Search

Proton exchange membrane fuel cell is an electrochemical power generation device. Leakage can cause it to degrade or even lead to an explosion. Fuel cell end plate sealing is one of the causes of leakage. In this paper, the hydrogen inlet sealing structure of the end plate is taken as the research object. Then the mechanical contact model of rubber sealing ring is established. Mooney-Rivlin hyperelastic constitutive model and FEM are used to analyse the influence of its initial compression, sealing gas pressure and operating temperatures on sealing performance. The results show that the Von Mises stress and contact stress of the sealing ring are distributed symmetrically. Both of them rise up with the increase of initial compression and sealing gas pressure, but reduce with the increase of the operating temperatures. This study can provide reference for the sealing design of proton exchange membrane fuel cell end plates.

A mechanical system and transmission system of plating machine based on the function requirement of multi-function automatic plating machine has been designed. It conforms to cloth characteristics, production efficiency, product uniformity and production cost requirement. It illustrates the key function in detail, including plating function, platen upgrade, cloth layer compressing, automatic selvage aligning mechanism, etc. The function parameter of plating machine shows as follows: cloth width is 2 m; plating velocity is 70 folding per minute; the platen lifting distance is 300 mm.

The lepton flavor violating process μ → eγ has been previously studied in a model of electroweak-scale right-handed neutrinos. In that work the decay amplitude was computed in unitarity gauge, augmented by some technical considerations that correct the leading term thus obtained. This complication arises because the mixing matrices appearing in the weak charged currents are not unitary in the model. In this paper, we recalculate the amplitude in Rξ gauge. The cancellation of the ξ dependence in the final result serves as a useful check to both the obtained amplitude and the technical points made in the previous work.

This paper presents a complex control system in which a large-scale of devices are controlled by micro control units (MCUs) based on embedded TCP/IP, with emphasis on the management of these MCUs through one or more reusable driving engines. The number of the driving engines bases on the scale of the devices and the real-time requirement. For most cases, one driving engine with one or more NICs ( Network Interface Cards ) is enough. Each device is controlled by a MCU to sample the device and the sampled data is delivered to applications through the driving engine that receives the driving data from the applications and transmits it to the MCU to drive device. The driving engine running on an industrial personal computer(IPC) communicates with the MCUs through the lower network, a TCP/IP network, while it communicates with the applications through the upper network, a TCP/IP network and(or) a reflective memory (RFM) network. The driving engine is a reusable software architecture and any number of MCUs can be integrated seamlessly in DLL(Dynamic Link Library) without any need to modify the architecture. To develop a new device control system, the only tasks is to implement the MCU embedded routines that must be done whenever any development methods applied and the MCU DLLs and then integrate the DLLs with the architecture. This MCU-based control method fits the man-in-loop simulators best with the most advantage of making the system wiring simple, elegant and clean than AD cards usually used and has some other beneficial features of software reusability, valid precision maintenance, more developing efficient, run-time and reliable performance.

This paper focuses on complex simulation systems with a large-scale of hardware controlled items to resolve the problems about the identification, sampling , driving, transformation and reference of hardware items. A formal resolving model with its software supporting system is presented to decouple the interdependence between hardware driving developers and application developers, avoid repeatedly developing on similar works and enable the seamless integration of hardware driving routines and application programs. The controlled items are identified and referred in a two-dimensional notation and implemented by an encoding transmission technology to pack message packets. A reusable API(Application Programming Interface) system supporting the two-dimensional notation is realized. The interface system makes specific hardware devices, network medium and application deployment transparent based on external configuration files (hardware configuration files and a net configuration file). In addition, it supports the auto- detections on hardware detection online and precision maintenance by priority transmission packets. The notation and its reusable supporting system can be used in hardware- related systems especially in man-in-loop simulators to make the developing efficiently and the integrating seamlessly and easily.

The parameter, as a means to reduce the randomness and blindness, will be optimized by genetic algorithm (GA) to realize predictive control for the pressure of the primary gas cooler and coordinate control values for pressure control of coke oven collector. As experience shows, the system not only ensures the coordination, speediness, and stability of the control system but can also effectively improve the precision, adaptive ability, and robustness.

This study evaluated the clinical value of the combined detection of serum cathepsin L (CL), heparanase (Hpa), and matrix metalloproteinase-9 (MMP-9) for determining the degree of ovarian cancer invasion and metastasis before surgery.Enzyme-linked immunosorbent assays were used to measure the serum content of CL, Hpa, and MMP-9 in 217 patients with untreated ovarian cancer before surgery, 100 patients with benign ovarian tumors, and 101 healthy women as controls. In addition, the degrees of invasion and metastasis were assessed by the 'gold standard' of clinicopathological diagnosis. The associations of the preoperative serum CL, Hpa, and MMP-9 levels with the clinicopathological factors and metastatic status were analyzed. Receiver operating characteristic (ROC) curve analysis was used to evaluate the usefulness of these markers for determining the degree of ovarian cancer invasion before surgery.The serum CL, Hpa, and MMP-9 levels were significantly higher (p=0.001) in patients with malignant ovarian cancer compared with patients with benign ovarian tumors and healthy controls. The serum CL level was significantly higher in patients with epithelial ovarian carcinoma compared with non-epithelial ovarian carcinoma (p=0.048), whereas the serum levels of Hpa (p=0.109) and MMP-9 (p=0.544) did not differ significantly between these two groups. The serum CL, Hpa, and MMP-9 levels correlated with the degree of differentiation and the FIGO staging (p0.05). The serum CL (p=0.030) and MMP-9 (p=0.010) levels were significantly associated with peritoneal metastasis, and the serum Hpa level (p=0.042) was associated with distant metastasis. A ROC curve analysis revealed sensitivity of 60.9%, 69.6%, and 72.2%, and specificity of 57.4%, 67.2%, and 68.9% for the preoperative serum levels of CL, Hpa, and MMP-9, respectively, as tumor markers for the degree of extra-pelvic metastasis.Elevated serum CL, Hpa, and MMP-9 levels are correlated with malignant invasion and progression in ovarian cancer. The combined detection of serum CL, Hpa, and MMP-9 may be useful for determining the extent of ovarian cancer metastasis before surgery.