摘要：Efficient catalysts enable MgH2 with superior hydrogen storage ***,we successfully synthesized a catalyst composed of Ce and Ni (***_(5) alloy) with splendid catalytic action for boosting the hydrogen storage property of magnesium hydride (MgH_(2))The MgH2–5wt%CeNi_(5) composite’s initial hydrogen release temperature was reduced to 174℃ and approximately 6.4wt%H_(2) was released at 275℃ within 10 ***,the dehydrogenation enthalpy of MgH_(2) was slightly decreased by adding CeNi_(5).For hydrogenation,the fully dehydrogenated sample absorbed 4.8wt%H_(2) at a low temperature of 175℃.The hydrogenation apparent activation energy was decreased from(73.60±1.79) to (46.12±7.33) kJ/*** analysis revealed that Mg_(2)Ni/Mg_(2)NiH_(4) and CeH_(2.73) were formed during the process of hydrogen absorption and desorption,exerted combined“Gateway”and“Spillover”effects to reduce the operating temperature and improve the hydrogen storage kinetics of MgH_(2).Our work provides an example of merging“Gateway”and“Spillover”effects in one catalyst and may shed light on designing novel highly-effective catalysts for MgH_(2) in near future.

摘要：利用“液电效应”产生的等离子体冲激声源在岩石破碎、地质导向、确定位置等方向有巨大的应用价值,目前关于等离子体放电回路中充电电压与放电特性、冲激波特性的关联性仍缺乏进一步深入了解。基于水下等离子体放电实验平台,建立水下等离子体冲激声源的仿真模型,对比分析冲激声源放电典型的电压、电流及冲激波波形的实测和仿真结果,通过仿真模型研究不同充电电压下的放电特性与冲激波特性。结果表明,当充电电压从15 kV提高到25 kV时,冲激波强度峰值增大了31.9%,冲激波能量增大了53.8%,因外电路能量增加速率大于冲激波能量增加速率促使其转化效率降低了28.4%。通过改变充电电压来预测冲激波特性,对比分析不同充电电压下的冲激波强度、能量损耗及能量转化效率等,为水下冲激声源不同工程应用选取最佳的充电电压提供参考依据,也可根据充电电压对冲激波特性影响来设计水下等离子体冲激声源的充电储能部分。

摘要：【目的】稻瘟病是水稻生产上的重要限制因素,挖掘与利用抗病基因是实现水稻高产稳产的重要保障。前期研究发现,稻瘟病抗性相关osa-miR-21可能通过靶向调控多胺氧化酶基因OsPAO4调节水稻稻瘟病抗性,但目前多胺氧化酶(Polyamine oxidases,PAOs)在水稻抗病中的功能研究尚未见报道。为进一步探究其在水稻抗病中的可能生物学功能,本研究利用CRISPR/Cas9编辑技术对水稻OsPAO4基因进行定点编辑并对其后代突变体进行分析。【方法】在OsPAO4第2外显子处设计了1个20 bp的编辑靶点,将靶点核苷酸片段克隆至pRGEB32载体,获得OsPAO4编辑载体。随后,利用农杆菌介导法转化水稻Pik-H4 NIL愈伤组织中,经过再生培养、潮霉素检测获得转基因阳性植株,并对T_(0)代植株靶位点附近DNA序列进行PCR和测序分析。【结果】OsPAO4基因被成功编辑,最终获得25个转基因阳性植株,并在T_(0)代产生多种突变类型:3株纯合突变、18株杂合突变和4株未发生编辑的植株。此外,T_(0)代杂合突变ospao4-8的颖壳颜色由紫色变为深灰色,且ospao4突变体中过氧化氢酶(Catalase,CAT)活性有所升高,推测OsPAO4可能参与水稻的基础免疫过程。【结论】创制了多种类型ospao4突变体材料,初步确定OsPAO4可能参与水稻免疫过程的调控,为进一步深入揭示OsPAO4基因的具体生物学功能和分子调控机制奠定了重要基础。