bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction‐Oxidation Potential and Dissolved Organic Matter Composition in Northern Peat Soil: Interactive Controls of Water Table Position and Plant Functional Groups
Authors: Kane E. S. , Veverica T. J. , Tfaily M. M. , Lilleskov E. A. , Meingast K. M. , Kolka R. K. , Daniels A. L. , Chimner R. A.
Published: October 2019

Globally important carbon (C) stores in northern peatlands are vulnerable to oxidation in a changing climate. A growing body of literature draws attention to the importance of dissolved organic matter (DOM) in governing anaerobic metabolism in organic soil, but exactly how the reduction‐oxidation (redox) activities of DOM, and particularly the phenolic fraction, are likely to change in an altered climate remain unclear. We used large mesocosms in the PEATcosm experiment to assess changes in peatland DOM and redox potential in response to experimental manipulations of water table (WT) position and plant functional groups (PFGs). WT position and PFGs interacted in their effects on redox potential and quantity and quality of DOM. Phenolics were generally of higher molecular weight and more oxidized with sedges in lowered WTs. Altered DOM character included changes in dissolved nitrogen (N), with higher N:[phenolics] with higher E4:E6 (absorbance ratio λ = 465:665) DOM in the lowered WT and sedge PFG treatments. Conversely, biomolecular assignments to amino‐sugars were largely absent from low‐WT treatments. Low WT resulted in the creation of unique N compounds, which were more condensed (lower H:C), that changed with depth and PFG. The accumulation of oxidized compounds with low WT and in sedge rhizospheres could be very important pools of electron acceptors beneath the WT, and their mechanisms of formation are discussed. This work suggests the effects of changes in vegetation communities can be as great as WT position in directly and interactively mediating peat redox environment and the redox‐activity of DOM.
Biogeochemical Behavior of Metals Along Two Permeable Reactive Barriers in a Mining‐Affected Wetland
Authors: von Gunten Konstantin , Bishop Brendan , Zhang Luyu , Muehlenbachs Karlis , Alam Md. Samrat , Konhauser Kurt O. , Alessi Daniel S.
Published: October 2019

The biogeochemistry of two alkaline permeable reactive barriers (PRBs) installed for remediation in a mining‐affected wetland was investigated in order to assess the importance of colloidal particles on metal removal processes in such systems. At the time of investigation, both PRBs were effective in removing U, Cu, and Zn (>95%) from groundwater but were slightly less efficient for Ni and Co (<90%). Previously installed groundwater wells allowed an in‐depth analysis of groundwater passing through the first PRB. Here, in an alkaline environment (pH 6.0–9.7), 11–14% of Ni, 36–37% of Co, 77–81% of Cu, 14–17% of U, and 10–19% of Fe were associated with organic matter and inorganic colloids, while upgradient in the more acidic environments (pH <6.0), ionic species and complexes (e.g., Co2+, Ni2+, Cu2+, and UO2H3SiO4+) dominated. Copper and U preferentially bound to larger colloidal fractions (>1 kDa), which might have promoted their sequestration. Uranium removal was likely further enhanced by U (VI) reduction in the alkaline and oxygen‐depleted conditions of the PRBs. The less efficient removal of Ni and Co, being target metals for remediation, was explained by a combination of their high solubility, unfavorable redox and pH conditions created by the alkaline PRBs, and their limited association with colloidal particles. These considerations are critical in the design of future PRBs for the remediation of similar systems.
Insolation and Glacial Meltwater Influence on Sea‐Ice and Circulation Variability in the Northeastern Labrador Sea During the Last Glacial Period
Authors: Griem Lisa , Voelker Antje H. L. , Berben Sarah M. P. , Dokken Trond M. , Jansen Eystein
Published: October 2019

