Nitrogen forms and decomposition of organic carbon in the southern Bohai Sea core sediments

Study on form characteristics of nitrogen in marine sediments is the primary method to research its biogeochemical cycling and nitrogen form characteristics in core sediments can reflect the process and results of early diagenesis in a certain degree. In this paper, Sequential extraction process in natural grain size was used for studying the existent forms of nitrogen in five core sediments of the southern Bohai Sea for the first time. Nitrogen was divided into two parts - transferable and fixed based on whether it could be extracted by the reagent. Distributions and early diagenesis of transferable nitrogen forms in the southern Bohai Sea were researched integratedly. Results indicate that IEF - N and OSF-N are predominant forms in transferable part in the studied core sediments. Contents of different nitrogen forms vary differently with depth, and have different diagenesis process. Decomposition constant of organic nitrogen (ON) and OC are about 15.51 -× 10^(-3)a^(-3)and 4.79× 10^(-3)a^(-1) respectively, and the decomposition content of biogenic elements C, N, P, Si has the sequence N>P>CSi. OC/TN (simplified as C/N in the following) ratio is much lower than OC/ON, which indicates that sediment preserves plenty of inorganic nitrogen (IN) and/or fixed nitrogen, and the decrease of OC/ON ratio with depth is due to ON reservation in sediments. Generally, transferable nitrogen accounts for more proportion of TN in the surface layer than in the deep layer of core sediments, whereas, some stable forms of nitrogen can activate and become transferable under appropriate environment, which induces the proportion of transferable nitrogen in TN in the deep layer to be almost the same as that in the surface layer.

An improved method for quantitatively measuring the sequences of total organic carbon and black carbon in marine sediment cores

Understanding global carbon cycle is critical to uncover the mechanisms of global warming and remediate its adverse ef fects on human activities.Organic carbon in marine sediments is an indispensable part of the global carbon reservoir in global carbon cycling.Evaluating such a reservoir calls for quantitative studies of marine carbon burial,which closely depend on quantifying total organic carbon and black carbon in marine sediment cores and subsequently on obtaining their high-resolution temporal sequences.However,the conventional methods for detecting the contents of total organic carbon or black carbon cannot resolve the following specific difficulties,i.e.,(1)a very limited amount of each subsample versus the diverse analytical items,(2) a low and fluctuating recovery rate of total organic carbon or black carbon versus the reproducibility of carbon data,and(3)a large number of subsamples versus the rapid batch measurements.In this work,(i)adopting the customized disposable ceramic crucibles with the microporecontrolled ability,(ii)developing self-made or customized facilities for the procedures of acidification and chemothermal oxidization,and(iii)optimizing procedures and carbon-sulfur analyzer,we have built a novel Wang-Xu-Yuan method(the WXY method)for measuring the contents of total organic carbon or black carbon in marine sediment cores,which includes the procedures of pretreatment,weighing,acidification,chemothermal oxidation and quantification;and can fully meet the requirements of establishing their highresolution temporal sequences,whatever in the recovery,experimental efficiency,accuracy and reliability of the measurements,and homogeneity of samples.In particular,the usage of disposable ceramic crucibles leads to evidently simplify the experimental scenario,which further results in the very high recovery rates for total organic carbon and black carbon.This new technique may provide a significant support for revealing the mechanism of carbon burial and evaluating the capacity of marine carbon accumulation and sequestration.

High-resolution mass spectrometric characterization of dissolved organic matter from warm and cold periods in the NEEM ice core

