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The characteristics of the runoff and sediment in the Yellow River were analysed and predicted Based on measured data of from 1951 to 2017. Initially, the phase characteristics of runoff and sediment were analysed by the cumulative anomaly curve method. After that, the trend and catastrophe of runoff and sediment are discuessed using the Mann-Kendall methods. The results revealed that the decreasing trend of runoff and sediment was significant, and the catastrophe time was 1979 and 1992, respectively. Finally, the evolution of the runoff and sediment was predicted quantitatively by using the ARMA model. The predictions indicated that, the Yellow River is likely to remain in the stage of low runoff and sediment.

Designed for 6500V 4H-SiC JBS diodes, a highly-efficient termination structure of a non-uniform multiple floating field limiting rings (MFFLR) featuring with a non-uniform ring spacing and a multiple region division is studied and purposed. For each region, ring spacing is modulated independently by a multiplication factor and a linear increment factor. The non-uniform MFFLR structure is simulated and optimized for a better electric field distribution and a higher breakdown voltage. Based on the simulation results, 4H-SiC JBS diodes with the optimized non-uniform termination designs are fabricated. Experimental results show that the SiC JBS diode with optimized non-uniform MFFLR termination structure can achieve a breakdown voltage of up to 7800 V, and its termination efficiency is about 94% of an ideal parallel-plane junction’s. Our results demonstrate that the optimized non-uniform MFFLR termination structure is capable for SiC JBS diodes with breakdown voltage of 6500V and above. Our results can provide a valuable design methodology of edge termination structures for other high-voltage SiC devices.

The numerical classification and ordination of plant communities can reveal the relationship between plant distribution and environment, with implications on vegetation restoration and forest management. Community types were classified using a clustering method based on 45 forest dynamic plots with each area of 0.04 hm运用数量化的方法对植物群落进行分类和排序,可以客观地揭示植物群落和环境之间的相互关系,为植被恢复和森林经营管理提供理论依据。以浙江杭州午潮山45个20 m×20 m的森林动态监测样地为研究对象,运用聚类和排序等数量化方法,分析亚热带常绿阔叶林的群落类型、生物多样性特征及群落与环境的关系。结果表明: 午潮山亚热带常绿阔叶林样地可划分为3个群落类型: 木荷群落、白栎-薄叶山矾群落和青冈群落。3个群落类型中,树木个体密度和胸高断面积均无显著差异,而物种丰富度差异显著。青冈群落的物种丰富度显著高于木荷群落,但与白栎-薄叶山矾群落无显著差异。冗余分析(RDA)排序表明,群落分布与环境因子有明显的相关性。土壤和地形等解释了群落分布46.4%的变异,土壤全磷、有效磷、速效钾含量,以及海拔、坡度、坡向和透光度对群落的分布有显著影响,而土壤全磷、速效钾含量和海拔可能是影响午潮山亚热带常绿阔叶林群落分布最重要的环境因素。53.6%未能解释的部分可能归因于人为干扰。.

Lacustrine rift basins commonly preserve a fairly complete record of the sediment source‐to‐sink (S2S) system, and consequently may form an ideal natural laboratory for establishing quantitative relationships between the various elements within the S2S system. The tectonic‐activity rate in the source (e.g., fault‐growth rate and fault‐activity rate), accommodation space and depositional system in the sink (e.g., areal extent and volume, as well as the depositional dip of the fan‐ and braid‐deltas) are genetically related and their quantitative correlations are explored. The Palaeogene succession on the southwestern margin of the Huanghekou Depressionin the Bohai Bay Basin, one of the largest lacustrine rift basins in eastern China, was chosen to study these relationships, using 3‐D seismic, core and well‐log data. The tectonic activity was strongly related to the sediment supply, accommodation space and morphology of the sink area. Three different rates of tectonic activity are identified; these led to changes in the basic features of the S2S system that influenced each other. In Members 4 and 3 (lower unit) of the Shahejie Fm. (40.44–44.7 Ma), strong tectonic activity led to significant uplift, resulting in the widest exposure of the provenance area to erosion, to a high sediment‐supply rate, to a steep slope and to a large accommodation space which controlled the development of several fan‐deltas with steep progradational angles. In Member 3 (upper unit) of Shahejie Fm. (37.89–40.44 Ma) and Member 3 of Dongying Fm. (30.2–33.28 Ma), decreased tectonic activity led to slower uplifting, resulting in a wider alluvial plain, longer transport distances, a lower sediment‐supply rate and less accommodation space, so that braid‐deltas with larger volumes and a gentler slope developed; In Members 1 and 2 of Shahejie Fm. (33.28–37.89 Ma) and Member 2 of Dongying Fm. (26.71–30.2 Ma), still further decreasing tectonic activity led to a still lower sediment‐supply rate, a more gentle depositional slope, less accommodation space, and the development of several braid‐deltas with a gentle angle. The quantitative relationships established here advance our understanding of the relationships within lacustrine source‐to‐sink systems, especially for tectonically controlled rift basins.

