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一种大型薄板箱体平面铣削方法

山东工业技术 2024年第2期 107-110页

作者：谭承志谭晓宇山东天河科技股份有限公司山东济宁273500 莱芜职业技术学院山东济南271100

在建筑机械中,尤其是国家提倡的模块化建筑,普遍采用薄板零件,尤其是一些箱体构件,其结构并不复杂精度要求也不太高,但由于刚度较差,在装夹过程中和切削力的作用下,易产生变形、震刀,造成尺寸超差、表面粗糙度低和零件铣穿现象。本文从... 详细信息

在建筑机械中,尤其是国家提倡的模块化建筑,普遍采用薄板零件,尤其是一些箱体构件,其结构并不复杂精度要求也不太高,但由于刚度较差,在装夹过程中和切削力的作用下,易产生变形、震刀,造成尺寸超差、表面粗糙度低和零件铣穿现象。本文从消除应力、减少刀具摩擦力等几方面,及降低焊接及加工过程中的受热变形引起的震动导致加工质量低等几方面提出了薄板箱体在加工过程中震刀难以控制的问题的有效技术方法,解决了相应技术难题。

关键词：大型薄板箱体铣削震刀消除共振粗糙度控制

Low-temperature heat capacities and standard molar enthalpy of formation of N-methylnorephedrine C11H17NO（s）

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Chinese Physics B 2008年第9期17卷 2859-2866页

作者： Di You-Ying Wang Da-Qi Shi Quan tan zhi-cheng College of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

This paper reports that low-temperature heat capacities of N-methylnorephedrine C11H17NO（s） have been measured by a precision automated adiabatic calorimeter over the temperature range from T=78K to T=400K. A solid to liquid phase transition of the compound was found in the heat capacity curve in the temperature range of T=342-364 K. The peak temperature, molar enthalpy and entropy of fusion of the substance were determined. The experimental values of the molar heat capacities in the temperature regions of T=78-342 K and T=364-400 K were fitted to two poly- nomial equations of heat capacities with the reduced temperatures by least squares method. The smoothed molar heat capacities and thermodynamic functions of N-methylnorephedrine C11H17NO（s） relative to the standard refer- ence temperature 298.15 K were calculated based on the fitted polynomials and tabulated with an interval of 5 K. The constant-volume energy of combustion of the compound at T=298.15 K was measured by means of an isoperibol precision oxygen-bomb combustion calorimeter. The standard molar enthalpy of combustion of the sample was calculated. The standard molar enthalpy of formation of the compound was determined from the combustion enthalpy and other auxiliary thermodynamic data through a Hess thermochemical cycle.

关键词： N-methylnorephedrine C11H17NO(s) heat capacity constant-volume energy of combus-tion standard molar enthalpy of formation

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Heat Capacities and Thermodynamic Properties of 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic Acid

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Chemical Research in Chinese Universities 2007年第4期23卷 460-464页

作者： XUE Bin WANG Jian-ya tan zhi-cheng WU Tong-hao School of Petrochemical Engineering Shenyang University of Technology Liaoyang 111003 P. R. China College of Chemistry Jilin University Changchun 130021 P. R. China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Science Dalian 116023 P. R. China

The heat capacities of 3-（ 2,2-dichloroethenyl）-2,2-dimethylcyclopropanecarboxylic acid （a racemic mixture, molar ratio of cis-/trans-structure is 35/65） in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% （ molar fraction）. A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and en- tropy of fusion, △fusHm, △fusSm, of the acid were determined to be （331.48±0.03 ） K, （16.321±0.031） kJ/mol, and （49.24±0.19） J/（ K·mol）, respectively. The thermodynamic functions of the sample, Ht-H298.15, Sr-S298.15 and Gr-G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric（TG） analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7.3 ×10^7 min^-1 , E =70.64 kJ/mol, respectively.

关键词： 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid Adiabatic calorimetry Heat capacity Thermodynamic function Thermal decomposition

Low-temperature Heat Capacities and Thermodynamic Properties of Hydrated Sodium Cupric Arsenate [NaCuAsO_4·1.5H_2O(s)]

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Chemical Research in Chinese Universities 2007年第5期23卷 574-578页

作者： CHEN Jing-tao DI You-ying tan zhi-cheng SUN Li-xian College of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 P. R. China Department of Chemistry Shaanxi Educational College Xi＇an 710061 P. R. China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian i 16023 P. R. China

Low-temperature heat capacities of the solid compound NaCuAsO4·1.5H2O（s）were measured using a precision automated adiabatic calorimeter over a temperature range of T=78 K to T=390 K.A dehydration process occurred in the temperature range of T=368-374 *** peak temperature of the dehydration was observed to be TD=（371.828±0.146）K by means of the heat-capacity *** molar enthalpy and entropy of the dehydration were ΔDHm=（18.571±0.142）kJ/mol and ΔDSm=（49.946±0.415）J/（K·mol）,*** experimental values of heat capacities for the solid（Ⅰ）and the solid-liquid mixture（Ⅱ）were respectively fitted to two polynomial equations by the least square *** smoothed values of the molar heat capacities and the fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated at an interval of 5 K.