The variable amounts of ice rafted debris (IRD) and foraminifers in North Atlantic sediments are related to the abrupt, millennial‐scale alteration from Greenland stadials to interstadials during the last glacial period and indicate past ice sheet instabilities, changes in sea‐ice cover and productivity. In the Norwegian Sea, Greenland stadials were likely characterized by an extensive, near‐perennial sea‐ice cover whereas Greenland interstadials were seasonally ice‐free. The variability in other areas, such as the Labrador Sea, remains, however, obscure. We therefore investigated deep‐sea sediment core GS16‐204‐22CC retrieved south of Greenland. Using a multiproxy approach, we distinguish two sediment regimes and hence different environmental conditions between ca. 65 and 25 ka b2k. Regime 1 (~65‐49 ka b2k) is characterized by the dominance of planktic foraminifers in the sediments. During late MIS4 and early MIS3, the site was covered by near‐perennial sea‐ice with occasional periods of iceberg discharge. During the younger part of regime 1 the northeastern Labrador Sea was seasonally ice‐free with hardly any icebergs melting near the site and long‐term environmental conditions were less variable. Regime 2 (~49‐25 ka b2k) is characterized by pronounced stadial‐interstadial variability of foraminifer and IRD fluxes, suggesting an extensive sea‐ice cover during most Greenland stadials and seasonally ice‐free conditions during most Greenland interstadials. During MIS2 environmental conditions were very similar to those of the younger part of regime 1. While all Heinrich (H) related Greenland stadials are marked by depleted oxygen isotope values at our core site, only H4 and H3 are associated with pronounced IRD peaks.
CO2 Release From Pockmarks on the Chatham Rise‐Bounty Trough at the Glacial Termination
Authors: Stott Lowell , Davy Bryan , Shao Jun , Coffin Richard , Pecher Ingo , Neil Helen , Rose Paula , Bialas Joerg
Published: October 2019

Seafloor pockmarks of varying size occur over an area of 50,000 km2 on the Chatham Rise, Canterbury Shelf and Inner Bounty Trough, New Zealand. The pockmarks are concentrated above the flat‐subducted Hikurangi Plateau. Echosounder data identify recurrent episodes of pockmark formation at ~100,000‐year frequency coinciding with Pleistocene glacial terminations. Here we show that there are structural conduits beneath the larger pockmarks through which fluids flowed upward toward the seafloor. Large negative Δ14C excursions are documented in marine sediments deposited next to these subseafloor conduits and pockmarks at the last glacial termination. Modern pore waters contain no methane, and there is no negative δ13C excursion at the glacial termination that would be indicative of methane or mantle‐derived carbon at the time the Δ14C excursion and pockmarks were produced. An ocean general circulation model equipped with isotope tracers is unable to simulate these large Δ14C excursions on the Chatham Rise by transport of hydrothermal carbon released from the East Pacific Rise as previous studies suggested. Here we attribute the Δ14C anomalies and pockmarks to release of 14C‐dead CO2 and carbon‐rich fluids from subsurface reservoirs, the most likely being dissociated Mesozoic carbonates that subducted beneath the Rise during the Late Cretaceous. Because of the large number of pockmarks and duration of the Δ14C anomaly, the pockmarks may collectively represent an important source of 14C‐dead carbon to the ocean during glacial terminations.
Late Pleistocene‐Holocene Slip Rate Along the Hasi Shan Restraining Bend of the Haiyuan Fault: Implication for Faulting Dynamics of a Complex Fault System
Authors: Matrau R. , Klinger Y. , Van der Woerd J. , Liu‐Zeng J. , Li Z. , Xu X. , Zheng R.
Published: October 2019

The Haiyuan fault is a major left‐lateral strike‐slip fault at the boundary between northeast Tibet and the Gobi platform. Combining measurements of offset alluvial terraces with 10Be‐26Al cosmogenic radionuclides dating, we bracket the late Quaternary slip rate along the Hasi Shan fault section (37°00′N, 104°25′E) of the Haiyuan fault. At our reference site, terrace‐riser offsets for five successive terraces range from ~5 to ~200 m, and associated cosmogenic radionuclide ages range from 9 ± 3 to 44 ± 7 kyr. These measurements yield a geological slip rate between 2.7 and 3.0 mm/year. Extending the offset measurements to the entire Hasi Shan front, it yields a slip rate of 3.2 ± 0.2 mm/year over the last ~50 kyr. Our rate is consistent with the lower estimates of other long‐term rates of 4 to 5 mm/year, as well as with geodetic rates of 3 to 5 mm/year, determined in the same area. About 150 km farther west, however, Holocene terraces and moraines offsets have suggested higher slip rate values, between 6 and 15 mm/year. We interpret such discrepancy between rates determined along the western section of the Haiyuan fault and rates determined in the Hasi Shan section as being related to the complex geometry of the Haiyuan fault system along its eastern part, with several active strands moving at the same time and resulting in distributed slip among several sections of the fault system.
The Decollement Depth of Active Thrust Faults in Italy: Implications on Potential Earthquake Magnitude
Authors: Petricca P. , Carminati E. , Doglioni C.
Published: October 2019

