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991.
辽河油田东部凹陷火山岩油藏较为集中分布.然而常规酸化效果较差.经采用三元酸(粉末硝酸、盐酸和氢氟酸)前置液压裂酸化后.获得显著的增产效果,进一步表明该项酸化工艺技术成熟,宜于推广应用。同时也面临技术集成再创新机遇.适应更广泛的地质需求。 相似文献
992.
Densitometry determination of dioxins using gold nanoparticlemodified dioxin response element probes
Li-Fan Zhao Li Li Yu-Qiu Gao Bo-Sheng Li Yuan-Yuan Li Chang-Hua Shi Tian Chen Wen-Jie Yang Xiao-Bo Li Shun-Qing Xu 《Gold bulletin》2007,40(4):305-309
This study aims to develop a rapid and sensitive densitometry bioassay of dioxins. It is known that dioxin ligand can bind
heterodimeric aryl hydrocarbon receptor (AhR) and trigger the formation of the complex of dioxin-AhR, AhR nuclear translocator
(Arnt), and dioxin-responsive element (DRE). We have established a rapid and sensitive method using nanoparticle-modified
DRE probes based on dioxin-dependent binding of DRE to AhR complex. Dioxins can trigger the binding of nanoparticle-modified
DRE probe to AhR complex. The nanoparticle-modified DRE probes in the dioxin-AhR-Arnt-DRE complexes immobilized on the microplates
were detected by measuring optical density after silver enhancement. Results showed that as little as 0.01 pM of TCDD could
be detected. Dioxins could be quantified accurately with the linear range from 1 nM to 0.01 pM. The coefficient of variation
was 5≈8% in this bioassay. The optical density of nanoparticle-based silver enhancement was produced in a dose- and time-
dependent manner. The dioxin concentrations in fly ash samples determined by this bioassay were comparable with that by the
standard HRGC/HRMS. Thus this bioassay is a sensitive and convenient cell-free bioassay of dioxin that is suitable for screening
of dioxins in environmental or food matrices. 相似文献
993.
Ying Bai Yanfeng Yin Na Liu Bingkun Guo Hongjun Shi Jianyong Liu Zhaoxiang Wang Liquan Chen 《Journal of power sources》2007
As the continuance of our series study on LiCoO2 surface modification, the complicated traditional surface coating method is replaced with simple addition of amorphous YPO4 and Al2O3 in commercial LiCoO2 or in commercial electrolyte based on our understanding to the improvement mechanism of surface modification. Comprehensive studies by X-ray photoelectron spectroscopy (XPS), gas chromatography and mass spectroscopy (GC–MS), inductively coupled plasma (ICP) and Fourier transformed infrared (FTIR) indicate that the products of spontaneous reaction between the additive and the LiPF6 based electrolyte are responsible for the performance improvements. 相似文献
994.
Understanding how the structure of the unit-cell affects the cryogenic performance of a Si power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is an important step toward optimizing of the device for cryogenic operations. In this paper, numerical simulations of the Si power Double Diffused MOSFET’ (DMOS) are performed at room temperature and cryogenic temperatures. Physically based models for temperature dependent silicon properties are employed in the simulations. The performances of power DMOS’ with various unit-cell structures are compared at both room temperature and low temperatures. The effect of the cell structure on the on-resistance and breakdown voltage of the device are analyzed. The simulation results suggest that the device optimized for room temperature operation can be further optimized at cryogenic temperatures. 相似文献
995.
王西文 《石油地球物理勘探》2007,42(3):362-361
《石油地球物理勘探》报道了我国石油地球物理勘探领域方法和技术的最新进展及所取得的成就,反映了我国石油地球物理勘探的科研水平和实际应用能力。面对我国新领域油气勘探的不断深入,石油地球物理勘探技术也不断地取得进步。2006年该刊共发表各类论文134篇,主要内容涉及7个方面:①野外地震采集技术;②地震资料处理方法和技术;③地震综合解释及油气预测方法和技术;④重磁电综合物探方法和技术;⑤测井技术应用;⑥地质研究;⑦专家综述和评述。 相似文献
996.
Johann Lepschy-v. Gleissenthal Richard Dietrich Erwin Märtlbauer Manfred Schuster Adalbert Süß Gerhard Terplan 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1989,188(6):521-526
Summary Bavarian cereals and wheat flour from the 1987 harvest were analysed for nivalenol (NIV) and deoxynivalenol (DON) using high performance liquid chromatography (HPLC) and for T-2 toxin and zearalenone (ZEA) by enzyme-linked-immunosorbent as say (ELISA). The study included 190 field samples of wheat, barley, rye and oat with visibly damaged ears, 45 samples of wheat intended for feed production and two series of wheat flour (type 550) and whole wheat flour collected in October 1987 and June 1988. The field samples examined showed a high DON contamination of wheat (87%) with an average of 3.96 mg/kg and a maximum of 43.8 mg/kg. Mean levels between 0.33 mg/kg and 0.27 mg/kg DON could be detected in barley, rye and oat. Of the wheat samples, 58% contained ZEA with a maximum of 1.560 mg/kg. The highest levels of ZEA were detected in samples which also showed high concentrations of DON. The NIV and T-2 toxin levels were comparatively low. Thirty percent of the samples showed NIV concentrations between 0.04 mg/kg and 0.29 mg/kg and 38% contained between 0.005 and 0.60 mg/kg of T-2. In the wheat samples for feed production, only DON was detected with an average of 0.190 mg/kg and a maximum of 0.75 mg/kg. The highest DON levels (0.58 mg/kg) from October 1987 were found in the wheat flour samples which were lower than the highest DON concentration (3.24 mg/kg) detected in the samples collected during June 1988. This fact was probably due to a substantial amount of non-contaminated wheat from 1986. The toxin concentrations in the whole wheat flour were not higher than in the type 550 flour. The regional distribution of the mean DON concentrations showed the highest levels in Middle and Lower-Franconia.
