bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydraulic Synchronization Control Research Status and Outlook
Authors: Wang Jiahui 
Published: August 2024

With the hydraulic synchronization control system in the industrial field of application is gradually widespread, synchronization control research is also more and more attention. Based on this background, this paper combines the current research status of hydraulic synchronization control system, from three aspects of the hydraulic synchronization system to discuss: 1) hydraulic synchronous drive system: analysis of the mechanical rigid synchronous drive system, hydraulic balance synchronous drive system, electro-hydraulic servo synchronous drive system three kinds of control, and summarize the advantages and disadvantages of the different control methods; 2) electro-hydraulic servo synchronization control strategy: master-slave synchronous control, equivalent synchronous control, cross-coupling synchronous control; 3) electro-hydraulic servo synchronous controller: PID control, adaptive robust control, neural network control; Finally, according to the analysis of the above three aspects of the research, the hydraulic synchronization control system outlook, the future of the hydraulic synchronization technology and electrical, Internet and other technologies integrated with each other, so that its control accuracy and response speed will be greatly improved and will gradually be applied to a number of applications. The future hydraulic synchronization technology and electrical, Internet and other technologies are integrated with each other, so that its control accuracy and response speed will be greatly improved and will be gradually applied to some high-precision industries, in order to promote the hydraulic synchronization control technology in the industrial field of research and application of reference.
Origin and fluxes of nitrous oxide along a latitudinal transect in western North Pacific: Controls and regional significance
Authors: Breider Florian , Yoshikawa Chisato , Abe Hitomi , Toyoda Sakae , Yoshida Naohiro 
Published: June 2015

AbstractNitrous oxide (N2O) is an atmospheric trace gas playing an important role in both radiative forcing and stratospheric ozone depletion. The oceans are the second most important natural source of N2O. The magnitude of the flux of this source is poorly constrained. Moreover, the relative importance of the microbial processes leading to the formation or the consumption of N2O in oceans remains unclear. We present here fluxes and isotope and isotopomer signatures of N2O measured at three stations located along a latitudinal transect in subtropical and subarctic western North Pacific. These results indicate that about 30% to 55% of the oceanic flux of N2O to the atmosphere originates from the deep euphotic and shallow aphotic zones. The sea‐to‐air fluxes of N2O calculated using an isotope mass balance model indicate that the emission rate of N2O in subarctic waters is about 2 times higher than in oligotrophic subtropical waters suggesting that nutrient‐rich water coming from the western subarctic gyre stimulates the N2O production. Moreover, isotopomer analysis has revealed that in shallow water N2O originates from nitrification and nitrifier denitrification processes, and its distribution in the water column is partly controlled by the incident solar radiation. The results of this study contribute to better constrain the global N2O budget and provide important information to better predict the future evolution of the oceanic emissions of N2O.
Why are biotic iron pools uniform across high‐ and low‐iron pelagic ecosystems?
Authors: Boyd P. W. , Strzepek R. F. , Ellwood M. J. , Hutchins D. A. , Nodder S. D. , Twining B. S. , Wilhelm S. W. 
Published: June 2015

AbstractDissolved iron supply is pivotal in setting global phytoplankton productivity and pelagic ecosystem structure. However, most studies of the role of iron have focussed on carbon biogeochemistry within pelagic ecosystems, with less effort to quantify the iron biogeochemical cycle. Here we compare mixed‐layer biotic iron inventories from a low‐iron (~0.06 nmol L−1) subantarctic (FeCycle study) and a seasonally high‐iron (~0.6 nmol L−1) subtropical (FeCycle II study) site. Both studies were quasi‐Lagrangian, and had multi‐day occupation, common sampling protocols, and indirect estimates of biotic iron (from a limited range of available published biovolume/carbon/iron quotas). Biotic iron pools were comparable (~100 ± 30 pmol L−1) for low‐ and high‐iron waters, despite a tenfold difference in dissolved iron concentrations. Consistency in biotic iron inventories (~80 ± 24 pmol L−1, largely estimated using a limited range of available quotas) was also conspicuous for three Southern Ocean polar sites. Insights into the extent to which uniformity in biotic iron inventories was driven by the need to apply common iron quotas obtained from laboratory cultures were provided from FeCycle II. The observed twofold to threefold range of iron quotas during the evolution of FeCycle II subtropical bloom was much less than reported from laboratory monocultures. Furthermore, the iron recycling efficiency varied by fourfold during FeCycle II, increasing as stocks of new iron were depleted, suggesting that quotas and iron recycling efficiencies together set biotic iron pools. Hence, site‐specific differences in iron recycling efficiencies (which provide 20–50% and 90% of total iron supply in high‐ and low‐iron waters, respectively) help offset the differences in new iron inputs between low‐ and high‐iron sites. Future parameterization of iron in biogeochemical models must focus on the drivers of biotic iron inventories, including the differing iron requirements of the resident biota, and the subsequent fate (retention/export/recycling) of the biotic iron.
Polar low climatology over the Nordic and Barents seas based on satellite passive microwave data
Authors: Smirnova Julia E. , Golubkin Pavel A. , Bobylev Leonid P. , Zabolotskikh Elizaveta V. , Chapron Bertrand 
Published: June 2015