关键词： NaCuAsO4·1.5H2O(s) Adiabatic calorimetry Heat capacity Thermodynamic function Dehydration process

Heat Capacity and Enthalpy of Fusion of Crystalline Pyrimethanil Decylate(C_(22)H_(33)N_3O_2)

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Chemical Research in Chinese Universities 2005年第6期21卷 697-701页

作者： SUN Xiao-hong LIU Yuan-fa tan zhi-cheng WANG Mei-han JIA Ying-qi College of Chemical Engineering Chemical Research Institute Northwest University Xi＇an 710069 P. R. China Department of Chemistry Northwest University Xi＇an 710069 P. R. China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 P. R. China

Low-temperature heat capacities of pyrimethanil decylate （ C22 H33 N3 O2 ） were precisely measured with an automated adiabatic calorimeter over the temperature range from 78 to 373 K. The sample was observed to melt at （311.04 ± 0.06） K. The molar enthalpy and entropy of fusion as well as the chemical purity of the compound were determined to be（45876± 12） J/mol, （147. 50 ±0. 05） J. mol^-1 · K^-1 and （99. 21 ±0. 03）% （mass fraction）, respectively. The extrapolated melting temperature for the absolutely pure compound obtained from fractional melting experiments is （311. 204±0. 035 ） K.

关键词： Pyrimethanil decylate Heat capacity Adiabatic calorimetry DSC

Heat Capacity and Thermodynamic Properties of Crystalline 2-Chloro- N, N-dimethylnicotinamide

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Chinese Journal of Chemistry 2005年第11期23卷 1490-1494页

作者： SUN, Xiao-Hong LIU, Yuan-Fa tan, zhi-cheng JI, Peng-Ju WANG, Mei-Han College of Chemical Engineering Chemical Research Institute Northwest University Xi'an Shaanxi 710069 China Department of Chemistry Northwest University Xi'an Shaanxi 710069 China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian Liaoning 116023 China

Low-temperature heat capacities of 2-chloro-N,N-dimethylnicotinamide were precisely measured with a high-precision automated adiabatic calorimeter over the temperature range from 82 K to 380 K. The compound was observed to melt at （342.15±0.04） K. The molar enthalpy AfusionHm, and entropy of fusion, △fusionSm, as well as the chemical purity of the compound were determined to be （21387±7） J·mol^-1, （62.51±0.01） J·mol^-1·K^-1, （0.9946±0.0005） mass fraction, respectively. The extrapolated melting temperature for the pure compound obtained from fractional melting experiments was （342.25±0.024） K. The thermodynamic function data relative to the reference temperature 298.15 K were calculated based on the heat capacity measurements in the temperature range from 82 to 325 K. The thermal behavior of the compound was also investigated by different scanning calorimetry.

关键词： 2-chloro-N,N-dimethylnicotinamide heat capacity adiabatic calorimetry

Low Temperature Heat Capacities and Thermodynamic Properties of Zinc L-Threonate Zn(C_4H_7O_5)_2(s) by Adiabatic Calorimetry

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Chemical Research in Chinese Universities 2008年第5期24卷 603-607页

作者： CHEN Jing-tao DI You-ying tan zhi-cheng CHEN San-ping GAO Sheng-li Department of Chemistry Shaanxi Educational College Xi＇an 710061 P. R. China College of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 P. R. China Department of Chemistry Northwest University Xi＇an 710069 P. R. China

Low-temperature heat capacities of the solid compound Zn（C4H7O5）2（s） were measured in a temperature range from 78 to 374 K, with an automated adiabatic calorimeter. A solid-to-solid phase transition occurred in the temperature range of 295？322 K. The peak temperature, the enthalpy, and entropy of the phase transition were determined to be （316.269±1.039） K, （11.194±0.335） kJ？mol-1, and （35.391±0.654） J？K-1？mol-1, respectively. The experimental values of the molar heat capacities in the temperature regions of 78？295 K and 322？374 K were fitted to two polynomial equations of heat capacities（Cp,m） with reduced temperatures（X） and [X = f（T）], with the help of the least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound, relative to that of the standard reference temperature 293.15 K, were calculated on the basis of the fitted polynomials and tabulated with an interval of 5 K. In addition, the possible mechanism of thermal decomposition of the compound was inferred by the result of TG-DTG analysis.

关键词： Zn(C4H7O5)2(s) Adiabatic calorimetry Low-temperature heat capacity Solid-to-solid phase transition Thermodynamic property TG-DTG

Learnware:small models do big

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Science China(Information Sciences) 2024年第1期67卷 39-50页

作者： zhi-Hua ZHOU zhi-Hao tan National Key Laboratory for Novel Software Technology Nanjing University

There are complaints about current machine learning techniques such as the requirement of a huge amount of training data and proficient training skills,the difficulty of continual learning,the risk of catastrophic forgetting,and the leaking of data privacy/*** research efforts have been focusing on one of those concerned issues separately,paying less attention to the fact that most issues are entangled in *** prevailing big model paradigm,which has achieved impressive results in natural language processing and computer vision applications,has not yet addressed those issues,whereas becoming a serious source of carbon *** article offers an overview of the learnware paradigm,which attempts to enable users not to need to build machine learning models from scratch,with the hope of reusing small models to do things even beyond their original purposes,where the key ingredient is the specification which enables a trained model to be adequately identified to reuse according to the requirement of future users who know nothing about the model in advance.

关键词： artificial intelligence machine learning learnware

Electrical characteristics of a fractional-order 3×n Fan network

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Communications in Theoretical Physics 2024年第4期76卷 176-187页

作者： zhi-Zhong tan Xin Wang Department of Physics Nantong UniversityNantong 226019China

In this article a new achievement of fractional-order 3×n Fan networks is *** the first step,the RT-I method is used to derive the general formulae of the equivalent impedance of fractional-order 3×n Fan *** the second part,the effects of five system parameters(L,C,n,α and β)on amplitude-frequency and phase-frequency characteristics are *** the same time,the amplitude-frequency and phase-frequency characteristics of the fractional order 3×n Fan network are revealed by Matlab *** work has important theoretical and practical significance for resistor network models in the field of natural science and engineering technology.

关键词： fractional-order circuit amplitude-frequency characteristics phase-frequency characteristics RT-V theory