Results 21 to 30 of about 3,931 (161)
Study on the New Method for the Construction of P-N Bond [PDF]
, 2015 磷酰胺酯是一类重要的有机中间体，含有磷酰胺酯结构的化合物具有广泛的生物活性，如抗菌、抗病毒、抗癌活性等。此外，其还可以应用于药物前体和阻燃剂等方面的研究。 早期合成磷酰胺酯最常用的方法是通过胺与磷酰卤反应来实现，但是这种方法不仅反应条件要求苛刻，而且需要前期处理剧毒的磷酰卤化合物。近几十年来，随着研究的不断深入，研究者们终于在合成磷酰胺酯的方法上取得了一系列的突破，但仍存在着一些不足之处。例如，Atherton-Todd法虽操作简便，但使用了计量的剧毒CCl4，在一定程度上又限制了该方法的广泛使用 ...
桑帅
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Integrative Conservation, Volume 4, Issue 4, Page 641-651, December 2025.Key Largo woodrats are a small and endangered island species, whose individuals tend to occur in family groups. Isolation from mainland populations, predation, and habitat fragmentation have caused genetic drift, leading to low overall diversity. Here, we found that a major category 4 hurricane promoted genetic diversity in the Key Largo woodrat ...
Taylor Ackley +5 more
wiley +1 more source
Gaoya dianqi, 2016 采用混合气体是解决气体开关设备低温运行的有效途径之一。文中基于真实气体模型,建立SRK状态方程的迭代形式,给出了SF6与CF4气体压力值在0.11 MPa,温度在223323 K范围内压缩因子曲线,分析了温度与压力对压缩因子的影响,给出了不同压力与温度下,SF6与CF4真实气体与理想气体压缩因子的偏离情况,确定混合气体的压缩因子的混合规则,分析了温度与压力对压缩因子的影响,确定混合气体的混合规则,获得了SF6、CF4及混合气体饱和蒸汽压与等密度曲线,得到了混合气体在不同使用条件下的充气与补气方案 ...
钟建英 +4 more
doaj
Progress of dye-sensitized water-splitting for hydrogen production [PDF]
, 2006 The mechanism of dye-sensitized water-splitting for hydrogen production is introduced. Research works on the use of different dye molecules and redox mediators are reviewed.
Leung, MKH, Leung, YC, Ni, M
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Global Change Biology, Volume 31, Issue 11, November 2025.This study assessed the potential impacts of climate and land‐use change on soil fungal diversity across four North American biomes. We found that climate change typically caused both diversity losses and gains, particularly in coniferous forests and among arbuscular mycorrhizal fungi, whereas land‐use change mainly reduced diversity, especially in ...
Wenqi Luo +5 more
wiley +1 more source
Gaoya dianqi, 2016 文中以SF6/N2混合气体作为比较,研究了CF3I/N2混合气体中绝缘子在工频电压和正、负极性雷电冲击电压下的沿面闪络特性。结果表明:在0.10.3 MPa下,CF3I/N2混合气体中绝缘子的工频闪络电压和雷电冲击闪络电压均随气压升高而增大;在较低气压下,CF3I/N2混合气体中绝缘子的负雷电冲击闪络电压比正极性下要低,而当气压高于某临界值时,负极性下闪络电压又会高于正极性;绝缘子在含30%CF3I气体的CF3I/N2混合气体中的绝缘性能基本介于含20%/30%SF6气体的SF6 ...
张辉, 肖登明, 赵谡, 李冰
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Global drivers of the conservation–invasion paradox
Conservation Biology, Volume 39, Issue 5, October 2025.Abstract The conservation–invasion paradox (CIP) refers to a long‐term phenomenon wherein species threatened in their native range can sustain viable populations when introduced to other regions. Understanding the drivers of CIP is helpful for conserving threatened species and managing invasive species, which is unfortunately still lacking. We compiled
Yanhua Hong, Zhiyong Yuan, Xuan Liu
wiley +1 more source
Gaoya dianqi, 2019 1 100 kV气体绝缘金属封闭输电线路（GIL）中SF6使用量较大,由于SF6气体具有很大的温室效应,因此,采用SF6/N2混合气体作为绝缘介质以减少SF6气体的使用量具有重要的社会意义。通过研究SF6/N2混合气体的绝缘、温升等特性,提出了适用于1 100 kV GIL的SF6/N2混合气体压力及混合比,研制了1 100 kV GIL样机,并进行了绝缘、温升试验研究,试验结果与仿真一致:混合气体压力不变的条件下,气体的绝缘强度随SF6比例的增加而增大,GIL导体、触指温升随SF6比例的增加而降低 ...
王志刚 +5 more
doaj
Selective hydrogenolysis of sorbitol on Ni/La202CO3 catalysts [PDF]
, 2017 采用共沉淀法制各了具有协同稳定作用的Ni/La2O2CO3催化剂，用于山梨醇选择性氢解为小分子醇的研究。采用X射线衍射、氢气程序升温还原、C02程序升温脱附和扫描电镜对催化剂进行了表征。考察了不同配比Ni、La的加氢位点和碱性调控对山梨醇氢解产物的影响。结果表明，Ni、La摩尔比为2：3时，山梨醇转化率达到98.6%，C2~c3多元醇的产率达到43.8%，催化剂经2次反应后对山梨醇的转化率仍高达90%。探究了催化剂从酸性到碱性调变过程中，山梨醇氢解的产物分布 ...
刘琪英 +4 more
core +1 more source
Integrative Conservation, Volume 4, Issue 3, Page 405-415, September 2025.Assessing the genetic diversity of edible insects harvested from the wild is a pre‐requisite for designing conservation and management policies. The caterpillars of Gynanisa maja (Saturniidae) are harvested in large numbers in mopane woodlands in southern Africa, where they represent a seasonal source of income and nutrition to many rural communities ...
Zwannda Nethavhani +3 more
wiley +1 more source