Stancu-Kantorovich 算子在 L_M~* 的饱和性

讨论Ｓｔａｎｃｕ－Ｋａｎｔｏｒｏｖｉｃｈ算子在Ｏｒｌｉｃｚ空间Ｌ＊Ｍ［０,１］中的饱和性,对于Ｍ（μ）∈Δ２,ｆ（ｘ）∈Ｌ＊Ｍ［０,１］证明了：Ｋｎ,ｓ（ｆ）－ｆＭ＝ｏ（１ｎ）ｆ（ｘ）＝ｃｏｎｓｔ;Ｋｎ,ｓ（ｆ）－ｆＭ＝Ｏ（１ｎ）ｆ（ｘ）∈ＳＭ,其中ＳＭ＝｛ｆ（ｘ）：存在ｈ（ｔ）∈Ｌ＊Ｍ［０,１］使ｆ（ｘ）＝ｆ（１２）＋∫ｘ１／２１ｔ（１－ｔ）∫ｔｋｈ（ｕ）ｄｕｄｔ,这里ｋ为任意实数｝．     

一类非线性规划的局部解与精确罚函数的研究

一类非线性规划的局部解与精确罚函数的研究林亮（桂林工学院桂林５４１００４）考虑非线性规划问题：（Ｐ）Ｍｉｎｆ（ｘ）ｓ１ｔ１ｇ（ｘ）≤０，ｈ（ｘ）＝０，ｘ∈Ｚ（１）其中ｆ，ｇ，ｈ分别为Ｒｎ到Ｒ，Ｒｍ，Ｒｌ上的函数，ＺＲｎ．对应问题（１），我们定义罚函数...     

R~N 上非齐次非线性椭圆型方程的多解性

讨论了问题－△ｕ＋μｕ＝Ｑ（ｘ）｜ｕ｜ｐ－２ｕ＋ｆ（ｘ）,ｕ∈Ｈ１（ＲＮ）的正解和变号解的存在性,这里Ｎ≥３,２＜ｐ＜２Ｎ／（Ｎ－２）,μ＞０,Ｑ（ｘ）∈Ｃ（ＲＮ）,且０ｆ≥０．     

一类二阶泛函微分方程振动解的性质

讨论了方程ｘ″（ｔ）＋ｐ（ｔ）ｆ（ｘ（ｇ（ｔ））＝ｒ（ｔ）振动解的渐近性和有界性，利用分离强迫项的方法，获得了几个新的结果．     

一类时滞直接控制系统绝对稳定的充要条件

讨论了一类时滞直接控制系统ｘ（ｔ）＝Ａｘ（ｔ）＋Ｂｘ（ｔ－τ）＋ｂｆ（σ（ｔ））,σ（ｔ）＝ｃＴｘ（ｔ）的绝对稳定性,获得了其一阶形式绝对稳定的充要条件的代数判据,对ｎ阶系统作了相应的推广．     

关于连续数方程的一个结果

证明了当ｎ，ｘ，ｒ为正整数且ｒ＞３，ｓ为非负整数ｇｅｄ（ｘ，（３２０ｓ＋１６２））＝１，丢番图方程［ｘ＋（３２ｓ＋１６２）ｋ］ｒ＝［ｘ＋（３２０ｓ＋１６２）ｎ］ｒ无整数解。     

时滞微分方程初值问题数值方法的误差估计

给出了求解时滞微分方程初值问题ｙ′（ｔ）＝ｆ（ｔ,ｙ（ｔ）,ｙ（ｔ－τ））,ｔ≥ｔ０ｙ（ｔ）＝φ（ｔ）,ｔ≤ｔ０｛的数值方法的整体误差估计,它不依赖于右端函数关于第二个变量的李普希兹常数．     

缩放微分方程隐式Euler方法的稳定性

给出了非线性缩放时滞微分方程初值问题ｙ′（ｔ）＝ｆ（ｔ,ｙ（ｔ）,ｙ（ｑｔ））,ｑ∈（０,１）,ｔ≥０,ｙ（０）＝ｙ０｛理论解渐近稳定的充分条件及数值方法的渐近稳定性概念,证明了隐式Ｅｕｌｅｒ方法是渐近稳定．     

