关键词： 事故预防   交付使用   控制   冷却   定义   设计   落锤锻   企业   人类工效学   锻造   锻压机   锤锻   操作   危害   卫生和安全要求   保健   热加工   液压的   液压控制系统   液压传动系统   使用说明书   机械   维护   机械工程   有色金属   职业安全   操作说明书   保护措施   可靠性   安全性   安全设计   安全装置   安全工程   安全措施   机械安全性   安全性要求   用户信息   工作场所安全性  

标准号: NF E88-051-2010

摘要： La présente Norme européenne s'applique aux : presses à forger hydrauliques à matrice ouverte pour le formage à chaud ; équipements de manutention et de refroidissement reliés au système de commande de la chaîne de forgeage, par exemple manipulateurs, mécanismes de manutention tournants, dispositifs d'inversement de matrices, tables et dispositifs à changement d'outils ; équipements de manutention conçus spécifiquement pour être utilisés dans la chaîne de forgeage, par exemple dispositifs de manipulation des matériaux, dispositifs de retournement ou de manutention montés sur les chariots élévateurs à fourche ou les appareils de levage à charge suspendue, *** spécifie les exigences de santé et de sécurité à toutes les phases du cycle de vie des équipements, ainsi que de leur conception, commande, construction, utilisation et é*** présente Norme européenne spécifie les exigences auxquelles doit satisfaire le fabricant afin d'assurer la santé et la sécurité des personnes lors de la construction, du transport, de la mise en service, du fonctionnement, de la maintenance et de la mise hors service, ainsi que dans le cas de défauts prévisibles tels que des dysfonctionnements potentiels des é*** présente Norme européenne traite tous les phénomènes, situations et événements dangereux significatifs pertinents pour les presses à forger hydrauliques à matrice ouverte pour le formage à chaud, lorsqu'elles sont utilisées comme prévu et dans des conditions raisonnablement prévisibles par le fabricant (voir Article 4).

关键词： Aerogels   Fractals   Mechanical properties   Molecular dynamics   Simulations  

摘要： In this article a study of the structural and mechanical properties of porous silica is presented. The procedure to prepare the samples consists in expanding single crystals of beta-cristobalite to reach the desired density followed by a thermal treatment. The resulting porous structures have densities in the range from 0.23 to 2.2 g/cm(3). The structure of the samples is studied by obtaining the fractal dimension using two different methods, one based on the pair distribution function and the other one based on the simulation of a scattering experiment. The values of the fractal dimension were found to be in good agreement with previously published data from experiments and comparable computer simulations. The mechanical properties, namely elastic modulus and strength, are studied through the simulation of a tension test. The elastic modulus and the strength relate to density by a power law characterized by exponents of 3.11 +/- 0.21 and 2.53 +/- 0.15 respectively. A comparison of that data to previously published data is included. The results proved that the direct expansion, coupled with thermal processing of the sample, leads to systems suitable to investigate the structure and the mechanical properties of silica aerogels. (C) 2010 Elsevier B.V. All rights reserved.

关键词： 农业机械化   现代农业   生产活动   主观因素  

摘要： 催促农业机械化的动力是什么？这似乎不是问题。但是，认真起来，还不一定一下子就说清楚。从农事生产活动来说，这个问题可以从两个视角来看。第一个角度是农业的外因，即人的主观因素，主要集中在4个方面。

