DC/DC switching converter is a strongly nonlinear control system. The study on chaotic phenomena and chaos control is a hotspot of the power electronics. In this paper the dynamical model of current-mode controlled boost converter has been studied. Based on expansion of ramp compensation method and parametric resonance perturbation method, we used three different perturbation signals (i.e. sine wave, saw tooth wave and triangular wave) to boost converter for controlling chaos, and presented criteria of performance evaluation. Meanwhile, from the evaluation principles introduced, it is indicated that triangular wave is a suitable choice of periodic compensation signal. Simulations and analysis are presented to provide practical and theoretical evidences for the proposed control method.

A spatially explicit landscape model LANDIS was applied to simulate the forest landscape changes under four management alternatives (no cutting, clear cutting, selective cutting I and II) in Youhao Forestry Bureau located in Small Xing' an Mountain from 2000 to 2200. The outcomes from LANDIS were combined with a landscape-level habitat suitability index (HSI) model in a GIS environment to assess Sciurus vulgaris habitat quality. The results showed that the increase of suitable habitat area and the decrease of marginally suitable area were the fastest under no cutting scenario, and the slowest under clear cutting scenario. Suitable habitat area increased faster while marginally suitable area decreased more slowly under selective cutting I scenario than under selective cutting II. Overall, the optimal management alternative of S. vulgaris habitat was in the sequence of no cutting, selective cutting I, selective cutting II, and clear cutting.

This paper studies the operating principle of Phase-Shifting (PS) Full-Bridge (FB) Zero-Voltage-Switched (ZVS) Converter and analyses particularly its topology, based on which it is found that PS FB ZVS converter is exactly equivalent to a buck converter topologically. Therefore, the complex phenomena such as bifurcation and chaos that are found frequently in buck converters can also arise in PS FB ZVS converter. Simulations validate this conclusion and some typical waveforms are provided.

DC-DC converters are the kernel parts in the switching power supplies. There are abundant dynamical behaviors in them. In order to discover all these linear and nonlinear phenomena, it is demanded to put forward some appropriate modeling methods. This article discusses the modeling methods, which aimed at some familiar DC-DC converters under the control of voltage and current mode. They include exact simulation model and discrete map. All results are brought with experiments. The study methods and process in this paper are suitable to the other converters operating under the control of voltage or current mode.

Modulating reference current with a compensating ramp is a traditional method to stabilize the operation of the peak current-mode controlled dc/dc Boost converter. In this paper, this method is applied to a PFC Boost converter for gaining the stable operation target. Time-domain waveforms obtained by computer simulations are provided to illustrate the control results. Analytical investigations confirm the results achieved by simulations, and the control parameter can also be calculated or predicted assuring the stable operation of PFC Boost converter.