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火炸药学报 2015年第4期38卷 1-4页

作者： david b.lempert Institute of Problems of Chemical Physics of Russian Academy of Sciences Semenov av.1ChernogolovkaMoscow Region 142432 Russia

It is shown that it is not correct to estimate energetic characteristics of different compounds of solid composite propellants by evaluation of the specific impulse values of these components serving as an only component in the *** an approach may turn the researcher to a wrong *** has to compare compound′s potential in formulations close to real,*** least with necessary amount of *** of specific impulse upon element content of highenthalpy CHNO oxidizer,its enthalpy of formation,and kind of binder have been found.

关键词： solid composite propellants high-enthalpy oxidizer energetic parameters estimation specific impulse

3,6-bis(2,2,2-trinitroethylnitramino)-1,2,4,*** and energy abilities as a component of solid composite propellants

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Defence Technology（防务技术） 2022年第7期18卷 1148-1155页

作者： Anatoly G.Korepin Natalia M.Glushakova david b.lempert Anatoly I.Kazakov Gennady V.Shilov Denis V.Korchagin Vadim M.Volokhov Elena S.Amosova Sergey M.Aldoshin Institute of Problems of Chemical Physics Ac.Semenov Avenue 1Chernogolovka142432Russian Federation

The work addresses to the study of the molecular and crystal structure and properties of a new energyintensive compound 3,6-bis(2,2,2-trinitroethylnitramino)-1,2,4,5-tetrazine(NbTAT),first obtained by the authors in *** compound crystallizes in the monoclinic system,space group P2(1)/n,density at room temperature 1.939 g/cm^(3).The energies of crystal packing and pairwise intermolecular interactions in NbTAT and its unnitrated analogue bTAT were calculated,and their comparative analysis was carried *** enthalpy of formation of NbTAT molecules was calculated by quantum-chemical methods using Gaussian 09,and the enthalpy of formation of NbTAT in the solid phase(618 kJ/mol)was *** energy capabilities of NbTAT as an oxidizer of solid composite propellants are *** is shown that in metal-free compositions NbTAT is significantly superior to ammonium perchlorate(AP),dinitramide ammonium salt(ADN),HMX,bTAT at all stages of rocket systems,and is comparable to the superdense CL-20 yielding to the latter at the lower stages and slightly winning at the upper stages.

关键词： Nitrogen heterocycles Quantum chemistry Enthalpy of formation 3,6-bis(2,2,2-trinitroethylnitramino)-1,2,4,5-tetrazine Crystal structure Energetic ability

Energetic Abilities of Solid Composite Propellants based on 3,4,5-Trinitropyrazole and Ammonium Dinitramide

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火炸药学报 2016年第3期39卷 17-20页

作者： lempert david b. CHUKANOV Nikita SHU Yuan-jie Institute of Problems of Chemical Physics Russian Academy of SciencesMoscow 142432Russia Xi′an Modern Chemistry Research Institute Xi′an 710065China

The investigation aims at the expansion of the basis of formulations of solid composite propellants by introducing new compositions with lower sensitivity to mechanic impact and improved thermal *** formulations based on trinitropyrazole(TNP)contains a binder(a hydrocarbon or active one),aluminum and inorganic oxidizer *** results show that a binary formulation TNP+active binder(18%-19%)(volume fraction)with no metal is well designed which would achieve high specific impulse(at Pc∶Pa=40∶1)of 248s,high density of 1.80g/cm3 and combustion temperature Tcabout 3 *** terms of energy,metal-free compositions with TNP lose a bit to those with HMX,only if HMX fraction in formulation is higher than 45%-50%.

关键词： solid composite propellants specific impulse 3,4,5-trinitropyrazole TNP binder ammonium dinitramide ADN

Estimation of the ballistic Effectiveness of 3,4-and 3,5-Dinitro-1-(trinitromethyl)-1H-Pyrazoles as Oxidizers for Composite Solid Propellants

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火炸药学报 2016年第2期39卷 16-21页

作者： lempert david b. DALINGER Igor L. SHU Yuan-jie KAZAKOV Anatolii I. SHEREMETEV Aleksei b. Institute of Problems of Chemical Physics Russian Academy of Sciences(IPCP RAS) Moscow 142432 Russia Zelinsky Institute of Organic Chemistry Russian Academy of Sciences Moscow 119991 Russia Xi'an Modern Chemistry Research Institute Xi'an 710065 China

The experimental values of the enthalpy of formation of two isomeric 3,4-and 3,5-dinitro-1-(trinitromethyl)-1H-pyrazoles have been obtained(261.5±5.0and 246.4±6.7kJ/mol for crystalline 3,4-and 3,5-dinitro-1-(trinitromethyl)-1H-pyrazoles,respectively).The ballistic effectiveness of these potential oxidizers in composite solid propellants was *** is shown that these two oxidizers may be successfully applied in metal-free compositions or with a small content of *** the bottom stage 3,4-dinitro-1-(trinitromethyl)-1H-pyrazole is a bit better than 3,5-dinitro-1-(trinitromethyl)-1H-pyrazole,for the upper stage the both oxidizers show the equal ballistic *** oxidizers allow to create metal-free solid composite propellants with the binder percentage not lower than 19%(volume fraction),with I3spequal to 256.5-257.0sat density equal to 1.72-1.74g/cm^3.