Vorkommen von Fusarium Mykotoxinen in bayerischem Getreide der Ernte 1987
Zusammenfassung Cerealien und Weizenmehle der bayerischen Ernte 1987 wurden mittels hochauflösender Flüssigchromatographie (HPLC) auf Nivalenol (NIV) und Deoxynivalenol (DON) Bowie mit Enzymimmunoassay auf T-2 Toxin und Zearalenon (ZEA) analysiert. Die Untersuchungen umfaßten 190 Feldproben von Weizen, Gerste, Roggen und Hafer, die alle optisch erkennbaren Fusarienbefall aufwiesen, 45 Futterweizenproben Bowie zwei Probenserien von Weizenmehlen der Type 550 und Vollkornweizenmehlen, die im October 1987 und im Juni 1988 gezogenwurden. — Die Untersuchungen der Feldproben ergaben eine hohe DON-Kontamination des Weizens (87%) mit einem durchschnittlichen Gehalt von 3,96 mg/kg und einem Maximalgehalt von 43,8 mg/kg. In Gerste, Roggen und Hafer konnten durchschnittlich zwischen 0,33 mg/kg und 0,27 mg/kg DON-nachgewiesen werden. 58% der Winterweizenproben wiesen Zearalenon mit einem Maximalgehalt von 1,56 mg/kg auf. Die höchsten ZEA-Werte wurden in Proben ermittelt, die gleichzeitig einen hohen DON-Gehalt aufwiesen. Die Konzentrationen von NIV und T-2 Toxin waren vergleichsweise niedrig. 30% der Proben hatten NIV-Gehalte zwischen 0,04 mg/kg und 0,29 mg/kg und 38% enthielten T-2 Toxin zwischen 0,005 mg/kg und 0,06 mg/kg. In den Futterweizenproben konnte DON als einziges Toxin mit einem Gehalt von durchschnittlich 0,19 mg/kg und maximal 0,75 mg/kg festgestellt werden. Die Weizenmehle, die im October 1987 gezogen wurden, wiesen maximal 0,58 mg/kg DON auf. Die Gehalte lagen damit medriger als die der Mehlproben vom Juni 1988, die maximal 3,24 mg/kg und durchschnittlich 0,26 mg/kg DON enthielten. Dieser Sachverhalt könnte auf Anteile von nicht kontaminiertem Weizen der Ernte 86 an den im October gezogenen Mehlproben zurückgeführt werden. Die Toxingehalte der Vollkornmehle waren nicht höher als die der Weizenmehle der Type 550. Die höchsten Durchschnittsgehalte von DON wurden in Mittel- und Unterfranken festgestellt.相似文献
997.
This paper presents a new method for the direct and accurate evaluation of strongly singular integrals in the sense of Cauchy principal values and weakly singular integrals over quadratic boundary elements in three-dimensional stress analysis and quadratic internal cells in two-dimensional elastoplastic analysis by the boundary element method. A quadratic triangle polar co-ordinate transformation technique is applied to reduce the order of singularity of the singular integrals. Next, a form of Stokes' theorem is introduced in order to remove the singularity in the Cauchy principal value integrals; therefore, the evaluation of these integrals can be carried out by standard Gaussian quadrature. Numerical examples of 2-D elastoplastic problems and a 3-D elastic problem show the effectiveness and efficiency of the method. 相似文献
998.
Franco Chialva Carlotta Frattini Aldo Martelli 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1985,181(1):32-34
Summary The essential oil obtained by steam distillation of cinchona bark (Cinchona spp.,Rubiaceae family) — a plant well known for its pharmacological properties, also employed in the food industry, especially in making liqueurs - was investigated. The oil, of completely unknown chemical composition, was analyzed by GLC and GLC/MS after separation on a silica gel column, and one hundred components were identified. The presence of 2-hexyl-3-methylmaleic anhydride is rather unusual.
Ungewöhnliche ätherische Öle mit aromatischen Eigenschaften. Die flüchtigen Aromastoffe der China-Rinde
Zusammenfassung Es wurde ätherisches Öl analysiert, das durch Wasserdampfdestillation von Chinarinde (Cinchona spp. derRubiaceae-Familie) gewonnen wurde. Diese Pflanze ist aufgrund ihrer pharmakologischen Eigenschaften bekannt und wird auch in der Lebensmittelindustrie verwendet, ganz besonders für die Likör- und Magenbitterherstellung. Die chemische Zusammensetzung dieses Öls war unbekannt. Nach Abtrennung auf einer Kieselgelsäule wurden im Öl mit GLC und GLC/MS etwa 100 Verbindungen identifiziert. Das Vorhandensein von 2-Hexyl-3-methyl-maleinsäureanhydrid ist ziemlich ungewöhnlich.相似文献
999.
ABSTRACT: The microbiological quality of farm-reared, tropical freshwater prawn ( Macrobrachium rosenbergii ) stored at 2 different temperatures was studied. The prawn muscle was found to have the initial bacterial load of 104 cfu/g. The lactics and vibrios were in the range of 102 cfu/g, while the E. coli , aeromonads, staphylococci, anaerobes, and molds were in the level of 101 cfu/g. Salmonella and Vibrio cholerae were present in the prawn muscle. The prawn muscle held at room temperature (28 ± 2 °C) was organoleptically acceptable up to 8 h, when the bacterial load was more than 106 cfu/g. However, the prawn muscle stored at freezer temperatures (−10 to −15 °C) was found to be in acceptable condition even after 30 d of storage and the bacterial load was fluctuating in the range of 103 to 104 cfu/g. 相似文献
1000.