70-um thick homoepitaxial layers with very low defect density were grown on 6-inch 4° off-axis wafers using hot-wall chemical vapor deposition (CVD). Process optimization resulted in reduction of the density of triangular defects from 1.01 cm-2 to 0.14 cm-2. The treatment of wafer (CMP or selection) was essential. The in-situ etch process was optimized prior to the epitaxial growth. Junction Barrier Schottky diodes fabricated on the epitaxial films presented a typical I–V characteristic and a block voltage of 6500 V.

Waterlogging, an abiotic stress, severely restricts crop yield in various parts of the world. Thus, we conducted a meta-analysis of 2,419 comparisons from 115 studies to comprehensively evaluate the overall change in crop yield induced by waterlogging in the global region. The results suggested that waterlogging obviously decreased crop yield by 32.9% on average, compared with no waterlogging, which was a result of a reduced 1,000-grain weight (13.67%), biomass (28.89%), plant height (10.68%), net photosynthetic rate (Pn, 39.04%), and leaf area index (LAI, 22.89%). The overall effect of a waterlogging regime on crop yield is related to the crop type; the crop yield reduction varied between wheat (25.53%) and cotton (59.95%), with an overall average value of 36.81% under field conditions. In addition, we also found that compared with no waterlogging, waterlogging in the reproductive growth stage (41.90%) caused a greater yield reduction than in the vegetative growth stage (34.75%). Furthermore, decreases in crop yield were observed with an extension in the waterlogging duration; the greatest decreases in crop yield occurred at 15 < D ≤ 28 (53.19 and 55.96%) under field and potted conditions, respectively. Overall, the results of this meta-analysis showed that waterlogging can decrease crop yield and was mainly affected by crop type, growth stage, and experimental duration.

This paper deals with a class of one element n-degree polynomial differential equations. By the fixed point theory, we obtain n periodic solutions of the equation. This paper generalizes some related conclusions of some papers.

The coupled Gerdjikov–Ivanov equation is investigated in this paper, which plays an important role in theoretical physics. According Lax pair, Darboux transformation, Darboux-dressing transformation and asymptotic expansion, some localized waves (breather wave, rogue waves and novel vector rogue waves) are obtained. Our work has great significance to theoretical experiments of the rogue wave generation mechanism and propagation trajectory.

A field experiment was implemented to discuss the effects of waterlogging and subsurface waterlogging stress on the grain yield, grain-filling characteristics, superoxide anion ( $${\text{O}}_{2}^{ \cdot - }$$ ) content, hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content, antioxidant enzyme activity, proline, soluble protein content and SPAD value of the spring maize (Zea mays L.) hybrids “Demeiya1” (DMY1) and “Keyu16” (KY16). The waterlogging and subsurface waterlogging treatments were conducted for different durations (3, 6, and 9 days and 5, 10, and 15 days, respectively) at the seedling (V3), jointing (V6), and tasseling (VT) stages. The results showed that the most significant effects of waterlogging and subsurface waterlogging stress occurred at the V3 stage, followed by the V6 stage and then VT stage. Waterlogging and subsurface waterlogging caused a decline in grain filling, which resulted in a decline in grain weight and ultimately caused an obvious decrease in yield. The content of $${\text{O}}_{2}^{ \cdot - }$$ and H2O2 as well as MDA increased with the prolongation of the duration of waterlogging and subsurface waterlogging, which caused an up-regulation of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, as well as increased proline and soluble protein contents and decreased SPAD value. In addition, we also demonstrated that KY16 is more sensitive than DMY1 to waterlogging and subsurface waterlogging.

