对焦偏移量对搭接标记处K值的影响

在射线检测中，控制“K值”符合标准要求对裂纹检出率起着至关重要的作用。根据我国JB／T4730．1－2005标准第4．1．2条规定：透照时射线柬中心一般应垂直指向透照区中心，但在实际检测的过程中最容易忽视。本文分别就3种最常见的透照方式：纵缝透照法、环缝的单壁外透法、双壁单影法计算分析了对焦偏移量与“K值”的定量关系，得到当偏移量超过10mm时，K值就可能超过标准要求而造成裂纹漏检。     

Origin软件在X射线机曝光曲线制作中的应用

射线探伤是工业无损检测中一个重要的检测手段，在锅炉、压力容器制造、检修行业得到广泛应用。X射线机作为一种常用的检测设备．在使用的过程中会因为相关元器件的消耗、老化而使原本适用的曝光曲线不再适用。而曝光曲线是描述在特定的条件下（胶片、增感屏、焦距、黑度、射源和暗室处理等一定），工件厚度与所需曝光参数之间的关系曲线。在射线照相检验中，利用曝光曲线可以迅速地确定透照不同厚度的工件所需的曝光参数，获得灵敏度较高的底片。因此曝光曲线是射线检验人员进行照相的重要工具。     

小管D类角焊缝射线照相检验

对于小管D类角焊缝射线照相检验,一般标准和参考书中没有对此项内容的规定和描述。该检验方法可用于一些特殊场合,虽然射线照相底片质量很难达到标准要求,但如果操作合理也可以达到较好的检验效果。本文根据对产品的射线照相检验,总结出一些小管角焊缝射线照相检验的经验。     

甲醇合成塔射线检验工艺研究

在制造鲁南工程醇合成塔过程中 ,因工件结构、形状等不利因素 ,其特殊位置接管及封头焊缝实施射线检验时 ,存在很多技术难点。通过现场分析研究 ,利用放射性同位素 (γ源 )照相灵活、便携的特点 ,制订可行的射线照相检验工艺 ,使问题得以最终解决。     

小口径管射线透照中几个问题探讨

本文阐述了小口径管射线透照中底片布置、象质计灵敏度、透照次数等问题。并经过分析，提出了双壁双影椭圆透照的适用条件。     

射线照相曝光曲线多用法

介绍射线照相曝光曲线的多种用法：“一点”法、“两点”法、系数法、变通法、当量法，可为日常RT有效检验选定或修正曝光参数提供快捷多通道。     

澄川地热田为避免硅结垢的pH值控制方法的研究

为避免硅结垢，实验检测了澄川地热田流体(SiO2浓度775mg／L)在3种pH值(5．0、6．5和7．3)条件下流过填装铝珠(直径1或2mm)的圆筒(直径50mm，高55mm)的效果，在各种pH值条件下的水流量都由5L／min逐渐减少到2～3L／min(在72小时内)。硅垢主要发现在顶部(距     

不锈钢小集箱不同透照方式对缺陷检出的讨论

不锈钢小集箱进行射线透照时,采用不同的透照方式对缺陷检出有很大影响,本文讨论Φ219X40mm不锈钢小集箱环缝射线透照使用Ir192采用中心曝光和双壁单影透照,对比底片缺陷检出效果。然后将试样纵向剖开,采用X光机在工件内贴片和在外贴片进行单壁透照,与前两种透照底片进行比较。可以看出,采用源中心曝光和双壁单影透照哪种方式对不锈钢小集箱缺陷检出率。集箱剖开进行单壁透照底片只作为结果对比,因为实际检测不允许此种检测方式。     

高铁酸钾对低碳氮比废水的去除效果及条件优化

为探讨一种用于处理低碳氮比(c(C)/c(N))猪场沼液的应急处理方法,采用高铁酸钾(K2FeO4)这种绿色氧化剂分别从投加量、pH值及温度等3个因素开展对猪场沼液中COD、NH3-N和TP的去除研究.结果表明,K2FeO4对NH3-N的去除效果不明显,但能快速有效去除沼液中的COD和TP,且呈现正相关的剂量关系.在400 mL猪场沼液中加入0.48 g高铁酸钾形成含有1200 mg/L K2FeO4的反应体系,反应120 min后,出水COD和TP质量浓度分别达146.0 mg/L和11.2 mg/L,去除率为49.7％和58.7％;而酸性体系可进一步提升其去除效率,在初始pH值为3.0时,对COD和TP去除率分别提升至92.1％和85.6％,出水质量浓度为23.0 mg/L和3.9 mg/L;而低温条件也更有利于促进该反应的进行.因此,可将K2FeO4作为去除猪场沼液的一种应急方法予以考虑和应用研究.     

