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1.
运用SPSS统计软件对我国31个省、直辖市和自治区的9个主要环境污染检测指标进行了因子分析,并将这9项指标归结为3个因子,在此基础上根据不同地区的因子得分情况对我国环境污染状况进行了总体比较和评价.研究结论表明,我国以工业大气污染为主的污染排序,前几位的省份是山西、河北、山东、河南、四川、江苏和辽宁等,它们是我国环境污染最严重的地区;污染情况比较理想的地区是西藏、海南、北京和青海等.这个结论有助于我国环境管理部门采取有效对策,有针对性地改善我国各地区的环境污染状况.  相似文献   

2.
王萌  王铮  邓嵘 《包装工程》2024,(10):96-105
目的 在移动互联网高速发展的背景下,了解用户使用知识获取类平台意愿的影响因素,为平台的设计和服务提供参考。方法 通过用户调研、因子分析和线性回归分析,发放问卷450份,确定影响用户使用知识获取平台的具体因素,并分析以上要素和用户使用意愿之间的影响关系,以及各因素间的内在关联程度。结果 因子分析显示,影响用户使用知识获取类平台的主要因素是社交互动、功能质量、有用性和安抚性,其中社交互动是影响用户使用意愿的最重要因素,接着依次为功能质量、安抚性和有用性。多元线性回归分析显示,社交互动和功能质量是影响安抚性的直接因素且社交互动对功能质量产生影响。有用性在促进社交互动的同时受到功能质量的影响。结论 知识获取平台在开发设计时应着重增强用户间的交流互动、提供完善的产品功能、聚集优质资源并提供针对性内容以缓解用户的知识焦虑,最终提升用户对平台的使用意愿。  相似文献   

3.
Abstract: In this work, the combined effect of indentation damage and of manufacturing defects of a hybrid laminate including jute hessian cloth (plain weave) and hemp fibres in an epoxy matrix has been investigated. With this aim, various non‐destructive evaluation (NDE) techniques have been employed, such as near‐infrared (NIR) reflectography, infrared thermography (IRT), holographic interferometry (HI) and digital speckle photography (DSP). In particular, two different methods of heating were applied during IRT data collection: pulse thermography and square pulse thermography (SPT). The first one using a mid‐wave infrared (IR) camera, while the second one using a long‐wave IR camera. In the same way, two different cameras working into the near‐ and short‐wave IR spectra were used, to compare different results from 0.74 to 14 μm. Data were processed applying principal component thermography (PCT), correlation and the robust second‐order blind identification (SOBI‐RO) algorithms. The latter is used for the first time to our knowledge in this work. The defects found were enhanced by image subtraction between the reflectogram and the transmittogram, distance transform and image fusion. In particular, data fusion from IRT and DPS images allowed clearly defining the extension of the indentation damage.  相似文献   

4.
分别对掺杂了新型发色团分子的聚甲基丙烯酸甲酯(PMMA)和纯的PMMA进行了热重分析,得到了2种体系在不同质量损失下的温度并计算了积分程序分解温度(IPDT).结果表明,掺杂后聚合物体系的热稳定性好于纯的PMMA.采用Achar方法和Coats-Redfern方法对2种体系热降解的动力学过程进行了分析,得到了对应的非等温动力学方程.  相似文献   

5.
1.IntroductionThe use of the Quantimet 900 imageanalysis system to simulate the growth kine-tics of ferrite by carbon diffusion inspheroidal graphite(SG)cast iron has beendiscussed[1].The results obtained from theQ900 agreed qualitatively with experiment.  相似文献   

6.
对航空燃油泵柱塞弹簧长期存在的折断失效原因进行了较为全面系统的分析,通过提高原材料冶金质量,改进柱塞弹簧制造工艺,采用超声波检查弹簧珠表面缺陷等手段提高柱塞弹簧质量,彻底地解决了其折断失效问题。  相似文献   

7.
《Journal of Modern Optics》2013,60(7):531-538
It is shown that a combination of two dielectric layers, each with an optical thickness of less than a quarter-wave, behaves to a great extent as one quarter-wave layer.  相似文献   

