技术测量中的误差分析与处理

技术测量中的误差分析与处理直接关系到机械产品的使用性能、寿命和经济性,在当今产品高性能高精度的要求下,必须十分重视这个问题.     

Desulphurization of damped battery paste by sodium carbonate and sodium hydroxide

The paper treats investigation of the desulphurization process of damped Pb-paste by Na₂CO₃ or NaOH. There is determined the effect of Na₂CO₃ (NaOH) concentration and the liquid–solid phase ratio on the process parameters (degree of desulphurization and degree of Na₂CO₃ (NaOH) utilization in function of the temperature and process duration). The optimum conditions for carrying out desulphurization of Pb-pastes by Na₂CO₃ or NaOH are determined in dependence of the used reactors (common reactor with laboratory agitator and rotary reactor of drum type). The content of inclusions in the solutions is examined with the purpose of producing sufficiently pure crystalline Na₂SO₄ for the industry.     

棉卷工艺改造为清梳联工艺的实践

为将A系列棉卷工艺改造为清梳联工艺,通过查阅有关资料,分析研究A系列开清棉流程和清梳联流程各单机的性能,确定了用A系列开清棉机与FA177B型棉箱,FA221D型高产梳棉机配套组成清梳联的方案.并经安装、调试和运转,证明各项技术指标稳定,节能和经济效益显著.     

树脂矿物复合材料加工中心床身静动态特性的研究

以某加工中心床身为研究对象,分别对由树脂矿物复合材料和铸铁材料制造的加工中心床身进行静动态特性分析。利用ABAQUS软件对两种床身在承受相同载荷条件下的变形进行了分析,研究了两种床身的固有频率和固有振型,并分析比较了是否考虑阻尼特性时两种床身的谐响应分析结果。结果显示：两种材料床身在静刚度接近的情况下,使用树脂矿物复合材料制作加工中心床身能有效提高床身的固有频率,并明显降低床身在受到外界激励时的动态响应。分析结果证明：采用树脂矿物复合材料制作的加工中心床身具有更好的动态特性,用树脂矿物复合材料作为机床床身有其独特的优点。     

红外光纤及其应用

介绍了适宜于制备红外光纤的材料及红外光纤制备工艺，综述了红外光纤在军事、光谱学、热成像、测温、红外通讯、激光能量传输等领域的应用。如果能继续降低红外光纤的传输损耗，增大优质光纤维长度，制备出适用的低噪声探测器，那么，红外光纤在上述领域的应用价值将更大，也将会开拓出更广阔的应用领域。     

FLOX® Steam Reforming for PEM Fuel Cell Systems

Primary energy savings and CO₂ reduction is one of the key motivations for the use of fuel cell systems in the energy sector. A benchmark of domestic cogeneration by PEMFC with existing large scale power production systems such as combined steam‐gas turbine cycle, clearly reveals that only fuel cell systems optimising overall energy efficiency (> 85%) and electrical efficiencies (> 35%) show significant primary energy savings, about 10%, compared with the best competing technology. In this context, fuel processing technology plays a dominant role. A comparison of autothermal and steam reforming concepts in a PEMFC system shows inherent advantages in terms of efficiency at low complexity for the latter. The main reason for this is that steam reforming allows for the straightforward and effective use of the anode‐off gas energy in the reformer burner. Consequently, practical electrical system efficiencies over 40% seem to be achievable, most likely by steam reformers. FLOX®‐steam reforming technology has reached a high state of maturity, offering diverse advantages including: compact design, stable anode off‐gas usage, high efficiency, as well as simple control behaviour. Scaling of the concept is straightforward and offers an opportunity for efficient adaptation to smaller (1 kW) and larger (50 kW) units.     

齿轮的CAXA线切割仿真与加工

采用CAXA线切割数控编程的软件系统,完成了齿轮造型、工艺及参数确定、加工轨迹生成及仿真、加工代码的生成及传输等,分析齿轮线切割加工的技巧。     

Fatty acid composition of three freshwater fishes under different storage and cooking processes

Fatty acid composition of common carp (Cyprinus carpio), Nile tilapia (Oreochromis niloticus) and tambacu, a hybrid of tambaqui (Colossoma macropomum) and pacu (Piaractus mesopotamicus), was evaluated by gas chromatography. Raw, roasted and steamed fishes with and without skin were analyzed fresh and after 15, 30 and 45 storage days at −20 °C. Total lipid content was 9.3 g/100 g in carp, 0.79 g/100 g in tilapia and 1.3 g/100 g in tambacu with skin, with reductions of about 63%, 39% and 71% in the fishes without skin, respectively. The carp showed a high content of monounsaturated fatty acids (about 50%). In tilapia, palmitic and oleic acids were present in larger proportion, 26.55% and 23.86%, respectively. In tambacu, the fatty acid profile was 37% saturated, 34% monounsaturated and 21% polyunsaturated. Fatty acid composition did not present wide variations due to storage time and preparation, indicating that the storage and cooking methods used did not interfere in fatty acid composition.     

基于BP神经网络的20CrMo钢激光强化工艺参数优化控制

以激光功率P、光斑直径D、扫描速度V等为输入参数,非相变硬化处理、相变硬化处理和熔凝处理等为输出参数,对材料为20CrMo合金结构钢进行激光强化处理工艺控制优化研究。通过大量试验与计算机模拟分析和对比,建立了激光工作参数与材料表面强化关系的BP神经网络工艺优化模型。经过与实验数据的比较,运用该模型可以方便、准确地选择激光工艺参数,控制材料表面强化类别和保证工作表面的质量,真实反映了激光加工工艺规律。     

一种实用视觉识别的仪表自动检定系统

介绍一种基于图像处理和神经网络识别技术的温控仪表自动检定系统。在系统中，计算机对被测仪表发出模拟热电偶测量信号，并获取被测仪表示显示值的视图，经过数字图像预处理后，采用神经网络感知器算法予以识别，得到仪表显示数。将被测仪表显示数与计算机内的测量值比较，其误差曲线即可确定该被测仪表的精度。