摘要:首先将3-氨丙基三乙氧基硅烷与凹凸棒土进行反应,得到氨基改性的凹凸棒土( A-ATT),再将A-ATT按不同比例与酐封端的聚酰胺酸进行反应,最后经热酰胺化过程,得到一系列聚酰亚胺/凹凸棒土复合薄膜。采用红外光谱(FT-IR)、动态光散射(DLS)、紫外光谱(UV-vis)、热重分析(TGA)、和动态机械热分析仪(DMTA)对合成的改性凹凸棒土和聚酰亚胺/凹凸棒土复合薄膜进行了表征。 UV-vis光谱表明,通过向聚酰亚胺薄膜中添加A-ATT可以改变聚酰亚胺薄膜的透光性。 TGA测试结果表明,随着A-ATT含量的增加,聚酰亚胺/凹凸棒土复合薄膜的热稳定性有所提高。由机械性能测试可知,当加入少量A-ATT时,聚酰亚胺/凹凸棒土复合薄膜的杨氏模量和拉伸性能有所提高,当A-ATT含量大于2.0%时,聚酰亚胺/凹凸棒土复合薄膜的机械性能有所下降。%The attapulgite was modified by using 3-aminopropyl triethoxysilane ( APTES) as coupling a-gent and the amino modified attapulgite ( A-ATT) was prepared at first.Then, the A-ATT reacted with the an-hydride groups of polyamide acid.Finally, a series of ATT@PI composites were obtained by thermal imidiza-tion.The structures and properties of the A-ATT and ATT@PI composites were characterized by Fourier trans-form infrared spectrometer ( FT-IR ) , laser light scattering, UV-vis spectra, thermogravimetric analysis ( TGA) and dynamic mechanical thermal analysis ( DMTA) .UV-vis spectra results showed that the optical transparency of the ATT@PI composites could be changed by adding A-ATT to the polyimide matrix.The TGA results showed that the thermal stabilities of the ATT@PI composites can be improved by adding a small amount of A-ATT.Moreover, the Young’ s modulus and tensile strength of ATT@PI composites can be im-proved by adding a small amount of A-ATT, whereas weakened by more than 2%A-ATT loading.
摘要:以马蹄河特大桥(上承式钢筋混凝土拱桥)为工程背景,分析了钢筋混凝土拱桥的第一类弹性稳定问题,研究不同加载方式、矢跨比、拱圈面内抗弯刚度对第一类稳定的影响。对该桥在恒载作用下的第一类弹性稳定问题、第二类弹性稳定问题(几何非线性问题)和第二类弹塑性稳定问题(极限承载力问题)进行了对比分析,并对达到极限荷载时的破坏形式和破坏过程进行了分析。%Matihe Super Bridge was taken as engineering background.The first class of elastic stability of reinforced concrete arch bridge was analyzed, and the effect of different loading modes, rise span ratio of arch and the in-plane bending stiffness on the first class of elastic stability were studied.And then the second kind of elastic stability problems( geometrically nonlinear problems) and the second kind of elastic-plastic sta-bility problem( the ultimate bearing capacity) under dead load were analyzed and the comparison of the results was made, and furtherly the damage forms and processes to achieve the ultimate load was analyzed.
摘要:于2013年3月至2014年10月,采用野外调查和室内饲养观察的综合方法,对陕西省洋县北部合征姬蛙繁殖期进行研究。结果显示:合征姬蛙产卵、蝌蚪水中生活时期多与稻田相关,稻田是蛙类的最佳栖息地;蛙类从卵到幼蛙成活率约3%;合征姬蛙产卵期较长;影响繁殖成活率因子从大到小的顺序是水源>挖沙>农药>捞鱼>水质>天敌。人工饲养蛙卵,放归田间,实验数据支持这一保护措施。%The author has studied the breeding of Microhyla mixture in the north of Yangxian county by the integrated approach between field investigation and laboratory from March 2013 to October 2014.The re-sults show that rice field is the habitat for frogs.Microhyla mixtura is closely associated with rice field in spaw-ning and tadpoles life period.The survival rate for frogs from egg to young frog is very low, being only 3%. The factors affecting the survival rate of frog reproduction include water source, dredging, pesticides, fishing, water quality and natural enemies, in descending order.Frog eggs are raised by artificial method, and then re-leased into the field, a protective measure is supported by experimental data.