Dissolved organic matter(DOM) is an important component of ice cores but is currently poorly characterized. DOM from one Holocene sample(HS, aged at 1600–4500 B.P.) and one Last Glacial Maximum sample(LS, aged at 21000–25000 B.P.) from the North Greenland Eemian Ice Drilling(NEEM) ice core were analyzed by ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS). CHO compounds contributed 50% of the compounds identified in negative-ionization mode in these two samples, with significant contributions from organic N, S, and P compounds, likely suggesting that marine DOM was an important source in these samples. Overall, the chemical compositions are similar between these two samples, suggesting their consistent DOM sources. However, subtle differences in the DOM between these two samples are apparent and could indicate differences in source strength or chemistry occurring through both pre-and post-depositional processes. For example, higher relative amounts of condensed carbon compounds in the HS DOM(5%), compared to the LS DOM(2%), suggest potentially important contributions from terrestrial sources. Greater incorporation of P in the observed DOM in the LS DOM(22%), compared to the HS DOM(13%), indicate more active microbiological processes that likely contribute to phosphorus incorporation into the DOM pool. Although these two samples present only a preliminary analysis of DOM in glacial/interglacial periods, the data indicate a need to expand the analysis into a broader range of ice-core samples, geographical locations, and glacial/interglacial periods.

Surgical treatment of severe anterior capsular organized hard core cataract: A case report

BACKGROUND Complicated cataract surgery is challenging,especially in cases of hard nuclear cataract with severe anterior capsule organization.It is important to avoid the risk of surgery and improve the surgical skills of surgeons.CASE SUMMARY A 60-year-old man presented with severe cataract and visual impairment.The anterior capsule of the lens was irregularly organized and pulled to the surrounding capsule,and white porcelain organized cord and brown-black lens nucleus were clearly visible.In phacoemulsification,maintaining the anterior capsule round and intact plays a key role in a successful surgery.In this case,if the conventional capsule treatment method was used,the anterior capsule would be torn.Therefore,we adopted a segmented anterior capsule treatment method,and a blasting method to release energy when dealing with the lens nucleus,and achieved good surgical results.CONCLUSION Complicated cataract surgery is challenging and requires precise skills.Operation plans should be made reasonably to predict the risk of surgery,and improve the visual quality of the patients.

End-group modulation of phenazine based non-fullerene acceptors for efficient organic solar cells with high open-circuit voltage

Phenazine-based non-fullerene acceptors(NFAs)have demonstrated great potential in improving the power conversion efficiency(PCE)of organic solar cells(OSCs).Halogenation is known to be an effective strategy for increasing optical absorption,refining energy levels,and improving molecular packing in organic semiconductors.Herein,a series of NFAs(Pz IC-4H,Pz IC-4F,Pz IC-4Cl,Pz IC-2Br)with phenazine as the central core and with/without halogen-substituted(dicyanomethylidene)-indan-1-one(IC)as the electron-accepting end group were synthesized,and the effect of end group matched phenazine central unit on the photovoltaic performance was systematically studied.Synergetic photophysical and morphological analyses revealed that the PM6:Pz IC-4F blend involves efficient exciton dissociation,higher charge collection and transfer rates,better crystallinity,and optimal phase separation.Therefore,OSCs based on PM6:Pz IC-4F as the active layer exhibited a PCE of 16.48%with an open circuit voltage(Voc)and energy loss of 0.880 V and 0.53 e V,respectively.Accordingly,this work demonstrated a promising approach by designing phenazine-based NFAs for achieving high-performance OSCs.

Dublin Core元素与CNM ARC字段的匹配、对应

对DC元素/子元素和CNMARC字段/子字段作了语义层上的匹配、对应,并就匹配、对应结果作了分析,指出建立二者之间的对应机制有助于连接对不同部分、不同来源的网络资源的组织、整理、检索和利用,并提出针对网络资源的著录和组织,CNMARC应作的改变。

网上资源的组织与管理——兼论Dublin Core

网络资源的组织与利用已成为新时期图书情报人员亟待解决的一个热点问题。本文简单介绍由OCL C牵头组织研制的网上资源著录标准 Dublin Core的有关情况 ,以期对这一问题的解决提供一些思路和方向。

