Isolated sub-30-as pulse generation of an He+ ion by an intense few-cycle chirped laser and its high-order harmonic pulses

We present an efficient method to generate a ultrashort attosecond (as) pulse when a model He+ ion is exposed to the combination of an intense few-cycle chirped laser pulse and its 27th harmonics. By solving the time-dependent Schroumldinger equation, we found that high-order harmonic generation (HHG) from He+ ion is enhanced by seven orders of magnitude due to the presence of the harmonic pulse. After optimizing the chirp of the fundamental pulse, we show that the cut-off energy of the generated harmonics is extended effectively to I-p+25.5U(p). As a result, an isolated 26-as pulse with a bandwidth of 170.5 eV can be obtained directly from the supercontinuum around the cut-off of HHG. To better understand the physical origin of HHG enhancement and attosecond pulse emission, we perform semiclassical simulations and analyze the time-frequency characteristics of attosecond pulse.

黄土高原生物气候分区与该区生态系统的恢复

根据不同的生物气候状况 ,可将黄土高原分成五个生物气候区 :暖温带湿润半湿润森林区、暖温带半湿润半干旱森林草原区、中温带半干旱典型草原区、中温带干旱半干旱荒漠草原区以及中温带干旱草原化荒漠区。紧密结合上述生物气候区域特征 ,将生态学的有关原理引入到该区的治理与生态恢复中 ,提出了治理黄土高原的新模式 :正确实施生物措施 ,人工模拟天然生态系统。该区的生态恢复应从系统的角度考虑 ,并严格遵守生态学的有关规律在不同的生物气候区构建与该区大环境一致的不同的生态系统 ,改变过去那种在黄土高原全面造林而又成效不佳的做法

Large-scale, rapid synthesis and application in surface-enhanced Raman spectroscopy of sub-micrometer polyhedral gold nanocrystals

Macromolecule-protected sub-micrometer polyhedral gold nanocrystals have been facilely prepared by heating an aqueous solution containing poly (N-vinyl-2-pyrrolidone) (PVP) and HAuCl4 without adding other reducing agents. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), ultraviolet-visible-near-infrared spectroscopy (UV-vis-NIR), and x-ray diffraction (XRD) were employed to characterize the obtained polyhedral gold nanocrystals. It is found that the 10:1 molar ratio of PVP to gold is a key factor for obtaining quasi-monodisperse polyhedral gold nanocrystals. Furthermore, the application of polyhedral gold nanocrystals in surface-enhanced Raman scattering (SERS) was investigated by using 4-aminothiophenol (4-ATP) as a probe molecule. The results indicated that the sub-micrometer polyhedral gold nanocrystals modified on the ITO substrate exhibited higher SERS activity compared to the traditional gold nanoparticle modified film. The enhancement factor (EF) on polyhedral gold nanocrystals was about six times larger than that obtained on aggregated gold nanoparticles (similar to 25 nm).

Deformation mechanism of polystyrene toughened with sub-micrometer monodisperse rubber particles

Core-shell polybutadiene-graft-polystyrene (PB-g-PS) rubber particles with different ratios of polybutadiene to polystyrene were prepared by emulsion polymerization through grafting styrene onto polybutadiene latex. The weight ratio of polybutadiene to polystyrene ranged from 50/50 to 90/10. These core-shell rubber particles were then blended with polystyrene to prepare PS/PB-g-PS blends with a constant rubber content of 20 wt%. PB-g-PS particles with a lower PB/PS ratio (<= 570/30) form a homogeneous dispersion in the polystyrene matrix, and the Izod notched impact strength of these blends is higher than that of commercial high-impact polystyrene (HIPS). It is generally accepted that polystyrene can only be toughened effectively by 1-3 mu m rubber particles through a toughening mechanism of multiple crazings. However, the experimental results show that polystyrene can actually be toughened by monodisperse sub-micrometer rubber particles. Scanning electron micrographs of the fracture surface and stress-whitening zone of blends with a PB/PS ratio of 70/30 in PB-g-PS copolymer reveal a novel toughening mechanism of modified polystyrene, which may be shear yielding of the matrix, promoted by cavitation.

Carbon ceramic electrodes modified with sub-micron particles of new methylene blue (NMB) intercalated alpha-zirconium phosphate

New methylene blue-intercalated a-zirconium phosphate (NMBZrP) was synthesized in the presence of n-butylamine and characterized by powder XRD, FTIR, TEM and elemental analysis. Sub-micron particles of NMBZrP in deionized water were apt to deposit onto the surface of graphite powder to yield graphite powder-supported NMBZrP, which was subsequently dispersed into methyltrimethoxysilane-derived gels to fabricate surface-renewable, stable, rigid carbon ceramic electrodes containing new methylene blue. Cyclic voltammetric studies revealed that peak currents of the NMBZrP-modified electrode were surface-confined at low scan rates but diffusion-controlled. at high scan rates. In addition, NMBZrP immobilized in a carbon ceramic matrix presented a two-electron, three-proton redox process in acidic aqueous solution in the pH range from 0.52 to 3.95.