摘要:利用光学显微镜、X-ray衍射仪、带能谱分析的扫描电子显微镜等手段研究了Ca对 Mg-12Al-12Zn2-Si合金组织和力学性能的影响。结果表明:加入Ca元素后合金中生成了弥散分布的CaSi2相,可作为Mg 2 Si相异质形核的核心,将块状和条棒状的Mg2 Si颗粒变为细小的多边形块状。当Ca含量为0.5%(质量分数)时,合金中Mg2 Si颗粒较细小且弥散分布,此时,合金的室温及高温力学性能达到最大。%Effects of Ca content on microstructure and mechanical properties of Mg-12Al-12Zn-2Si alloy have been investigated by optical microscopy, X-ray diffraction and scanning electron microscopy with energy dispersive spectrometry, etc.The results show that the CaSi2 phase generated from the alloy with dispersive distribution with the addition of Ca contents can become the core of heterogeneous nucleation of Mg2 Si phase, the morphology of Mg2 Si particle in the alloys changed from the petal shaped, stick shaped into polygon shaped.When the Ca content is 0.5% mass fraction, the morphology of Mg2 Si particle in the alloys would change into small and dispersive distribution.At the same time, the room temperature and elevated tempera-ture mechanical properties of the alloy can reach the maximum.
摘要:根据复杂四轴数控加工的方法和特点,建立四轴数控加工刀具轨迹数学模型,通过NX对一个旋转槽类零件进行四轴铣削仿真加工,生成数控加工刀路及NC代码。利用NX和VERICUT良好的交互性建立机床模型,对加工过程机床仿真,并对相应程序进行检验和优化,得到更加合理的NC程序,对实际的数控加工具有指导意义。%Four axis machining method and characteristics for four axis complex surface parts is intro-duced.And the mathematical model of tool path is established.Milling rotating groove parts through NX is conducted to generate NC cutter path and NC program.Machine model is built by making use of good interac-tion of NX and VERICUT and machine processing simulation is thus achieved, and correspondign program is tested and optimizated with the result of more reasonable NC program.The way is instructive for actual CNC machining.
摘要:为提高产品设计质量,研究了利用组件框架技术,通过创建典型模型库系统,实现对典型产品模型的存储、可视化预览以及特征信息的提取。在已有产品模型的基础上实现快速智能化操作。基于CAA的CATIA二次开发的基本原理和方法,以面向对象的程序语言来驱动模型库中产品的特征信息实现重用,可使产品设计效率有很大的提高。%To improve the quality of product design, the research uses component framework technology to achieve the storage, visual preview and retrieval of characteristic information of typical product model by creating the typical model base system, thus realizing the purpose of rapid smart operation based on the in-use product model.The technology research of CATIA secondary development based on CAA basic principle and method of object oriented programming language to drive the feature information of the products in the reuse can greatly improve the efficiency of product design.
摘要:针对复合型Tschebyscheff方程的一类边值问题,研究了其解的结构,发现该边值问题解的表达式可以通过Tschebyscheff方程的两个线性无关解( Tschebyscheff多项式和第二类Tschebyscheff函数)和边值条件、交界面条件的系数组装得到,并提出求解该类边值问题的一个新解法———相似构造法。%Based on the question of boundary value problem of composite Tschebyscheff system, this paper studies the structure of the solution, and it discoversthat the expression of solution of the boundary prob-lem is acquired by structuring two linearly independence solutions of Tschebyscheff equation ( Tschebyscheff polynomial and the second category Tschebyscheff function) and the coefficients of right boundary condition, left boundary condition and interface condition.The paper puts forward a new method of solving this class boundary value problem:the similar constructive method.
摘要:为得到不同转速下主轴的回转精度,采用双向动态测量法测量液体静压轴承电主轴的径向位移误差,借助激光位移传感器记录主轴径向误差数据,利用自主开发的数据处理软件实现测量数据的误差分离,通过最小二乘圆法评定主轴的回转精度,为主轴最优工作转速的选取提供理论依据。%The experiment measures the radial displacement error of hydrostatic bearing electric spindle using two-direction dynamic measurement method.With a laser displacement sensor to record the error on ra-dial direction, the research has developed a data processing software to realize the error separation of measured data.The rotation accuracy is determined by the least squares method.The study can provide a reference for the selection of optimal spindle working speed.
