Results 101 to 110 of about 1,435,259 (250)
New Phytologist, EarlyView.Biosynthesis and accumulation of tanshinones in the periderm of Salvia miltiorrhiza during secondary root growth. Summary Perennial herbs develop long‐lived roots that undergo repeated cycles of secondary growth, during which the periderm functions as a protective barrier and a major site of specialized metabolite accumulation.
Licheng Liu +19 more
wiley +1 more source
四川大学学报. 自然科学版, 2005 采用sol-gel方法预合成钙钛矿结构的PZT,采用固相法预合成MnSb2O6,然后用制得的PZT和MnSb2O6为原料,利用干压法和粉末电磁成型法成型,合成xPMnS-(1-x)PZN压电陶瓷,探讨了成型工艺对材料结构与性能的影响.结果表明粉末电磁压制法成型的样品致密度均达到了95%以上,性能均高于干压法制备的材料,当x=0.55时综合性能可达到最佳,分别为kp=0.46,Qm=391,tanδ=0.54%,ε3T3/ε0=1739,d33=347pC/N.
赵然, 周静, 魏长松, 陈文
doaj
, 2000 一种微波加热合成分子筛膜的方法，其特征在于制备过程如下：（１）分子筛合成液的配制，配方为aNa2O：Al2O3：5SiO2：bH2O,a=5.0～20.0,b=500～４０００；（２）将多孔基膜置于合成液中，利用微波加热合成，温度为５０℃～１００℃，合成时间为１０～６０分钟；（３）洗涤烘干。本发明方法合成的分子筛膜具有高的分离性能，且合成时间短 ...
杨维慎, 徐晓春, 刘杰, 林励吾
core
Accountability in Government Use of AI: Citizen Concerns and Preferences
Public Administration, EarlyView.ABSTRACT Government adoption of AI opens the “pandora's box” of accountability, a core aspect of public value. Despite the centrality of governmental AI accountability, citizens' concerns and preferences in holding governments accountable for AI usage remain poorly understood.
Naikang Feng, Yanto Chandra
wiley +1 more source
四川大学学报. 自然科学版, 1990 合成了一类新型的冠醚化合物,它们不仅具有冠醚络合金属离子的特性,还具有液晶的特性。还发现这些冠醚与金属离子络合后.仍然有液晶性质,因而这种液晶具有导电性;同时还发现液晶冠醚要形成具有液晶性质的络合物,主要决定于形成络合物的阴离子的结构。
谢明贵 +4 more
doaj
, 2014 近年来，共轭烯炔在学术界和工业界都引起高度关注。这是因为共轭烯炔是许多天然产物、药物和生物活性物质的重要砌块，许多抗生素和抗癌药物中都含有共轭烯炔结构单元，如抗真菌药物特比萘芬（Terbinafin）、抗癌抗生素达内霉素（dynemicin）和卡里奇霉素（Calicheamycin）等。另一方面，共轭烯炔还是有机合成中重要的原料和中间体。它可以和多种烯烃、炔烃以及自身等共轭体系发生偶联反应，合成出一系列具有独特性质的共轭型有机分子；它可以发生[4+2]环化反应以及自身分子内的成环反应 ...
张帅
core
Public Administration, EarlyView.ABSTRACT As the public sector increasingly adopts AI‐powered automated decision systems (ADS), understanding how citizens experience and value ADS use in public decision‐making is both normatively and practically important. Therefore, we examine and compare the effects of seven attributes of public values on citizens' support for ADS adoption in two ...
Guimin Zheng +4 more
wiley +1 more source
四川大学学报. 自然科学版, 2010 目前已有的航迹关联方法虽然能很好地解决二传感器二目标或者二传感器多目标航迹融合问题,但处理多传感器多目标航迹关联问题时效果较差.因航迹关联问题实际上是判决融合问题,作者提出用Dempster合成规则的思想来解决之,但必须要对合成规则有新的推广.推广后的方法不仅能解决二传感器航迹关联问题,而且还能解决多传感器航迹关联问题.当传感器证据相互冲突或不够准确的时候,经典的Dempster合成规则无法应用,而推广的Dempster合成规则可解决该问题.最后作者给出了一个四传感器二航迹关联的例子 ...
马艳霞, 屈小媚
doaj
, 2005 对生物质气、工业合成气、重整后生物质气及配氢后生物质气4种合成气进行了合成甲醇的研究．发现甲醇产率顺序为工业合成气〉重整生物质气〉配氢生物质气〉生物质气，生物质气合成甲醇产率较低主要是因为其为富CO2体系，实验同时发现（H2-CO2）／（CO＋CO2）比值在1．5～2之间时，（H2-CO2）／（CO＋CO2）比值对液相产物中甲醇选择性没有明显影响 ...
王铁军 +4 more
core
Powerful representation of the poor? German welfare associations' narrative advocacy during COVID‐19
Policy Studies Journal, EarlyView.Abstract The COVID‐19 pandemic sparked unprecedented experimentation in the German social assistance system, leading to changes previously considered impracticable by policymakers. This included a sanctions moratorium, easier access to benefits, and temporary cash transfers, all of which were advocated by welfare associations—key organized interests ...
Christopher Smith Ochoa
wiley +1 more source