To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
In this study, the petrology, zircon U–Pb ages, Lu–Hf isotopic compositions, whole-rock geochemistry and Sr–Nd isotopes for newly recognized low-Mg and high-Mg adakitic rocks from the North Altun orogenic belt were determined. The results will provide important insights for understanding the continuities of the North Qilian and North Altun orogenic belts during early Palaeozoic time. The low-Mg adakitic granitoids (445 to 439 Ma) are characterized by high SiO2 (69–70 wt %), low Mg no. (43–48) and low Cr and Ni contents. In contrast, the high-Mg adakitic granitoids (425 to 422 Ma) have relatively lower SiO2 (65–67 wt %), higher Mg no. (60–62) and higher Cr and Ni contents. The low-Mg adakitic rocks have high initial 87Sr/86Sr ratios (0.7073–0.7084), negative εNd(t) (−1.9 to −4.0) and εHf(t) values (−6.8 to −2.0), and old zircon Hf model ages (1.4–1.7 Ga). In contrast, the high-Mg adakitic rocks show lower initial 87Sr/86Sr ratios (0.7044–0.7057), higher εNd(t) (−0.7 to 3.1) and positive εHf(t) values (2.0 to 6.9), with younger zircon Hf model ages (0.9–1.2 Ga). These results suggest that the low-Mg adakitic rocks were probably generated by the partial melting of thickened crust, whereas the high-Mg adakitic rocks were derived from the anatexis of delaminated lower crust, which subsequently interacted with mantle magma upon ascent. The data obtained in this study provide significant information about the geological and tectonic processes after the closure of the Altun Ocean. The continent–continent collision and thickening probably occurred during 450–440 Ma with the formation of low-Mg adakitic rocks, and the transition of the tectonic regime from compression to extension probably occurred at 425–422 Ma with the formation of high-Mg adakitic rocks. The geochemical, geochronological and petrogenetic similarities between the North Altun and North Qilian adakitic rocks suggest that these two orogenic belts were subjected to similar tectonomagmatic processes during early Palaeozoic times.
Part of the energy of low solar corona may be released and converted to plasma energy that may be the dominant source of solar flares. Recently, many physical mechanisms have been proposed to accelerate ions and electrons. In the magnetic mirror device of fusion research, ion cyclotron instability and the energetic ion losses have been discovered and the plasma becomes electron rich.
For modern management and full resource sharing among libraries and scientific departments both in Chinese and worldwide observatories, we established the computer system of library management and information retrieval during the period 1984-1987.
The system is composed of ten component sub-systems:
1.Book ordering system. This system can produce orders for books and periodicals, balance accounts, produce statistics as well as claims for outstanding book orders.
2.Book cataloguing system. This system can catalogue books under certain rules while appending new records of books to the databases. It can also produce catalogue cards and produce written reports about the new books.
3.Book retrieval system has the ability to search for a specific book in several ways.
4.Book lending or circulation system. This system is a complete circulation system; including book lending, renewals, waiting lists, and recall of borrowed books.
5.Periodical management system. This system is in charge of processing of periodicals and magazines in the library, including cataloguing, management, and lending.
6.Scientific information retrieval system. One can retrieve scientific information by keywords or in many other ways.
7.Internal material booking system. It can make orders of internal materials, claims for materials outstanding and make exchanges with other observatories and institutions both in or outside the country.
8.Internal material management system. It can do the work that is analogous to that done with books and periodicals.
9.Information relationship system. It handles exchanges of information between institutions. Computer system of library management ... at Shaanxl 183
10.Scientific information network management system. It manages affairs within a certain information network.