摘要:This paper uses a development method of dynamic and static B/S structure to have designed and implemented static news system based on dynamically generated technology.It overcomes such shortcom-ings as low efficiency, poor security and poor concurrency in traditional dynamic website.At the same time, it also keeps the advantages of dynamic website, such as real-time update, access statistics, facilitate interaction and so on.%使用动静态B/S结构开发方法,设计并实现了基于动态生成技术的静态新闻系统,克服了传统动态网站访问效率低下、安全性差、并发性差等缺点,同时继承了动态网站实时更新、访问率统计、便于交互等优点。
摘要:为了客观评价高校毕业生就业质量与水平,首先依据模糊聚类分析和主成分分析法构建一套高校毕业生就业质量评价体系,然后运用基于三角模糊层次分析法赋权的模糊综合评判法建立相应的评价模型,最后将该模型运用于铜陵学院2014届毕业生就业质量的评价中。结果表明,该届毕业生的就业水平为“二级”,就业水平较好。同时通过实例应用,对影响高校毕业生就业质量的15个因素的相对重要性进行了排序,并得到了劳动报酬、社会保障、工作的安全性以及就业政策这4个二级指标对高校毕业生就业质量影响较大的结论。%In order to objective and reasonable evaluation of college graduates and the level of employ-ment quality, this paper on the basis of research on the method of fuzzy cluster analysis and principal compo-nent analysis method to construct a set of college graduates employment quality evaluation system, and then the corresponding evaluation model is established by using the fuzzy comprehensive evaluation method of triangular fuzzy AHP weighting based on the evaluation of the model used in the final will be the quality of employment of graduates in 2014 of Tongling University, the results show that the graduates employment belongs to “level two” this level, the level of employment is better, at the same time, through the example application, but also the relative importance of the 15 factors affecting the employment of college graduates quality were sorted, and obtained the labor remuneration, social security, work security and employment policy in the 4 level two inde-xes can greatly affect the employment quality of the graduates in University.
摘要:对于太阳能吸收式制冷系统中管壳式发生器温度参数测量不准确的问题,采用多点标定Pt500温度传感器测出的数据得出关于R-T特性关系并对此关系进行分段,利用最小二乘法拟合和误差评估原理确定出对Pt500温度传感器最佳的校正方程。最后,用实验验证R-T特性关系与所得的最佳校正方程逼近度最高,即明显地提高了管壳式发生器温度测量的准确度。%The problem remains that solar energy absorption cooling system shell-and-tube generator for temperature parameter can not be accurately measured.Through the Pt500 temperature sensor for multi-point calibration, the study obtains R-T property relationship.which is further segmented.By least-squares fitting and utilizing the principle of error estimation, the corrective equation of the most suitable Pt500 temperature sensor is determined.The conclusions of experiments confirm that the actual characteristics of R-T and the cor-rective equation have the highest approximation, which more effectively improves the accuracy of solar energy absorption cooling system shell-and-tube heat exchanger of temperature measurement.