AbstractA new climatology of polar lows over the Nordic and Barents seas for 14 seasons (1995/1996–2008/2009) is presented. For the first time in climatological studies of polar lows an approach based on satellite passive microwave data was adopted for polar low identification. A total of 637 polar lows were found in 14 extended winter seasons by combining total atmospheric water vapor content and sea surface wind speed fields retrieved from Special Sensor Microwave/Imager data. As derived, the polar low activity in the Norwegian and Barents Seas is found to be almost equal, and the main polar low genesis area is located northeastward of the North Cape. For the Barents Sea, a significant correlation is found between the number of polar lows and mean sea ice extent. Individual indicative polar low characteristics (i.e., diameter, lifetime, distance traveled, translation speed, and maximum wind speed) are also presented.
Experimental constraints on coesite abundances in eclogite and implications for the X seismic discontinuity
Authors: Knapp Nadia , Woodland Alan B. , Klimm Kevin 
Published: June 2015

AbstractWe have experimentally tested the possibility that the coesite‐stishovite transition in eclogite bodies is responsible for the X discontinuity, a locally observed, low‐impedance jump in seismic wave velocities at 260–330 km depth. We determined phase relations and free SiO2 abundances in three natural‐analog eclogite compositions that simulate different subduction scenarios in terms of pressure‐temperature conditions and whether or not melt extraction occurred. Eclogitic compositions representing residues after either shallow or deep melting contain either no coesite or else too little (<4 wt %) to produce the observed impedance contrast for the X discontinuity. Only an unmodified mid‐ocean ridge basalt (MORB) composition was found to contain just enough coesite (6–8 wt %) to be consistent with the expected impedance contrast when it transforms to stishovite. However, we assert that MORB cannot remain compositionally unmodified during subduction down to ~300 km. Fluid loss due to dehydration reactions during the transformation from basalt to eclogite lowers bulk SiO2 content. In addition, the MORB wet solidus intersects the coesite‐stishovite boundary at ~290 km, implying that at greater depths a melt phase should be present before stishovite stability is reached. Our data indicate that melt generation is an efficient means of lowering the free SiO2 content in the mineral assemblage. This study also confirms previous work indicating that exsolution of SiO2 from the Ca‐Eskola (Ca0.5AlSi2O6) component in clinopyroxene is not a feasible mechanism for producing significant stishovite upon reaching its stability field. We conclude that the coesite‐stishovite transition in eclogite bodies is not a viable petrological explanation for the X discontinuity.
Volume transports of the Wyrtki jets and their relationship to the Indian Ocean Dipole
Authors: McPhaden Michael J. , Wang Yi , Ravichandran M. 
Published: June 2015