金属有机骨架材料光热/光动力联合治疗的策略及进展

背景:金属有机骨架(metal-organic frameworks,MOFs)是一种由金属节点和有机配体组成的新型多孔材料。部分MOFs自身即具备光热转化能力或光动力效应,亦可作为载体负载光热剂或光敏剂,在激光诱导下产生活性氧或升高温度发挥光疗作用,被广泛应用于抗菌及抗肿瘤等生物医学领域。当MOFs同时具有这两种光疗作用时,可发挥协同治疗的效应,以弥补单独使用一种光疗方法的不足。目的:按照不同的结构总结目前提出的MOFs光热/光动力联合治疗策略,以期为联合治疗材料MOFs的结构设计、功能负载及临床应用场景提供新的思路。方法:以“金属有机骨架/金属有机框架,光动力治疗,光热治疗”为中文检索词,“Metal-organic frameworks,photodynamic therapy,photothermal therapy,phototherapy”为英文检索词,检索了PubMed、Web of Science、ScienceDirect、中国知网和万方数据库的文献,最终纳入76篇进行综述分析。结果与结论:①光热/光动力联合治疗可发挥相互增强的协同作用。②现有光热/光动力联合治疗策略主要包括了改性MOFs骨架赋予其光热、光动力效应,将光疗剂封装于MOFs,光疗剂与MOFs形成核壳结构,光疗剂在MOFs内原位还原,将光疗剂附着于MOFs表面以及热解MOFs以形成MOFs衍生的碳材料等其他特殊改性方法。③要构建特定的光疗MOFs结构,必须综合考虑光疗剂和MOFs的种类、尺寸、结合方式,选择不同的合成策略。封装结构合成过程简单,但仅适用于小粒径光疗剂;核壳结构稳定,但合成过程繁复;原位还原对光疗剂尺寸无特殊限制,但难以精确控制光疗剂在MOFs内部的生长;表面附着结构的合成步骤简便,但不能避免光疗剂提前聚集猝灭;热解MOFs合成条件要求高,且只有特定的MOFs才能实现。④现有的光热/光动力联合治疗策略主要被应用于抗菌、抗肿瘤治疗并表现出优异性能,具体的应用领域与光疗剂和MOFs自身的性质有关,还有部分用于类风湿性关节炎、抗凝溶栓治疗,其潜在应用场景十分广阔。⑤光热剂和光敏剂的临床转化目前仍处于起步阶段,其面临的关键挑战包括生物安全性评估激光照射参数的优化以及高效大规模合成方法的开发。

CORE理念下政府与体育社会组织合作博弈

随着全民健身上升到国家战略,体育社会组织呈现出日渐快速发展势头的同时,与政府之间的CORE战略性博弈的关系也日渐凸显,终极目标是在利益均衡下的合作博弈与竞争。在基于经典的博弈模型的基础上,政府与体育社会组织合作博弈过程中产生内驱动力的同时,在对社会资源整合利用的前提下,二者从共同的基本利益出发,在博弈中注重合作与协同、合作与激励等方式协调竞争与合作,从而使社会效益最大化。最终通过彼此的合作与协调在相互竞争与合作中取得双赢,使得新常态下的政府与体育社会组织合力为体育事业和社会经济建设发展发挥最大的正能量。

Banana-shaped electron acceptors with an electron-rich core fragment and 3D packing capability

The emergence of Y6-type nonfullerene acceptors has greatly enhanced the power conversion efficiency(PCE)of organic solar cells(OSCs).However,which structural feature is responsible for the excellent photovoltaic performance is still under debate.In this study,two Y6-like acceptors BDOTP-1 and BDOTP-2 were designed.Different from previous Y6-type acceptors featuring an A–D–Aʹ–D–A structure,BDOTP-1,and BDOTP-2 have no electron-deficient Aʹfragment in the core unit.Instead,there is an electron-rich dibenzodioxine fragment in the core.Although this modification leads to a marked change in the molecular dipole moment,electrostatic potential,frontier orbitals,and energy levels,BDOTP acceptors retain similar three-dimensional packing capability as Y6-type acceptors due to the similar banana-shaped molecular configuration.BDOTP acceptors show good performance in OSCs.High PCEs of up to 18.51%(certified 17.9%)are achieved.This study suggests that the banana-shaped configuration instead of the A–D–Aʹ–D–A structure is likely to be the determining factor in realizing high photovoltaic performance.

