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SC200 cyclotron is a compact superconducting cyclotron for proton therapy developed by the ASIPP (Hefei, China)-JINR (Dubna, Russia) collaboration. In this paper, some beam dynamics simulations are done to evaluate the magnetic field of SC200 measured by mapping system. Magnetic field is optimized by shimming bars and coils to make sure beam can be accelerated to the entrance of extraction system. The optimization of isochronism of magnetic field, beam radial oscillation caused by imperfect first harmonic of magnetic field, magnetic vertical focusing force and radial magnetic field at median plane are presented. The tolerance of imperfect average magnetic field bump and radial magnetic field are studied by beam dynamics simulation.

Ischemic stroke is a common disease in neurology, which seriously affects people's normal work and quality of life and brings a heavy social burden. The nanoparticle carrier generally consists of natural polymer material or synthetic polymer material. Among the synthetic polymer materials, PLGA is one of the most popular carrier materials in recent years. This paper introduces the application of PLGA nanomaterials in ischemic stroke, and reviews the application of PLGA nanomaterials in the diagnosis and tissue repair of ischemic stroke, and drug delivery of neuroprotective drugs. It provides a theoretical basis for the research progress of PLGA nanotechnology in the treatment of anti-stroke and the development of anti-stroke drugs.

Additional file 1.

The cuprate high-temperature superconductors exhibit many unexplained electronic phases, but it was often thought that the superconductivity at sufficiently high doping is governed by conventional mean-field Bardeen-Cooper-Schrieffer (BCS) theory[1]. However, recent measurements show that the number of paired electrons (the superfluid density) vanishes when the transition temperature Tc goes to zero[2], in contradiction to expectation from BCS theory. The origin of this anomalous vanishing is unknown. Our scanning tunneling spectroscopy measurements in the overdoped regime of the (Pb,Bi)2Sr2CuO6+δ high-temperature superconductor show that it is due to the emergence of puddled superconductivity, featuring nanoscale superconducting islands in a metallic matrix[3,4]. Our measurements further reveal that this puddling is driven by gap filling, while the gap itself persists beyond the breakdown of superconductivity. The important implication is that it is not a diminishing pairing interaction that causes the breakdown of superconductivity. Unexpectedly, the measured gap-to-filling correlation also reveals that pair-breaking by disorder does not play a dominant role and that the mechanism of superconductivity in overdoped cuprate superconductors is qualitatively different from conventional mean-field theory.

Majorana bound states are putative collective excitations in solids that exhibit the self-conjugate property of Majorana fermions - they are their own antiparticles. In iron-based superconductors, zero-energy states in vortices have been reported as potential Majorana bound states, but the evidence remains controversial. Here, we use scanning tunneling noise spectroscopy to study the tunneling process into vortex bound states in the conventional superconductor NbSe2, and in the putative Majorana platform FeTe0.55Se0.45. We find that tunneling into vortex bound states in both cases exhibits charge transfer of a single electron charge. Our data for the zero-energy bound states in FeTe0.55Se0.45 exclude the possibility of Yu-Shiba-Rusinov states and are consistent with both Majorana bound states and trivial vortex bound states. Our results open an avenue for investigating the exotic states in vortex cores and for future Majorana devices, although further theoretical investigations involving charge dynamics and superconducting tips are necessary., Comment: 15 pages, 4 figures, and 16 pages for supplementary information

The nanopore-based biosensing technology is built up on the fluctuation of the ionic current induced by the electrokinetic translation of a particle penetrating the nanopore. It is expected that the current change of a deformable bioparticle is dissimilar from that of a rigid one. This study theoretically investigated the transient translocation process of a deformable particle through a nanopore for the first time. The mathematical model considers the Poisson equation for the electric potential, the Nernst-Planck equations for the ionic transport, the Navier-Stokes equations for the flow field, and the stress-strain equation for the dynamics of the deformable bioparticle. The arbitrary Lagrangian-Eulerian method is used for the fully coupled particle-fluid dynamic interaction. Results show that the deformation degree of the particle, the velocity deviation, and the current is different from the rigid particle. The deformation degree of the particle will reach the maximum when the particle passes a nanopore. Because of the deformation of particles, the total force applied on deformable particles is larger than that of rigid particles, resulting in larger velocity deviation and current deviation. The influences of the ratio of the nanoparticle radius to the Debye length and surface charge density of the nanopore are also studied. The research results illustrate the translocation mechanism of a deformable nanoparticle in the nanopore, which can provide theoretical guidance for the biosensing technology based on the nanopore.