AbstractThe equatorial Indian Ocean is characterized by strong eastward flows in the upper 80–100 m during boreal spring and fall referred to as the Wyrtki jets. These jets are driven by westerly winds during the transition seasons between the southwest and northeast monsoons and represent a major conduit for mass and heat transfer between the eastern and western sides of the basin. Since their discovery over 40 years ago, there have been very few estimates from direct observations of the volume transports associated with these currents. In this paper we describe seasonal‐to‐interannual time scale variations in volume transports based on 5 years of unique measurements from an array of acoustic Doppler current profilers in the central equatorial Indian Ocean. The array was centered at 0°, 80.5°E and spanned latitudes between 2.5°N and 4°S from August 2008 to December 2013. Analysis of these data indicates that the spring jet peaks in May at 14.9±2.9 Sv and the fall jet peaks in November at 19.7±2.4 Sv, around which there are year‐to‐year transport variations of 5–10 Sv. The relationship of the interannual transport variations to zonal wind stress forcing, sea surface temperature, sea surface height, and surface current variations associated with the Indian Ocean Dipole (IOD) are further highlighted. We also illustrate the role of wind‐forced equatorial waves in affecting transport variations of the fall Wyrtki jet during the peak season of the IOD.
Spatial considerations of stream hydraulics in reach scale temperature modeling
Authors: Schmadel Noah M. , Neilson Bethany T. , Heavilin Justin E. 
Published: June 2015

AbstractWhile a myriad of processes control water temperature, the most significant in streams without notable shading or groundwater inputs are surface heat fluxes at the air‐water interface. These fluxes are particularly sensitive to parameters representing the water surface area to volume ratio. Channel geometry dictates this ratio; however, it is currently unclear how spatial variability in stream hydraulics influences temperature predictions or how the contribution of the boundary condition influences interpretation of processes most sensitive to this variability. To investigate these influences over long reach scales, we used high‐resolution spatial observations collected over a 25 km reach within a Laplace‐domain solution to a two‐zone temperature transient storage model. We found that for the study reach and flow condition, changes in the surface area to volume ratio did not generally coincide with changes in stream temperature. Though, notable changes in cumulative mean residence time corresponded with changes in the temperature extremes throughout the study reach. The surface heat fluxes were clearly the most sensitive to spatially variable hydraulics that translated into high residence times once the contribution of the boundary condition decayed. Consistent with solute transport, reach segment lengths that reflect the spatial correlation in observations were necessary to capture the spatial influences of hydraulics on temperature predictions. This approach provides a fundamental step for determining whether spatial detail related to stream hydraulics is important to support accurate temperature predictions and how best to represent that detail.
Global hydrology 2015: State, trends, and directions
Authors: Bierkens Marc F. P. 
Published: June 2015

AbstractGlobal hydrology has come a long way since the first introduction of the primitive land surface model of Manabe (1969) and the declaration of the “Emergence of Global Hydrology” by Eagleson (1986). Hydrological submodels of varying complexity are now part of global climate models, of models calculating global terrestrial carbon sequestration, of earth system models, and even of integrated assessment models. This paper reviews the current state of global hydrological modeling, discusses past and recent developments, and extrapolates these to future challenges and directions. First, established domains of global hydrological model applications are discussed, in terms of societal and science questions posed, the type of models developed, and recent advances therein. Next, a genealogy of global hydrological models is given. After reviewing recent efforts to connect model components from different domains, new domains are identified where global hydrology is now starting to become an integral part of the analyses. Finally, inspired by these new domains of application, persistent and emerging challenges are identified as well as the directions global hydrology is likely to take in the coming decade and beyond.
Silver‐Mediated Oxidative Fluorotrifluoromethylation of Unactivated Alkenes
Authors: Yu Wei , Xu Xiu‐Hua , Qing Feng‐Ling 
Published: June 2015

AbstractAn efficient regioselective fluorotrifluoromethylation of unactivated alkenes has been developed. The reaction of alkenes with (trifluoromethyl)trimethylsilane (TMSCF3) and Selectfluor in the presence of silver trifluoromethanesulfonate (AgOTf), cesium fluoride (CsF), and iodobenzene diacetate [PhI(OAc)2] in N,N‐dimethylformamide (DMF) at −20 °C gave the corresponding fluorotrifluoromethylated products in moderate to good yields. The silver salt turns out to be crucial for this transformation.magnified image
Visible Light‐Mediated Metal‐Free Synthesis of Vinyl Sulfones from Aryl Sulfinates
Authors: Meyer Andreas Uwe , Jäger Stefanie , Prasad Hari Durga , König Burkhard 
Published: June 2015