Lodging is a major element restricting the yield and quality of spring maize (Zea mays L.). A 2-year field experiment was implemented to explore the effects of flooding and waterlogging stress on the vascular bundle structure, mechanical properties of the stem and yield of two spring maize hybrids, Demeiya1 (DMY1) and Keyu16 (KY16), in Northeast China. Flooding and waterlogging treatments were conducted for different durations (3, 6, and 9 days for flooding and 5, 10, and 15 days for waterlogging) at the seedling (V3), jointing (V6), and tasseling (VT) stages. The results showed that plant height, ear height, stem diameter, stem length, rind penetration strength and transverse bending strength of the third base internode, cortical thickness, number of vascular bundles and stem bleeding intensity all significantly decreased with increasing duration of flooding or waterlogging. These changes led to a decline in the lodging ability of stems and ultimately caused a reduction in yield in both spring maize hybrids. Both maize varieties were most vulnerable to flooding and waterlogging stress at the V3 stage, followed by the V6 and VT stages, and the longer the flooding or waterlogging duration, the more significant the effects of flooding or waterlogging stress on the stem characteristics and grain yield of both spring maize hybrids.

This work aimed to discuss the effects of exogenous abscisic acid (ABA) on the root growth regulation of maize seedlings under chilling stress. The roots of the maize cultivar Zhengdan 958 were irrigated with ABA (10−7, 10−6, 10−5 and 10−4 M) at the third true leaf stage under chilling duration (0, 2, 4, 6, and 8 days). The biomass, the phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO) enzyme activities, total phenolic and flavonoid contents, the ferric reducing ability of plasma (FRAP) antioxidant capacity, and 2,2-azinobis (3-ethlbenzothiazo-line-6-sulfonic acid) diammonium salt radical (ABTS·+) scavenging capacity of the roots of maize seedlings were measured after the treatment. The results showed that appropriate concentrations of exogenous ABA effectively enhanced root biomass, increased PAL and PPO enzyme activities, and significantly increased total phenolic contents and flavonoid contents. Moreover, the ABA markedly improved the FRAP antioxidant capacity and ABTS·+ scavenging capacity under low-temperature stress. These results indicate that ABA-treated maize seedlings are resistant to chilling stress and that the optimum concentration of ABA is 10−5 M. Exogenous applications of ABA have a concentration effect in alleviating chilling stress, in which low concentrations have a promoting effect and high concentrations have an inhibiting effect.

The dynamics of the nonlinear Schrödinger equation with Kerr law nonlinearity with two perturbation terms are investigated. By using Melnikov method, the threshold values of chaotic motion under periodic perturbation are given. Moreover we also study the effects of the parameters of system on dynamical behaviors by using numerical simulation. The numerical simulations, including bifurcation diagram of fixed points, chaos threshold diagram of system in three-dimensional space, maximum Lyapunov exponent, and phase portraits, are also plotted to illustrate theoretical analysis and to expose the complex dynamical behaviors. In particular, we observe that the system can leave chaotic region to periodic motion by adjusting controllere, amplituded1, and frequencyω2of external forcing which can be considered a control strategy, and when the frequenciesyω2andω1approach the maximum frequency of disturbance, the system turmoil intensifies and control intensity increases.

Chaos appears in the whole process of fiber-optic signal propagation with one external perturbation due to the absence of damping. Via adding a proper controller, chaos cannot be suppressed when the controller’s strength is weak. With the increase of the controller strength, the fiber-optic signal can stay in a stable state. However, unstable phenomenon occurs in the propagation of the fiber-optic signal when the strength exceeds a certain degree. Moreover, we discuss the parameters’ sensitivity to be controlled. Numerical results show that vibration, oscillation and escape can occur during the transmission of optic signals with different parametric regions.

This article establishes a model of industrial structures evolution law by sustainable development method. Making use of the data from 1993 to 2012 in China, the author simulates the evolution of three industries outputs. Then, the author analyses the law and inducement of industry structures evolution in China, and gives advices on sustainable development of industrial structure upgrading.