8.
《Strain》2018,54(2)
A methodology for finding the yield point of epoxy resins, both neat and particulate toughened, is described. Trends of the effect that particulate filling has on the time dependent response of these materials were constructed from observations made with stereo‐based digital image correlation (3D–DIC), namely, creep and stress relaxation at constant load. The use of 3D–DIC also enabled the observation of differences in deformation mechanisms resulting from the particle addition. The focus is put on the technique's potential to characterise materials and produce clear relationships between composition and mechanical strain response. The methodology proposed herein allows the observation and study of multiple deformation mechanisms from a single test, and thus can potentially minimise the number of specimens needed for a comprehensive test campaign.  相似文献   

9.
Purpose: To investigate the physical stability and drug release-related properties of the aqueous polymer dispersions Kollicoat® SR 30 D and Aquacoat® ECD (an ethylcellulose-based dispersion) in the presence water-soluble polymers (pore formers) with special attention to the potential flocculation of the polymer dispersions. Methods: A precise characterization of the flocculation phenomena in undiluted samples was monitored with turbidimetric measurements using the Turbiscan Lab-Expert. Theophylline or propranolol HCl drug-layered pellets were coated with Kollicoat® SR 30 D and Aquacoat® ECD by the addition of water-soluble polymers polyvinyl pyrrolidone (Kollidon® 30 and 90 F), polyvinyl alcohol–polyethylene glycol graft copolymer (Kollicoat® IR), and hydroxypropyl methylcellulose (Pharmacoat® 603 or 606) in a fluidized bed coater Glatt GPCG-1 and drug release was performed according to UPS paddle method. Results: Stable dispersions were obtained with both Kollicoat® SR 30 D (a polyvinyl acetate-based dispersion) and Aquacoat® ECD with up to 50% hydrophilic pore formers polyvinyl alcohol-polyethylene glycol graft copolymer (Kollicoat® IR) and polyvinyl pyrrolidone (Kollidon® 30). In general, Kollicoat® SR 30 D was more stable against flocculation than Aquacoat® ECD. Stable dispersions were also obtained with higher amounts of water-soluble polymer or by reducing the concentration of the polymer dispersion. Flocculated dispersions resulted in porous films and, thus, in a sharp increase in drug release. Conclusions: Kollicoat® SR 30 D was more resistant to flocculation upon addition of water-soluble polymers than Aquacoat® ECD. The continuous adjustment of drug release from Kollicoat® SR 30-coated pellets was possible with Kollicoat® IR amounts over a broad range.  相似文献   

10.
介绍一种点式光纤半导体温度传感器的研究及其在电力设备安全监测中的应用情况.实际应用表明,所研制的传感器具有较高精度,精度为0.5℃(-20~125℃),价格低,性能稳定,具有很高的性价比.  相似文献   

11.
Mixture breakage of particles in various sizes is common in industrial mills, and breakage behavior is influenced by size composition. But studies on particle breakage are conducted to narrowly sized samples. In this paper, tentative works are made to investigate interaction among super clean coal in mixture breakage from aspects of breakage rate, energy consumed characteristics and energy split factors. Experimental results demonstrate that breakage rate of coarse particles in mixture breakage increases if compared with that in single breakage. Particle size is modelled into classical breakage equation, and the modified model is successfully applied to mixture breakage. Energy split factor of component is determined based on the balance of specific energies of components in heterogeneous breakage and energy-size equation, and consumed energy (W) of component in multi-component grinding is calculated. Calculated energy split factors of components are all above one in various mixed conditions, so energy efficiency (value of product t10 at the same specific energy) decreases if compared with that of single breakage. Energy split analyses are also conducted for mixture breakage of middling coals, which illustrates that the method is robustness for energy-size reduction process influenced by associated minerals in coal.  相似文献   

12.
王英伍  杨皓  宁平  李凯  李山  黄彬 《材料导报》2017,31(15):50-59
从污泥基活性炭的制备及其在水和大气环境领域的应用两个部分进行了综述。主要总结了3种传统制备方法的原理;同时,对比了7种不同制备方法的优缺点和主要用途,汇总了通过添加农作物秸秆和矿物来提升污泥活性炭性质的相关研究。污泥基活性炭在环境领域的应用主要包括其对废水中有机染料、有机药物、小分子有机化合物和重金属的吸附以及其对硫化氢等工业废气和甲醛等室内废气的净化。另外,分别举例说明了不同来源污泥基活性炭的用途和性能。最后,总结分析了污泥基活性炭在研究中存在的问题以及今后的主要发展方向。  相似文献   

