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Freddy H. Escobar Matilde Montealegre-M. 《Journal of Petroleum Science and Engineering》2008,61(1):15-20
Besides the regular four flow regimes normally seen during a pressure test of horizontal wells, it is possible, under special circumstances, to observe such additional flow regimes as spherical, hemi-radial, linear (reservoir channel) and elliptical. The last flow regime is characterized by a slope of 0.36 of the pressure derivative curve and occurs between the early linear flow and the pseudo-radial flow periods. This may have been overlooked in horizontal well test analysis, because it is often masked by the other flow regimes, unless the conditions are just right.The elliptical flow regime has been previously mentioned by very few researchers, Issaka et al. [Issaka, M.B., Zaoral, K., Ambastha, A.K. and Mattar, L., 2000: “Determination of Horizontal Permeability Anisotropy from Horizontal Well Tests,” SPE Saudi Arabia Section Technical Symposium, Dhahran, Saudi Arabia, 21–23 October.], Chacon et al. [Chacon, A., Djebrouni, A. and Tiab, D., 2004. “Determining the Average Reservoir Pressure from Vertical and Horizontal Well Test Analysis Using Tiab's Direct Synthesis Technique”. SPE 88619, Proceedings, SPE Asia Pacific Oil & Gas Conf. & Exhibition, Perth, Australia, 18–20 October.] and Escobar et al. [Escobar, F.H., Munoz, O.F., and Sepulveda, J.A., 2004. “Horizontal Permeability Determination from the Elliptical Flow Regime for Horizontal Wells”. CT&F — Ciencia, Tecnología y Futuro. Vol. 2 Num. 5. p. 83–95. Dec.]. A methodology for its characterization has been also introduced using the pressure derivative concept and TDS technique [Escobar, F.H., Munoz, O.F., and Sepulveda, J.A., 2004. “Horizontal Permeability Determination from the Elliptical Flow Regime for Horizontal Wells”. CT&F — Ciencia, Tecnología y Futuro. Vol. 2 Num. 5. p. 83–95. Dec.]. However, conventional analysis for the characterization of this has not yet been reported in the literature. This flow regime is very useful to estimate the horizontal permeability, especially, when the pseudo-radial flow is very short or unclear, or simply, when it is desired to verify that estimation.In this paper, equations for the estimation of the horizontal permeability and elliptical skin factor are developed for both gas and oil horizontal wells, so that the mentioned parameters can be estimated, respectively, from the slope and intercept of linear plot of pressure versus time to the power 0.36. The equations were successfully tested with two field examples previously worked in the literature. 相似文献
3.
Facile Two‐Step Synthesis of All‐Inorganic Perovskite CsPbX3 (X = Cl,Br, and I) Zeolite‐Y Composite Phosphors for Potential Backlight Display Application 下载免费PDF全文
Jia‐Yi Sun Freddy T. Rabouw Xian‐Feng Yang Xie‐Yi Huang Xi‐Ping Jing Shi Ye Qin‐Yuan Zhang 《Advanced functional materials》2017,27(45)
Recently developed CsPbX3 (X = Cl, Br, and I) perovskite quantum dots (QDs) hold great potential for various applications owing to their superior optical properties, such as tunable emissions, high quantum efficiency, and narrow linewidths. However, poor stability under ambient conditions and spontaneous ion exchange among QDs hinder their application, for example, as phosphors in white‐light‐emitting diodes (WLEDs). Here, a facile two‐step synthesis procedure is reported for luminescent and color‐tunable CsPbX3–zeolite‐Y composite phosphors, where perovskite QDs are encapsulated in the porous zeolite matrix. First zeolite‐Y is infused with Cs+ ions by ion exchange from an aqueous solution and then forms CsPbX3 QDs by diffusion and reaction with an organic solution of PbX2. The zeolite encapsulation reduces degradation and improves the stability of the QDs under strong illumination. A WLED is fabricated using the resulting microscale composites, with Commission Internationale de I'Eclairage (CIE) color coordinates (0.38, 0.37) and achieving 114% of National Television Standards Committee (NTSC) and 85% of the ITU‐R Recommendation BT.2020 (Rec.2020) coverage. 相似文献
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Juqing Liu Zongqiong Lin Tianjun Liu Zongyou Yin Xiaozhu Zhou Shufen Chen Linghai Xie Freddy Boey Hua Zhang Wei Huang 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(14):1536-1542
Highly reduced graphene oxide (rGO) films are fabricated by combining reduction with smeared hydrazine at low temperature (e.g., 100 °C) and the multilayer stacking technique. The prepared rGO film, which has a lower sheet resistance (≈160–500 Ω sq−1) and higher conductivity (26 S cm−1) as compared to other rGO films obtained by commonly used chemical reduction methods, is fully characterized. The effective reduction can be attributed to the large “effective reduction depth” in the GO films (1.46 µm) and the high C1s/O1s ratio (8.04). By using the above approach, rGO films with a tunable thickness and sheet resistance are achieved. The obtained rGO films are used as electrodes in polymer memory devices, in a configuration of rGO/poly(3‐hexylthiophene) (P3HT):phenyl‐C61‐butyric acid methyl ester (PCBM)/Al, which exhibit an excellent write‐once‐read‐many‐times effect and a high ON/OFF current ratio of 106. 相似文献
6.
