Ecological Optimum Population of Binzhou City Based on PEER Model

Taking into account the regional carrying capacity,the population capacity and optimum population of Binzhou City from 2007 to 2017 under certain economic,resource and environmental conditions were calculated based on PEER model.The results show that the population capacity of Binzhou City during 2007-2017 ranged from 6.03 million to 6.43 million,and ecological optimum population was between 5.05 million and 5.34 million.The actual population of the city was between 3.74 million and 3.94 million.The impact of the "two-child" policy on population growth was small,and there was still room for population growth.The population pressure index was greater than 0.7 and less than 1,showing that economic and resource population carrying capacity had certain surplus but were still not optimistic.Environmental pressure index was relatively high,and population carrying capacity was low.

The Disagreement between Anisotropic-Isotropic Diffuse Solar Radiation Models as a Function of Solar Declination: Computing the Optimum Tilt Angle of Solar Panels in the Area of Southern-Italy

In this paper a simulation to maximize the global solar radiation on a sloped collecting surface was applied to typical latitudes in the area of southern Italy, to calculate the optimum tilt angle of solar panels on building structures or large photovoltaic power plants located in that geographical area. Indeed, the area of southern Italy and in particular Sicily and Calabria are the top of European locations for acquiring solar energy. Some models of diffuse solar irradiance were taken into account to determine panels inclinations that maximized the impinging solar radiation by means of global horizontal solar radiation data provided from the Italian Institute of ENEA (Italy). An algorithm was used for the simulation providing a set of tilt angles for each latitude. The optimum tilt angle values obtained from the simulation resulted to be strictly related to the model of diffuse solar radiation that was used. Indeed, the disagreement between the values obtained using anisotropic models of diffuse solar radiation and those obtained from the isotropic model resulted to decrease significantly with increasing solar declination, showing that the isotropic model can be reliable only in summer months.

振动压路机的能量传递模型与作业参数优化研究

为提高振动压路机作业过程的压实质量,研究了振动压路机的能量传递模型与作业参数优化。首先基于U-K方程建立“碾轮-被压实材料”的系统振动动力学模型,结合能量守恒提出振动压路机能量传递模型;然后以振动频率和压实速度作为寻优工作参数,构建路面压实质量的优化模型;最后通过案例验证证明了所提方法的可行性与有效性。结果表明:工作频率与被压实材料的固有频率比值保持在√2~2范围内,可避免共振带来的影响;初始阶段低速碾压,材料性能稳定后提高碾压速度可保证高效压实,得出振动频率在21.8~27 Hz、压实速度在2.36~2.91 km/s范围内,可达到最优的压实效果。所提的能量传递模型、作业参数优化模型为保障振动压路机压实质量奠定了基础,为提高振动压路机压实质量和效率提供了参考。

滨海盐碱稻区水稻氮肥适宜用量及运筹模式研究

通过在辽河三角洲滨海盐碱稻区设置田间小区试验,探明了不同氮肥用量(0~420 kg/hm^(2))和运筹模式(基肥∶蘖肥∶穗肥分别为6∶3∶1与4∶3∶3,以下简称6∶3∶1模式与4∶3∶3模式)对水稻生长发育以及产量品质的影响。通过对水稻分蘖动态调查研究表明,两种氮肥运筹模式下水稻平均茎蘖数均与施氮量呈显著正相关(r^(2)≥0.90),同时,6∶3∶1模式下氮肥用量对水稻平均茎蘖数的影响程度高于4∶3∶3模式。通过分析不同施氮量与产量的相关关系,发现了两者符合线性加平台肥料效应模型,拟合得到6∶3∶1模式与4∶3∶3模式下的最佳施氮量(EONR)分别为216 kg/hm^(2)(210~235 kg/hm^(2))与316 kg/hm^(2)(300~332 kg/hm^(2)),6∶3∶1模式的EONR比4∶3∶3模式高46.3%。通过考查两种氮肥运筹模式下的氮素利用率指标,发现4∶3∶3模式下各处理氮素利用率(37.2%~40.8%)显著高于6∶3∶1模式(29.9%~34.2%)。通过分析稻米营养与食味品质,在兼顾产量的前提下,再次明确了6∶3∶1模式与4∶3∶3模式下适宜氮肥用量分别为300~332与210~235 kg/hm^(2)。综合考虑水稻产量、氮素利用率以及稻米品质3个指标,推荐辽河三角洲滨海盐碱稻区的适宜氮肥施用量为210~235 kg/hm^(2),最宜采用的氮肥运筹模式为4∶3∶3。研究结果可以为辽河三角洲盐碱稻区合理施肥与氮肥高效利用提供切实的技术指导,为该地区水稻产业绿色发展提供理论支撑。

