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排序方式: 共有133条查询结果,搜索用时 15 毫秒
1.
This paper reports the GC determination of 20 organochlorine pesticides in Chinese drugs Flos Ionicerae and Moluodan etc by the present method of Japan for determinaing pesticide residues. The results suggest that except Folium Isatidis, Radix Codonopsis and Sanqi Pian all accord with the for provisions pesticide residues in Japanese foodstuffs.  相似文献   
2.
We examined the thrombolytic properties of a novel modified human tissue plasminogen activator (PA) (E6010), in which cysteine 84 is replaced by serine, and which has a prolonged biologic half-life (t1/2). We compared the thrombolytic efficacy of continuous intracoronary (i.c.) infusion of E6010 with that of recombinant human tissue PA (rt-PA) in a canine model with copper coil-induced 1-h-old coronary artery thrombi and also compared the relation between thrombolytic efficacy and plasma clearance represented by pharmacokinetic parameters of i.c.-infused E6010 and rt-PA. Sixty-minute E6010 and rt-PA i.c. infusions were compared. The thrombolytic effects of i.c.-infused E6010 and rt-PA, represented by time to reperfusion (TR), reperfusion rate at 60 min (RR), and reocclusion rates at 60 min after reperfusion (OR) were as follows. E6010: Dose 0.06, 0.15, 0.3 (mg/kg/h); TR 25 +/- 10, 15 +/- 10, 13 +/- 5 (min); RR 100, 100, 100 (%); and OR 0, 0, 17 (%), respectively. Recombinant t-PA: Dose 0.06, 0.15, 0.3 (mg/kg/h); TR 47 +/- 12, 18 +/- 17, 14 +/- 4 (min); RR 50, 75, 100 (%); and OR 100, 33, 33 (%), respectively. These findings indicate that E6010 has more potent thrombolytic activity than rt-PA.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
3.
工艺参数对陶瓷注射成型的影响与分析   总被引:3,自引:0,他引:3  
本研究通过改变注射温度,注射压力,保压压力等几个主要参数,对形状,体积不同的注射成型体,试条,圆柱及子部件进行了一系列注射工艺实验。相应地对成型体的密度,弯曲强度及烧结体的密度和强度进行测量,并从陶瓷注射成型混合物的流动行为,热物理特性方面对注射这一复杂过程进行分析,探讨工艺参数对成型过程的内在影响,从而确定合理的注射工艺条件。  相似文献   
4.
Ongoing developments in broadband digital networks and optical devices require mechanical components having nano-metric surface finishes and ultra precision shapes. Such components are processed using the technology of diamond micro-machining in which diamond tools are extensively used. However, these tools are susceptible to chemical attack at high temperatures and induce severe wear, especially when cutting ferrous materials. As a result, these diamond tools need to be redefined (i.e., resharpened) on a regular basis in order to facilitate micro-cutting and to generate nano-metric surface finishes. This paper describes a new way of diamond tool edge re-sharpening and its conditions to achieve both increased accuracy and material removal rate.  相似文献   
5.
6.
Although curcumin is considered to have various therapeutic effects, its use as a functional food or supplement is restricted owing to its low water solubility and bioavailability. To increase the solubility of curcumin in water, the use of polyvinylpyrrolidone (PVP) and vinylpyrrolidone-vinyl acetate copolymers with a pyrrolidone skeleton was noted to be promising. In particular, the bi-component formulations of curcumin/PVP prepared through spray drying exhibited an amorphous state in powder X-ray diffraction observations and temporally increased the apparent solubility of curcumin to over 5000 times that of untreated curcumin; nevertheless, after 24 h, the solubility decreased owing to the unstable supersaturated state of curcumin. The addition of α-cyclodextrin (α-CyD) in the bi-component curcumin/PVP formulation helped maintain the supersaturated state of curcumin, whereas the addition of β- and γ-CyD led to the collapse of the supersaturated state. The addition of α-CyD can likely help inhibit the nucleation and crystal growth of curcumin, through the interaction among the solubilized units of curcumin/PVP and α-CyD.  相似文献   
7.
We demonstrate that domain structure of single-layer graphene grown by ambient pressure chemical vapor deposition is strongly dependent on the crystallinity of the Cu catalyst. Low energy electron microscopy analysis reveals that graphene grown using a Cu foil gives small and mis-oriented graphene domains with a number of domain boundaries. On the other hand, no apparent domain boundaries are observed in graphene grown over a heteroepitaxial Cu(111) film deposited on sapphire due to unified orientation of graphene hexagons. The difference in the domain structures is correlated with the difference in the crystal plane and grain structure of the Cu metal. The graphene film grown on the heteroepitaxial Cu film exhibits much higher carrier mobility than that grown on the Cu foil.  相似文献   
8.
The effects of morphological changes on the thermal expansion, toughness and heat resistance of polyamide‐6 (PA)/styrene–ethylene–butylene–styrene (SEBS)/polyphenylene ether (PPE) blends were investigated. Compared with the typical ‘sea (PA matrix)–island (PPE domain)–lake (SEBS in PPE domain)’ morphology, an injection‐molded ternary blend with a preferential distribution of SEBS component at the interface between PA and PPE exhibited a low coefficient of linear thermal expansion (CLTE) in the flow direction. This low CLTE was ascribed to the deformation of SEBS and PA into a co‐continuous microlayer network structure during injection molding. Consequently, the expansion preferentially occurred towards the thickness direction. Further CLTE reduction either by a change in PA viscosity or by the selective location of an inorganic filler was examined, and its influences on impact strength and heat resistance are discussed based on transmission electron microscopy observations. © 2015 Society of Chemical Industry  相似文献   
9.
We conducted the welding experiment using three kinds of test piece, actual size, diaphragm and butt joint. Then, we examined the influence on strength, cooling time and carbon equivalent of weld metal by welding conditions on the different test pieces. We calculated an estimate of cooling time and chemical components. Consequently, we concluded that the strength of weld metal can be estimated by heat input, interpass temperature, carbon equivarent of welding wire and shape of test piece.  相似文献   
10.
Poly(acrylic acid) (PAA), poly(methacrylic acid) (PMA), and poly(vinyl alcohol) (PVA), which have oxygen species as functional groups, were utilized as a binder for graphite electrodes, and the electrochemical reversibility of lithium intercalation was examined in PC medium and ionic liquid electrolyte, lithium bis(trifluoromethanesulfonyl)amide dissolved in 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)amide (BMP-TFSA). Columbic efficiency of 75–80% with more than 300 mAh g?1 was achieved upon first reduction/oxidation cycle in both electrolytes using these binding polymers, which were significantly improved in comparison to a conventional PVdF binder (less than 45% of columbic efficiency for the first cycle). For the graphite-PVdF electrode, co-intercalation and/or decomposition of PC molecules solvating to Li ions were observed by the electrochemical reduction, resulting in the cracking of graphite particles. In contrast, the co-intercalation and decomposition of PC molecules and BMP cations for the first reduction process were completely suppressed for the graphite electrodes prepared with the polymers containing oxygen atoms. It was proposed that the selective permeability of lithium ions was attained by the uniform coating of the graphite particles with PAA, PMA, and PVA polymers, because the electrostatic interaction between the positively charged lithium ions and negatively charged oxygen atom in the polymer should modulate the desolvation process of lithium ions during the lithium intercalation into graphite, showing the similar functions like artificial solid-electrolyte interphase.  相似文献   
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