关于‖n∑k=1│x—xk│^S│lk（x）│^t‖的界

给出了‖ｎ∑ｋ＝１│ｘ－ｘｋ│＾ｓ│ｌｋ（ｘ）│＾ｔ‖的下界，ｓ，ｔ为非负实数。     

一阶非线性偏差变元微分方程解的振动性

一阶非线性偏差变元微分方程解的振动性唐先华（中南工业大学长沙４１００８３）１原有基础考虑如下形式的泛函微分方程ｘ′（ｔ）＋ｎｉ＝１Ｐｉ（ｔ）ｆｉ（ｘ（ｇｉ１（ｔ）），ｘ（ｇｉ２（ｔ）），…，ｘ（ｇｉｍｉ（ｔ）））＋ｈ（ｔ，ｘ（ｔ），ｘ（ｇ１（ｔ））...     

Development of integrated solutions for the decentralisation of electricity supply to power-hungry regions

The relevance of the study is conditioned by the need for practical development and implementation of integrated solutions for the decentralisation of power supply to various geographical regions suffering from a shortage of electric energy due to pronounced problems with the energy supply. The purpose of this study is to identify the main aspects of the development of integrated solutions for the decentralisation of energy supply to power-hungry regions, which may be of significant practical importance from the standpoint of improving the quality of energy supply to such regions. The leading methodological approach in this study is a combination of methods of system analysis of existing principles for the development of integrated solutions for the decentralisation of electricity supply to regions suffering from power shortages, with an analytical investigation of various aspects of electricity supply to power-hungry regions, which is of significant practical importance in terms of improving the quality of electricity supply to remote settlements and districts of the Republic of Kazakhstan. The results obtained clearly indicate the existence of significant prospects for the use of alternative sources of electricity in the issues of decentralisation of power supply to power-hungry regions, and also demonstrate the sequence of development and practical implementation of integrated solutions aimed at timely solving this problem, aimed at meeting the demand for electric energy of residential facilities in these regions and industrial production located in them. The results of this study and the conclusions formulated on their basis are of significant practical importance for employees of power supply systems, who solve practical issues of electric energy supplies to remote geographical regions suffering from power shortages.     

Improvement of automatic control systems of high-power turbines of PAO tubroatom for nuclear power plants

The main technical solutions applied by PAO Turboatom used as the compensatory measures at the increase of the period of nonstop operation of nuclear power plants' (NPP) turbines with VVER-1000 type reactors up to 18 months are (1) replacing the standard hydraulic speed controller with an electronic one, (2) introduction of overclocking protection, (3) modernization of units of stop-control valves of high pressures, (4) installation of locking dampers on the receiver tubes of turbines of the first and second modification, and (5) improving the quality of repairs by reviewing the requirements for their implementation. The introduction of complex diagnostics of a control system on the basis of automatic treatment of results of registration of working parameters of the turbine is allocated as a separate prospective direction. Using an electronic controller of speed makes it possible to simplify the procedure of its inclusion in work at the failure of an electro-hydraulic system of control and vice versa. The regimes of maintaining the turbine rotor speed, steam pressure on the outlet of turbine, and the positions of main servomotors were introduced into the functions of the electronic controller. An electronic controller of speed includes its own electro-hydraulic transducer, turbine rotor speed sensor, and sensors of the position of main servomotors. Into the functions of electro- hydraulic control system and electronic speed controller, the function of overclocking protection, which determines the formation of commands for stopping the turbine at the exceeding of both the defined level of rotation speed and the defined combination of achieved rotation speed and angular acceleration of rotor, was introduced. To simplify the correction of forces acting on the control valve cups, the design of the cups was changed, and it has the profiled inserts. The solutions proposed were implemented on K-1100-60/1500-2M turbines of Rostov NPP. From the composition of control system of already made turbines, the devices of speed switching of moving of control flaps for opening and hydraulic damper in the servomotors of regulating flaps were excluded; the fists of the control valves providing the increased valve stroke for opening and the construction of filters for regulation, electro-hydraulic converters, oil draining device, etc. was changed.     