Thrust fault ruptures during earthquakes do not often propagate down to the brittle‐ductile transition. Lithological variations control the behavior and depth of regional basal thrusts and decollement planes. Thrust fronts may be discontinuous along strike, limiting the dimension of single coseismic ruptures. These factors control the maximum expected magnitude in one region. This is the case of Italy where the convergence of few millimeter per year in the Apennines accretionary prism and along the retrobelt of the Alps generates compressional earthquakes with moderate to strong magnitudes. Here, using geological and geophysical data, we first compile a map of the undulated active basal thrust decollement for Italy that occurs from 1 to 17‐km depth. Then, we verify the relationship between the length of seismogenic ruptures in thrust faults (Lf) and the maximum depth of thrust faulting (zmax) of related earthquakes and find that their ratio (Lf/zmax) ranges between 2 and 4. Finally, we compute the potential seismogenic volume and estimate the maximum magnitude using an empirical relationship that multiplies the decollement depth and the Lf/zmaxratio. Maximum calculated magnitude is 6.7 ± 0.37 (depending on Lf/zmaxand fault dip angle), consistent with the largest magnitude of thrust‐related earthquakes recorded in Italy (6.5–7.0). Lower magnitudes are predicted in the Ionian Seas at the external front of the Apennines where smaller crustal volumes are involved, whereas higher magnitudes are expected in the southern Po Basin, the western Adriatic Sea, Sicily offshore, and the Southern Alps where the decollement is deeper and the brittle volumes are far greater.
Terrane Boundary Reactivation, Barriers to Lateral Fault Propagation and Reactivated Fabrics: Rifting Across the Median Batholith Zone, Great South Basin, New Zealand
Authors: Phillips Thomas B. , McCaffrey Ken J. W.
Published: October 2019

Prominent preexisting structural heterogeneities within the lithosphere may localize or partition deformation during tectonic events. The NE‐trending Great South Basin, offshore New Zealand, formed perpendicular to a series of underlying crustal terranes, including the dominantly granitic Median Batholith Zone, which along with the boundaries between individual terranes exert a strong control on rift physiography and kinematics. We find that the crustal‐to‐lithospheric scale southern terrane boundary of the Median Batholith Zone is associated with a crustal‐scale shear zone that was reactivated during Late Cretaceous extension between Zealandia and Australia. This reactivated terrane boundary is oriented at a high angle to the faults defining the Great South Basin. We identify a large granitic laccolith along the southern margin of the Median Batholith, expressed as subhorizontal packages of reflectivity and acoustically transparent areas on seismic reflection data. The presence of this strong granitic body inhibits the lateral southwestward propagation of NE‐trending faults, which segment into a series of splays that rotate to align along the margin as they approach. Further, we also identify two E‐W‐ and NE‐SW‐oriented basement fabrics, likely corresponding to prominent foliations, which are exploited by small‐scale faults across the basin. We show that different mechanisms of structural inheritance are able to operate simultaneously, and somewhat independently, within rift systems at different scales of observation. The presence of structural heterogeneities across all scales needs to be incorporated into our understanding of the structural evolution of complex rift systems.
Students’ competence in translating between different types of chemical representations
Authors: Gkitzia Vasiliki , Salta Katerina , Tzougraki Chryssa
Published: October 2019

Meaningful understanding of chemistry, among others, includes the ability of an individual to think simultaneously at macroscopic, submicroscopic and symbolic levels, and this presupposes the competence to translate between different types of chemical representations. In this study, we investigated 11th grade Greek students’ and 3rd year undergraduate chemistry students’ ability to translate chemical representations from one level of chemistry (e.g., submicroscopic) into another (e.g., symbolic) concerning the basic chemical concepts: “chemical element”, “chemical compound”, “aqueous solution” and “solid state of matter”, which have already been taught in earlier grades. We followed a mixed method design in which both quantitative and qualitative research instruments were developed and used. These instruments consisted of multiple choice and open-ended questions, which included real pictures (macroscopic), symbolizations and submicroscopic diagrams. Various representations of the three types were given to the students and they were asked to choose or to construct an equivalent one of a different type. Our results showed that the 11th grade students’ ability to move across the three levels of chemistry is very low, while the 3rd year undergraduate chemistry students’ performance is higher but not satisfactory. In addition, the results obtained from the application of “translation questions” between the three levels of chemistry highlighted many students’ alternative conceptions, some of which still persist among the undergraduate students. The students showed lower performance in translations concerning the concepts “chemical compound” and “aqueous solution” than those concerning the concepts “chemical element” and “solid state of matter”. The students also showed the lowest level of performance in translating the submicroscopic representations into the symbolic ones. Generally, our results indicate that translating between different types of chemical representations is a very challenging task, which depends on students’ conceptual understanding.
A cell-penetrating peptide-assisted nanovaccine promotes antigen cross-presentation and anti-tumor immune response
Authors: Liu Xiaoxuan , Liu Jiale , Liu Dan , Han Yanfeng , Xu Haiyan , Liu Lanxia , Leng Xigang , Kong Deling
Published: October 2019