关键词： 业务流程管理   动力机械行业   集成信息系统   体系结构   价值链模型   通用业务模式   企业信息化  

摘要： 业务流程管理是实现企业各种业务环节整合的管理模式，主要是在企业内部进行变革，改变职能管理机构重叠、业务重复操作多、流程复杂多变且无完整的闭合环节等，使得机构不重叠、业务不重复、流程简洁稳定且闭环等，从而能够缩短流程运转周期并节约企业运营成本。业务流程管理在企业中的地位举足轻重，已经渗透到了企业管理的每一个环节，任何一项业务战略的实施都肯定有其有形或无形的相应操作流程。通过业务流程建模，可以为企业提供一个架构，用于确保信息系统与持续改进的业务流程紧密配合，业务流程建模是搭建在信息系统与业务流程之间的桥梁。\n 本文在广泛阅览和分析国内外相关资料的基础上，结合所学知识，运用系统科学的方法，分析动力机械行业企业的发展背景及面临的问题。经由业务流程再造（Business Process Reengineering，简称BPR）及完整的管理信息系统执行优化后的业务流程来解决动力机械企业面临的问题。通过分析业务流程建模的理论基础及体系结构，引出当今先进的集成信息系统体系结构（Architecture of Integrated Information System，简称ARIS）方法体系作为本研究的建模方法。分析对比动力机械行业本土企业及在我国的外资企业的业务模式及其优劣，研究出适合该行业企业的通用业务模式及价值链模型。基于动力机械企业的价值链模型，利用ARIS建模方法并结合ESIA分析法（Eliminate，Simplify，Integrate，Automate，简称ESIA分析法）对应组织视图、功能视图、过程视图分别为动力机械企业的通用业务模式建立组织模型、功能模型和过程模型，基于扩展事件驱动过程链（Extended Event driven Process Chain，简称eEPC）的过程建模方法建立销售业务过程、采购业务过程、生产业务过程和物流业务过程，完成动力机械企业通用业务模式的业务流程建模，用于解决动力机械企业业务流程再造及ERP建设问题。\n 结合VP公司ERP建设，利用建立的企业模型实现VP公司业务流程再造及企业信息化管理的目标。对企业现存流程仿真分析，发现瓶颈问题并进行流程优化，以达到业务流程再造的目的。对比分析VP公司模型应用前后的组织结构和核心业务过程，充分说明了基于ARIS的动力机械行业业务流程建模能够为动力机械企业的组织结构革新、业务流程再造及ERP建设提供模型化的方法体系。本研究具有实现动力机械企业业务流程优化及信息化建设的参考价值，同时具备向各行业企业扩展研究的意义。

关键词： hydrogen chloride   hydration structure   dynamical properties   hydrogen bond   acid dissociation   proton transfer   simulation   QMCF  

摘要： An ab initio quantum mechanical charge field (QMCF) molecular dynamics simulation has been performed to study the structural and dynamical properties of a dilute aqueous HCl solution. The solute molecule HCl and its surrounding water molecules were treated at Hartree-Fock level in conjunction with Dunning double-zeta plus polarization function basis sets. The simulation predicts an average H-Cl bond distance of 1.28 angstrom. which is in good agreement with the experimental value. The H(HCl)center dot center dot center dot O(w). and Cl(HCl)center dot center dot center dot H(w), distances of 1.84 and 3.51 angstrom were found for the first hydration shell. At the hydrogen site of HCl, a single water molecule is the most preferred coordination, whereas an average coordination number of 12 water molecules of the full first shell was observed for the chloride site. The hydrogen bonding at the hydrogen site of HCl is weakened by proton transfer reactions and an associated lability of ligand binding. Two proton transfer processes were observed in the QMCF MD simulation, demonstrating acid dissociation of HCl. A weak structure-making/breaking effect of HCl in water is recognized from the mean residence times of 2.1 and 0.8 ps for ligands in the neighborhood of Cl and H sites of HCl, respectively. (C) 2009 Wiley Periodicals. Inc. J Comput Chem 31: 1785-1792, 2010

关键词： heat treating   shaping   superalloys  

摘要： Wire specimens, d = 0.1 mm, made of Ti-(50.6-50.8)at.%-Ni alloy were exposed to thermo-mechanical treatment (TMT), thus making the samples straight and providing them with high superelasticity (epsilon(se)). It was established that the most effective method of TMT is annealing with deformation at 500 and 300 A degrees C. The optimum mode of treatment was used in the research of mechanical fatigue of alloys with high superelastic properties. Two stages characterizing the alloy behavior under mechanical cycling were found out: failure accumulation and fracture. It was shown that the duration of the cycles is determined by the value of the preset deformation (sigma(set)) in relation to the deformation on the plateau-shaped area. The results of low-cycle fatigue of the alloys under investigation were processed by means of the method of least squares. The equations of prognosis of longetivity at the preset level of deformation are presented.