Mussels are typical macrofouling organisms in the world. In this study, the interaction between the settlement of Mytilus coruscus plantigrades and bacterial community on coloured substrata was determined. Bacterial communities in biofilms developed on seven coloured substrata were analysed by Illumina Miseq sequencing. The mussel settlement response to coloured substrata with no biofilms was also examined. Flavobacteria, Alphaproteobacteria and Gammaproteobacteria were the first, second and third most dominant groups in seven biofilm samples. The results suggest that the inducing activities of these biofilms on plantigrade settlement varied with coloured substrata and the lowest percentage of settlement was observed on biofilms on the green substratum. High-throughput sequencing showed that bacterial community in biofilms also changed with the substratum colour. No significant difference in the inducing activity on plantigrade settlement was observed between the coloured substrata with no biofilms. Thus, difference in plantigrade settlement response may be correlated to the changes in bacterial community on coloured substrata. This finding extends current knowledge of interaction among mussel settlement and bacterial community variability.
Boron-doped, single (∼54 nm) or double (∼21 + 54 nm) Si1−xGex layers were epitaxially grown on 300-mm-diameter p−-Si(100) device wafers with 20 nm technology node design features, by ultrahigh vacuum chemical vapor deposition. The Si1−xGex/Si wafers were annealed in the temperature range of 950–1050 °C for 60 s to investigate the effect of annealing on possible changes of Ge content and Si stress near the Si1−xGex/Si interface. High spectral resolution, micro-Raman spectroscopy was used as a nondestructive characterization technique with five excitation wavelengths of 363.8, 441.6, 457.9, 488.0, and 514.5 nm. Ge diffusion and generation of compressive stress at the Si1−xGex/Si interface were measured on all annealed wafers. Ge diffusion and the accumulation of compressive Si stress after annealing showed significantly different behaviors between single- and double-layer Si1−xGex/Si wafers. Raman characterization results were compared with secondary ion mass spectroscopy and high-resolution x-ray diffraction results.
We have measured at room temperature polarized visible and near-infrared and unpolarized mid-infrared (2.7 μm) emission spectra of Er3+ in LiNbO3 (LN) crystals grown from congruent melts doped with 0.0/0.5, 0.5/0.5, and 1.0/0.5 mol%/mol% In2O3/Er2O3. From the measured emission spectra, the emission and absorption cross section spectral distributions were analyzed based on McCumber theory and discussed in comparison with those spectra of only Er-doped LN bulk material and/or Ti: Er: LN waveguide structure and with the results from the unpolarized absorption measurements. For the 530 and 1530 nm transitions, the cross section value, polarization dependence, and spectral shape all change from the only Er-doped material to the In–Er-codoped crystal and show definite In2O3 doping level effect. The 559, 673, 996, and 1530 nm emission lifetimes were also measured and used to evaluate nonradiative multiphonon relaxation rate. The calculated radiative, measured lifetimes, and multiphonon relaxation rate also show In-codoping effects.
The development of crystallographic texture in thin film longitudinal recording media is discussed. Polycrystalline thin films may obtain their crystallographic texture by means of a nucleation process such as epitaxial nucleation on a polycrystalline underlayer or by means of a process involving a preferred growth direction. In this paper we will discuss various epitaxial nucleation textures that are obtained in media produced for magnetic recording. We will discuss the way that the underlayer controls the crystallographic texture of the magnetic layer, as well as methods used to control the texture of the underlayer itself. We give a brief overview of some of our recent findings in the growth of NiAl and FeAl films used for underlayers. Finally we will briefly discuss what we have called the tilted electron beam technique. In this technique selected area electron diffraction patterns are obtained at different angles of tilt and the development of arcs in the patterns is analyzed so as to determine the type and amount of crystallographic texture which is present in the films.