Exogenous antigens processed in the cytosol and subsequently cross-presented on major histocompatibility complex class I (MHC-I) molecules activate cytotoxic CD8+ lymphocytes (CTL), which are crucial in cancer immunotherapy.
Real-time pressure monitoring system for microfluidic devices using deformable colloidal crystal membrane
Authors: Choi Jang Han , Shim Tae Soup
Published: October 2019

Real-time, in situ internal pressure monitoring in a microchannel is realized by a deformable colloidal crystal membrane.
A Griffiths-like phase and variable range hopping of polarons in orthorhombic perovskite Pr2CrMnO6
Authors: Aswathi Kaipamangalath , Palakkal Jasnamol P , Lekshmi P. Neenu , Varma Manoj R
Published: October 2019

Orthorhombic Pr2CrMnO6synthesized by the Pechini method establishes a way to exploring the charge, lattice and spin degrees of freedom in praseodymium based perovskites.
Mechanism of densification in low-temperature FLASH sintered lead free potassium sodium niobate (KNN) piezoelectrics
Authors: Serrazina Ricardo , Dean Julian S. , Reaney Ian M. , Pereira Luis , Vilarinho Paula M. , Senos Ana M. O. R.
Published: October 2019

Lead-free potassium sodium niobate (K0.5Na0.5NbO3, KNN) piezoelectric ceramics have been densified at temperatures lower than 300 °C using atmosphere-water assisted FLASH sintering.
Readdressing the UV solar variability with SATIRE-S: non-LTE effects
Authors: Tagirov R. V. , Shapiro A. I. , Krivova N. A. , Unruh Y. C. , Yeo K. L. , Solanki S. K.
Published: October 2019

Context. Solar spectral irradiance (SSI) variability is one of the key inputs to models of the Earth’s climate. Understanding solar irradiance fluctuations also helps to place the Sun among other stars in terms of their brightness variability patterns and to set detectability limits for terrestrial exoplanets.

Aims. One of the most successful and widely used models of solar irradiance variability is Spectral And Total Irradiance REconstruction model (SATIRE-S). It uses spectra of the magnetic features and surrounding quiet Sun that are computed with the ATLAS9 spectral synthesis code under the assumption of local thermodynamic equilibrium (LTE). SATIRE-S has been at the forefront of solar variability modelling, but due to the limitations of the LTE approximation its output SSI has to be empirically corrected below 300 nm, which reduces the physical consistency of its results. This shortcoming is addressed in the present paper.

Methods. We replaced the ATLAS9 spectra of all atmospheric components in SATIRE-S with spectra that were calculated using the Non-LTE Spectral SYnthesis (NESSY) code. To compute the spectrum of the quiet Sun and faculae, we used the temperature and density stratification models of the FAL set.

Results. We computed non-LTE contrasts of spots and faculae and combined them with the corresponding fractional disc coverages, or filling factors, to calculate the total and spectral irradiance variability during solar cycle 24. The filling factors have been derived from solar full-disc magnetograms and continuum images recorded by the Helioseismic and Magnetic Imager on Solar Dynamics Observatory (SDO/HMI).

Conclusions. The non-LTE contrasts yield total and spectral solar irradiance variations that are in good agreement with empirically corrected LTE irradiance calculations. This shows that the empirical correction applied to the SATIRE-S total and spectral solar irradiance is consistent with results from non-LTE computations.
Magnetic properties of the protostellar core IRAS 15398-3359
Authors: Redaelli E. , Alves F. O. , Santos F. P. , Caselli P.
Published: October 2019

Context. Magnetic fields can significantly affect the star formation process. The theory of the magnetically driven collapse in a uniform field predicts that the contraction initially happens along the field lines. When the gravitational pull grows strong enough, the magnetic field lines pinch inwards, giving rise to a characteristic hourglass shape.