关键词： Mechanical milling   Crystalline oxides   Phase transformation kinetics  

摘要： This work investigates the kinetics of the anatase-to-rutile phase transformation of TiO2 powders during ball milling. Two elementary stages are observed, namely the transformation of anatase to the TiO2 II phase and of this latter to rutile. Such consecutive reactions were studied under inelastic impact regimes. Based on a suitable modeling of transformation kinetics, the fraction of powder processed on average at each collision was estimated. The mass of powder involved in phase transformation and microstructural refinement processes at each collision was then worked out by a systematic variation of the powder charge inside the reactor. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

关键词： caval vein   fluid resuscitation   septic shock   severe sepsis   mechanical ventilation  

摘要： Early optimization of fluid status is of central importance in the treatment of critically ill patients. This study aims to investigate whether inferior vena cava (IVC) diameters correlate with invasively assessed hemodynamic parameters and whether this approach may thus contribute to an early, non-invasive evaluation of fluid status. Thirty mechanically ventilated patients with severe sepsis or septic shock (age 60 +/- 15 years;APACHE-II score 31 +/- 8;18 male) were included. IVC diameters were measured throughout the respiratory cycle using transabdominal ultrasonography. Consecutively, volume-based hemodynamic parameters were determined using the single-pass thermal transpulmonary dilution technique. This was a prospective study in a tertiary care academic center with a 24-bed medical intensive care unit (ICU) and a 14-bed anesthesiological ICU. We found a statistically significant correlation of both inspiratory and expiratory IVC diameter with central venous pressure (p = 0.004 and p = 0.001, respectively), extravascular lung water index (p = 0.001, p < 0.001, respectively), intrathoracic blood volume index (p = 0.026, p = 0.05, respectively), the intrathoracic thermal volume (both p < 0.001), and the PaO2/FiO(2) oxygenation index (p = 0.007 and p = 0.008, respectively). In this study, IVC diameters were found to correlate with central venous pressure, extravascular lung water index, intrathoracic blood volume index, the intrathoracic thermal volume, and the PaO2/FiO(2) oxygenation index. Therefore, sonographic determination of IVC diameter seems useful in the early assessment of fluid status in mechanically ventilated septic patients. At this point in time, however, IVC sonography should be used only in addition to other measures for the assessment of volume status in mechanically ventilated septic patients. (C) 2010 Elsevier Inc.

关键词： AC power supply   DRAM   energy-aware systems   energy harvesting   integrated circuits   low-power design   scaling   self-timed   power-on reset  

摘要： Passive energy harvesting from mechanical vibration has wide application in wearable devices and wireless sensors to complement or replace batteries. Energy harvesting efficiency can be increased by eliminating AC/DC conversion. A test chip demonstrating self-timing, power-on reset circuitry, and dynamic memory for energy harvesting AC voltages has been designed in 180 nm CMOS and tested. An energy scalable DSP architecture implements FIR filters that consume as little as 170 pJ per output sample. The on-chip DRAM retains data for up to 28 ms while register data is retained down to a supply voltage of 153 mV. Circuit operation is confirmed for supply frequencies between 60 Hz and 1 kHz with power consumption below 130 mu W. Reaching the limits of miniaturization will require approaching the limits of power dissipation. We extrapolate from this DSP architecture to find the minimum volume required for mechanical vibration energy harvesting sensors.

关键词： Deposition rates  

摘要： Using a Hull cell with a rotating cylindrical electrode (RCE), the effect of the hydrodynamic conditions on the deposition rate and its micro- and macrodistribution and the composition and microhardness of the cobalt-tungsten coatings deposited from a citrate electrolyte containing cobalt sulphate (0.2 mol/l) and sodium tungstate (0.2 mol/l) at pH - 6.7 and the solution temperature of 60 degrees C in the Re numbers range of 0 - 3000 is examined. It is shown that the hydrodynamic deposition conditions have no effect whatsoever on the surface roughness, but they slightly influence the electrolyte's throwing power. The correlation between the intensity of the hydrodynamic flows, the deposition rate (due to the current efficiency's increase), and the composition of the coatings (along with their distribution over the surface) is established. It is shown that certain modes of the process at a high deposition rate make it possible to reach a high uniformity of the coating's composition with a high tungsten content, which results in obtaining the maximum surface microhardness.