一台秸秆热分解锅炉烟气温焓值的计算

烟气温焓表的计算作为锅炉传热计算的核心,在锅炉设计中具有非常重要的位置,其数值的准确与否直接影响各受热面布置的合理性,也是影响产品性能的重要因素.锅炉燃用生物质燃料的设计过程中,烟气温焓值的计算目前尚没有比较成熟的计算资料.介绍了参与设计的一台秸秆热分解燃料锅炉设计过程中烟气温焓表的计算方法.通过分析,阐述了同类技术应用中,锅炉烟气温焓值的计算要点.     

质量中心孔和几何中心孔在曲轴加工中的优化

曲轴动平衡质量直接影响发动机的震动、噪声等机械性能和使用寿命,在大批量、自动化生产过程中,合理选用曲轴中心孔形式对减少初始不平衡量、去重量、加工节拍、料废率和剩余不平衡量至关重要,文章介绍了中心孔选用的基本原则。结合1.8L和1.5L曲轴不同类型中心孔的实际优化过程,介绍了中心孔优化的一般流程、方法及优化过程中必须考虑钻中心孔与动平衡的相位问题,在投产初期采用分模号优化中心孔是快速提高动平衡合格率的有效方法。     

Exploring future hydrogen development and the impact of policy: A novel investment-led approach

It is generally recognised that the primary tools being utilised today for hydrogen energy forecasting and policy development take a least-cost approach. While useful for comparing the viability of different technologies from a cost perspective, it is argued that these models fail to capture the potential value contribution such technologies could offer companies and, in consequence, the likelihood of their receiving investment. The authors propose a novel model for forecasting the deployment of hydrogen energy systems based on a company value maximisation approach designed to assist governments in the development of appropriate policy instruments. In this paper a theoretical relationship between market sector valuations and investment activity is presented using 3 value metrics, namely net present value (NPV), earnings per share (EPS) and sum of the parts (SOP). It is shown that, as the electricity and transport fuel markets begin to converge, examination of the effects of different policy measures through the value-led model can highlight otherwise hidden counter incentives. The model further recognises that the propensity to invest in hydrogen differs according to the characteristics of the company looking to make the investment and the implications for policy-makers regarding levels of support are also discussed in the paper.     

Limit moment of local wall thinning in pipe under bending

In engineering practice, pipe containing local wall thinning may be subjected to bending load. The existence of local wall thinning on pipe surface impairs the load-carrying capacity of pipe. In order to maintain the integrity of the pipe containing local wall thinning, it is very important to develop a method to evaluate such a pipe with local wall thinning under bending. In this paper, the limit moment of local wall thinning pipe under pure bending is computed employing 3D elastic–plastic finite element analysis. The results show that the limit moment of pipe is affected not only by the width of defect but also by the longitudinal length of defect. When the longitudinal length of defect overpasses some critical value, the results from net-section collapse criterion (NSC) are in very reasonable agreement with the results from finite element analysis. Therefore, the NSC formula can conservatively be used to assess the limit load-carrying capability of local wall thinning pipe under bending.     

Generalized Fisher index or Siegel–Shapley decomposition?

It is generally believed that index decomposition analysis (IDA) and input–output structural decomposition analysis (SDA) [Rose, A., Casler, S., Input–output structural decomposition analysis: a critical appraisal, Economic Systems Research 1996; 8; 33–62; Dietzenbacher, E., Los, B., Structural decomposition techniques: sense and sensitivity. Economic Systems Research 1998;10; 307–323] are different approaches in energy studies; see for instance Ang et al. [Ang, B.W., Liu, F.L., Chung, H.S., A generalized Fisher index approach to energy decomposition analysis. Energy Economics 2004; 26; 757–763]. In this paper it is shown that the generalized Fisher approach, introduced in IDA by Ang et al. [Ang, B.W., Liu, F.L., Chung, H.S., A generalized Fisher index approach to energy decomposition analysis. Energy Economics 2004; 26; 757–763] for the decomposition of an aggregate change in a variable in r = 2, 3 or 4 factors is equivalent to SDA. They base their formulae on the very complicated generic formula that Shapley [Shapley, L., A value for n-person games. In: Kuhn H.W., Tucker A.W. (Eds), Contributions to the theory of games, vol. 2. Princeton University: Princeton; 1953. p. 307–317] derived for his value of n-person games, and mention that Siegel [Siegel, I.H., The generalized “ideal” index–number formula. Journal of the American Statistical Association 1945; 40; 520–523] gave their formulae using a different route. In this paper tables are given from which the formulae of the generalized Fisher approach can easily be derived for the cases of r = 2, 3 or 4 factors. It is shown that these tables can easily be extended to cover the cases of r = 5 and r = 6 factors.     