基于耦合辐射模型的太阳能集热器倾角优化研究

为了使太阳能集热器获得更多的太阳辐射量,须对集热器倾角进行优化。文章在建立倾斜面太阳辐射计算模型的基础上,分别优化直接辐射、散射辐射的计算过程。以太阳能集热器运行期间倾斜面接收最大辐射量为求解目标,借助MATLAB对集热器倾角进行优化分析,得到月度最佳倾角和年度最佳倾角。其中天津地区的太阳能集热器年度最佳倾角为36.3°,比当地纬度略小;月度最佳倾角为10~64°,表现为夏季小冬季大的特点。相较于水平放置,在年度最佳倾角和月度最佳倾角下,太阳能集热器接收的年太阳辐射量可分别增加12.4%,17.3%;相较当地纬度作为倾角时,以月度最佳倾角值逐月调整接收的太阳辐射量可增加5.0%。分别以广州、拉萨、济南和长春为例,计算得到上述地区的年、月最佳倾角。对不同地区进行对比分析发现,直接辐射占比较高的地区逐月改变最佳倾角可获得更高的能量增益。

基于疫苗接种的SEIHRVI传染病模型分析与最优控制

为研究疫苗接种对控制传染病的影响,建立了具有标准发生率的传染病模型。通过推导得出模型的基本再生数,给出地方病平衡点的存在条件。借助构造Lyapunov函数证明了平衡点的全局稳定性。应用Pontryagin最大值原理分析了最优控制问题,得出最优控制策略。结果表明:提高疫苗接种率和效力能有效控制疾病传播;注意自我保护,及时接种以及重视治疗一定程度上可减小疾病爆发的规模。

火炬树在北美和中国空间分布差异对比及防范入侵措施

火炬树原产于北美洲东部,引进中国后主要栽培于贫瘠土壤上,用于植树造林和保持水土。然而其入侵性和扩散能力较强,管控不当将会严重破坏侵入地生态系统的多样性。采用了GIS和MaxEnt模型相结合的方法,模拟了火炬树在北美和中国地区的适宜分布区域,分析了主要环境影响因素,并利用ROC曲线验证模型结果的准确度。研究结果表明:火炬树在北美和中国的适宜分布区域都主要集中在30°-40°N气候相对湿润地带;影响MaxEnt模型预测结果的关键环境因子都是气候因子;预测模型的AUC值都大于9。但两个地区的部分环境因子的阈值范围存在明显差异,说明在入侵中国后火炬树的气候空间和生态位发生了较大变化,对中国本地的生态系统构成一定威胁。可为防疫监测和林业部门的工作提供参考依据,有助于其制定早期预警和监管措施,从而有效防治中国地区火炬树的入侵和保护生物多样性。

基于阻抗优化的电缆环流抑制装置参数设计

针对现有高压电缆金属护套环流抑制装置投入和退出缺乏灵活性,确定抑制阻抗数值时未考虑护套感应电压超标、功率损耗过大等问题,设计了一种能根据现场情况对护套环流抑制阻抗进行动态投入或退出的环流抑制装置。首先,阐述了该抑制装置的结构和动作流程;接着分析了抑制阻抗分别为纯电阻、纯电感和电阻电感组合三种类型时护套环流、感应电压和护套损耗的变化特性;在此基础上,建立优化模型求解满足护套环流和感应电压要求时使功率损耗最小的最佳阻抗值,基于最佳阻抗值对晶闸管等元件的参数进行配置。结果表明,所提方法可以得到满足工程要求的电缆抑制阻抗最优值,实现良好的环流抑制效果。

基于P-E-R和成本收益模型的青岛市适度人口规模研究

基于P-E-R模型,选取反映经济发展和资源利用水平的各项指标,通过加权分析建立回归模型,对青岛市适度人口规模进行了研究,同时从成本收益角度分析构建了适度人口测度模型考察了青岛市的城镇化质量,以新型城镇化发展为焦点,为应对未来人口增长提供了资源配置方案及建议.结果表明:青岛市经济人口承载力优势显著,明显高于资源人口承载力;现阶段青岛市人口发展符合适度人口规模,人口增长存在一定空间,但人口增长速度低于全国水平;预计到2035年,青岛市人口约为1200万人.