摘要:In order to explore a new enhancement algorithm for image denoising by adaptive consistency for the exploration and test in image enhancement and denoising effect, the paper adopts the adaptive construc-tion of orthogonal multiresolution Wedgelet transform denoising method, and conducts a simulation test using a black and white image.It is concluded that the method is efficient in short running time, fast convergence speed, small mean square error, great noise ratio and good de-noising effect.%为探索增强图像一致性自适应消噪的新算法,并检验其在图像增强和消噪中的功效,采用构建正交多分辨率Wedgelet变换的自适应消噪方法,利用黑白图像进行了计算机仿真实验,结果表明:从仿真实验中得出该算法在图像增强图像消噪方面比传统的Beamlab200工具箱运行时间短,收敛速度快,均方误差小,信噪比大,消噪效果优势明显。
摘要:The study focuses on antioxidant performance and safety evaluation of acute toxicity of sala-mander skin mucus.The study first uses pyrogallol autoxidation and DPPH method to determine salamander mucus to superoxide anion radical( O-·2 ) scavenging and DPPH radical scavenging.Then it experiments with giant salamander breeding mice fed to test acute toxicity of Andrias davidianus skin mucus and analyses toxic constituents of mucus temperament by using GC-MS chromatography.The results show that the clearance rate of Salamander mucus flour to superoxide anion radical and to DPPH radical scavenging is 6.77%and 90.25%respectively, and that LD50 value of Andrias mucus powder is 4.64 g/kg and toxic ingredient is imethyl disul-fide ( C2 H6 S2 ) .It concludes that Andrias mucus is antioxidant and low in toxicity, and that it can be devel-oped for health care products after detoxification.%为研究大鲵皮肤黏液的抗氧化性及急毒性安全性评价,利用邻苯三酚自氧化法和DPPH法,测定了大鲵黏液对超氧阴离子自由基( O-·2)及DPPH自由基的清除率;通过对小鼠灌胃饲养实验检测大鲵皮肤黏液的急毒性,并采用气质联用色谱分析黏液中的毒性成分。结果显示:大鲵黏液对超氧阴离子自由基的清除率为6.77%,对 DPPH 自由基的清除率为90.25%;大鲵黏液全粉的LD50值为4.64 g/kg,毒性成分为二甲基二硫醚( C2 H6 S2)。表明大鲵黏液具有抗氧化性和低毒性,经脱毒后可开发为保健产品。
摘要:根据LED显示屏的工作原理,提出了一种基于FPGA的大屏幕LED图文显示屏控制系统设计方案。系统采用移位芯片74HC595构建驱动电路,通过串行方式输出驱动信号,利用FPGA构建核心控制电路,采用Verilog HDL语言编写程序,完成显示汉字数据的读出,按照串行方式产生行、列扫描信号和控制信号,动态扫描并驱动LED显示屏。实验测试结果表明:系统可以实现汉字滚动显示,整个系统外围电路简单,易于扩展。%According to the working principle of LED display, a design scheme of large screen LED display control system based on FPGA was proposed.The driver circuit was built by the shift chip 74HC595 to generat the drive signals through the serial output mode.The core control circuit was built by FPGA and the reading of Chinese characters data was completed by using the Verilog HDL language to write program.Row and column scanning signal and the control signal were generated on the basis of the serial way, and then the dynamic scanning and driving LED led display was performed.The experimental results show that:the system can achieve the Chinese characters scrolling display, and the peripheral circuits of the whole system are simple and easy to expand.
摘要:采用CBS-QB3方法构建了C7 H15自由基裂解反应势能剖面。计算结果表明,4种不同构型的C7 H15自由基(1-C7 H15,2-C7 H15,3-C7 H15,4-C7 H15)发生多种不同类型的β位断裂,裂解成C2—C6烯烃和新的自由基。新的自由基继续发生β位断裂,形成诸如CH3自由基以及CH2眫CH2、CH3 CH眫CH2等烯烃。此外,利用VKLab程序包及Wigner 校正模型在200~3000 K温度范围内计算了4种C7 H15自由基各类β位断裂反应速率常数。其中1-C3 H7→C2 H4+CH3反应速率常数的结果与试验结果非常吻合。%The potential energy surfaces of theβ-scission of heptane radicals were performed using the CBS-QB3 method.The results show that the β-scission of 1-C7 H15 , 2-C7 H15 , 3-C7 H15 and 4-C7 H15 radicals involves many different kinds of β-scission reactions to produce olefins and other radicals.Compared to the small n-alkanes, larger n-alkanes can produce more alkyl radicals, which may generate more intermediates and have more possible pathways.Main products were C2~C6 olefins, methyl raticals and hydrogen radicals. The rate constants of all reactions with Eckart correction were calculated by the VKLab program package.The rate constant of 1-C3 H7→C2 H4 +CH3 reaction within the temperature range of 200~3 000 K is in good agree-ment with available experimental values.