Aims. We investigate the magnetic field structure of a young Class 0 object, IRAS 15398-3359, embedded in the Lupus I cloud. Previous observations at large scales have suggested that this source evolved in an highly magnetised environment. This object thus appears to be an ideal candidate to study the magnetically driven core collapse in the low-mass regime.

Methods. We performed polarisation observations of IRAS 15398-3359 at 214 μm using the SOFIA telescope, thus tracing the linearly polarised thermal emission of cold dust.

Results. Our data unveil a significant bend of the magnetic field lines from the gravitational pull. The magnetic field appears ordered and aligned with the large-scale B-field of the cloud and with the outflow direction. We estimate a magnetic field strength of B = 78 μG, which is expected to be accurate within a factor of two. The measured mass-to-flux parameter is λ = 0.95, indicating that the core is in a transcritical regime.
The infrared bands of polycyclic aromatic hydrocarbons in the 1.6–1.7 μm wavelength region
Authors: Chen Tao , Luo Yi , Li Aigen
Published: October 2019

Context. The 3.3 μm aromatic C–H stretching band of polycyclic aromatic hydrocarbon (PAH) molecules seen in a wide variety of astrophysical regions is often accompanied by a series of weak satellite bands at ∼3.4–3.6 μm. One of these sources, IRAS 21282+5050, a planetary nebula, also exhibits a weak band at ∼1.68 μm. While the satellite features at ∼3.4–3.6 μm are often attributed to the anharmonicities of PAHs, it is not clear whether overtones or combination bands dominate the 1.68 μm feature.

Aims. In this work, we examine the anharmonic spectra of eight PAH molecules, including anthracene, tetracene, pentacene, phenanthrene, chrysene, benz[a]anthracene, pyrene, and perylene, to explore the origin of the infrared bands in the 1.6–1.7 μm wavelength region.

Methods. Density functional theory (DFT) in combination with the vibrational second-order perturbation theory (VPT2) was used to compute the anharmonic spectra of PAHs. To simulate the vibrational excitation process of PAHs, the Wang–Landau random walk technique was employed.

Results. All the dominant bands in the 1.6–1.7 μm wavelength range and in the 3.1–3.5 μm C–H stretching region are calculated and tabulated. It is demonstrated that combination bands dominate the 1.6–1.7 μm region, while overtones are rare and weak in this region. We also calculate the intensity ratios of the 3.1–3.5 μm C–H stretching features to the bands in the 1.6–1.7 μm region, I3.1 − 3.5/I1.6 − 1.7, for both ground and vibrationally excited states. On average, we obtain ⟨I3.1 − 3.5/I1.6 − 1.7⟩≈12.6 and ⟨I3.1 − 3.5/I1.6 − 1.7⟩≈17.6 for PAHs at ground states and at vibrationally excited states, respectively.
Different Kinds of Methods and Materials for Determination of Bisphenol A in Urine and In Water
Authors: Shi Yanpeng , Shan Xiaoyue , Shao Ji , Ye Haipeng , Tan Siwei
Published: October 2019

Bisphenol A (BPA; 4,4’-(propane-2,2-diyl) diphenol) is a very important chemical raw material, but which is damaged to human beings and animals. Then, enrichment and detection of BPA in urine and water is particularly important. This paper summarized and compared the difference kinds of methods and materials for determination of Bisphenol A in human urine and water.
Lift/Drag Characteristics of Different Ice Accretion Airfoil
Authors: Feng Yupeng , Zhang Bin , Chen Bin
Published: October 2019

Aircraft icing has influence on the preliminary safety and performance evaluation of airplane. In this paper, based on different ice shapes (none, rime, mixed), the aerodynamic models of airfoil are established to analyze. Various lift/drag characteristics are obtained by numerical simulation using computational fluid dynamics (CFD) under different icing conditions. Navier-Stokes (N-S) equation and Spalart-Allmaras (S-A) turbulence model are adopted. The results show: 1. It’s obvious that lift-drag characteristics are different under various ice shapes. The lift coefficient (α=0° ∼7°): CL none>CL rime>CL mixed, the drag coefficient (α=0° ∼7°): CD none<CD rimeVp rime>▽p mixed, which has important effect on the speed of airstream flow and the flow separation at the front zone of airfoil.
Effects of K+, Na+, Mg2 And B4O72- Coexistence Impurities on Crystalline Characteristics of Lithium Carbonate
Authors: Ma Yanfang , Zhang Zhihong , Li Kanshe , Pang Dengke
Published: October 2019

