Unprecedented VSe2/graphene nanocomposites are synthesized through a hydrothermal route. A large number of hexagonal VSe2 sheets anchored on the graphene sheets can be observed. The thicknesses and lengths of VSe2 sheets are controlled by graphene sheets. VSe2/graphene nanocomposite prepared with 15 mg graphite oxide (VSe2/G-15) exhibits the best electrochemical lithium storage properties such as charge/discharge capacities, cycle stability and rate capability when used as an anode material for lithium-ion batteries. (C) 2014 Elsevier B.V. All rights reserved.
Wang, Yaping
Choi, Hyung-Kyoon
Brinckmann, Josef A.
Jiang, Xue
Huang, Linfang
Highlights • Analytical techniques for chemical analysis of Panax quinquefolius (North American ginseng) are reviewed. • Both advantages and disadvantages among different analytical techniques are summarized. • The challenges encountered in the chemical analysis of P. quinquefolius are briefly discussed. Abstract Panax quinquefolius (PQ) is one of the best-selling natural health products due to its proposed beneficial anti-aging, anti-cancer, anti-stress, anti-fatigue, and anxiolytic effects. In recent years, the quality of PQ has received considerable attention. Sensitive and accurate methods for qualitative and quantitative analyses of chemical constituents are necessary for the comprehensive quality control to ensure the safety and efficacy of PQ. This article reviews recent progress in the chemical analysis of PQ and its preparations. Numerous analytical techniques, including spectroscopy, thin-layer chromatography (TLC), gas chromatography (GC), high-performance liquid chromatography (HPLC), liquid chromatography/mass spectrometry (LC/MS), high-speed centrifugal partition chromatography (HSCPC), high-performance counter-current chromatography (HPCCC), nuclear magnetic resonance spectroscopy (NMR), and immunoassay, are described. Among these techniques, HPLC coupled with mass spectrometry (MS) is the most promising method for quality control. The challenges encountered in the chemical analysis of PQ are also briefly discussed, and the remaining questions regarding the quality control of PQ that require further investigation are highlighted.
A detection device and detection method of an electric oil submersible plunger pump (4); the detection device is connected to accumulator tanks (1), first and second valves (2), first and second pressure transmitters (3) and a to-be-measured electric oil submersible plunger pump (4) via a pipeline (10), and is connected via a cable (7) to an electric control box (6) and a motor (8) located in a simulation well (9), and acquires the pressure and flow values of the liquid, the stroke speed of the pump, and the working power usage rate data of the motor (8) by simulating operation site conditions. The detection device has good simulation of job site conditions, and can accurately measure the operation parameters of the electric oil submersible plunger pump (4) at different working rates and the maximum lifting force, pump efficiency and discharge capacity thereof under different stroke speeds, thus allowing the electric oil submersible plunger pump (4) to safely and efficiently lift in an oil well.
The present invention provides a new method for synthesizing maxacalcitol and an intermediate thereof. According to the method, the maxacalcitol is creatively synthesized through the steps of: taking vitamin D2 as an initial raw material, obtaining a compound represented by formula II, oxidizing, chirally reducing, grafting with a side chain, introducing a hydroxyl group on the C-1 position, and photochemically overturning.
A dual pipe network water injection system pressure dividing point determination method, comprising the following steps: step 1, acquiring technical parameters of a water injection system and an individual well governed thereby; step 2, establishing an operation efficiency and pressure dividing point mathematical model of "Single water injection system and dual pressure system water injection pipe network", and acquiring relationship functions between operation efficiency and pressure and the water quantity according to the mathematical model; step 3, setting up an iteration simulation method to calculate the calculation range and calculation step length of pressure dividing points; step 4, substituting each parameter value into the mathematical model to conduct iterative solving so as to obtain the solution set of the operation efficiency, and drawing the solution set data curve of the operation efficiency via the solution set, the curve being a parabolic curve; step 5, the top point of the parabola is the highest point of a pipe network efficiency, and a pressure point numerical value corresponding to the top point is the best pressure dividing point for outward delivery.
The invention is directed to a formula (I), or a pharmamceutically acceptable salt thereof, wherein R1, R2a, R2b and R3-R7 are herein. The invention is also directed to compositions containing a compound of formula (I) and to the use of such compounds in the inhibition of mutant IDH proteins having a neomorphic activity. The invention is further directed to the use of a compound of formula (I) in the treatment of diseases or disorders associated with such mutant IDH proteins including, but not limited to, cell-proliferation disorders, such as cancer.
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