Molecular dynamics simulation of sub-transition for polyethersulfone

Molecular dynamics (MD) simulations of a polyethersulfone (PES) chain are carried out in the amorphous state by using the Dreiding 2.21 force field at four temperatures. Two types of molecular motion, i.e, rotations of phenylene rings and torsions of large segments containing two oxygen atoms, two sulfur atoms, and five phenylene rings on the backbone, are simulated. The modeling results show that the successive phenylene rings should be in-phase cooperative rotations, whereas the successive large segments should be out-of-phase cooperative torsions. By calculating the diffusion coefficient for the phenylene ring rotations, it is found that this rotation contributes to the beta -transition of PES.

Tectonic geomorphology of the Ryukyu Trench-Arc-Backarc System: geological-geophysical exploration and mapping

OKINAWA TROUGH; BASIN

Bioenergetic responses of sub-adult sea cucumber Apostichopus japonicus (Selenka) (Echinodermata: Holothuroidea) to temperature with special discussion regarding its southernmost distribution limit in China

1. This paper investigated the bioenergetic responses of the sea cucumber Apostichopus japonicus (wet weights of 36.5 +/- 1.2 g) to different water temperatures (5, 10, 15, 20, 25 and 30 degrees C) in the laboratory. 2. Results showed that theoretically the optimal temperatures for energy intake and scope for growth (SFG) of sub-adult A. japonicus was at 15.6 and 16.0 degrees C, respectively. The aestivation threshold temperature for this life-stage sea cucumber could be 29.0 degrees C by taking feeding cessation as the indication of aestivation. 3. Our data suggests that A. japonicus is thermo-sensitive to higher temperature, which prevents it from colonising sub-tropical coastal zones. Therefore, water temperature plays an important role in its southernmost distribution limit in China. 4. The potential impact of global ocean warming on A. japonicus might be a northward shift in the geographical distribution. Crown Copyright (C) 2009 Published by Elsevier Ltd, All rights reserved.

渤海湾地区前第三系构造特征及其演化研究

Based on fine structural interpretation on seismic profiles of buried-hills in Huanghua depression, structural interpretation and balanced cross-section restoration of regional seismic profiles, drawing structural maps of main seismic interfaces, residual strata distribution of different ages in the Bohai Bay region and structural survey in the western Shandong uplifted area and the intracontinental orogeny of Yanshan mountain, the paper has studied pre-tertiary structural styles and tectonic evolution of the Bohai Bay region. There mainly develop 5 types of pre-tertiary structural style that are extension structure, compression structure, strike-slip structure, negative inversion structure and sliding structure in the Bohai Bay region. Among these 5 types of structural style, extension structure develops detachment fault and its controlling fault terrain structure and fault break slop; compression structure develops reverted fold, fault propagation fold, fault bent fold, imbricate thrust structure and triangle zone; strike-slip structure develops positive flower structure, negative flower structure, en-echelon structure and brush structure; negative reversion structure develops Indosinian compression and Yanshanian extension negative reversion structure, late Yanshanian compression and Cenozoic extension negative reversion structure; sliding structure develops interlayer sliding structure and detachment structure. According to Cangdong fault of SN direction, Zhangjiakou – Penglai fault and Qihe – Guangrao fault of NWW direction, the Bohai Bay region can be divided into 6 sub-regions in which structural direction and style is different from each other. Structural maps of bottom boundary of Cenozoic and upper Paleozoic manifest that main NNE structural direction is formed from late Yanshanian to Himalayan movement and minor NWW structural direction and a string of area more than 8000m are mainly suggest that Indosinian tectonic pattern strongly influence on Yanshanian and Himalayan movement. Residual strata distribution characteristics of middle to upper Neoproterozoic in the Bohai Bay region manifest that middle- to neo- aulacogen position may be corresponding to late Mesozoic uplifted zone. Residual Paleozoic distribution characteristics of main ENN suggest that structural alteration should be resulted from late Yanshanian to Himalayan movement while which of minor NWW structures suggest that deeper structure should restrict shallower structure. Structural patterns of main EW fold direction in the Bohai Bay region and thrust structure in eastern part are formed late Triassic in studied area. Granite magma intrusion of early to middle Jurassic mainly develops Yanshan mountain zone. Late Mesozoic rifting basins of NEE direction are widely distributed in the Bohai Bay region and granite magma intrusions are mainly distributed in Tancheng – Rongcheng zone. Mesozoic structural evolution in the Bohai Bay region is related to scissor convergent from east to west between North China plate and Yangtze plate and gradually reinforcing of the west circum-pacific tectonic tract while basin and range province of late Jurassic and early Cretaceous may be mainly related to lithospheric thinning of North China craton in late Mesozoic.