Potential Applications of X-ray Fluorescence Core Scanner in Elemental Analyses of the Muddy Sediments on the Coastal Shelves of China and in Ecological Study

Large areas of muddy sediments on the coastal shelves of China provide important samples for studying climate and ecological changes. Analysis of a large number of such samples, which is essential for systematic study on environmental information recorded in mud areas because of complicated sedimentary environment and variable sedimentary rate, requires a fast and economical method. In this study, we investigated the potential of X-ray fluorescence core scanner （XRFS）, a fast analytical instrument for measuring the elemental concentrations of muddy sediments, and observed a significant correlation between the element concentrations of muddy sediments determined by regular X-ray fluorescence spectrometer （XRF） and XRFS, respectively. The correlations are mainly determined by excitation energy of elements, but also influenced by solubility of element ions. Furthermore, we found a striking link between A1 concentrations and marine-originated organic carbon （MOC）, a proxy of marine primary productivity. This indicates that MOC is partly controlled by sedimentary characteristics. Therefore, XRFS method has a good potential in fast analysis of a large number of muddy sediment samples, and it can also be used to calibrate MOC in ecological study of coastal seas.

An Explosive Organic/Inorganic Hybrid: Synthesis and Thermal Property of Octa(2,4-dinitrophenyl)silsesquioxane

Octaphenylsilsesquioxane(OPhS) was prepared by a modifying method and a new core-shell nanocomposite, octa(2,4-dinitrophenyl)silsesquioxane, [(R_2PhSiO_ 1.5)_8, R=—NO_2, ODNPhS], was synthesized by nitration of OPhS in a mixed acid solution of nitric and sulfuric acids at about 60 ℃. Their molecular structures were determined by DRIFTS, 1H NMR, 13C NMR spectra analysis. The thermal analysis shows that ODNPhS is an explosive that detonates at about 420 ℃.

Core-shell structured 1,4-benzoquinone@TiO_2 cathode for lithium batteries

Organic carbonyl compounds are considered as promising candidates for lithium batteries due to theirhigh capacity and environmental friendliness, However, they suffer from serious dissolution in the elec-trolyte, leading to fast capacity decay. Here we report core-shell structured 1,4-benzoquinone@titaniumdioxide （BQ@TiO2） composite as cathode for lithium batteries. The composite cathode can deliver a highdischarge capacity of 441.2 mA h/g at 50 mA/g and a high capacity retention of 80.7% after 100 cycles. Thegood cycling performance of BQ@TiO2 composite can be attributed to the suppressed dissolution of BQ,which results from the physical confinement effect of Ti02 shell and the strong interactions between BQand Ti02. Moreover, the combination of ex situ infrared spectra and density functional theory calculationsreveals that the active redox sites of BQ are carbonyl groups. This work provides an alternative way tomitigate the dissolution of small carbonyl compounds and thus enhance their cycling stability.

Synthesis and Characterization of Polystyrene/Nanosilica Organic-Inorganic Hybrid

A polystyrene（PS）/nanosilica organic-inorganic hybrid material was prepared from styrene monomer and commercial aqueous silica sol containing large amounts of Si-OH by means of emulsion polymerization. The nanosilica sol was modified by the addition of the reactive coupling agent methacrylexy propyltrimethoxysilane （ MPS）, and the resulting latex particles were protected by surfactants such as sodium dodecyl sulphonate（ SDS）, hydroxypropyl methyl cellulose （ HMPC）, and poly （vinylpyrrolidone） （PVP）. The effects of the type of surfactant, the amount of surfactant, and the coupling agent on the shape and stability of the resulting latex particles were investigated. The TEM observation indicates that among SDS, HMPC, and PVP, SDS is the best surfactant. When the content of SDS is 0. 5% and the amount of MPS is 7% in the system, the latex with obvious core-shell structure could be obtained. The average diameters of the monodispersed particles range from 182 to 278 nm, and the average number of silica beads for each composite are 1325 and 4409, respectively. The FrIR analysis shows that PS was chemically linked to silica through MPS. The thermal gravimetric analysis shows that when there is a higher silica content, the hybrid composites have a better heat resistance.