Absolute quantification of cerebral blood flow, cerebral blood volume and mean transit time is desirable in the determination
of tissue viability thresholds and tissue at risk in acute ischaemic stroke, as well as in cases where a global reduction
in cerebral blood flow is expected, for example, in patients with dementia or depressive disorders. Absolute values are also
useful when comparing sequential examinations of tissue perfusion parameters, for example, in the monitoring and follow-up
of various kinds of therapy. Regardless of the method employed, a number of assumptions and approximations must be made to
obtain absolute measures of perfusion. Furthermore, the different stages of data acquisition and processing are associated
with various degrees of uncertainty. In this review, the problems of particular relevance to absolute quantification of cerebral
perfusion parameters using dynamic susceptibility contrast magnetic resonance imaging are discussed, and possible solutions
are outlined. 相似文献
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8.
Xiaoying Qi Can Xue Xiao Huang Yizhong Huang Xiaozhu Zhou Hai Li Daojun Liu Freddy Boey Qingyu Yan Wei Huang Steven De Feyter Klaus Müllen Hua Zhang 《Advanced functional materials》2010,20(1):43-49
A novel dendrimer‐templating method for the synthesis of CuO nanoparticles and the in situ construction of ordered inorganic–organic CuO–G2Td(COOH)16rice‐shaped architectures (RSAs) with analogous monocrystalline structures are reported. The primary CuO nanoparticles are linked by the G2Td(COOH)16 dendrimer. This method provides a way to preserve the original properties of primary CuO nanoparticles in the ordered hybrid nanomaterials by using the 3D rigid polyphenylene dendrimer (G2Td(COOH)16) as a space isolation. The primary CuO nanoparticles with diameter of (6.3 ± 0.4) nm are synthesized via four successive reaction steps starting from the rapid reduction of Cu(NO3)2 by using NaBH4 as reducer and G2Td(COOH)16 as surfactant. The obtained hybrid CuO–G2Td(COOH)16 RSA, formed in the last reaction step, possesses a crystal structure analogous to a monocrystal as observed by transmission electron microscopy(TEM). In particular, the formation process of the RSA is monitored by UV–vis, TEM, and X‐ray diffraction. Small angle X‐ray scattering and Fourier transform infrared spectroscopy are used to investigate the role of the dendrimer in the RSA formation process. The obtained results illuminate that Cu2+? COO? coordination bonds play an indispensable role in bridging and dispersing the primary CuO nanoparticles to induce and maintain the hybrid RSA. More importantly, the RSA is retained through the Cu2+? COO?coordination bonds even with HCl treatment, suggesting that the dendrimers and Cu2+ ions may form rice‐shaped polymeric complexes which could template the assembly of CuO nanoparticles towards RSAs. This study highlights the feasibility and flexibility of employing the peculiar dendrimers to in‐situ build up hybrid architectures which could further serve as templates, containers or nanoreactors for the synthesis of other nanomaterials. 相似文献
9.
Van Campenhout K Goenaga Infante H Goemans G Belpaire C Adams F Blust R Bervoets L 《The Science of the total environment》2008,394(2-3):379-389
The effect of metal exposure on the accumulation and cytosolic speciation of metals in livers of wild populations of European eel with special emphasis on metallothioneins (MT) was studied. Four sampling sites in Flanders showing different degrees of heavy metal contamination were selected for this purpose. An on-line isotope dilution method in combination with size exclusion (SE) high pressure liquid chromatography (HPLC) coupled to Inductively Coupled Plasma time-of-flight Mass Spectrometry (ICP-TOFMS) was used to study the cytosolic speciation of the metals. The distribution of the metals Cd, Cu, Ni, Pb and Zn among cytosolic fractions displayed strong differences. The cytosolic concentration of Cd, Ni and Pb increased proportionally with the total liver levels. However, the cytosolic concentrations of Cu and Zn only increased above a certain liver tissue threshold level. Cd, Cu and Zn, but not Pb and Ni, were largely associated with the MT pool in correspondence with the environmental exposure and liver tissue concentrations. Most of the Pb and Ni and a considerable fraction of Cu and Zn, but not Cd, were associated to High Molecular Weight (HMW) fractions. The relative importance of the Cu and Zn in the HMW fraction decreased with increasing contamination levels while the MT pool became progressively more important. The close relationship between the cytosolic metal load and the total MT levels or the metals bound on the MT pool indicates that the metals, rather than other stress factors, are the major factor determining MT induction. 相似文献
10.
Verstrepen KJ Van Laere SD Vercammen J Derdelinckx G Dufour JP Pretorius IS Winderickx J Thevelein JM Delvaux FR 《Yeast (Chichester, England)》2004,21(4):367-377
The yeast alcohol acetyl transferase I, Atf1p, is responsible for the major part of volatile acetate ester production in fermenting Saccharomyces cerevisiae cells. Some of these esters, such as ethyl acetate and isoamyl acetate, are important for the fruity flavours of wine, beer and other fermented beverages. In order to reveal the subcellular localization of Atf1p and further unravel the possible physiological role of this protein, ATF1::GFP fusion constructs were overexpressed in brewer's yeast. The transformant strain showed a significant increase in acetate ester formation, similar to that of an ATF1 overexpression strain, indicating that the Atf1p-GFP fusion protein was active. UV fluorescence microscopy revealed that the fusion protein was localized in small, sphere-like organelles. These organelles could be selectively stained by the fluorescent dye Nile red, indicating that they contained high amounts of neutral lipids and/or sterols, a specific characteristic of yeast lipid particles. Purification of lipid particles from wild type and ATF1 deletion cells confirmed that the Atf1p-GFP fusion protein was located in these organelles. Furthermore, a clear alcohol acetyl transferase activity could be measured in the purified lipid particles of both wild type and transformed cells. The localization of Atf1p in lipid particles may indicate that Atf1p has a specific role in the lipid and/or sterol metabolism that takes place in these particles. 相似文献