Background and Objective: The objectives of this study were to investigate the effects of land use and land cover transitions on soil physico-chemical properties, and to comparatively study soil microbial activity in ecological restoration red soil region of subtropical southern China. Methods: A field experiment was conducted in a natural forest, four ecological restoration forests and an adjacent farmland. Based on the stable carbon isotopes of SOM, the δ13C values data confirm the 6 sites for soil sampling in this study were the ideal location for studying land cover transitions. The data showed that the soil physical, chemical and biological properties under the natural forest were significantly healthier than under cultivation. During forest re-growth on farmland, the ecological restoration time were 34, 26, 15 and 10a, respectively, and the SOM content, C/N, soil colony counts, soil basal respiration and soil enzyme activities significantly increased and approached values of virgin forest. Results & Conclusion: In general, the SOM content and soil microbial activities in ecological restoration forest were usually intermediate between the natural forest and farmland, and there was significant (P< 0.05) difference between forest and farmland. The results indicated that, because of appropriate climatic conditions of red soil subtropical southern China, the dynamic balance of soil ecosystems can be reconstructed and restored in several years or decades.

ObjectiveTo establish the association between serial levels of inflammatory cytokines in cord blood and perinatal characteristics and bronchopulmonary dysplasia (BPD) in preterm infants.Methods147 premature infants with gestational age ≤32 weeks who were born and hospitalized in the First Affiliated Hospital of Zhengzhou University between July 2019 and August 2021 were enrolled in this retrospective case–control study. Multiple microsphere flow immunofluorescence was used to detect seven cytokines in cord blood collected within 24 h of birth. Demographics, delivery characteristics, maternal factors, neonatal characteristics, and clinical outcomes were collected for the two groups. An unconditional logistic regression model was used in this study to assess the clinical variables.ResultsIL-6 cord blood levels at birth were significantly higher in the BPD group than in the non-BPD group, but the odds ratio (OR) was very small (OR = 1). No differences in other cytokine concentrations were observed between the two groups. Multivariable logistic regression analysis demonstrated that increased maternal white blood cell (WBC) count on admission and lower birth weight increased the risk of BPD progression.ConclusionsIncreased IL-6 cord blood levels at birth in preterm infants may have trivial significance for predicting BPD. Furthermore, higher maternal WBC count on admission and lower birth weight increased the risk of BPD.

With the development of energy storage technology, more and more battery energy storage stations (BESSs) are connected to the power grid to restrain fluctuation and intermittency of renewable energy generation on the stability of the power grid. However, the connection with BESS will change the topology and power flow direction of the power grid. Therefore, based on the actual geographical wiring diagram and related data, this paper describes a grid model to analyze the influence of BESS connected to the power grid on power flow and node voltage. When the voltage of each node is stable, the genetic algorithm is applied to study how to select the access position and control the power of centralized or distributed BESSs to minimize the active power loss of the power grid. It provides guidance and reference for future location planning and control strategy of BESSs in the power grid.

The transthoracic impedance measurement is one of the important functions of an automated external defibrillator (AED). In this paper, the basic knowledge of transthoracic impedance measurement is introduced, and a simple transthoracic impedance measurement system combined with the defibrillation process is proposed. The system is composed of a high voltage detection circuit, defibrillation current detection circuit, AD acquisition and data processing and other parts, without additional hardware excitation measurement structure, which is conducive to the portable design of AED. The measurement results show that the error of transthoracic impedance measured by this system is less than 5%.

In this paper we discuss the sufficient and necessary conditions for multiple Alexandrov spaces being glued to an Alexandrov space. We propose a Gluing Conjecture, which says that the finite gluing of Alexandrov spaces is an Alexandrov space, if and only if the gluing is by path isometry along the boundaries and the tangent cones are glued to Alexandrov spaces. This generalizes Petrunin's Gluing Theorem. Under the assumptions of the Gluing Conjecture, we classify the $2$-point gluing over $(n-1,\epsilon)$-regular points as local separable gluing and the gluing near un-glued $(n-1,\epsilon)$-regular points as local involutional gluing. We also prove that the Gluing Conjecture is true if the complement of $(n-1,\epsilon)$-regular points is discrete in the glued boundary. In particular, this implies the general Gluing Conjecture as well as a new Gluing Theorem in dimension 2., Comment: 23 pages, 2 figures

Additional file 3 P values of two-way ANOVA for the effects of temperature variations and seawater acclimation on PLFA-related indices in rainbow trout.

Additional file 2. Integrated data of PLFA composition in this research.

Additional file 1. Fatty acid composition of the diet.

Additional file 1: Fig. S1 Confirmation and purity examination of isolated PC and NPC fractions after liver perfusion. a Gene expression of Alb, Vim, Stab2, and CD163 in LC, PC, and NPC fractions by qPCR. Fold change between PC and NPC was indicated (n = 3). b. Representative images of PCs and NPCs 24 h after isolation. Scale bar: 100 μm. Data are shown as means ± SD. LC: liver cell; PC: parenchymal cell; NPC: non-parenchymal cell.