基于力法的格构梁节点荷载分配方法及悬臂段长度优化设计

格构梁节点荷载简化分配方法的不足在于无法考虑2个方向的梁上其他节点荷载的影响且对文克尔(Winkler)地基上梁的类型进行了主观假定。为克服格构梁节点荷载简化分配方法的上述缺点,提出了一种基于力法的格构梁节点荷载分配方法。根据节点静力平衡条件及变形协调条件,新的格构梁节点荷载分配方法通过构建并求解线性方程组,能够合理地将作用在节点的集中力分别分配给2个方向的纵梁和横梁。进一步地,引入一个格构梁边坡锚固案例并等比例地增加纵梁和横梁的悬臂长度。不同基床系数条件下,基于新的节点荷载分配方法将格构梁节点荷载分配给纵梁和横梁,然后对各梁单独进行弯矩计算。以悬臂最大正弯矩与跨中最大负弯矩比值的绝对值接近1为评价指标,对格构梁最优悬臂长度进行了评价。节点荷载分配结果表明,随着悬臂长度的增加,分配给纵梁和横梁的荷载逐渐趋于稳定。弯矩计算结果表明,随着基床系数的增大,悬臂长度对格构梁弯矩的影响逐渐减弱。不同边坡基床系数条件下,当悬跨比在0.2~0.4之间时,悬臂各梁最大正弯矩与跨中最大负弯矩趋于均衡。因此,基于力法理论的节点荷载分配方法的提出为格构梁内力的精确分析及悬臂长度优化设计提供了可靠的理论依据。

基于历史坡面位移监测数据的滑坡变形预测

根据最优加权组合理论,结合多个适应不同曲线特征的数学模型,建立最优加权组合模型用于滑坡变形的预测。基于实际滑坡监测数据分析,对加权组合模型及单一模型在数据拟合精度及预测精度方面进行了分析比较。拟合数据的结果表明,加权组合模型的拟合精度最高,预测值与实际值比较吻合,因此加权组合模型可提高滑坡变形临近时段的预测精度,预测数据可用于滑坡的临滑预警。

选煤厂智能配煤系统研究与应用

为解决传统配煤方式严重依赖人工经验、数据反馈较为滞后、操作复杂、劳动强度大等问题,在分析蒙大矿业选煤厂配煤系统现状的基础上,通过对智能配煤算法和控制进行研究,开发了一套智能配煤系统。该系统选用模糊控制进行比例配煤或煤质配煤,能够依据用户要求以及各产品仓的产品质量、储量情况,自动给出最优配煤方案。生产实践表明:该系统可根据煤质数据在线调节配煤比例,使蒙大矿业选煤厂混煤产品吨煤发热量提高了9.85 J,增加收益73.45万元/a,同时避免了“亏卡”现象带来的经济纠纷;实现减员3人,节约人工成本30万元/a。智能配煤系统的研究与应用,实现了选煤厂配煤的智能化、高效化与系统化,对产品煤质提升和选煤效率管控具有积极意义,且该系统具有可复制性,可广泛应用于类似条件的选煤厂配煤系统中。

Optimum municipal wastewater treatment plant design with consideration of uncertainty

A newly developed model for the optimum municipal wastewater treatment plant(MWTP) design is presented. Through introducing the interval variables, the model attempts to consider the effects of uncertainties caused by the fluctuation of the wastewater quality and quantity during the design of MWTP. The model solution procedure is illustrated in detail, and a numerical example is given to verify the feasibility and advantage of the model. Furthermore, the possibility of the model application is briefly outlined.

Non-equal-interval direct optimizing Verhulst model that x(n) be taken as initial value and its application

To overcome the deficiencies of the existing Verhulst GM(1,1) model, based on the existing grey theory, a non-equal-interval direct optimum Verhulst GM(1,1) model is built which chooses a modified n-th component x(n) of X(0) as the starting condition of the grey differential model. It optimizes a modified β value and the background value, and takes two times fitting optimization. The new model extends equal intervals to non-equal-intervals and is suitable for general data modelling and estimating parameters of the direct Verhulst GM(1,1). The new model does not need to pre-process the primitive data, nor accumulate generating operation (AGO) and inverse accumulated generating operation (IAGO). It is not only suitable for equal interval data modelling, but also for non-equal interval data modelling. As the new information is fully used and two times fitting optimization is taken, the fitting accuracy is the highest in all existing models. The example shows that the new model is simple and practical. The new model is worth expanding on and applying in data processing or on-line monitoring for tests, social sciences and other engineering sciences.

The Application of Optimum Decision in Oilfield Development

The major steps of oilfield development are given in this paper. The optimal model of oilfield development is built and the methods of optimum decision analysis are studied. The solution and analysis of the optimal tactics have been set up according to the data collected in the oilfield.

