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分析了人民币汇率机制改革中选择“参考一篮子货币”制的原因;在肯定这次汇率制度改革给我国带来的有利影响,同时指出了参考一篮子货币制在短期内将面临的问题,并进一步提出关于完善该汇率制度的相关措施和建议,以期对我国汇率制度改革提供参考。 相似文献
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Antibiotic and multi-drug resistant (MDR) Salmonella poses a significant threat to public health due to its ability to colonize animals (cold and warm-blooded) and contaminate freshwater supplies. Monitoring antibiotic resistant Salmonella is traditionally costly, involving the application of phenotypic and genotypic tests over several days. However, with the introduction of cheaper semi-automated devices in the last decade, strain detection and identification times have significantly fallen. This, in turn, has led to efficiently regulated food production systems and further reductions in food safety hazards. This review highlights current and emerging technologies used in the detection of antibiotic resistant and MDR Salmonella. 相似文献
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Brett J. Kagan Charlotte M. Ermine Stefano Frausin Clare L. Parish Jess Nithianantharajah Lachlan H. Thompson 《International journal of molecular sciences》2021,22(9)
Neonatal arterial ischemic stroke is one of the more severe birth complications. The injury can result in extensive neurological damage and is robustly associated with later diagnoses of cerebral palsy (CP). An important part of efforts to develop new therapies include the on-going refinement and understanding of animal models that capture relevant clinical features of neonatal brain injury leading to CP. The potent vasoconstrictor peptide, Endothelin-1 (ET-1), has previously been utilised in animal models to reduce local blood flow to levels that mimic ischemic stroke. Our previous work in this area has shown that it is an effective and technically simple approach for modelling ischemic injury at very early neonatal ages, resulting in stable deficits in motor function. Here, we aimed to extend this model to also examine the impact on cognitive function. We show that focal delivery of ET-1 to the cortex of Sprague Dawley rats on postnatal day 0 (P0) resulted in impaired learning in a touchscreen-based test of visual discrimination and correlated with important clinical features of CP including damage to large white matter structures. 相似文献
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《中国稀土学报(英文版)》2022,40(5):709-716
A series of new oxyapatite red phosphors Ca3Y7(BO4)(SiO4)5O doped with different concentrations of Eu3+ were successfully synthesized by high temperature solid state method. The X-ray diffraction (XRD) Rietveld refinement results show that the structure of the phosphor belongs to space group P63/m and Eu3+ ion replaces Y3+ ion. The emission spectrum consists of the characteristic emission peaks corresponding to Eu3+ under the excitation of 274 nm and the dominant emission peak is at 614 nm (5D0→7F2 of Eu3+). The concentration quenching effect occurs and the optimized Eu3+ concentration is 4.0 mol%. The energy level diagram for luminous mechanism is also given and the non-radiative energy transfer mechanism between Eu3+ is mainly exchange interaction. The CIE coordinate is close to the ideal red light and the color purity is higher than 99.79%. Moreover, the phosphor exhibits moderate thermal stability because the photoluminescence intensity at 423 K is still maintained at higher than 78.97% of that at room temperature. The internal quantum efficiency of Ca3Y7(BO4)(SiO4)5O:4.0 mol%Eu3+ phosphor is 58.2%. A red light emitting diode (LED) device based on it can emit bright red light. The CCT values of the device are basically unchanged when driven by various bias current. The results show that Ca3Y7(BO4)(SiO4)5O:Eu3+ is a new type of oxyapatite red fluorescent material with good comprehensive performances. 相似文献
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高压水清除氧化皮技术 总被引:2,自引:0,他引:2
本文系统地介绍了联邦德国Werner and Pfteiderer公司用高压水清除轧件及锻件表面氧化皮的新技术,包括高压水清除氧化皮的机理,水耗量及压力计算、喷嘴的设计、液压系统及轧制钢板和锻件表面氧化皮的高压水清理装置 相似文献