Additional file 2: Fig. S2 Setup of transwell co-culture for HSCs and hepatic stem cells. HSCs were seeded on the membrane of transwell inserts with a 0.4 mm pore size. c-Kit−CD29+CD49f+/lowCD45−Ter-119− hepatic stem cells were sorted by flow cytometry and seeded on 6-well plate pre-coated with type IV collagen. Co-culture for HSCs and hepatic stem cells was set up 1 day later. HSCs: hepatic stellate cells.

Magnetic sensing platform techniques have been used in many years in an attempt to better evaluate the likelihood of recoverable hydrocarbon reservoirs by determining the depth and pattern of sedimentary rock formations containing magnetic minerals, such as magnetite. Utilizing airplanes, large-area magnetic surveys have been conducted to estimate, for example, the depth of igneous rock and the thickness of sedimentary rock formations. In this case, the vector magnetic survey method can simultaneously obtain the modulus and direction information of the Earth's magnetic field, which can effectively reduce the multiplicity on data inversion, contribute to the quantitative interpretation of the magnetic body and obtain more precise information and characteristics of magnetic field resource, so as to improve the detection resolution and positioning accuracy of the underground target body. This paper presents a state-of-the-art review of the application situations, the technical features, and the development of the vector magnetic sensing platform-technical aspects for different application scenarios, i.e., ground, wells, marine, airborne, and satellites, respectively. The potential of multi-survey sensing platform technique fusion for magnetic field detection is also discussed., Comment: 2 columns, 16 pages, 15 figures

A bifunctional sulfonated polyaniline nanofiber mat (NFM) was synthesized by oxidative polymerization and by using polyacrylonitrile nanofiber mat (NFM) as the template. The adsorption capacity of the NFM for fluoroquinolones (FQs) is distinctly improved and the adsorption was a spontaneous process. According to theoretical calculations, hydrogen bonding and ion-exchange interaction are the two major kinds of interaction mechanisms between adsorbent and FQs. The adsorption and desorption properties for FQs were systematically evaluated by adsorption isotherms and by thermodynamic and kinetic studies. The results indicate that the NFM is a viable sorbent for FQs because of rapid mass transfer and good adsorption/desorption efficiency. The NFM is re-usable for at least 20 cycles without decline in performance. Following desorption of the FQs with 10% (V/V) formic acid/acetonitrile, they were quantified by UPLC with MS/MS detection. The sorbent was applied to the solid phase extraction of the FQs norfloxacin, ciprofloxacin, ofloxacin, enrofloxacin, danofloxacin, pefloxacin, marbofloxacin, lomefloxacin and difloxacin from water and biological fluids. Figures of merit include (a) low limits of detection (0.5–1.5 ng L−1 for water, 0.016–0.052 μg L−1 for urine and serum), (b) high recoveries from spiked samples (82.3%–109.4%) with low relative standard deviations (1.1%–12.3%); (c) short extraction times (2 min), and (d) low adsorbent dosage (4 mg).

This paper focuses on the problem of multiple unmanned aerial vehicles (UAV) biomimetic formation control, which wild geese collective behavior is based on. Wild geese can realize long distance flight by effectively utilizing the upwash airflow in formation flight to save energy. The bionic mechanism of multiple UAVs formation is discussed, and kinematic model of UAVs based on the wild geese behavior mechanism is designed. In order to reduce the fuel consumption, the quadratic optimal control is introduced into the design of formation controllers. A numerical simulation is carried out and the simulation results show that the UAVs can form a stable close flight formation under the proposed UAVs close formation controller based on the wild geese behavior mechanism.

The translational motion of small particles in an electrokinetic fluid flow through a constriction can be enhanced by an increase of the applied electric potential. Beyond a critical potential, however, the negative dielectrophoresis (DEP) can overpower other forces to prevent particles that are even smaller than the constriction from passing through the constriction. This DEP choking phenomenon was studied previously for rigid particles. Here, the DEP choking phenomenon is revisited for deformable particles, which are ubiquitous in many biomedical applications. Particle deformability is measured by the particle shear modulus, and the choking conditions are reported through a parametric study that includes the channel geometry, external electric potential, and particle zeta potential. The study was carried out using a numerical model based on an arbitrary Lagrangian-Eulerican (ALE) finite-element method.

