Series Of Key Parameters Research Articles

Well-Test Interpretation Model of Water-Injection Well in a Low-Permeability Reservoir and Its Application

For low-permeability reservoirs, water-flooding development is usually adopted, which leads to induced fractures near the wellbore, increasing reservoir heterogeneity, and making water-flooding development more complex. This paper focuses on low-permeability reservoirs, considering the characteristics of induced fractures and elliptic-flow composite, and the well-test model for injection wells is established. The mathematical model in Laplace space is obtained through dimensionless transformation and Laplace transformation. Subsequently, the Mathieu function is introduced to obtain the bottom hole pressure, and the pressure response curve is drawn. The six flow stages of the curve are defined, and the sensitivity of parameters such as half-length of induced fractures, range of lateral-swept area, permeability in unswept area, and outer boundary distance at constant pressure are analyzed. The results show that the half-length of the fracture mainly affects the linear flow of the fracture, the range of the lateral wave-affected area mainly affects the radial flow of the swept area, the permeability of the unswept area mainly affects the radial flow of the unswept area, and the outer boundary distance at constant pressure mainly affects the boundary flow. Based on the production performance of a certain injection well in J Oilfield, a series of key parameters are obtained through analytical solution model inversion, including the induced-fracture half-length of 10.32 m, the lateral-swept range of elliptic partition flow of 128.95 m, the permeability of the swept area of 6.87 mD, and the mobility ratio of 119.92, which show the superiority of the analytical solution model.

Rapid thermal response and sensitivity analysis of proton exchange membrane fuel cell stack with ultra-thin vapor chambers

Vapor chamber (VC) embedded in proton exchange membrane fuel cell (PEMFC) stacks is an effective approach for thermal management of PEMFC stacks due to high thermal conductivity and temperature uniformity of VC. To quantitatively analyze the effect of VC on the dynamic thermal response of PEMFC stacks, a thermal equivalent circuit model is developed for PEMFC stacks cooled by VC. Each component in the stacks is regarded as a corresponding thermal resistance in the heat transfer process. The heat capacity of components is also applied on the model to couple the dynamic response. A series of key parameters on the thermal performance of the stacks are analyzed. The analysis result shows that the stacks have the fast temperature rise within 60 s of the start-up phase and VC nicely decrease the thermal response time of stacks. Parameters on temperature sensitivity of the stacks are also discussed. Thermal contact resistance and cooling velocity are significant factors on temperature sensitivity of stacks, but the temperature sensitivity becomes lower and even less than 0.01 with the increase of velocity. These works will help to design and optimize the thermal management system of PEMFC stacks.

Research on the influencing factors of small bending radius elbow stamping based on CAE simulation

The elbow with small bending radius is widely used in heating system and line collecting system, but its processing is difficult. Using the way of sheet metal stamping processing half elbows, and then welding the two half elbows is an effective method. There are a series of key parameters in the process of elbow stamping, which directly affect the forming result. Using sheet metal stamping software for stamping simulation, and comparing the effects of the parameters on thinning and principal stresses, we can see the specific effects of different parameters on the shaping. The main influencing factors of elbow stamping include friction coefficient, clearance, blank holding force and sheet metal thickness. For the friction coefficient and blank holder force, it should be selected near the minimum value. For clearance and sheet metal thickness, it is proportional to the forming effect.

Extraction of triazole fungicides in environmental waters utilizing poly (ionic liquid)-functionalized magnetic adsorbent

This work prepared a new poly (ionic liquid)-functionalized magnetic adsorbent (PFMA) for the extraction of triazole fungicides (TFs) in environmental waters prior to determination by high performance liquid chromatography/diode array detection (HPLC-DAD). A polymerizable ionic liquid, 1-methyl-3-allylimidazolium bis(trifluoromethylsulfonyl)imide was employed to copolymerize with divinylbenzene on the surface of modified magnetite to fabricate the PFMA. The morphology, spectroscopic and magnetic properties of the new adsorbent were investigated by different techniques. A series of key parameters that influence the extraction performance including the amount of PFMA, desorption solvent, adsorption and desorption time, sample pH value and ionic strength were optimized in detail. Under the optimum conditions, the prepared PFMA could extract targeted TFs effectively and quickly under the format of magnetic solid-phase extraction (MSPE). Satisfactory linearities were achieved in the range of 0.1–200.0μg/L for triadimenol and 0.05–200.0μg/L for other TFs with good coefficients of determination above 0.99 for all analytes. The limits of detection (S/N=3) and limits of quantification (S/N=10) for TFs were in the range of 0.0050–0.0078μg/L and 0.017–0.026μg/L, respectively. Environmental waters including lake, river and well waters were used to demonstrate the applicability of developed MSPE-HPLC-DAD method, and satisfactory recoveries and repeatability were obtained.