餐厨垃圾高温厌氧消化连续运行性能：有机物转化效率、发酵稳定性与代谢活性

在高温(50±1)℃条件下处理实际工程的餐厨垃圾,采用全混式厌氧反应器（CSTR）进行了80d的连续试验。试验以水力停留时间（HRT）20 d启动,HRT 15 d连续运行,研究了反应器启动和运行期间的发酵特性,解析了餐厨垃圾厌氧消化运行稳定性和代谢活性。试验结果表明,在HRT 15 d、有机负荷（OLR）为7.3 kgCOD/(m3·d)的条件下,容积产甲烷率为2.2L/(L·d),挥发性固体（VS）的甲烷产率达到480L/kgVS左右,有机物转化率约为95%。批次试验表明,高温产甲烷菌代谢乙酸能力较强,在适宜pH下可承受10000mg/L的乙酸浓度。餐厨垃圾的高温降解速率快,10 d达到90%的产气,有承受更高负荷的可能。系统pH稳定在7.6～7.7,总氨氮和自由氨浓度低于抑制水平。研究结果表明,餐厨垃圾的高温厌氧消化可实现较高的产气潜力和有机物去除率,系统稳定性好且有机物转化效率高,具有应用于工程高温餐厨垃圾厌氧处理的潜力。     

Enhancing power generation of piezoelectric bimorph device through geometrical optimization

In this paper, it is demonstrated that the power output of a bimorph energy harvesting device can be significantly enhanced through geometrical optimization. The results of the study show that the maximum power is generated when the length of piezoelectric layer is 1/3 and the length of proof mass is 2/3 of the total device length. An optimized device with a total volume of approximately 0.5 cm³ was fabricated and was experimentally characterized. The experimental results show that the optimized device is capable of delivering a maximum power of 1.33 mW to a matched resistive load of 138.4 kΩ, when driven by a peak mechanical acceleration of 1 g at the resonance frequency of 68.47 Hz. This is a very significant power output representing a power density of 2.65 mW/cm³ compared to the value of 200 μW/cm³ normally reported in literature.     

Excel软件在煤炭检测报告中的应用

煤炭分析结果的计算工作量大、繁琐费时。在煤炭检测报告中应用Excel软件,只要输入几个原始测定数据,Excel软件将会在瞬间完成全部计算工作并自动生成一份完整漂亮的检测报告。简化了工作程序,节省了时间,提高了工作效率。Excel软件不仅是财务、统计人员的好帮手,在理化检测工作中也大有用武之地。     

Influence of pH value on the structure and electronic property of the passive film on 316L SS in the simulated cathodic environment of proton exchange membrane fuel cell (PEMFC)

The influence of pH value on the electronic property of the passive film on 316L SS in the simulated cathodic environment of the proton exchange membrane fuel cell (PEMFC), was investigated by potentiodynamic polarization curve, electrochemical impedance spectra and Mott–Schottky plot. The pH value effect on the composition and structure of the passive film on 316L SS was detected by X-ray photoelectron spectroscopy (XPS). The results showed that the passivity of 316L SS was enhanced, the transfer resistance of the film/solution interface significantly increased with the increase in pH value. Mott–Schottky analysis revealed that the passive film on 316L SS appeared a p-n heterojunction, the donor and acceptor densities within the passive film decreased, and the flat band potential moved to the positive direction with the increment of pH value. XPS results implied that the thickness of the passive film increased with increasing pH value. The passive film on 316L SS exhibited the duplex structure, in which the outer film was mainly composed of Cr-oxide and the inner film was dominantly consisted of Fe-oxides when the pH value was less than 3. In the case of pH 5H₂SO₄ solution, Fe-oxides were the major component throughout the inner and outer films.     

投影栅线法测量物体三维形貌研究

应用投影栅线法测量三维形貌既可以直观地判别被测物的外形,如检查对称性、缺陷检测等,还能得到实际的三维尺寸,这对于进行模型设计、现场测试等都很实用,因而,该方法受到广泛关注和应用。设计了新的应用投影栅线法测量三维变形的设备,并将其应用在汽车模型的三维形貌测量上,实际应用表明:该设备具有实时显示、操作方便、精度高等优点。     

The effect of additives on the oxidation stability of biodiesel

In the present study, it was aimed to examine the degradation of biodiesel and the changes that occur in the cold flow characteristics of biodiesel obtained from safflower oil as a result of the modification of the production process steps that leads to a state in which the process is not realized completely despite the addition of antioxidant additives that stabilize the cold flow characteristics of the fuel and the effects of the modification of the production process steps on fuel characteristics. The study is focused on the modification of the production process. Some samples showed very rapid decomposition in the first 3 hours but the rest took nearly 3 days to reach 200 microsiemens. But then the derivative this value due to the rate of oxidation 0.04 h showed.