A modified random fiber removal algorithm is proposed to numerically study transverse elastic properties of unidirectional carbon fiber reinforced pyrolytic carbon (C/C) composites. This method can efficiently generate the Representative Volume Element (RVE) of composites with random distribution fibers. On the basis of the numerical homogenization strategy, the effect of interphase between carbon fiber and pyrolytic carbon on the mechanical behaviors of unidirectional C/C composites are investigated. Meanwhile, periodic boundary conditions and linear elastic constitutive materials are taken into account. For validation, numerical calculations are compared with these obtained by atomic force microscopy (AFM) tests, which shows that more accurate results will be pursued when the interphases are considered. In addition, the influences of interphase parameters including the thickness, modulus, and Poisson’s ratio, on the effective transverse behavior of unidirectional C/C composites are studied numerically.The results demonstrate that the effective transverse properties of unidirectional C/C composites are mainly determined by the interphase modulus and independent of the interphase Poisson’s ratio. If the interphase thickness (less than 140 nm) of unidirectional C/C composites are very small, the modulus of interphase beyond 8 GPa makes little effect on the effective transverse properties.

To improve the accuracy of photovoltaic power prediction under haze weather, a short-term PV power prediction method combining the PM2.5 forecast and SVR model is proposed. The WRF-CHEM air quality model is used to realize the simulation calculation of PM2.5 concentration, combined with the historical output data of PV power plants, and based on the SVR machine learning model to build a direct mapping relationship model between multiple meteorological elements and PV output. A forecast experiment was carried out for a certain area in North China, and the results showed that the proposed method can effectively improve the accuracy of PV power forecasting under haze weather conditions, thereby providing strong support for power grid dispatch and operation.

The UK-China research project Low carbon climate-responsive Heating and Cooling of Cities (LoHCool) investigates enhanced indoor summer comfort in the 9 Billion m2 of building stock of the challenging Hot Summer and Cold Winter (HSCW) zone of China. The HSCW region lies South of the Huai River-Qin Mountain line below which central heating and cooling are deemed 'not required'. If this central government direction is relaxed, a significant carbon penalty could arise if the existing building stock is sealed and air conditioned to Western standards. LoHCool investigates the alternative strategy of increasing the existing stock's resilience to climate through low energy, low technology adaptation. The approach is applied here to typical slab building forms in Hangzhou and Chongqing in the East and West of the HSCW zone. Internal thermal conditions are simulated using the dynamic thermal model EnergyPlus calibrated using field data. Insofar as ventilation is a critical component of the adaptation schemes proposed, the local wind environment of the case study buildings is simulated using an advanced large eddy simulation model, Fluidity. Out of these diagnostic analyses, adaptation schemes are configured, specified and modelled, and found to significantly increase comfort with viable payback periods although supplementary cooling will be required as the century advances.

Improving the thermal insulating performance of porous building materials is of great practical significance for building energy conservation. In this work, silica aerogels (SA) with ultralow thermal conductivity were proposed as an appropriate candidate to be integrated with autoclaved aerated concrete (AAC) to produce novel SA-AAC composites with higher thermal insulating performance by physical solution impregnation method. The pore-structures, mechanical and thermal properties of the SA-AAC composites were probed by various experimental tests. According to the microscopy and porosimetry results, SA were observed to adhere to the surface walls of the AAC holes, thus reducing the amount of macro-sized pores. In addition, the improved thermal insulating performance of AAC was successfully achieved with the relative improvement depending on the porosity of the pristine AAC. At the mass fraction of SA of ~7%, the highest relative improvement was found to be ~30% The results of this work exhibited a great potential of this novel SA-AAC composite in engineering applications.

We report the first detection of the host galaxy of a strong 2175 ��$ $ dust absorber at z = 2.12 towards the background quasar SDSS J121143.42+083349.7 using HST/WFC3 IR F140W direct imaging and G141 grism spectroscopy. The spectroscopically confirmed host galaxy is located at a small impact parameter of ~ 5.5 kpc (~ 0.65$''$). The F140W image reveals a disk-like morphology with an effective radius of 2.24 $\pm$ 0.08 kpc. The extracted 1D spectrum is dominated by a continuum with weak emission lines ([O\III] and [O\II]). The [O\III]-based unobscured star formation rate (SFR) is 9.4 $\pm$ 2.6 M$_{\odot}$yr$^{-1}$ assuming an [O\III]/H$��$ ratio of 1. The moderate 4000 ��$ $ break (Dn(4000) index $\sim$ 1.3) and Balmer absorption lines indicate that the host galaxy contains an evolved stellar population with an estimated stellar mass M$_*$ of (3 - 7) $\times$ 10$^{10}$ M$_{\odot}$. The SFR and M$_*$ of the host galaxy are comparable to, though slightly lower than, those of typical emission-selected galaxies at $z$ $\sim$ 2. As inferred from our absorption analysis in Ma et al. (2015, 2017, 2018), the host galaxy is confirmed to be a chemically-enriched, evolved, massive, and star-forming disk-like galaxy that is likely in the transition from a blue star-forming galaxy to a red quiescent galaxy., 7 pages, 4 figures; accepted for publication in ApJL

The attribute reduction algorithm of radix sort to integer digit sequence table is not ideal. In this paper, based on how integers is stored in computer memory, low and high storage mode is designed for the solving algorithm of U/C chain structure of a new reasonable optimization. The time complexity of the algorithm from O (K|C| |U|) is reduced to O (K|C| |U| log (|M|)). The efficiency of the algorithm is improved by 3.8%.