Simulation of Potential Production and Optimum Population Quantitative Indices for the Second Hybrid Rice

The article established the HDRICE model by modifying the structure of the ORYZA1 model and revising its parameters by field experiments. The HDRICE model consists of the modules of morphological development of rice, daily dry matter accumulation and partitioning, daily CO2 assimilation of the canopy, leaf area, and tiller development. The model preferably simulated the dynamic rice development because of the thorough integration of the effects of temperature and light on the rates of rice development, photosynthesis, respiration, and. other ecophysiological processes. In addition, this model has attainable grain yield in the test experiment that showed the potential yield of cultivar Xieyou 46 ranged from 11 to 13 tons ha-~. Besides, the model was used to optimize the combinations of the transplanting date, seedling age and density for cultivar Xieyou 46 at Jinhua area, and the population quantitative indices to attain the potential yield such as maximum stems, effective panicles, filled grain number/leaf area, and so on. The result showed that the combination of transplanting date on July 25, seedling age of 35 days and base seedling density of 1.33 x 106ha-1 is the optimum combination for the second hybrid rice production in Jinhua County, China. And the maximum stems, the effective panicles, the filled grain per panicle, the peak of optimum LAI, LAI in later filling stage, and the filled grain number/leaf were 6.03×10^6ha, 3.99×10^6ha, 119.2, 8.59, 5-6, and 0.64, respectively.

Semi-Automatic Modeling Technique of Torque Converter Flow Passage

The modeling technique of hydrodynamic torque converter flow passage was investigated. The semi-automatic modeling technique of torque converter flow passage was proposed. The flow passage model of each converter wheel is considered as a revolution entity sliced by two curved surfaces. In order to generate the revolution entity, a new approximation method, condition optimum arc approximation, was proposed. The method was used to approximate the meridional streamlines of the inner and outer wall. As a result, the three-dimensional revolution entity can be conveniently generated. In order to create slice surfaces, the central stream surface of flow passage was approximated with a quadric surface. The normal vector of the quadric surface and the thickness/thickness-function of bade were used to calculate the discrete point coordinates of blade surfaces. Via the rotation transformation to the coordinates, the discrete point coordinates of slice surfaces were obtained. A parameterized program code used for the hydrodynamic torque converter design and semi-automatic modeling was developed. Modeling errors were calculated and analyzed. The flow passage model was generated in several minutes with the help of the program code, Auto CAD and Solidworks software. Finally, the model was inputted into Gambit, and the pre-processing task used for the numerical simulation of torque converter flow field was successfully completed. The investigation results show that the semi-automatic modeling not only can ensure the accuracy of modeling, but also librates the research and design workers of torque converter from the time-consuming modeling work, which paves the way for the numerical simulation of the complex flow field of the hydrodynamic torque converter.

Reliability-Based Full-Life Cycle Optimum Design of Offshore Jacket Platform

Based on the consideration of operation environment and structural property, an optimum design model of offshore jacket platform is developed in this paper, namely, the reliability-based full-life cycle optimum design model. In this model, the time-dependent reliability assessment method for structural members is established by combination of the decrease of sectional size and performance deterioration of material. The initial investment, maintenance cost and failure loss cost are assembled into the model. The total cost of the platform structure system in its full service period is chosen as the objective function, and the initial reliabilities of the layer elements partitioned in advance are taken as the design variables. Different models are obtained, depending on whether the system reliability constraint is considered or not. This optimum design model can result in the lowest full-life cost and the optimal initial layer reliability of an offshore jacket platform in the design of marine structures. The feasibility of this model is illustrated with an actual jacket platform in the Liaodong Gulf as an example.

HYPERSTATIC STRUCTURE MAPPING MODEL BUILDING AND OPTIMIZING DESIGN

Hyperstatic structure plane model being built by structural mechanics is studied. Space model precisely reflected in real stress of the structure is built by finite element method （FEM） analysis commerce software. Mapping model of complex structure system is set up, with convenient calculation just as in plane model and comprehensive information as in space model. Plane model and space model are calculated under the same working condition. Plane model modular construction inner force is considered as input data; Space model modular construction inner force is considered as output data. Thus specimen is built on input data and output dam. Character and affiliation are extracted through training specimen, with the employment of nonlinear mapping capability of the artificial neural network. Mapping model with interpolation and extrpolation is gained, laying the foundation for optimum design. The steel structure of high-layer parking system （SSHLPS） is calculated as an instance. A three-layer back-propagation （BP） net including one hidden layer is constructed with nine input nodes and eight output nodes for a five-layer SSHLPS. The three-layer structure optimization result through the mapping model interpolation contrasts with integrity re-analysis, and seven layers structure through the mapping model extrpulation contrasts with integrity re-analysis. Any layer SSHLPS among 1-8 can be calculated with much accuracy. Amount of calculation can also be reduced if it is appfied into the same topological structure, with reduced distortion and assured precision.