关键词： composite solid propellants high-enthalpy oxidizer energetic parameters estimation specific impulse ballistic effectiveness

Energetic Opportunities of Solid Composite Propellants Containing Some Hypothetic Furazano-[3,4-d]-pyridazine-based Derivatives

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火炸药学报 2016年第5期39卷 28-34页

作者： lempert david b. DOROFEENKO Ekaterina M. SHU Yuan-jie JIANG Wei-dong WU Zong-kai WANG Ke LIU Xiao-qiang Institute of Problems of Chemical Physics Russian.Academy of Sciences(IPCP RAS)Moscow 142432 Russia Xi'an Modern Chemistry Research Institute Xi'an 710065China School of Chemistry and Environmental Engineering Sichuan.University of Science and EngineeringZigong Sichuan.643000China

Six furazano-[3,4-d]-pyridazine-based derivatives as main compounds in solid composite propellants have been *** was shown that the use of some furazano-[3,4-d]-pyridazine-based derivatives as main compounds in solid composite propellants can considerably increase ballistic parameters compared with HMX if the compounds under consideration contain difluoramine *** the use of the compounds under consideration may be successful only in the presence of an active binder and 10%-30% of AP or ADN as additional oxidizers.

关键词： solid composite propellant furazano-[3,4-d]-pyridazine-based derivative energetic specific impulse

The great catastrophe: causes of the Permo-Triassic marine mass extinction

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National Science Review 2024年第1期11卷 37-50页

作者： Paul b.Wignall david P.G.bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

Measuring,processing,and generating partially coherent light with self-configuring optics

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Light(Science & Applications) 2024年第11期13卷 2726-2733页

作者： Charles Roques-Carmes Shanhui Fan david A.b.Miller 1E.L.Ginzton Laboratory Stanford University348 Via PuebloStanfordCA 94305USA

Optical phenomena always display some degree of partial coherence between their respective degrees of *** coherence is of particular interest in multimodal systems,where classical and quantum correlations between spatial,polarization,and spectral degrees of freedom can lead to fascinating phenomena(e.g.,entanglement)and be leveraged for advanced imaging and sensing modalities(e.g.,in hyperspectral,polarization,and ghost imaging).Here,we present a universal method to analyze,process,and generate spatially partially coherent light in multimode systems by using self-configuring optical *** method relies on cascaded self-configuring layers whose average power outputs are sequentially *** optimized,the network separates the input light into its mutually incoherent components,which is formally equivalent to a diagonalization of the input density *** illustrate our method with numerical simulations of Mach-Zehnder interferometer arrays and show how this method can be used to perform partially coherent environmental light sensing,generation of multimode partially coherent light with arbitrary coherency matrices,and unscrambling of quantum optical *** provide guidelines for the experimental realization of this method,including the influence of losses,paving the way for self-configuring photonic devices that can automatically learn optimal modal representations of partially coherent light fields.

关键词： coherent modal generating

Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina Hromada Patrick Heimel Markus Kerbl LászlóGál Sylvia Nürnberger barbara Schaedl James Ferguson Nicole Swiadek Xavier Monforte Johannes C.Heinzel Antal Nógrádi Andreas H.Teuschl-Woller david Hercher Department Life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria Ludwig boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of Hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

Review of screening for pancreatic cancer in high risk individuals

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World Journal of Gastroenterology 2011年第19期17卷 2365-2371页

作者： Alina Stoita Ian D Penman david b Williams Department of Gastroenterology St Vincent's Hospital 390 Victoria StreetDarlinghurst2010NSWAustralia Centre for Liver and Digestive Disorders Royal Infirmary of Edinburgh51 Little France CrescentEdinburghEH16 4SAUnited Kingdom

Pancreatic cancer is difficult to diagnose at an early stage and is associated with a very poor *** percent of pancreatic cancers result from genetic susceptibility and/or familial *** from families with multiple affected first-degree relatives and those with a known cancer-causing genetic mutation have been shown to be at much higher risk of developing pancreatic *** efforts have focused on detecting disease at an earlier stage to improve survival in these high-risk *** article reviews high-risk groups,screening methods,and current screening programs and their results.

关键词： Pancreatic cancer Familial cancer Cancer screening Risk factors Endoscopic ultrasound Hereditary cancer

Three-Dimensional Sub-100 nm Super-Resolution Imaging of biological Samples Using a Phase Ramp in the Objective Pupil

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Nano Research 2011年第6期4卷 589-598页

作者： david baddeley Mark b. Cannell Christian Soeller Department of Physiology University of Auckland Private Bag 92019 Auckland 1142 New Zealand

Localisation microscopy overcomes the diffraction limit by measuring the position of individual molecules to obtain optical images with a lateral resolution better than 30 nm. Single molecule localisation microscopy was originally demonstrated only in two dimensions but has recently been extended to three dimensions. Here we develop a new approach to three-dimensional （3D） localisation microscopy by engineering of the point-spread function （PSF） of a fluorescence microscope. by introducing a linear phase gradient between the two halves of the objective pupil plane the PSF is split into two lateral lobes whose relative position depends on defocus. Calculations suggested that the phase gradient resulting from the very small tolerances in parallelism of conventional slides made from float glass would be sufficient to generate a two-lobed PSF. We demonstrate that insertion of a suitably chosen microscope slide that occupies half the objective aperture combined with a novel fast fitting algorithm for 3D localisation estimation allows nanoscopic imaging with detail resolution well below 100 nm in all three dimensions （standard deviations of 20, 16, and 42 nm in x, y, and z directions, respectively）. The utility of the approach is shown by imaging the complex 3D distribution of microtubules in cardiac muscle cells that were stained with conventional near infrared fluorochromes. The straightforward optical setup, minimal hardware requirements and large axial localisation range make this approach suitable for many nanoscopic imaging applications.

关键词： Single molecules nanoscopy point-spread function engineering immunocytochemistry localisation microscopy