We present 13 new 2175 �� dust absorbers at z_abs = 1.0 - 2.2 towards background quasars from the Sloan Digital Sky Survey. These absorbers are examined in detail using data from the Echelle Spectrograph and Imager (ESI) on the Keck II telescope. Many low-ionization lines including Fe II, Zn II, Mg II, Si II, Al II, Ni II, Mn II, Cr II, Ti II, and Ca II are present in the same absorber which gives rise to the 2175 �� bump. The relative metal abundances (with respect to Zn) demonstrate that the depletion patterns of our 2175 �� dust absorbers resemble that of the Milky Way clouds although some are disk-like and some are halo-like. The 2175 �� dust absorbers have significantly higher depletion levels compared to literature Damped Lyman-�� absorbers (DLAs) and subDLAs. The dust depletion level indicator [Fe/Zn] tends to anti-correlate with bump strengths. The velocity profiles from the Keck/ESI spectra also provide kinematical information on the dust absorbers. The dust absorbers are found to have multiple velocity components with velocity widths extending from ~100 to ~ 600 km/s, which are larger than those of most DLAs and subDLAs. Assuming the velocity width is a reliable tracer of stellar mass, the host galaxies of 2175 �� dust absorbers are expected to be more massive than DLA/subDLA hosts. Not all of the 2175 �� dust absorbers are intervening systems towards background quasars. The absorbers towards quasars J1006+1538 and J1047+3423 are proximate systems that could be associated with the quasar itself or the host galaxy., 27 pages, 32 figures, 31 tables; Accepted for publication in MNRAS

We present the cold neutral content (H I and C I gas) of 13 quasar 2175 ��$ $ dust absorbers (2DAs) at $z$ = 1.6 - 2.5 to investigate the correlation between the presence of the UV extinction bump with other physical characteristics. These 2DAs were initially selected from the Sloan Digital Sky Surveys I - III and followed up with the Keck-II telescope and the Multiple Mirror Telescope as detailed in our Paper I. We perform a correlation analysis between metallicity, redshift, depletion level, velocity width, and explore relationships between 2DAs and other absorption line systems. The 2DAs on average have higher metallicity, higher depletion levels, and larger velocity widths than Damped Lyman-$��$ absorbers (DLAs) or subDLAs. The correlation between [Zn/H] and [Fe/Zn] or [Zn/H] and log$��$V$_{90}$ can be used as alternative stellar mass estimators based on the well-established mass-metallicity relation. The estimated stellar masses of the 2DAs in this sample are in the range of $\sim$ 10$^9$ to $\sim$2 $\times$ 10$^{11}$ $M_{\odot}$ with a median value of $\sim$2 $\times$ 10$^{10}$ $M_{\odot}$. The relationship with other quasar absorption line systems can be described as (1) 2DAs are a subset of Mg II and Fe II absorbers, (2) 2DAs are preferentially metal-strong DLAs/subDLAs, (3) More importantly, all of the 2DAs show C I detections with logN(C I) $>$ 14.0 cm$^{-2}$, (4) 2DAs can be used as molecular gas tracers. Their host galaxies are likely to be chemically enriched, evolved, massive (more massive than typical DLA/subDLA galaxies), and presumably star-forming galaxies., 12 pages, 11 figures; accepted for publication in MNRAS

With the vigorous promotion of national policies and funds, green campus construction is booming in Chinese universities. It's in great need to develop an evaluation system, as a long-term mechanism, to assess and compare the sustainability performance in different Chinese universities, and to guide the green campus revolution in Chinese universities. Aiming at the characteristics of green campus evolution in China, a campus sustainability evaluation system is developed, that contains five categories of Organization & Management (C1), Energy & Resource Saving (C2), Friendly Environment (C3), Campus Culture (C4), and Social Outreach (C5). The indicators include mandatory indicators, all of which must be met in order to pass the evaluation, and optional indicators, which take the form of scoring. The scores of all optional indicators should be accumulated to get the final score. The achievements and shortcomings of sustainable campus development in a pilot Chinese university were revealed by this system as a case study, and the results indicate more attention should be paid on C1, C2, C4, and hence detailed suggestions were put forward. Discussions are made in terms of the potential contribution and the limitation of this evaluation system, and the capacity building needed to generalize the evaluation in China.