济阳坳陷深层地质构造与演化

Based on geophysical and geological data in Jiyang depression, the paper has identified main unconformity surfaces (main movement surfaces) and tectonic sequences and established tectonic and strata framework for correlation between different sags. Based on different sorts of structural styles and characteristics of typical structures, the paper summarized characteristics and distribution of deep structures, discussed evolution sequence of structure, analyzed the relation between tectonic evolution and generation of petroleum. The major developments are as following: Six tectonic sequences could be divided from bottom to top in the deep zone of Jiyang depression. These tectonic sequences are Cambrian to Ordovician, Carboniferous to Permian, lower to middle Jurassic, upper Jurassic to lower Cretaceous, upper Cretaceous and Kongdian formation to the fourth member of Shahejie formation. The center of sedimentation and subsidence of tectonic sequences distinguished from each other in seismic profiles is controlled by tectonic movements. Six tectonic evolution stages could be summarized in the deep zone in Jiyang depression. Among these stages, Paleozoic stage is croton sedimentation basin; Indosinian stage, open folds of EW direction are controlled by compression of nearly SN direction in early Indosinian (early to middle Triassic) while fold thrust fault of EW – NWW direction and arch protruding to NNE direction are controlled by strong compression in late Indosinian (latter Triassic); early Yanshanian stage (early to middle Jurassic), in relatively weak movement after Indosinian compressional orogeny, fluviolacustrine is deposited in intermontane basins in the beginning of early Yanshanian and then extensively denudated in the main orogenic phase; middle Yanshanian (late Jurassic to early Cretaceous), strike-slipping basins are wide distribution with extension (negative reversion) of NW – SE direction; latter Yanshanian (late Cretaceous), fold and thrust of NE – NNE direction and positive reversion structure of late Jurassic to early Cretaceous strike-slipping basin are formed by strong compression of NW–SE direction; sedimentation stage of Kongdian formation to the fourth member of Shahejie formation of Cenozoic, half graben basins are formed by extension of SN direction early while uplift is resulted from compression of nearly EW direction latterly. Compression system, extension system and strike-slip system are formed in deep zone of Jiyang depression. According to identifying flower structure of seismic profiles and analysis of leveling layer slice of 3D seismic data and tectonic map of deep tectonic interface, strike-slip structures of deep zone in Jiyang depression are distinguished. In the middle of the Jiyang depression, strike-slip structures extend as SN direction, NNW direction in Huimin sag, but NNE in Zhandong area. Based on map of relict strata thickness, main faults activity and regional tectonic setting, dynamic mechanisms of deep structure are preliminary determination. The main reason is the difference of direction and character of the plate’s movement. Development and rework of multi-stage tectonic effects are benefit for favorable reservoir and structural trap. Based on tectonic development, accumulation conditions of deep sub-sags and exploration achievements in recent years, potential zones of oil-gas reservoir are put forward, such as Dongying sag and Bonan sag.

孤岛油田油藏动态模型和开发环境及剩余油分布

This paper is an important part of the national "863" topic :"Reservoir dynamic model, the development environment and the forecast of remaining oil". In this paper, multi-theory, method and technology are synthesized, and sufficiently use the computer method. We use unifies of qualitative and quota, unifies of macroscopic and microscopic, unifies of dynamic and quiescent description of reservoir, unifies of comprehensive research about reservoir and physical mathematical simulation, unifies of three-dimensional and four-dimensional description of reservoir to research the reservoir of channel sand in Gudao oilfield. and we do some research about the last 10 years of the more than 30 year high pressure water injection and polymer water flooding development, dynamic changes and geologic hazard of reservoir fluid field. It discloses the distribution, genesis and controlling factors. The main innovation achievement and the understanding are: we built-up the framework of the strata and structure, and found genetic type, spatial distribution and aeolotropism of the upper Guantao member. We form the macroscopic and microscopic reservoir model of dynamic evolution, disclose the character, distribution of the macroscopic and microscopic parameter，and the relationship with remaining oil. Next we built-up the model about hydrosialite, and find the styles, group of styles, formation mechanism and controlling factors of the reservoir, disclose the affection of the hydrosialite to remaining oil, pollution of the production environment of oilfield and geologic hazard. The geologic hazards are classified to 8 styles first time, and we disclose the character, distribution law, formation mechanism and controlling factors of the geologic hazard. We built-up the model of the distribution of remaining oil in different periods of Gudao oilfield, and disclose the macroscopic and microscopic formation mechanism of remaining oil in different periods, forecast the distribution of the mobile remaining oil, and find that the main cause of the dynamic evolution of all the sub-models of reservoir fluid field is the geologic process of the reservoir development hydrodynamic force. We develop the reservoir fluid field, research of environment disaster and the description about the support theory, method and technology. The use of this theory in Gudao oilfield has obtained very good economic efficiency, and deepened and develops development geology about the continental facies fault-trough basin, and theory of geologic hazard.