环境工程专业有机化学教学中核心素养的构建与实践

基于新工科办学理念,在地方应用型大学教育改革进程中,核心素养的构建备受关注。核心素养体系的构建和发展会大力提升大学整体的办学水平。就当前环境工程专业有机化学课程教学的发展来看,核心素养理念为完善课程教学方法提供了良好的理论基础,并对课程规划与改革指明了正确的方向。基于核心素养的有机化学教学必须改变教师的观念,充分满足学生个性需求,突破传统有机化学教学模式的壁垒,最终培养出会沟通、会协作、会解决实际环境工程问题的应用型人才。

建立和完善信息秩序:图书馆学的核心价值

全球信息环境不断变化,图书馆学发展面临着更多新的挑战,守正创新的重要性随之凸显,其关键在于明晰图书馆学的核心价值。文章从图书馆学核心价值的逻辑起点出发,明确研究对象决定核心价值,以及“图书馆学的研究对象是面向信息检索的信息组织”这一首要前提。同时,研究联系信息秩序建设的紧迫性与图书馆学主导信息秩序建设的应然性,提出图书馆学的核心价值是建立和完善信息秩序,并借助图书馆学的三大功能加以彰显,包括坚持通过守正创新完善学科体系的学术功能、兼顾专业人才培育与全民信息素养提升的教育功能,以及引导与推动信息社会治理的应用功能。

未来课程重构的现实依据、参考框架和国际共识——基于国际组织的视角

课程作为教育系统内部最为核心的要素之一,一直是国际组织面向未来的教育报告所关注的重点。不确定性是众多国际组织对未来社会的一致判断,而各成员国的现行课程体系惯性强大、革新缓慢、脱离现实,不足以让学生应对未来社会的挑战。面对这种巨大的张力,各国际组织基于自身定位,将课程重新置于国家和全球议程的中心,提出了以“未来能力或技能”为核心素养的参考框架,并在未来课程的概念定位、价值取向、参与主体、重构原则等方面形成了一定的共识。

市域铸牢中华民族共同体意识的“一核多元”公共传播组织体系

铸牢中华民族共同体意识的核心内容是“五个认同”,其拓展的新领域是市域层级。市域层级既是国家层面的执行者和落实者,也是县域层级的指导者和推动者,具有承上启下的作用。作为一种治理实践解决方案,公共传播可融入市域铸牢中华民族共同体意识,二者在价值目标、实践主体、实践内容和手段上具有内在的耦合关系。公共传播组织体系是市域铸牢中华民族共同体意识有序有效传播的重要保障。从实践回应看,目前的铸牢中华民族共同体意识的传播组织体系仍存在结构的“碎片化”、内部纵横向关系的“紊乱化”和功能的“梗阻化”。为此,结合我国国情,基于“元-”理念,重塑“一核多元”公共传播组织体系,主要内容包括四个方面:加强新时代党组织对传播的领导核心地位;促进市域政府机构在传播中的行政职能转变;激发社区群团组织、社会组织、经济组织、自治组织的传播活力;培育和提升社区居民个人的公共精神和传播参与意识。

高校团组织践行社会主义核心价值观研究

党的十八大以来,高校团组织建设工作得到前所未有的加强,社会主义核心价值观教育等相关活动在高校全体师生中引发了广泛的参与和深刻的共鸣,团组织建设对大学生学习成长的统领作用显著提升且成果丰硕。在不断总结团组织教育工作经验的基础上,集中力量推进团组织加强社会主义核心价值观教育研究,进一步深化大学生群体对社会主义核心价值观的理解,是高校团组织全面践行立德树人根本任务的必由之路。