Energy consumption model and energy efficiency evaluation for CNC continuous generating grinding machine tools

Abstract

Machine tool, which is the basis energy consumed device in manufacturing system, its energy consumption model and energy efficiency evaluation are the prerequisites for energy saving in manufacturing. Considering the multi-energy-sources features,analysed the mathematical model of a CNC continuous generating grinding machine tool from the view of energy constitute. The energy sources of a CNC continuous generating grinding machine tool are classified into gear grinding system, grinding wheel dressing system and auxiliary system. Based on the power balance equations of energy flow, the energy flow system of a CNC continuous generating grinding machine tool is established. And then the energy consumption mathematical model of a CNC continuous generating grinding machine tool is set up by combining the power balance equations with the operating features of three kinds of energy sources. The case study shows that the proposed energy consumption model can provide fundamental support for energy consumption forecasting, energy efficiency analysis and energy-saving optimisation during the machine tool operation process.     

自然资源代际转移模型研究

代际均衡发展是可持续发展的核心内容之一，而代际均衡的实现在目前情况下有赖于代际主动财富转移改策实施。政府的宏观调控是实施这一政策的有力手段。具体的措施可开征“资源代际补偿税”以建立专项基金制度     

资源代际管理与可持续发展

代际均衡发展是可持续发展战略的重要方面,代际均衡发展的物质基础是代际财富均衡。自然资源是代际财富均衡分配的主要内容,需要进行资源代际管理来保证可持续发展战略的实现。     

Determination of polybrominated diphenyl ethers in soil and sediment from an electronic waste recycling facility

In this study samples of ten species of fish were analyzed for concentrations of organochlorine pesticides, PCBs and heavy metals (Pb, Cd, and Cu). Fish were captured using electric fishing on ten sites along the Dr?me river (Rh?ne-Alpes region). Quantitative determination of the organochlorine and PCBs compounds was performed by gas chromatography-electron-capture detection (GC-ECD). The concentrations of heavy metals were determined by atomic absorption spectrophotometry. Samples contained detectable concentrations of lindane, PCBs, and heavy metals but at concentrations below the maximum residue limit (MRL). Non-parametric statistical analysis was performed to distinguish groups of sites with different levels of contamination. PCBs concentrations increased along the river with four groups of sites significantly different from each other. Cadmium concentrations were below the MRL. Lead contamination showed two groups significantly different and a repartition similar to PCBs. Copper contamination was correlated with the localization of vineyards. We assessed the potential effects of contamination the otter (Lutra lutra). The concentrations of all pollutants analyzed in fish sampled in this study are lower than the threshold values described in literature. The Dr?me river is relatively unpolluted river, and the establishment of otter populations should not be affected by pollution.     

亚铁催化声化学降解罗丹明B

比较了不同金属离子对罗丹明B的声化学降解作用，发现超声时加入Fe^2＋反应速率常数为单独超声波降解时的1．6倍，反应在前5h内符合假一级动力学。研究了亚铁离子强化声化学对罗丹明B的降解作用，考察了Fe^2＋用量，溶液初始pH值，曝气，反应温度和超声功率等因素对脱色速率的影响。研究表明，酸性条件有利于染料的脱色；有曝气时的声化学脱色速率常数是单独超声时的6倍；声化学反应的活化能较低，反应在低温就可以进行；超声功率的改变对脱色速率的影响不大。UV-VIS扫描图谱显示，染料在225nm和256nm处的紫外吸收明显降低，初步探讨了罗丹明B的降解机理。     

一氯苯在钒钛催化剂表面亲核取代反应的DFT计算

采用DFT计算方法对一氯苯在V2O5(001)和脱钛矿表面氧上的亲核取代反应的机理进行了分析。对不同DFT泛函在氯代芳香烃-过渡金属氧化物体系计算中的准确性进行了验证,发现采用B3LYP泛函得到的过渡态相对能量与标准值的偏差为9.63 kJ/mol,产物相对能量的偏差为8.79 kJ/mol,可以用于反应路径的推断。对亲核取代反应的机理进行了分析:首先苯环上与氯原子连接的碳原子受到表面氧的攻击,氯原子被驱离环平面;然后C—O健开始形成,同时C—Cl健断裂;最后苯酚盐结构形成,而驱离的氯原子与提供一个空轨道的过渡金属原子连接。与V2O5(001)表面及脱钛矿(100)和(101)表面相比,脱钛矿(001)表面的桥位氧是亲核取代最有可能发生的位置,吸附能为193.77 kJ/mol,吸附能垒为135.33 kJ/mol。     

Strictly protected areas are not necessarily more effective than areas in which multiple human uses are permitted

The International Union for Conservation of Nature (IUCN) classifies protected areas into six categories, ranging from strict nature reserves to areas where multiple human uses are permitted. In the past, many researchers have questioned the effectiveness of multiple-use areas, fueling an unresolved debate regarding their conservation value. The literature so far has been inconclusive: although several studies have found that strictly protected areas are more effective, others have found the opposite, and yet others that the two types do not differ. To help resolve this debate, we reviewed the literature on protected areas and conducted our own analysis using > 19 000 terrestrial protected areas worldwide. We found that the differences between strictly protected areas and areas in which multiple human uses are permitted are often small and not statistically significant. Although the effectiveness of protected areas worldwide varies, other factors, besides their assigned IUCN category, are likely to be driving this pattern.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01426-5) contains supplementary material, which is available to authorized users.     

焙烧镁铝水滑石的制备及其对水中Cl-和SO42-的吸附特性

采用共沉淀法制备了n(Mg):n(Al)=3:1的镁铝水滑石(LDH),进一步通过焙烧得到改性产物LDO,用XRD与FT-IR对LDO进行了表征,系统研究了其对水中Cl-和SO42-的吸附特性。结果表明:焙烧温度为400℃时,LDO对Cl-和SO42-的吸附量较焙烧前分别提高了75.00%和78.20%;pH值在4~10之间,LDO对Cl-和SO42-的吸附量基本无变化;LDO对Cl-和SO42-的吸附分别符合准一级、准二级动力学模型,吸附等温线均可以用Langmuir方程来描述,最大吸附量分别为61.88和227.79 mg/g。LDO对不同浓度的盐渍土洗盐废水的吸附研究结果表明,LDO对洗盐废水中Cl-和SO42-的去除具有较好的效果。LDO投加量相同情况下,Cl-和SO42-浓度分别为60.71和50.03 mg/L时,LDO对Cl-和SO42-的吸附量分别为16.97和22.85 mg/g;当废水中Cl-和SO42-浓度分别为585.75和513.08 mg/L时,LDO对Cl-和SO42-的吸附量分别为0.89和112.47 mg/g。以上研究结果表明,利用LDO处理轻度的氯化物(氯化物硫酸盐)型盐渍土洗盐废水和中度硫酸盐(硫酸盐氯化物)型盐渍土洗盐废水时,吸附效果较好。     

修复受污染水体的潜流人工湿地微生物多样性研究

进行了潜流人工湿地修复受污染水体试验研究,并比较单一植物与单一填料系统与多种植物系统与多种填料系统的处理效果.运用PCR-DGGE技术研究3种不同类型的潜流人工湿地中微生物种群结构,结合多样性分析和聚类分析方法,分析了人工湿地微生物种群结构特征.