交联聚乙烯交联度对材料击穿强度的影响

为了研究XLPE材料交联度对其电气性能的影响,制备不同交联度的XLPE样本并对其进行电气击穿实验,分析在不同的交联度区间范围内样本击穿场强变化。利用温度-时间控制法制备六组不同交联度的XLPE样本;利用差式扫描量热仪测量得到样本结晶度;利用交流变压器测量得到样本的击穿强度。实验结果表明,随着交联度上升,样本击穿场强呈先上升后下降趋势。在交联度为0%～75%区间范围内,样本击穿场强增加2%。在交联度为75%～88%范围内,样本击穿场强增加21.2%。而在交联度为88%～92%范围内,样本击穿场强下降5.3%。分析认为,样本的击穿强度与样本交联度和材料均匀程度有关。当交联度较低时,样本的击穿强度主要由样本交联度决定,随着交联度上升,样本击穿强度增加。但由于此时局部材料结构较为不均匀,因此击穿强度增加幅度不大。而当交联度上升至75%时,材料形成较为密集、均匀的三维网状结构,导致样本击穿场强大幅上升。而当交联度继续增加时,此时样本结晶度下降幅度较大,局部材料结构变得不均匀,导致样本击穿强度下降。     

Using the sensors of shaft position for simulation of misalignments of shafting supports of turbounits

Examples of using the method developed for the earlier proposed concept of the monitoring system of the technical condition of a turbounit are presented. The solution methods of the inverse problem—the calculation of misalignments of supports based on the measurement results of positions of rotor pins in the borings of bearings during the operation of a turbounit—are demonstrated. The results of determination of static responses of supports at operation misalignments are presented. The examples of simulation and calculation of misalignments of supports are made for the three-bearing “high-pressure rotor–middle-pressure rotor” (HPR–MPR) system of a turbounit with 250 MW capacity and for 14-supporting shafting of a turbounit with 1000 MW capacity. The calculation results of coefficients of the stiffness matrix of shaftings and testing of methods for solving the inverse problem by modeling are presented. The high accuracy of the solution of the inverse problem at the inversion of the stiffness matrix of shafting used for determining the correcting centerings of rotors of multisupporting shafting is revealed. The stiffness matrix can be recommended to analyze the influence of displacements of one or several supports on changing the support responses of shafting of the turbounit during adjustment after assembling or repair. It is proposed to use the considered methods of evaluation of misalignments in the monitoring systems of changing the mutual position of supports and centerings of rotors by half-couplings of turbounits, especially for seismically dangerous regions and regions with increased sagging of foundations due to watering of soils.     

印度工程锅炉给水泵选型设计探讨

结合美国机械工程师协会（AmericanSocietyofMechanicalEngineers,ASME）和国内标准规范,对印度某300Mw电站工程合同中给水泵在正常额定选型工况、锅炉安全阀起跳以及甩负荷选型最大连续蒸发量（boil—ermaximumcontinuerate,BMCR）工况的选型参数行分析,得到高压给水泵扬程和流量选型计算和设计的依据,提出给水泵按BMCR工况选型,再以锅炉汽包安全阀起跳和电网频率波动2种工况作为给水泵选型的出力校验方法,可作为今后同类工程技术谈判的依据和设计基础。     

Analysis of the degree of sparkling of certain commutator plates of electric machines by the photo-stroboscopic method

Analysis of the causes of failure showed that failures of a commutator and brush assembly (CBA) of electric machines make up 10–15% of the total number of failures. Many different methods to control the degree of sparkling of the CBA plates based on the measurement of different physical values and connected with the CBA sparkling processes were developed. The article describes a method of automated analysis of the degree of sparkling of certain commutator electric machine with the use of stroboscopic photo recording of sparkling and computer processing of the photo images of the sparkling plates aiming at obtaining the degree of sparkling for each collector plate. Processing methods of such images using the original OpenCV software library including image identification, classification and obtaining of the integral image and its analysis were considered. The proposed method allows the degree of sparkling under the trailing edge of the brush for each commutator plate to be determined. Determination is carried out for a large number of switching cycles for each brush, which allows statistical error to be avoided; in addition, automation of measurements decreases the influence of human factor on the test result.     