The course PLC has the characteristics of strong applicability and practicality. Currently, in the course of teaching it exits many shortcomings such as the single teaching form, having less intuitive and vivid, contacting with the other professional courses not closely and so on. Based on this, the paper proposes a project-driving teaching method using the multimedia technology integrating with much knowledge of the professional courses. The teaching method can melt the boring theory learning to the specific project to enrich teaching content, enhance students' learning interest and improve the comprehensive application ability of specialized knowledge of students. Index Terms - PLC, the project-driving teaching, integration of multi professional courses

In view of the serious misalignment, the mathematical model's uncertainty, the characteristic of the system operating point changing fiercely of the heating furnace temperature control system, this paper designed a new type of intelligent control system - PID neural network system (PIDNN) which melt the PID control rule in the neural network. This system has the quick reasoning speed and the strong anti-interference ability.

In this study, blind source separation (BSS) method was applied to separate the multi-channel fault vibration signals generated by a rotor. As the signals were non-stationary, an algorithm based on spatial time-frequency distributions was applied to the experimental vibration signals to obtain the non-stationary vibration sources that were mutually independent. Further, AR modeling estimates of these sources were calculated with BURG method. A neural network was applied to the AR modeling parameters to perform the fault classification. The separation results of an experiment on a rotor’s multi-fault show that this method is feasible for fault diagnosis.

In this paper, a Z 4-equivariant quintic planar vector field is studied. The Hopf bifurcation method and polycycle bifurcation method are combined to study the limit cycles bifurcated from the compounded cycle with 4 hyperbolic saddle points. It is found that this special quintic planar polynomial system has at least four large limit cycles which surround all singular points. By applying the double homoclinic loops bifurcation method and Hopf bifurcation method, we conclude that 28 limit cycles with two different configurations exist in this special planar polynomial system. The results acquired in this paper are useful for studying the weakened 16th Hilbert’s Problem.

Objective To observe the effects of bloodletting puncture at Jing-Well points in the distal ends of the finger and toe on survival rate, survival time, and brain edema in rats with cerebral ischemia. Methods Fifty-four male Sprague-Dawley rats were randomly divided into five groups: normal, sham operation, model, bloodletting puncture at Jing-Well points in distal ends of finger and toe, and puncture without bloodletting at these points. Middle cerebral artery occlusion models were established according to Longa's method. The brains were taken 48 h after the model was established. Brain water content, brain density, brain coefficient, survival rate, and survival time in each group were measured. Results After bloodletting puncture, the survival time of the rats was prolonged, their brain water content and brain coefficient were reduced, and brain density was increased. Conclusion Bloodletting puncture at Jing-Well points in the distal ends of the finger and toe can improve function in ischemic brain edema.

To grasp the international developing tendency of acupuncture research and provide some references for promoting acupuncture and moxibustion internationalization process, the articles about acupuncture in Science Citation Index (SCI) periodicals in 2007 were retrieved by adopting the retrieval tactics on line in combination with database searching. Results indicate that 257 articles about acupuncture had been retrived from the SCI Web databases. These articles were published in 125 journals respectively, most of which were Euramerican journals. Among these journals, the impact factor of the Journal of the American Medical Association (JAMA), 25. 547, is the highest one. It is shown that the impact factors of the SCI periodicals, in which acupuncture articles embodied are increased, the quality of these articles are improved obviously and the types of the articles are various in 2007, but there is obvious difference in the results of these studies due to the difference of experimental methods, the subjects of these experiments and acupuncture manipulations. Therefore, standardization of many problems arising from the researches on acupuncture is extremely imminent.

An experiment in grasping objects with the right or the left hand was designed to determine handedness in 300 children from 6 months to 3 years of age. The results indicated that the frequency of using either the right or the left hand was around 50% within 1 year of age. The percentage of right-handed children increased with age, reaching 69.4% at 1-1.5 years of age, 71.3% at 1.5-2 years, 76.9% at 2-2.5 years, and 81.5% at 2.5-3 years. The frequency of right-handedness among boys increased faster than that among girls. The experiment showed that there were cases of grasping objects with both hands, but the frequency decreased rapidly after 1.5 years of age. The proportion of left-handed children with one or both left-handed parent(s) was higher than that among children with two right-handed parents. The children displayed preferences in terms of the color of objects and the nature of toys.