摘要:利用高效液相法测定14个不同产地盘龙七中岩白菜素的含量。色谱条件:色谱柱为Inertsil ODS-3C18(4.6 mm ×150 mm,5μm)柱,乙腈-0.2%磷酸溶液(9∶91)为流动相,流速1.0 mL/min,检测波长275 nm,柱温30℃。岩白菜素在15~75μg/mL范围内呈良好的线性关系, Y =14942.0X -428.6(R2=0.9998),平均加样回收率100.58%,RSD为1.77%( n=6)。分析结果表明,不同产地盘龙七中岩白菜素的含量不同,其含量随产地的不同而显示出一定的差异,其变化范围在14.68~70.19 mg/g,含量较为丰富。本研究建立盘龙七药材中岩白菜素含量测定方法,并分析检测了产自陕西、甘肃、四川三省14个产地盘龙七中岩白菜素的含量,其结果可为盘龙七药材的质量控制提供科学依据。%The contents of bergenin in Rhizoma Bergeniae Scopulosae from different areas were deter-mined by using HPLC.The chromatographic separation was carried out using Inertsil ODS-3 C18 column (4.6 mm ×150 mm,5 μm), the mobile phase was acetonitrile:0.2%phosphoric acid (9∶91), the detec-tion wavelength was set at 275 nm, the temperature was 30℃, and the flow rate was 1.0 mL/min.The cali-bration curve was linear in the range of 15 ~75 μg/mL and the regression equation for bergenin was Y =14 942.0X -428.6 (R2 =0.999 8) , the average recovery was 100.58% with RSD of 1.77%( n =6). The results showed that there are some differentces in the content of bergenin among different areas,and that the contents of bergenin were ranges betweenfrom 14.68~70.19 mg /g.This method is simple, efficient and accurate, which can be used for the analysis of bergenin in Rhizoma Bergeniae Scopulosae.
摘要:针对玉树地区的某太阳能采暖建筑,使用DeST软件对改造前后的采暖负荷进行了计算分析,在室内温度18℃、16℃和14℃三种工况下,建筑节能率分别达到24%、27%和31%,改造后建筑具有显著的节能效果。使用PolySun软件对该建筑太阳能采暖系统进行了节能分析,并综合太阳能集热器性能、系统规模、集热器安装倾角、水箱体积、地理位置等因素对太阳能采暖系统性能的影响进行了分析,所得结论为太阳能采暖系统的推广提供了技术支持。%The paper makes an analysis of the heating load of solar energy in buildings in Yushu district with DeST software.The results show that the modified architecture has remarkable energy saving effect, ener-gy-saving rate being 24%, 27% and 31% respectively when room temperature is at 18 ℃, 16 ℃, and 14 ℃.Meanwhile, with PolySun software, the paper analyzes the energy saving of the solar heating system in-cluding the solar collector performance,system scale, installing angle, water tank volume, geographical posi-tion, geographical location, etc.The results of the analysis provide technical support for the popularization of solar heating system.
摘要:依据世界动物地理区划和中国动物地理区划,对山西历山自然保护区食蚜蝇科昆虫区系分析。经鉴定该区本次调查发现食蚜蝇科昆虫3亚科11族47属107种,其中管蚜蝇亚科6族16属37种,巢穴蚜蝇亚科1族1属1种,食蚜蝇亚科4族30属69种,其中毛斑胸蚜蝇Spilomyia manicata ( Rondani,1865)首次在中国记录,山西省新记录种64种,未定种7种。通过本次调查,使山西省食蚜蝇科昆虫的种类记录达到159种。基于100种已知种类和47属的资料分析,发现山西历山自然保护区食蚜蝇科昆虫种类成分以古北区和东洋区共有种为主要成分,单纯的古北区成分略优于单纯的东洋区成分;从属的分布看,多区属比例高达70.21%,单区属成分所占比例较低。山西历山自然保护区食蚜蝇科昆虫区系具有明显的过渡性和复杂性。%Among the syrphids samples collected from Lishan Natural Reserve as part of an ongoing sur-vey of Syrphids fauna in Shanxi Province, 107 species, 47 genera and 11 tribes in three subfamilies of Syrphi-dae were recognized, in which 69 species and 30 genera of 4 tribes were identified to belong to the biggest subfamily Syrphinae, 37 species and 16 genera of 6 tribes were Eristalinae, and only one species from Mier-odontinae.Among them, one species, Spilomyia manicata ( Rondani, 1865 ) , was recorded from China for the first time, 64 species were newly recorded to Shanxi Province, and 7 species were undefined.The records of Syrphidae in Shanxi Province reached 159 species according to the survey.Based on the analysis of 100 known species and 47 genera in the fauna of Syrphids from Lishan Natural Reserve, the results showed that Palaearctic region and Oriental region were predominant, and elements of Palaeretic species were slightly more abundant than those of Oriental species.According to the distributional types, the subfamily Syrphinae multi-zoogeographical genera are predominant (70.21%), while the proportion of single-zoogeographical genera is relatively low.The results showed that the fauna of Syrphids of the Lishan Natural Reserve in Shanxi Province is transitional and complex.
