Φ400数控飞锯机的设计

介绍了一种新型数控飞锯机,它结构合理,能够实现对运动中各种型材的连续切割.其控制系统采用工控机与PLC相结合,及变频器共同控制.试运行表明,该锯机与普通锯机相比,锯切频率由1-3提高到4-6,定尺精度由±8 mm提高到±5 mm.     

斑嘴鸭卵的人工孵化研究

研究了人工饲养条件下斑嘴鸭卵的形态学特征、人工孵化及出雏行为等问题,结果表明:鲜卵重平均为6 1.35± 1.89g,长径 5 6.84± 1.30mm,短径 43.5 5± 0.97mm,孵化期为 2 8.0 4± 0.94天;孵化失重率(Y)与孵化天数(X)之间的关系为Y =1.0 10 6 - 0.0 0 72X     

基于径向基神经网络的Delta机器人位置精度补偿

针对Delta并联机器人末端控制精度问题,提出一种基于RBF的提高Delta并联机构运动学控制精度的方法。首先对Delta并联机器人的运动学逆解进行分析,探讨了影响控制精度的因素和现有提高控制精度方法的局限性。其次,求解Delta并联机器人的工作空间,结合实际工作,通过试验采集训练样本。以末端实际位置为输入样本,末端的期望位置与实际位置之差为输出样本,进行RBF神经网络模型训练,得到末端实际位置与位置偏差之间的非线性映射关系,基于此设计位置补偿策略。最后,在Delta机器人平台上进行实验验证,使用训练好的RBF网络结合运动学逆解,对Delta机器人末端进行轨迹跟踪控制。实验结果表明,末端控制误差由±30mm减小到±5mm,有效的减少了末端位置误差,为Delta机器人精准控制提供了一种简单易行的方法。     

一种GIS中不规则曲线数字化的精度评定方法

通过分析GIS中曲线数字化的特征点与非特征点的性质,提出用曲率变化比较法建立由特征点组成的数学模型,分别对特征点进行拟合,并与其数字化的值比较,以此来分析GIS中不规则曲线数字化的精度。根据试验结果,得出不规则曲线数字化中误差为±0.28～±0.35mm,符合对手扶数字化线状目标的理论分析和模拟试验的±0.24～±0.32mm的结果。     

谷氨酰胺限制对rCHO细胞生长和代谢的影响

考察了rCHO细胞(Ch inese ham ster ovary,中国仓鼠卵巢细胞)在批培养和谷氨酰胺限制流加培养过程中的生长、代谢特性。实验发现随着谷氨酰胺浓度的下降,谷氨酰胺的比消耗速率以及氨和丙氨酸的比生成速率显著下降。与批培养相比,在谷氨酰胺限制流加培养过程中,培养时间延长,活细胞密度增加,达到2.4×106cells/mL;谷氨酰胺的代谢途径发生改变,代谢副产物生成明显减少,YAmm/G ln由1.04 mm o l/mm o l略微下降到0.92 mm o l/mm o l,YA la/G ln由0.35 mm o l/mm o l下降到0.08 mm o l/mm o l,YX/G ln由0.383×109cells/mm o l增加至0.504×109cells/mm o l,YAmm/X由2.59×1-0 9mm o l/cell下降到1.85×1-0 9mm o l/cell,表明谷氨酰胺代谢的能量利用率显著提高,也证明其参与细胞合成代谢的分率增加。     

上海地区淡剑夜蛾发生规律及其防治

淡剑夜蛾一年发生4—5代,以老龄幼虫在草坪根部表面层越冬．1龄、2龄、3龄、4龄、5龄、6龄幼虫头壳宽分别为0．33±0．13mm,0．60±0．07mm,0．93±0．10mm,1．28±0．20mm,1．66±0．10mm,1．92±0．13mm．幼虫期总食叶量为52．17cm^2．雌雄性比1：1．24．在室外喷雾2000倍20％杀灭菊脂、2000倍20％米满、4000倍20％除虫脲、2000倍10％除尽、4000倍5％氯氰菊酯、1000倍25％灭幼脲三号和6000倍1％阿维菌素7d后的校正死亡率分别在85．60％-96．20％．     