天山南北山前盆地中-新生代沉积记录及其动力学分析

It has been long known that intense multiple Mesozoic-Cenozoic intracontinental deformations have controlled the grand scale basin-range structural evolution of the Tianshan and its adjacent basins. So it is important to study the sedimentary records of the piedmont basins along the two sides of the Tianshan synthetically for the continental geodynamic research.We carried out a magnetostratigraphy study on Cretaceous- Tertiary succession and U-Pb dating analysis of detrital zircons from the representative sandstone samples of the Mesozoic-Cenozoic deposits in Kuqa Subbasin, northern Tarim Basin, combining our previous results of multiple depositional records from different profiles including paleocurrent data, conglomerate clast, sandstone framswork grains, detrital heavy minerals and geochemistry analysis, so the multiple intracontinental tectonic processes of Tianshan and their depositional response in the Kuqa Subbasin can be revealed. The results show that the tectonic evolution of the Tianshan Orogen and the sedimentary processes of the Kuqa Subbasin can be divided into four periods: early Triassic(active period), from middle Triassic to late Jurassic(placid period), from early Cretaceous to Tertiary Paleocene(active period) and from Neogene to present (intensely active period). Simultaneously，the depositional records reveal the provenance types and tectonic attributes in different periods. As follows, the lower Triassic with a dominant age ranging from 250 to 290Ma of the Zircons, which were principally derived from alkali feldspar granites and alkaline intrusion obviously, relative to the magma activity in Permian. In middle Triassic-late Jurassic, the two samples collected from the Taliqike formation and the Qiakemake formation respectively show the age peak at 350～450Ma, which was relative to the subduction of the Tarim Block to Yili-Central Tianshan Plate. In this period the provenance of the Kuqa deposits was the Central Tianshan arc orogenic belts distantly with little height predominance.During early Cretaceous-Paleogene, two major zircons age spectra at 240~330Ma and 370~480Ma have been acquired, with some other not dominant age ranges, indicating complicated provenance types. In Neogene, the detrital zircons age dating ranges from 460 to 390 Ma primarily. What’s more, the newer chronology of the stratigraphy and the older source age, indicating that Tianshan was uplifted and exhumated further strongly. Further study on the heavy mineral and the detrital zircons age dating of the Mesozoic-Paleogene representative profiles in southern Junggar Basin, combined with the published results of the sandstone framework grains, we consider that it occurred obvious sedimentary and tectonic changes occurred in the inside of Jurassic, from late Jurassic to early Cretaceous and form early Cretaceous to late Cretaceous. On this faces, there are remarkable changes of the steady minerals and unstable minerals, the sandstone maturity and the age spectra of the detrital zircons. Compared the sedimentary records from the two sides of the Tianshan, We find that they are different obviously since Middle Jurassic. It can be concluded that Tianshan have uplifted highly enough to influence the paleo-climatic. According to the current strata division, the structural activity apparently showed a migration from north to south. That is to say, the South Tianshan uplift later than the north, especially from late Jurassic to early Cretaceous , but it was uplifted and exhumated more strongly. Furthermore, correlating the depositional records and tectonic styles in the Kuqa-South Tianshan basin-range conjugation site in the east with the west, the obvious differentiation between the west and the east from the Cretaceous especially in Tertiary along the Tianshan-Kuqa belt was revealed, probably showing earlier uplifting in the east while greater exhumation depth and sediment rates in the west. In addition, the contacting style of Kuqa subbasin to the Tianshan Orogenic belts and the basement structure are also inconsistent at different basin-range conjugation sites. It is probably controlled by a series of N-S strike adjusting belts within the Kuqa subbasin, or probably correlated with the material difference at the complicated basin-range boundary. The research on the Mesozoic-Cenozoic tectonic-depositional response in the piedmont basins along the two sides of the Tianshan shows that the basin-filling process was controlled by the intracontinental multicyclic basin-range interactions, especially affected by the intense tectonic differentiations of basin-range system, which can’t be illuminated using a single evolutionary model.