This paper takes microblog as an example, recognising names in finance and economics field by the algorithm combining the use of rules and probability calculation. This method firstly get the candidate names through calculating the probabilities, then choose from the candidate names by matching them with corresponding rules which contain positive rules and negative rules .This method has good robustness and flexibility.

In order to save mobile phone memory and improve the rate of loading resource, which could improve the user experience about the application, this paper put forward a kind of asynchronous loading mechanism which was optimized by combining SoftReference and LRU algorithm. Further more, it realized an application using asynchronous loading resources to verify the mechanism on the android platform. This mechanism offers a strong support both in theory and technology to improve the function of smart phone.

We study the mean absorption spectrum of the Damped Lyman alpha population at $z\sim 2.6$ by stacking normalized, rest-frame shifted spectra of $\sim 27\,000$ DLAs from the DR12 of BOSS/SDSS-III. We measure the equivalent widths of 50 individual metal absorption lines in 5 intervals of DLA hydrogen column density, 5 intervals of DLA redshift, and overall mean equivalent widths for an additional 13 absorption features from groups of strongly blended lines. The mean equivalent width of low-ionization lines increases with $N_{\rm HI}$, whereas for high-ionization lines the increase is much weaker. The mean metal line equivalent widths decrease by a factor $\sim 1.1-1.5$ from $z\sim2.1$ to $z \sim 3.5$, with small or no differences between low- and high-ionization species. We develop a theoretical model, inspired by the presence of multiple absorption components observed in high-resolution spectra, to infer mean metal column densities from the equivalent widths of partially saturated metal lines. We apply this model to 14 low-ionization species and to AlIII, SIII, SiIII, CIV, SiIV, NV and OVI. We use an approximate derivation for separating the equivalent width contributions of several lines to blended absorption features, and infer mean equivalent widths and column densities from lines of the additional species NI, ZnII, CII${}^{*}$, FeIII, and SIV. Several of these mean column densities of metal lines in DLAs are obtained for the first time; their values generally agree with measurements of individual DLAs from high-resolution, high signal-to-noise ratio spectra when they are available., Comment: Resubmitted after referee revision. Added evolution of metal-line equivalent widths with redshift (Section 5). Added assessment of result dependencies on sample and methodology. Comparison of relative abundances of DLAs vs Milky Way ISM and halo (Figure 16). Publicly available videos of composite quasar and DLA spectra realizations here: https://github.com/lluism/

The Baryon Oscillation Spectroscopic Survey (BOSS) has collected more than 150,000 $2.1 \leq z \leq 3.5$ quasar spectra since 2009. Using this unprecedented sample, we create a composite spectrum in the rest-frame of 102,150 quasar spectra from 800 \AA\ to 3300 \AA\ at a signal-to-noise ratio close to 1000 per pixel ($\Delta v$ of 69 km~s$^{-1}$). Included in this analysis is a correction to account for flux calibration residuals in the BOSS spectrophotometry. We determine the spectral index as a function of redshift of the full sample, warp the composite spectrum to match the median spectral index, and compare the resulting spectrum to SDSS photometry used in target selection. The quasar composite matches the color of the quasar population to within 0.02 magnitudes in $g-r$, 0.03 magnitudes in $r-i$, and 0.01 magnitudes in $i-z$ over the redshift range $2.2, Comment: 24 pages, 19 figures, accepted by AJ

We prove that the Euclidean plane is the only Riemannian plane with total curvature and free of conjugate points that satisfies Playfair's version of the parallel postulate.

A kind of integrable couplings of soliton equations hierarchy with self-consistent sources associated with is presented by Yu. Based on this method, we construct a new integrable couplings of the classical-Boussinesq hierarchy with self-consistent sources by using of loop algebra . In this paper, we also point out that there exist some errors in Yu's paper and have corrected these errors and set up new formula. The method can be generalized other soliton hierarchy with self-consistent sources.

The Chinese Area Positioning System (CAPS) is a new positioning system developed by the Chinese Academy of Sciences based on the communication satellites in geosynchronous orbit. The CAPS has been regarded as a pilot system to test the new technology for the design, construction and update of the BeiDou Navigation Satellite System (BDS). The system structure of CAPS, including the space, ground control station and user segments, is almost like the traditional Global Navigation Satellite Systems (GNSSs), but with the clock on the ground, the navigation signal in C waveband, and different principles of operation. The major difference is that the CAPS navigation signal is first generated at the ground control station, before being transmitted to the satellite in orbit and finally forwarded by the communication satellite transponder to the user. This design moves the clock from the satellite in orbit to the ground. The clock error can therefore be easily controlled and mitigated to improve the positioning accuracy. This paper will present the performance of CAPS-based relative positioning and velocity estimation as assessed in Beijing, China. The numerical results show that, (1) the accuracies of relative positioning, using only code measurements, are 1.25 and 1.8 m in the horizontal and vertical components, respectively; (2) meanwhile, they are about 2.83 and 3.15 cm in static mode and 6.31 and 10.78 cm in kinematic mode, respectively, when using the carrier-phase measurements with ambiguities fixed; and (3) the accuracy of the velocity estimation is about 0.04 and 0.11 m/s in static and kinematic modes, respectively. These results indicate the potential application of CAPS for high-precision positioning and velocity estimation and the availability of a new navigation mode based on communication satellites.

