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121.
丁腈橡胶、腰果油改性酚醛树脂的研究   总被引:5,自引:0,他引:5  
以丁腈橡胶粉和腰果油改性酚醛树脂为改性剂,通过对多种原料、橡胶助剂、摩擦性能调节剂的研究和配方筛选,制得高性能载重汽车刹车片内衬材料。该材料磨耗低、抗冲击强度高、硬度和摩擦系数适中、高温抗热衰退明显,生产过程中可省去投资大、能耗高的密炼工艺,具有重要的工业价值。  相似文献   
122.
Nickel nanoparticles (<10 nm) were successfully synthesized using a reductive method of nickel chloride with sodium borohydride in the ethanol/poly- vinylpyrrolidone (PVP) system. The effects of three factors, such as the concentration of the nickel ions, the time of reaction, and the amount of PVP (surfactant), were discussed. The possible growth process of the particles and optimum reactive conditions was also investigated. The result of transmission electron microscopy (TEM) reveals that these nickel nanoparticles are spherical. The average diameter could be controlled as 2-5 nm under selected conditions. High-resolution TEM and energy-dispersive spectroscopy results indicates that the nickel nanoparticles are pure. The UV-visible light absorption spectrum shows that the peaks of nickel nanoparticles moves toward the short wavelength along with the decrease of sizes.  相似文献   
123.
水玻璃、硅溶胶复合型壳,表面层应用硅溶胶锆英粉涂料,用来生产精铸件,尤其是高合金钢铸件,其表面粗糙度可达3.2,比水玻璃型壳的精铸件表面粗糙度参数值有所降低,约低1~1.5级,尺寸精度也有所提高。  相似文献   
124.
Shaped-charge principles, including analytical work, computer-code simulations, and experimental results, are reviewed. It is assumed that the reader has a basic understanding of the functioning of shaped charges, and emphasizes developments in recent years. The survey is divided into four sections: Liner Collapse, Jet Formation, Jet Breakup, and Target Penetration. Only traditional shaped charges are covered; kinetic-energy penetrators and self-forging-fragment warheads are not included. Ninety-nine references are cited.  相似文献   
125.
The pathophysiology of sepsis involves inflammation and hypercoagulability, which lead to microvascular thrombosis and compromised organ perfusion. Dipeptidyl peptidase (DPP)-4 inhibitors, e.g., linagliptin, are commonly used anti-diabetic drugs known to exert anti-inflammatory effects. However, whether these drugs confer an anti-thrombotic effect that preserves organ perfusion in sepsis remains to be investigated. In the present study, human umbilical vein endothelial cells (HUVECs) were treated with linagliptin to examine its anti-inflammatory and anti-thrombotic effects under tumor necrosis factor (TNF)-α treatment. To validate findings from in vitro experiments and provide in vivo evidence for the identified mechanism, a mouse model of lipopolysaccharide (LPS)-induced systemic inflammatory response syndrome was used, and pulmonary microcirculatory thrombosis was measured. In TNF-α-treated HUVECs and LPS-injected mice, linagliptin suppressed expressions of interleukin-1β (IL-1β) and intercellular adhesion molecule 1 (ICAM-1) via a nuclear factor-κB (NF-κB)–dependent pathway. Linagliptin attenuated tissue factor expression via the Akt/endothelial nitric oxide synthase pathway. In LPS-injected mice, linagliptin pretreatment significantly reduced thrombosis in the pulmonary microcirculation. These anti-inflammatory and anti-thrombotic effects were independent of blood glucose level. Together the present results suggest that linagliptin exerts protective effects against endothelial inflammation and microvascular thrombosis in a mouse model of sepsis.  相似文献   
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Multimedia Tools and Applications - Matrix coding based data hiding (MCDH) using linear codes (syndrome coding) is an efficient coding method for steganographic schemes to improve their embedding...  相似文献   
128.
Abstract : A major challenge of targeted cancer therapy is the selection for drug-resistant mutations in tumor cells leading to loss of treatment effectiveness. p97/VCP is central regulator of protein homeostasis and a promising anticancer target because of its vital role in cell growth and survival. One ATP-competitive p97 inhibitor, CB-5083, has entered clinical trials. Selective pressure on HCT116 cells dosed with CB-5083 identified five different resistant mutants. Identification of p97 inhibitors with different mechanisms of action would offer the potential to overcome this class of resistance mutations. Our results demonstrate that two CB-5083 resistant p97 mutants, N660 K and T688 A, were also resistant to several other ATP-competitive p97 inhibitors, whereas inhibition by two allosteric p97 inhibitors NMS-873 and UPCDC-30245 were unaffected by these mutations. We also established a CB-5083 resistant cell line that harbors a new p97 double mutation (D649 A/T688 A). While CB-5083, NMS-873, and UPCDC-30245 all effectively inhibited proliferation of the parental HCT116 cell line, NMS-873 and UPCDC-30245 were 30-fold more potent in inhibiting the CB-5083 resistant D649 A/T688 A double mutant than CB-5083. Our results suggest that allosteric p97 inhibitors are promising alternatives when resistance to ATP-competitive p97 inhibitors arises during anticancer treatment.  相似文献   
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