13.
The possibility of using phase-correlation analysis of an image in optoelectronic devices to measure small angular and linear displacements of objects is considered. It is shown that the measurement accuracy is thereby increased.__________Translated from Izmeritel’naya Tekhnika, No. 5, pp. 37–39, May, 2005.  相似文献   

14.
This study is aimed at exploring the possibility of improving the interfacial adhesion strength of betelnut fibres using different chemical treatments namely 4% and 6% of HCl and NaOH respectively. The fibre specimens were partially embedded into different thermosetting polymer matrix (polyester and epoxy) as reinforcement blocks. Single fibre pullout tests were carried out for both the untreated (Ut) and treated betelnut fibres with different resins and tested under dry conditions. Scanning electron microscopy was used to examine the material failure morphology. The studies revealed the differences of interfacial adhesion strengths for the various test specimens of betelnut fibres treated with the polyester and epoxy matrix which followed in the order of: N6 ? N4 > H4 > Ut > H6. It was proven that fibres treated with 6% of NaOH exhibits excellent interfacial adhesion properties. The interfacial adhesion shear strength of these fibres using polyester and epoxy has improved by 141% and 115% correspondingly compared to untreated fibre under the same treatment.  相似文献   

15.
为了减小偏流角对空间光学相机成像质量的影响,分析了偏流角对空间光学相机成像质量的影响,对偏流角产生的原因及其像移补偿原理进行了研究。根据某空间光学相机的特点,采用在相机上设计调偏流机构的方法进行偏流角的补偿。通过几种常用的调偏流机构的比较,确定了采用双向丝杆螺母驱动的调偏流方案实现焦平面偏流角的调整。对调偏流机构进行了有限元分析,分析结果表明调偏流机构具有较高的刚度和动态强度。对调偏流机构进行了振动试验,并在试验前后进行调偏流机构精度的闭环检测,检测结果表明调偏流机构精度优于1′,调偏流机构偏流角调整范围为+5°~-5°,满足设计要求,实现了高精度的偏流角补偿。该调偏流机构具有强度高、刚度高、结构紧凑、稳定性好等优点。  相似文献   

16.
17.
On the basis of the Jablonski diagram, the photophysical properties of optical agents are highly associated with biomedical function and efficacy. Herein, the focus is on organic/polymer optical agents and the recent progress in the main strategies for regulating their photophysical properties to achieve superior cancer diagnosis/phototheranostics applications are highlighted. Both the approaches of nanoengineering and molecular design, which can lead to optimized effectiveness of required biomedical function, are discussed.  相似文献   

18.
基于灰色理论的电站机组状态监测与故障诊断方法   总被引:1,自引:0,他引:1  
本文主要研究了灰色理论在大型旋转机械的状态监测与故障诊断中的方法与应用问题。鉴于一般关联度分析方法在故障诊断应用中没有考虑到特征参数对诊断结果的不同影响,本文提出了加权关联度这一新概念,并给出了加权关联度用于旋转机械诊断中的方法与步骤。这种诊断方法能根据诊断结果采用自学习修正方法来修正关联度参数,提高诊断的准确度,并有很好的前景。  相似文献   

19.
厌氧发酵产氢系统的启动与乙醇型发酵优势菌群的建立   总被引:4,自引:0,他引:4  
针对乙醇型发酵这一具有较高产氢能力的有机废水产酸发酵类型,通过小试模型实验和中试系统的运行实验,研究了发酵生物制氢污泥反应系统的启动规律和驯化乙醇型发酵优势菌群的对策。研究表明,厌氧活性污泥和好氧活性污泥都可作为发酵生物制氢污泥反应系统启动的种泥,在接种量不低于6.5gVSS/L,进水有机物浓度3000~5000gCOD/L,pH4.0~4.6,HRT8~11h等控制条件下,反应系统可在45d左右建立起乙醇型发酵菌群的优势地位,发酵气体中的氢气含量达到40%~50%。  相似文献   

20.
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