Spherical aberrations of the thermal lens of the active media are severe when solid state lasers are strongly pumped. The fundamental mode proflle deteriorates due to the aberrations. Self-consistent modes of a resonator with aberrations are calculated by using the Fox{Li difiraction iterative algorithm. Calculation results show that the aberration induced fundamental mode beam quality deterioration depends greatly on the resonator design. The tolerance of a ∞at{∞at resonator to the aberration coe‐cient is about 30‚ in the middle of stability, where ‚ is the wavelength of laser beam. But for a dynamically stable resonator, 2‚ of spherical aberration will create difiraction loss of more than 40%, if inappropriate design criteria are used. A birefringence compensated laser resonator with two Nd:YAG rods is experimentally studied. The experimental data are in quite good agreement with simulation results.

Spermatogonial stem cells (SSCs), which were isolated from chicken (Gallus gallus) embryo testes 16 days after laying, were cultured, subcultured, and induced into adipocytes in vitro. The differentiated cells were identified by oil red-O staining. Dexamethasone, insulin and 3-isobutyl-1-methylxanthine (IBMX) were tested for their induction potential. About 7–21 days after induction, SSCs differentiated into adipocytes, and the resulting adipocytes strongly expressed peroxisome proliferation activation receptor-γ (PPAR-γ). The assay outcome showed that an optimal treatment consisted of dexamethasone, insulin and IBMX application for 3 days and insulin for 1 day (3 cycles), then insulin for 21 days. The differentiation ratio was 85%, better than the combined use of dexamethasone, insulin and IBMX (PPin vitro into adipocytes.

Purpose: To investigate the possible relationship between myopia progression and near accommodative lag. Methods: A 1-year longitudinal study was carried out to measure the accommodative response and myopia progression in 62 children with mild and progressing myopia at two visits: they were 10.81 ± 1.60 years old with refractive error −1.70 ± 0.76 D on entry. Repeated measurements included refractive error, ocular biometry and accommodative response at 33 cm. The refractive error was determined by autorefraction after cycloplegia; ocular biometry by A-scan ultrasonography; and accommodative response by an open-field autorefractor. Results were based on the right eye and analysed by paired t-test and Pearson’s correlation coefficient. Results: Myopia progression in the year was −0.72 ± 0.37 D (p 0.10 for all). There was no significant difference in myopia progression between myopic children with greater than, compared to less than the mean amount of near lag (p = 0.36). Conclusions: This study demonstrates no statistically significant relationship between myopia progression and near accommodation lag in children with mild and progressing myopia. There is no evidence that near lag provides a stimulus to progression in this stage of myopia.

Residential environment quality is one of the basic elements for quality of life, as well as the main support for activities of economy, culture and society. In this paper, the authors selected the Changjiang Delta Region of China as the study area, which is in the fastest growing region of China and having a great influence on other cities. First, questionnaire surveys focusing on residential attributes, residential satisfaction, residential preferences and residential selection factors were carried out. Then through analysis, the authors established the residential environment evaluation system and models for this area. They also found the principal components for residential selection and residential preference of citizens. The results of this research not only can give direction to the development and improvement of the residential environment of Chinese cities, but also can contribute to other similar areas in Asia.

A method for quantitative determination of atractylenolide II in rat plasma using reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with UV spectrometry was established. From a variety of compounds and solvents tested, atractylenolide III was selected as the internal standard (IS) and ethyl acetate was found to be the best solvent for extracting atractylenolide II from plasma samples. RP-HPLC analysis of the extracts was performed on an analytical column (DIKMA ODS, 150 x 4.6 mm; i.d., 5 microm) equipped with a security guard pre-column system. There was good linearity over the range 0.05-5.0 microg/mL (r > 0.99). The recoveries were more than 90.0% in plasma, and the intra- and inter-day coefficients of variation were less than 10.0% in all cases. The limit of detection (LOD) was 0.025 microg/mL and the lower limit of quantification (LLOQ) was 0.05 microg/mL. The RP-HPLC method was applied to quantitate atractylenolide II in rat plasma within 24 h in a pharmacokinetics study where experimental rats received a single dose of atractylenolide II (60 mg/kg).