Heat transfer enhancement in steam-turbine condensers with the use of surface-active substances

A technology of the enhancement of the power efficiency of steam-turbine plants (STPs) is proposed by the treatment of surfaces of a piped condenser system over the steam and water sides with the use of surface-active substances (SAS). The transition of filmwise condensation into dropwise makes it possible to increase the heat-transfer coefficient by 50–70% because of hydrophobization of outside surfaces of the steam side that results in vacuum extension at minimum operating costs. The resulting data are verified by laboratory investigations and full-scale tests. The accumulation rate of thermobarrier deposits over the water side decreases by a factor of 6–8, and, correspondingly, the overhaul life connected with the refinement of condenser pipes increases. The maintenance of the hydrophobic film of SAS at the outside surface of condenser pipes can be provided by the periodic injection of SAS on the inlet of a low-pressure cylinder (CLP) of the turbine both in the period of short-time stops and during the operation of STPs. At the same time, because of the additional dispersion of the liquid phase, the rate of drop-impact erosion of the blade row decreases by 30%.     

Trends in the development of industrially assimilated renewable energy: the problem of resource restrictions

An analysis of the dynamics of the development of wind and solar energy and potential resource restrictions of the dissemination of these technologies of energy generation associated with intensive use of rare earth metals and some other mineral resources are presented. The technological prospects of various directions of decisions of the problem of resource restrictions, including escalating of volumes of extraction and production of necessary mineral components, creating substitutes of scarce materials and development of recycling are considered. The bottlenecks of each of the above-mentioned decisions were founded. Conclusions are drawn on the prospects of development of the Russian high-tech sectors of the economy in the context of the most probable decisions of the problem of resource restrictions of wind and solar energy. An increase in extraction and production of rare earth metals and some other materials, stimulation of domestic research and development (R&D) to create the permanent magnets of new types and new technologies of wind-powered generation, and reduction of the resource-demand and technology development of recycling the components of power equipment are the most prospective directions of progress. The innovations in these directions will be in demand on the European, Chinese, and North American markets in the near decades due to the end of the life cycle (approximately 30 years) of wind and solar energy projects started at the turn of the 20th–21st centuries (the beginning of exponential growth in plants). The private investors and relevant regional and federal government agencies can use the qualitative characteristics of the dynamics of industrially assimilated renewable energy to choose the most promising investment orientations in energy projects and selection of the most economically sound development methods of energy and related industries.     

基于复杂网络的产品竞争网的特性研究

专业镇经济是珠三角经济的重要特征之一,本文对以同类和关联产品为纽带的专业镇经济,从复杂网络的角度进行了分析.在专业镇企业集群的产品竞争网构建方面,提出了一个新颖的竞争选择度模型.通过基于竞争选择度模型的专业镇产品竞争网的建模分析,可以发现珠三角专业镇的产品竞争网具有比较典型的无标度和小世界特征.经过对广东顺德地区2个国内比较著名的专业镇产品竞争网的实证分析,可以大致得出与产品竞争网理论推导相符合的结论.     

Considering the summation of the effect of harmful substances during the calculation of the environmentally safe waste water discharge

This article presents the technique of assessing the maximum allowable (standard) discharge of waste waters with several harmful substances into a water reservoir. The technique makes it possible to take into account the summation of their effect provided that the limiting harmful indices are the same. The expressions for the determination of the discharge limit of waste waters have been derived from the conditions of admissibility of the effect of several harmful substances on the waters of a reservoir. Mathematical conditions of admissibility of the effect of wastewaters on a reservoir are given for the characteristic combinations of limiting harmful indices and hazard classes of several substances. The conditions of admissibility of effects are presented in the form of logical products of the sums of relative concentrations that should not exceed the value of 1. It is shown that the calculation of the process of wastewater dilution in a flowing water reservoir is possible only on the basis of a numerical method to assess the wastewater discharge limit. An example of the numerical calculation of the standard limit of industrial enterprise wastewater discharges that contain polysulfide oil, flocculant VPK-101, and fungicide captan is given to test this method. In addition to these three harmful substances, the water reservoir also contained a fourth substance, namely, Zellek-Super herbicide, above the waste discharge point. The summation of the harmful effect was taken into account for VPK-101, captan, and Zellek-Super. The reliability of the technique was tested by the calculation of concentrations of the four substances in the control point of the flowing reservoir during the estimated maximum allowable wastewater discharge. It is shown that the value of the maximum allowable discharge limit was almost two times higher for the example under consideration, taking into account that the effect of harmful substances was unidirectional, which provides a higher level of environmental safety for them.