The Orai1-STIM1 constructed store-operated Ca2+ channels (SOCs) have been found to exert several essential Ca2+ entry/signaling cascades, e.g., the generation of immune response in T lymphocytes. Although biochemical and novel imaging evidence appear to indicate that Orai1 and STIM1 interact with each other to achieve store-operated Ca2+ entry (SOCE), the detailed mechanism of functional SOCE in situ has yet to be fully understood. In this study, green fluorescence protein (EGFP as donor) targeted to either the N- or C-terminal of Orai1 (wild type or ▵1-90+▵267-301 double deletion type) and mOrange (as acceptor) tagged STIM1 were used to comprise a fluorescence resonance energy transfer (FRET) pair within living PC12 cells. The fluorescence lifetime map and histogram/distribution of each single cell, determined by one-photon excitation fluorescence lifetime imaging microscopy (FLIM), was used to visualize FRET and show the Orai1 homodimer and Orai1-STIM1 binding. Both the color-coded lifetime map and the distribution of EGFP-tagged Orai1 significantly changed after the administration of thapsigargin, the SOCE stimulating agent. The FRET efficiency from each experimental set was also calculated and compared using double exponential analysis. In summary, we show the detailed interactions Orai1-Orai1 and Orai1-STIM1 within intact living cells by using the FLIM-FRET technique.
Congruent Er:Mg:LiNbO3 crystals were grown by the Czochralski method from the melts containing fixed 0.5 mol% Er2O3 while varied MgO content ranged from 0.0 to 8.0 mol%. The Mg and Er contents in the crystals were determined by neutron activation analysis. In the presence of Er codopant, the Mg threshold concentration with respect to optical damage is determined from the measured OH absorption spectra. The results show that the Er codopant has less effect on both the Mg threshold concentration and Mg segregation coefficient, which is within 1.13–1.23 as the Mg concentration is below the threshold while within 0.88–0.98 when above the threshold, consistent with the only MgO doping case. On the other hand, the practical Er concentration in the crystal is closely related to the Mg content and shows definite Mg threshold effect. Below the threshold, the Er concentration decreases linearly with the increased Mg concentration in the crystal; above the threshold, the decrease is more remarkable and follows another linear function. The Mg concentration effect on the Er segregation coefficient is discussed from the viewpoint of the Mg doping effect on the solubility of Er ions in the crystal.
An equation is derived for the growth rates of the beam-plasma instability excited by non-thermal electrons with arbitrary distribution function, and it is shown that the reactive instability does not depend on the assumption of a monoenergetic distribution. Hence the properties of electromagnetic waves are calculated for the hollow beam and loss-cone distribution. Hence the properties of electromagnetic waves are calculated for the hollow beam and loss-cone distribution functions. The general characteristics and structures of the growth rates are similar to the results for the monoenergetic distribution, but there are still some differences in the relation between the growth rates and the relevant parameters, such as the ambient parameter ωpe/Ωe, the angle of propagation θ and the pitch angle a. The main purpose of this paper is to compare the properties of the beam-plasma instability (reactive) and the electron-cyclotron maser instability (kinetic) under similar ambient conditions. The calculations show that both kinds of instabilities are easily excited at larger angles of propagation with respect to the ambient magnetic field, which means that both depend mainly on the free energy of the non-thermal electrons perpendicular to the magnetic field. The magnitudes of the growth rates of the two kinds of instabilities are comparable under the same ambient conditions. However, because the non-resonant wave—particle interaction is taken into consideration for the beam-plasma instability, which makes the resonant peaks broaden and connect with each other, the spectra of the beam-plasma instability are also more complicated than that of the maser instability, and the range of the angle of propagation of the growing waves in the non-resonant case is also larger than that in the resonant case.
The gene ap36 encoding a protein elicitor from Alternaria sp. was fused downstream of the slh (S-layer homology) motif of Bacillus thuringiensis S-layer protein gene ctc. The recombinant gene was then transferred into B. thuringiensis plasmid-free derivative strain BMB171. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the SLH–Ap36 fusion protein was expressed in B. thuringiensis BMB171. After tomato (Lycopersicum esculentum) leaves were treated for 90 min with the recombinant strain cultured at 28°C for 24 h, the activity of peroxidase and the amount of proline of tomato leaves were increased to 57.14% and 131.59%, respectively, compared to the control, and after the tomato leaves were treated with the cultured recombinant strain for 4 days, the activity of phenylalanine ammonia lyase was also higher than that in the control. Furthermore, tubers of treated potato (Solanum tuberosum) plants showed higher resistance to rot disease caused by Erwinia corotovora SCG1 compared to the control treatments.