抗心律失常药物作用最佳靶点研究

目的:通过研究乌头碱、哇巴因致心律失常作用的离子靶点,揭示抗心律失常药物作用的最佳靶点。方法:采用全细胞膜片钳技术研究乌头碱、硅巴因对大鼠单个心室肌细胞动作电位时程(APD)、L-型钙电流(ICa)、钠电流(INa)、内向整流钾电流(IK1)以及瞬时外向钾电流(Ito)的作用。结果:乌头碱(1μM)使大鼠单个心室肌细胞90%复极化动作电位时程(APD90)从给药前的150.23±7.02ms延长至236.03±23.22ms(n=8,p<0.01)。ICa在0mV刺激电位下从-727.9±178.0pA增加至-1082.1±222.2pA(n=6,p<0.01);IK1在-110mV刺激电位下从-2122.0±511.1pA增加到-2536.3±386.5pA;乌头碱(1μM)抑制Ito,在+50mV刺激电压下,Ito从3203.6±617.1pA下降到2809.0±547.3pA。同时增加INa。哇巴因5μM使大鼠心肌细胞APD缩短(APD90从86.3±25.2ms缩短至58.9±20.8msn=5,p<0.01),ICa在+10mV刺激电位下从-1326.9±318.9pA减少到-782.3±395.3pA;使Ik1从-1868.3±187.8pA增加到-2392.8±366.7pA(刺激电压-120mV,n=10,p<0.01);使Ito从1272.7±317.6pA增加到1706.6±485.5pA(刺激电压+60mV,n=5,p<0.01)。结论:乌头碱、哇巴因诱发心律失常发生的活性点或最佳靶点是ICa,INa,IK1,Ikr和Iks。APD缩短或过度延长均可致心律失常,一个理想的抗心律失常药物应对心     

公差表示法

1.参量与其公差的单位相同时,单位可以只写1次.例如:12.5 mm±0.2 mm可写为(12.5±0.2)mm.公差用百分数表示时:"λ=550 nm±2%”是错误的,应写为λ=550×(1±0.02)nm. 2.参量的上、下公差不相等但单位相同时公差分别写在参量的右上、右下角,且单位只需写1次,例如:10+0.1-0.2 g;当参量与公差的单位不相同时单位要分别写出,例:30 cm+5-3 mm. 3.参量上、下公差的有效数字应全部写出.例如:18+0.200-0.255 mg. 4.参量上、下公差有1个为0时,其前边的符号可省略.例如:273+1 0 K. 5.表示2个绝对值相等公差相同的量值范围时,范围号不能省略. 例如(-7.0±0.5)～(7.0±0.5)℃. 6.表示带百分数公差的中心值时,百分号只需写1次.例如:(65±5)%.     

迭代学习法在开关式液压阀位置控制中的应用

阐述了一种新型振动下料机的基本组成,分析了其液压送进装置的传统行程开关控制方法所存在的问题,明确指出了采用迭代学习控制的必要性和可行性.研制出了由微机、开关式液压阀及位移传感器等组成的液压送进装置的计算机智能控制系统.研究表明,在迭代学习智能控制方法中所用的控制提前量呈现正态分布,从而建立了确定最优学习因子和控制提前量等关键控制参数的计算公式.试验结果表明,整个系统的鲁棒性好,采用该智能控制方法可使送进缸停止位置的误差由原来的±5 5mm降低为±0 8mm.因此,不仅满足了实际工作的要求,而且具有重要的推广价值.     

钴和甲基吡啶络合物的研究

在水溶液中鈷和吡啶,3-甲基吡啶,4-甲基吡啶形成紅色的1:1絡离子。由光密度及pH的测定,計算了在离子强度0.5,pH05—6,钴离子和配位体浓度比1:1到1:7的范围內鈷和吡啶,3-甲基吡啶,4-甲基吡啶的絡合平衡常数K_1分別为12±1,13±1,及23±1各配位体的絡合常数的对数与共和氢离子締合常数的对数成正比关系,logK_1/logK_B=0.20。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has