摘要:对比研究热浸镀Zn-0.5Al-1.5Mg、Zn-2Al -1.5Mg和Zn-2Al -1.5Mg-03.Si合金镀层组织与耐腐蚀性。用X射线衍射仪、扫描电子显微镜及能谱仪分析了合金镀层的组成相和显微组织,用全浸腐蚀试验和中性盐雾试验表征了合金镀层的耐腐蚀性能。结果表明:Zn-Al-Mg和Zn-Al-Mg-Si合金镀层主要由Zn相、Al相和MgZn2相组成;合金镀层主要含有Zn+MgZn2二元共晶组织和Zn+Al+MgZn2三元共晶组织;Al和Si有细化镀层晶粒作用,添加 Si能提高Zn-Al-Mg-Si合金镀层的耐腐蚀性能。%The microstructure and the corrosion resistance of hot dip Zn-0.5Al-1.5Mg,Zn-2Al-1.5Mg and Zn-2Al-1.5Mg-0.3Si alloy coatings were comparatively investigated.The composition phases and the mi-crostructures of coatings were analyzed by X-ray diffractometer,scanning electron microscope and energy dis-persive spectrometer.The corrosion resistance of coatings was characterized by full immersion corrosion and neutral salt spray test.The results indicate that the Zn-Al-Mg and Zn-Al-Mg-Si alloy coatings are mainly com-posed of Zn phase,Al phase and MgZn2 phase, the Zn+MgZn2 eutectic and Zn+Al+MgZn2 eutectic were found in alloy coatings, the element of Al and Si can refine the grain size, adding Si in the Zn-Al-Mg alloy bath can enhance alloy coatings’ resistance to corrosion.
摘要:Based on the existing research results of soil structure, through the analysis and study the es-sence of traditional soil structural parameters, the paper proposes the soil structural parameters represented by the tangent modulus based on equivalent elastomer views.And then, in order to derive the soil structural resid-ual degrees, the paper defines the parameters concerning effects of the three external factors, namely disturb-ance, loading and humidification, on soil structure.Finally, the paper gives the expressions of structural re-sidual degrees of normally consolidated clay, loose sand, medium-dense sand and over-consolidated clay and dense sand, under different external conditions.The structural parameters indicated by tangent modulus can better represent soil structural characteristics.%在已有的关于土的结构性研究成果的基础上,深入分析了他们提出的土的结构性参数的实质,建议采用以切线模量为参数描述土体结构性参数;定义了扰动、加荷、浸水这3种外部作用影响土体结构性的参数,获取土的结构性残余度;给出不同外部条件下,正常固结粘土、松砂及中密砂和超固结粘土及密实砂的结构性残余度的表达式。结果表明,采用切线模量描述的结构性参数能够较好反应土的结构性。
摘要:The standard harmony search algorithm can only solve continuous optimization problems, whereas the ordered sample cluster belongs to discrete optimization problems.Combining the Fisher algorithm and the harmony search algorithm,an improved harmony search algorithm is proposed to be used for discrete optimization problems,and for classifying ordered sample.The experimental results show that classification re-sult is consistent with the actual.The conclusion shows that the improved harmony search algorithm is a global optimal algorithm and its result is better than the Fisher algorithm.%标准和声算法只能解决连续型优化问题,而有序样本聚类属于离散型优化问题。将Fisher算法和和声算法相结合,提出一种改进和声算法,使之能够用于离散型优化问题,并利用其对有序样本进行分类。数值仿真实验结果表明,该算法分类结果符合实际。结论表明改进和声算法是一种全局最优算法,分类结果优于Fisher算法。