In the impulsive phase of solar flares, the electrostatic waves can be excited during magnetic reconnection. The proton and electron at reconnecting X points can be accelerated by perpendicular propagating electrostatic waves.
The initial-boundary value problem of two-dimensional
incompressible fluid flow in stream function form is considered.
A prediction-correction Legendre spectral scheme is proposed, which is
easy to be performed.
The numerical solution possesses the accuracy
of second-order in time and higher order in space. The
numerical experiments show the high accuracy of this approach.
It is proved that a system of three-wave coupling with weak damping
same sign of the coupling coefficients can be completely described by the
Weierstrass function. On the basis of the bifurcation theory of the Weierstrass
function that we have developed, criteria are found for distinguishing
phases of the three-wave coupling, namely the stable phase and the excited
explosive and auto-explosive phases. Two kinds of explosion mechanisms
three-wave coupling are found and described. The mechanism for the excited
explosive phase is normal because trigger energy is required in such a
mechanism and the threshold λth is proportional to δ2
(δ is the frequency
mismatch), whereas the anomalous mechanism for the auto-explosive phase
does not need any trigger – only proper changes of internal parameters
the absolute invariant J less than 27 are required.
In addition, the repetition
period of the explosive instability is given. Finally, the effects of weak
on the bifurcation structure of the explosive instability in three-wave
interactions are analysed.
The effects of the propagation angle of electromagnetic waves and
angle of non-thermal electrons on the electron cyclotron maser instability
beam–plasma instability are compared. It is pointed out if the direction
propagation of electromagnetic waves is opposite to the direction of the
electrons, the maser instability will be suppressed, and hence it cannot
the radiation with narrow bandwidth excited by energetic electrons propagating
downwards in solar flares, such as millisecond spikes, blips and the type
bursts with positive-frequency drift. This discrepancy may be solved by
non-resonant wave–particle interaction in the beam–plasma instability,
which the electromagnetic waves propagating in the same direction as the
injected electron beam are mainly composed of the ordinary modes (left-circular
polarization), while the electromagnetic waves propagating in the
opposite direction to the beam are mainly composed of the extraordinary
(right-circular polarization). This result is compared with a typical model
magnetic tube in solar flares, in which the non-thermal electrons propagating
upwards excite spikes, blips and type III bursts in the metre and decimetre
bands, while the electron beams propagating downwards excite these temporal
and spectral structures in the microwave bands.
The crystal structure of the spinel polymorph of Fe2SiO4, synthesized at high temperature (900°C) and high pressure (70 kbar), was studied by the Rietveld analysis of X-ray powder diffraction data collected with a Guinier-Hägg camera. The compound is cubic, space group , with cell dimension: a= 8.2413(6) Å, V= 559.8(1) Å3, Z= 8, Cell Wt. = 1630.2, Dx= 4.835 g·cm−3, Do= 4.75 g·cm−3. The figure of merit is F10= 92(0.011, 10). The final R value is RF= 0.058. The crystal has a mixed normal-inverse spinel structure. The site occupancy refinement showed that 37.9% of the silicon was found in the octahedral site (M site), while 18.9% of the iron occupied the tetrahedral site (T site). Due to the larger displacement of Si4+ion by Fe2+ion, the positional parameter of oxygen atom (0.3689) is smaller than that of X-ray single crystal structure (0.3658), and the average Si-O bond (1.697(1)Å) is longer and Fe-O bond (2.112(1)Å) is shorter than those of X-ray single crystal structure.
Crystallographic and X-ray powder diffraction data were derived from a sample of (Na0.5Bi0.5)TiO3 synthesized by standard ceramic techniques. The powder data were indexed on a monoclinic cell having the space group P2 or Pm, which differed from a previously reported rhombohedral cell.
Email your librarian or administrator to recommend adding this to your organisation's collection.