Results 31 to 40 of about 5,854 (159)

The Construction and Utilization of on-line Normal-Phase Liquid Chromatography × Reversed-Phase Liquid Chromatography System and the Study on the Chemical Constituents of Toad Skin [PDF]

open access: yes, 2017
本文旨在构建一个正相色谱(NPLC)与反相色谱(RPLC)联用的在线二维分析与制备液相色谱系统。首先,通过设计一个新型的高温蒸发辅助吸附(TEAA)接口,解决了流动相不兼容问题,实现了正相色谱与反相色谱的在线联用。该接口可以使正相溶剂在高温下迅速蒸发,将样品富集在正相富集柱上,继而利用洗脱液洗脱富集的样品,稀释后富集在反相富集柱上,进一步在反相色谱中得到分离。进而,以蟾皮醇提物为样品溶液,对TEAA接口的一系列参数进行了优化,包括正相富集的温度、真空度,正相富集柱的洗脱时间和重生时间。其次 ...
李加福
core  

High nitrogen enrichment buffers plant photosynthesis against herbivory damage

open access: yesFunctional Ecology, Volume 40, Issue 1, Page 229-238, January 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Herbivorous insects and nitrogen deposition are key drivers of ecosystem productivity under global change. However, their combined effects on plant photosynthesis, particularly during insect outbreaks, remain poorly understood in natural ecosystems.
Yongqiang Zhang   +6 more
wiley   +1 more source

Preliminary study on quorum sensing system in Novosphingobium pentaromativorans US6-1 for BaP biodegradation [PDF]

open access: yes, 2017
一直以来,多环芳烃(PAHs)污染治理已经成为环境科学关注的热点问题。微生物修复因具有强降解能力和对环境友好等特点,被认为是环境中多环芳烃去除的主要途径。近些年来,人们在筛选高效降解菌和探究多环芳烃代谢路径等方面都取得了进展,然而微生物在菌群水平上是如何应对多环芳烃所带来的胁迫压力目前尚不清楚。本论文以一株能广谱和高效地降解2至5环PAHs的革兰氏阴性细菌—新鞘氨醇杆菌US6-1(NovosphingobiumpentaromativoransUS6-1)为研究对象,利用显微镜观察 ...
詹清
core  

Composition and structure of extraction residue of direct coal liquefaction residue and recycle of active phase of iron catalyst [PDF]

open access: yes
In order to solve the problem of iron source supply for large-scale direct liquefaction catalyst, and meanwhile realize the harmless separated-utilization of extraction residue from coal liquefaction, this paper conducted a research on the recovery of ...
Dao LI   +5 more
core   +1 more source

Return of the Swamp Rabbit: Sylvilagus aquaticus Occupancy Increased and Expanded Along the Northern Extent of Its Distribution Range 沼泽兔的回归:沼泽兔 (Sylvilagus aquaticus) 在其分布范围北缘的分布率上升并向外扩张

open access: yesWildlife Letters, Volume 3, Issue 4, Page 161-172, December 2025.
Swamp rabbit (Sulvilagus aquaticus) in southeast Missouri is increasing and expanding, with occupancy probabilities of 0.66 in 2010–2012 and 0.79 in 2021–2022. ABSTRACT Swamp rabbits (Sylvilagus aquaticus) are a bottomland hardwood specialist that have experienced range contraction at the northern and western extents of their range.
Thanchira Suriyamongkol   +6 more
wiley   +1 more source

The Future of AI in the GCC Post‐NPM Landscape: A Comparative Analysis of Kuwait and the UAE

open access: yesPolitics &Policy, Volume 53, Issue 6, December 2025.
ABSTRACT Comparative evidence of how two Gulf Cooperation Council (GCC) states translate artificial intelligence (AI) ambitions into post–New Public Management (post‐NPM) outcomes are scarce because most studies focus on Western democracies. To fill this gap, we examine constitutional, collective choice, and operational rules that shape AI uptake in ...
Mohammad Rashed Albous   +2 more
wiley   +1 more source

不同覆被土壤结构稳定性对侵蚀泥沙氮磷流失的影响

open access: yesShuitu Baochi Xuebao, 2011
以沂蒙山区的棕壤为例,利用野外原位模拟降雨试验,在分析比较5种典型覆被土壤结构稳定性的基础上,探讨不同土地覆被土壤结构稳定性对侵蚀泥沙全氮(N)、全磷(P)流失的影响。结果表明,土壤结构稳定性以山楂园和侧柏林较好,金银花和荒草地次之,花生地最差。不同土地覆被类型泥沙全N、全P流失特征差异明显,泥沙流失率与其全N、全P流失参量间具有显著的相关关系。土壤结构稳定性通过调节侵蚀产沙进而影响泥沙中N、P的流失特征,山楂园等土壤结构稳定性较好,侵蚀过程中更多地选择性搬运粘粒及精细颗粒,致使泥沙全N ...
于兴修, 马骞, 刘前进, 张含玉
doaj  

光动力抗菌纳米制剂研究进展 [PDF]

open access: yes, 2019
新兴的光动力抗菌疗法是无创激发式治疗手段,主要利用近红外光作为光源,激活富集在病灶部位的光敏剂并产生活性氧自由基,最终实现对目标病菌的杀伤作用。相对比与传统的抗生素治疗,光动力抗菌疗法具有创伤性小,副作用低,不易产生耐药性等优点,在抗菌治疗方面有很大临床应用前景。随着生物材料与纳米医学技术的发展,小分子光敏剂纳米功能化后其生物兼容性和生物安全性得到优化,量子产率和病灶部位富集率显著提升,为其临床应用提供了新思路。本文结合小分子光敏剂纳米化策略方法实例 ...
任恩, 刘刚, 庞鑫, 张昌, 李蕾
core  

Multiple global change factors alter the scaling of nitrogen to phosphorus in alpine plants

open access: yesFunctional Ecology, Volume 39, Issue 8, Page 2044-2055, August 2025.
Read the free Plain Language Summary for this article on the Journal blog. Abstract The stoichiometry and allometry of nitrogen (N) and phosphorus (P) reflect nutrient absorption and dynamic allocation by plants, and can be regulated by global change factors (e.g. nitrogen enrichment, climate warming and altered precipitation). Yet, how multiple global
Jiapu Li   +10 more
wiley   +1 more source

旱作农田沟垄微型集雨结合覆盖玉米种植试验研究

open access: yesShuitu Baochi Xuebao, 2005
田间沟垄微型集雨结合覆盖技术有效地利用了膜垄的集水和沟覆盖的蓄水保墒功能,改变了降雨的时空分布,使降雨集中富集在种植沟中,显著地提高了降水的利用效率,特别是小雨的利用率。研究结果表明:土垄的平均集水效率为7% ,而垄上覆膜后集水效率为87% ,膜垄能产生径流的最小降雨量为0 8mm。田间沟垄微型集雨结合覆盖技术能提高土壤贮水量,增加玉米的产量。垄上覆膜结合沟覆盖处理玉米产量比平地增加2 339~5 2 97kg/hm2 (44 %~14 3% ) ,水分利用效率基本都在2kg/m3 以上。
李小雁 张瑞玲
doaj  

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