AbstractVisible light and eosin Y catalyze the synthesis of vinyl sulfones from aryl sulfinates and alkenes by a photoredox process. The reaction scope is broad in aryl sulfinates and alkenes and the general and simple procedure provides a metal‐free alternative for the synthesis of synthetically valuable vinyl sulfones.magnified image
tert‐Butyl Sulfoxides: Key Precursors for Palladium‐Catalyzed Arylation of Sulfenate Salts
Authors: Gelat Fabien , Lohier Jean‐François , Gaumont Annie‐Claude , Perrio Stéphane 
Published: June 2015

AbstractThe present report describes an efficient and clean generation of sulfenate salts (R1SO−) by pyrolysis of readily available tert‐butyl sulfoxides to give sulfenic acids (R1SOH) and traceless isobutene, followed by hydrogen abstraction with a weak inorganic base (K3PO4). The relevance of this process was exemplified through an in situ palladium‐catalyzed cross‐coupling reaction with aryl halides/triflates leading to aryl sulfoxides. The operationally simple CS bond‐forming protocol developed uses Pd(dba)2 as catalyst and Xantphos as ligand in toluene or a toluene/H2O mixture. Further extensions include the use of di‐tert‐butyl sulfoxide as an equivalent for sulfur monoxide dianion (SO2−) and the development of diastereoselective versions in the [2.2]paracyclophane and biaryl series.magnified image
Alumina‐Supported Copper Iodide: An Efficient and Recyclable Catalyst for Microwave‐Assisted Synthesis of 1,4‐Disubstituted 1,2,3‐Triazoles via Three‐Component Reaction in Water
Authors: Agalave Sandip G. , Pharande Shrikant G. , Gade Swapna M. , Pore Vandana S. 
Published: June 2015

AbstractA one‐pot procedure for the synthesis of 1,4‐disubstituted 1,2,3‐triazoles by a three‐component reaction of allyl or benzyl halides, sodium azide, and terminal alkynes over a neutral alumina‐supported copper iodide catalyst has been developed. The products were isolated by simple filtration followed by washing of the catalyst with acetone. The products were obtained in almost pure form in up to 98 % yield (TON 495). The catalyst can be recycled for more than eight subsequent reactions. The halides are directly converted into triazoles via in situ formation of azides and thus handling of hazardous azides can be avoided. The broad scope of this protocol is shown by the synthesis of a variety of diversely substituted 1,2,3‐triazoles and also two‐component azide‐alkyne click reaction. The key features of this procedure are the use of water as a solvent, recyclability of the catalyst up to eight runs without appreciable loss of activity, and high yields of products. The catalyst has been fully characterized by FTIR, solid‐state NMR and EDX spectroscopy, ESEM, TGA, and XRD.
Small‐Molecule‐Mediated Degradation of the Androgen Receptor through Hydrophobic Tagging
Authors: Gustafson Jeffrey L. , Neklesa Taavi K. , Cox Carly S. , Roth Anke G. , Buckley Dennis L. , Tae Hyun Seop , Sundberg Thomas B. , Stagg D. Blake , Hines John , McDonnell Donald P. , Norris John D. , Crews Craig M. 
Published: June 2015

AbstractAndrogen receptor (AR)‐dependent transcription is a major driver of prostate tumor cell proliferation. Consequently, it is the target of several antitumor chemotherapeutic agents, including the AR antagonist MDV3100/enzalutamide. Recent studies have shown that a single AR mutation (F876L) converts MDV3100 action from an antagonist to an agonist. Here we describe the generation of a novel class of selective androgen receptor degraders (SARDs) to address this resistance mechanism. Molecules containing hydrophobic degrons linked to small‐molecule AR ligands induce AR degradation, reduce expression of AR target genes and inhibit proliferation in androgen‐dependent prostate cancer cell lines. These results suggest that selective AR degradation may be an effective therapeutic prostate tumor strategy in the context of AR mutations that confer resistance to second‐generation AR antagonists.
Photoredox‐Catalyzed Reductive Coupling of Aldehydes, Ketones, and Imines with Visible Light
Authors: Nakajima Masaki , Fava Eleonora , Loescher Sebastian , Jiang Zhen , Rueping Magnus 
Published: June 2015