Supercapacitors Performance Evaluation

The performance of a supercapacitor can be characterized by a series of key parameters, including for instance the cell capacitance, operating voltage, equivalent series resistance, power density, energy density, and time constant. To accurately measure these parameters, a variety of methods have been proposed and used among academia and industry. As a result, some confusion has been caused due to the inconsistencies between different evaluation methods and practices. Such confusion hinders effective communication of new research findings, and creates a hurdle in transferring novel supercapacitor technologies from research labs to commercial applications. Based on public sources, this review article is an attempt to inventory, critique and hopefully streamline the commonly used instruments, key performance metrics, calculation methods, and major affecting factors for supercapacitor performance evaluation. Thereafter the primary sources of inconsistencies are identified and the possible solutions are suggested correspondingly, with emphasis on device performance vs. material property and the rate dependency of supercapacitors. We hope, by using reliable, intrinsic and comparable parameters produced, the existing inconsistencies and confusion can be largely eliminated so as to facilitate further progress in the field.

Supercapacitors Performance Evaluation

The performance of a supercapacitor can be characterized by a series of key parameters, including the cell capacitance, operating voltage, equivalent series resistance, power density, energy density, and time constant. To accurately measure these parameters, a variety of methods have been proposed and are used in academia and industry. As a result, some confusion has been caused due to the inconsistencies between different evaluation methods and practices. Such confusion hinders effective communication of new research findings, and creates a hurdle in transferring novel supercapacitor technologies from research labs to commercial applications. Based on public sources, this article is an attempt to inventory, critique and hopefully streamline the commonly used instruments, key performance metrics, calculation methods, and major affecting factors for supercapacitor performance evaluation. Thereafter the primary sources of inconsistencies are identified and possible solutions are suggested, with emphasis on device performance vs. material properties and the rate dependency of supercapacitors. We hope, by using reliable, intrinsic, and comparable parameters produced, the existing inconsistencies and confusion can be largely eliminated so as to facilitate further progress in the field.

Characterization of Shape-Memory Trifunctionally Cross-Linked Polyurethanes, with Varying Hard and Soft Segments

A family of potential shape-memory trifunctionally cross-linked polyurethanes (SMPs) was achieved with varying the hard segments. The molecular weight of the soft segment poly(oxytetramethylene) (PTMO) was held constant. The polymers were employed with and without chain extender. They were characterized by means of structural studies and creep tests over a range of temperatures, and hence their shape-memory performance was determined. More crystallization was observed in the materials with hard domains based on the flexible diisocyanate 4,4′-dibenzyl diisocyanate (DBDI) extended with 1,4-butanediol (BDO). A series of key parameters characterizing shape-memory performance was determined: the temperature position of the peak (Tpeak), the half-width of the peak (δT), and the minimum value of the 30 s isochronal creep modulus E(30 s) Emin. While the peak temperature and modulus increased with increasing cross-link density, the width of the peak was observed to decrease with increasing cross-link density. The materials were found to vary systematically with details of the network structure.

基于非晶硅的微桥结构阵列制作工艺研究

The critical technology for fabrication of the micro-bridge structure based on amorphous silicon (a-Si) films is studied. As a key technology in the fabrication of the micro-bridge structure, the sacrificial layer technology, including the preparation of polyimide thin films (i.e., curing, wet etching, and plasma etching processes), is systematically researched, and a series of key parameters are obtained. An improved process ∞ow of self-supporting micro-bridge structure is established. Experimental results and scanning electron microscope (SEM) images show that the fabrication technology presented is simple and feasible. A 160£120 micro-bridge array is successfully fabricated using this method. OCIS codes: 040.3060, 130.6010, 230.4000. doi: 10.3788/COL201008S1.0218. In recent years, the development and application of uncooled infrared focal plane arrays technology have received more attention from internal and external researchers. All the thermal infrared detectors exhibit a change in some measurable properties that accompany a change in temperature of the sensitive element. The manifestation of the temperature increment depends on the detection mechanism. The thermal infrared detectors can be divided into three basic kinds: bolometer,