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra.

Reverberation mapping (RM) measurements of broad-line region (BLR) lags in z>0.3 quasars are important for directly measuring black hole masses in these distant objects, but so far there have been limited attempts and success given the practical difficulties of RM in this regime. Here we report preliminary results of 15 BLR lag measurements from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project, a dedicated RM program with multi-object spectroscopy designed for RM over a wide redshift range. The lags are based on the 2014 spectroscopic light curves alone (32 epochs over 6 months) and focus on the Hbeta and MgII broad lines in the 100 lowest-redshift (z0.3 quasars., Replaced with the accepted version (ApJ); minor revisions in the presentation

The pervasive interstellar dust grains provide significant insights to understand the formation and evolution of the stars, planetary systems, and the galaxies, and may harbor the building blocks of life. One of the most effective way to analyze the dust is via their interaction with the light from background sources. The observed extinction curves and spectral features carry the size and composition information of dust. The broad absorption bump at 2175 Angstrom is the most prominent feature in the extinction curves. Traditionally, statistical methods are applied to detect the existence of the absorption bump. These methods require heavy preprocessing and the co-existence of other reference features to alleviate the influence from the noises. In this paper, we apply Deep Learning techniques to detect the broad absorption bump. We demonstrate the key steps for training the selected models and their results. The success of Deep Learning based method inspires us to generalize a common methodology for broader science discovery problems. We present our on-going work to build the DeepDis system for such kind of applications.

We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) and Type Ia supernova (SN) data. We take advantage of high-precision BAO measurements from galaxy clustering and the Ly-alpha forest (LyaF) in the BOSS survey of SDSS-III. BAO data alone yield a high confidence detection of dark energy, and in combination with the CMB angular acoustic scale they further imply a nearly flat universe. Combining BAO and SN data into an "inverse distance ladder" yields a 1.7% measurement of $H_0=67.3 \pm1.1$ km/s/Mpc. This measurement assumes standard pre-recombination physics but is insensitive to assumptions about dark energy or space curvature, so agreement with CMB-based estimates that assume a flat LCDM cosmology is an important corroboration of this minimal cosmological model. For open LCDM, our BAO+SN+CMB combination yields $\Omega_m=0.301 \pm 0.008$ and curvature $\Omega_k=-0.003 \pm 0.003$. When we allow more general forms of evolving dark energy, the BAO+SN+CMB parameter constraints remain consistent with flat LCDM. While the overall $\chi^2$ of model fits is satisfactory, the LyaF BAO measurements are in moderate (2-2.5 sigma) tension with model predictions. Models with early dark energy that tracks the dominant energy component at high redshifts remain consistent with our constraints. Expansion history alone yields an upper limit of 0.56 eV on the summed mass of neutrino species, improving to 0.26 eV if we include Planck CMB lensing. Standard dark energy models constrained by our data predict a level of matter clustering that is high compared to most, but not all, observational estimates. (Abridged), Comment: 38 pages, 20 figures, BOSS collaboration paper; v2: fixed inconsistent definitions of DH, added references; v3: version accepted by PRD, corrected error resulting in significantly weaker constraints on decaying dark matter model

We report the detection of a strong Milky Way-type 2175 ��$ $ extinction bump at $z$ = 2.1166 in the quasar spectrum towards SDSS J121143.42+083349.7 from the Sloan Digital Sky Survey (SDSS) Data Release 10. We conduct follow up observations with the Echelle Spectrograph and Imager (ESI) onboard the Keck-II telescope and the Ultraviolet and Visual Echelle Spectrograph (UVES) on the VLT. This 2175 ��$ $ absorber is remarkable in that we simultaneously detect neutral carbon (C I), neutral chlorine (Cl I), and carbon monoxide (CO). It also qualifies as a damped Lyman alpha system. The J1211+0833 absorber is found to be metal-rich and has a dust depletion pattern resembling that of the Milky Way disk clouds. We use the column densities of the C I fine structure states and the C II/C I ratio (under the assumption of ionization equilibrium) to derive the temperature and volume density in the absorbing gas. A Cloudy photoionization model is constructed, which utilizes additional atoms/ions to constrain the physical conditions. The inferred physical conditions are consistent with a canonical cold (T $\sim$ 100 K) neutral medium with a high density ($n$(H I) $\sim$ 100 cm$^{-3}$) and a slightly higher pressure than the local interstellar medium. Given the simultaneous presence of C I, CO, and the 2175 ��$ $ bump, combined with the high metallicity, high dust depletion level and overall low ionization state of the gas, the absorber towards J1211+0833 supports the scenario that the presence of the bump requires an evolved stellar population., 18 pages, 17 figures, to be published in MNRAS