AbstractKetyl radical and amino radical anions, valuable reactive intermediates for CC bond‐forming reactions, are accessible through a CO/CNR umpolung. However, their utilization in catalysis remains largely underdeveloped owing to the high reduction potential of carbonyl compounds and imines. In the context of photoredox catalysis, tertiary amines are commonly employed as sacrificial co‐reducing agents. Herein, an additional role of the amine is proposed, in which it is essential for the organocatalytic substrate activation. The combination of photoredox catalysis and carbonyl/imine activation enables the reductive coupling of aldehydes, ketones, and imines under mild reaction conditions.
PID for the stabilization of high‐order unstable delayed systems with possible complex conjugate poles
Authors: Hernández‐Pérez Miguel A. , del Muro‐Cuéllar Basilio , Velasco‐Villa Martin 
Published: June 2015

AbstractThis work considers the stabilization problem of n‐dimensional unstable linear systems with time delay, specifically with one unstable pole and n‐1 stable poles, which could be complex conjugate. Necessary and sufficient conditions are stated to guarantee the stability of the system in closed loop with a P, PI, PD, or PID controller. The performance of the control strategies are evaluated by considering the linear approximation of an unstable continuously stirred tank reactor and a high‐order academic system. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Development of ionic and non‐ionic natural gum‐based bigels: Prospects for drug delivery application
Authors: Sahoo Saikat , Singh Vinay K. , Uvanesh K. , Biswal Dibyajyoti , Anis Arfat , Rana Usman Ali , Al‐Zahrani Saeed M. , Pal Kunal 
Published: June 2015

ABSTRACTRecently, much attention has been focused on the development of gel based formulations for controlled drug delivery applications. Herein, we report the effect of the ionic (gum acacia) and the non‐ionic (guar gum) gums on the properties of the bigels prepared with fluid‐filled organogels. The microscopic study suggested the presence of flocculated structure in guar gum bigel, whereas, a de‐flocculated structure was observed in gum acacia bigel. Infrared spectroscopy suggested the presence of polysaccharides in the bigels. The mechanical properties of the guar gum bigel were better than gum acacia bigel. The conductivity and the release properties suggested superior properties of gum acacia bigel. This indicated that the ionic nature of acacia bigel played a major role in controlled drug delivery, making it a potential bigel for desired pharmaceutical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42561.
Synthesis and Application of [3.3.0]Furofuranone in Total Synthesis
Authors: Peng Xiao‐Shui , Ylagan Ridge Michael P. , Siu Yuk Ming , Wong Henry N. C. 
Published: June 2015

AbstractThe synthesis and application of [3.3.0]furofuranone species has received considerable attention from the scientific community. During the last twenty years, there has been a remarkable increase in publications focusing on their relevant method development as well as applications to natural product synthesis. This tutorial review discusses instructive examples to give a special emphasis on the development of new synthetic approaches and important applications to the total synthesis of natural products.
Tandem Regioselective Substitution and Palladium‐Catalyzed Ring Fusion Reaction for Core‐Expanded Boron Dipyrromethenes with Red‐Shifted Absorption and Intense Fluorescence
Authors: Zhou Xin , Wu Qinghua , Feng Yuanmei , Yu Yang , Yu Changjiang , Hao Erhong , Wei Yun , Mu Xiaolong , Jiao Lijuan 
Published: June 2015

AbstractA selective method for the core‐extension of boron dipyrromethene (BODIPY) with two annulated indole rings with exclusive syn‐connectivity is reported. The method is based on a regioselective nucleophilic substitution reaction of 2,3,5,6‐tetrabromoBODIPY with aryl amines, followed by palladium‐catalyzed intramolecular C−C coupling ring fusion. The unsymmetrical core‐expanded BODIPY with annulated indole and benzofuran rings was also synthesized by stepwise and regioselective nucleophilic substitution and palladium‐catalyzed intramolecular C−C coupling reaction. The diindole‐annulated BODIPY was unambiguously characterized by single‐crystal X‐ray analysis. The optical properties of the present core‐expanded BODIPYs were studied, revealing clearly red‐shifted absorption and emission bands and enhanced absorption coefficients upon annulation.