Crystallization of lithium carbonate was performed in the presence of mixture analogous to those of Salt Lakes. Lithium carbonate exists in a crystalline system of containing K+, Na+, Mg2+ and B4O7
2- impurities and the solubility decreases with the composition of impurities increases. In addition, effects of impurity composition on Li2CO3 crystal morphology, crystal size and purity were also thoroughly examined.
Stability of CIS (001) Surface: First-Principles Study
Authors: Guo Yu , Liu Ying , Zhao Lili , Yang Rui
Published: October 2019

In this paper, the stability of CIS (001) surface is studied through first-principles calculations. It is revealed that, different atom-terminated surface models have different formation energy. For many possible structural patterns, the stability of CIS (001) surface are also become more complicated.
The Atomic Structure of Polar Cuinse2 (001) Surface
Authors: Guo Yu , Liu Chunmei , Wang Junling , He Zhenni , Wang Yang
Published: October 2019

Through the first-principles calculations, we studied the atomic structure of polar CuInSe2 (001) surface. It is revealed that polar CuInSe2 (001) surface has different atomic structure for different atom-terminated surface models. Before and after relaxation, the atomic structure of different atom-terminated surface models is various. Bond lengthens are also changed.
Progress in Preparation of Cr2O3 Hollow Micro/Nano-Sphere
Authors: Luo Qiuyi , Zhou Shen , Cheng Haifeng
Published: October 2019

The preparation methods of Cr2O3 hollow micro/nano-sphere are summarized. The preparation methods are mainly divided into hard template method, soft template method and template-free method. The advantages and disadvantages of different methods are introduced and discussed. At the same time, the preparation methods of Cr2O3 hollow micro/nano-spheres are prospected
Experimental study on friction stir spot welding of 5A06 aluminum alloy
Authors: Liu Jianmin , Sun Qian , Zhou Hong
Published: October 2019

In this paper, 5A06 aluminum alloy was filled with friction stir spot welding. Mechanical properties and metallographic tests were carried out on the welded joint. By observing the microstructure of the weld, the effects of different welding parameters on the mechanical properties and cross section formation of the filler friction stir spot welded joint were analyzed. The results show that the welding time has the greatest influence on the shear resistance and tensile properties of the friction spot welding joint, and the increase of the rotation speed of the spot welding tool will enhance the tensile properties of the joint.
Classification of Subjective Cognitive Decline in Alzheimer’s Disease Through Resting-State Hemodynamic Response Function
Authors: Zhang Yong , Tang Xiaoying , Zhang Yihe , Zeng Xiaotian , Dong Guozhao
Published: October 2019

As a super-early stage of Alzheimer’s disease (AD), there is no unified structural change in imaging nor significant difference in assessments in the Subjective Cognitive Decline (SCD), lack of effective clinical diagnosis. The hemodynamic response function (HRF), as the basis of functional magnetic resonance imaging(fMRI), represents the tendency of specific cortex voxel over time after specific stimulation, reflecting the sensitivity and activation of neurons. We equalize the spontaneous dynamic change of the cerebral cortex in resting state to equivalent stimulation for activation, extend the application of HRF. The possible lesion is selected through priori knowledge both academically and clinically. The parameters of HRF: peak, time to peak and FWHM were extracted as the basis for classification via support vector machine (SVM). The SCD group was found deactivation in specific frontal, hippocampus, inferior temporal and occipital regions especially. The classification accuracy between the healthy controls (HC) can reach 74%, which could be great referable in clinical pre-diagnosis. It highlights the possible ROI for SCD stage, provides new methods and research materials for pre-diagnosis of early-stage Alzheimer’s disease as a typical brain-related disease.
The Research of General Reaction: Synthesis of Erythromycin Derivatives Impurities about N-demonomethyl Compounds
Authors: Zhang Tingting , Yao Guowei , Rongji Dai S
Published: October 2019

Erythromycin derivatives have been used as antibacterial drugs in clinic for many years. As lacking of relevant impurities, those drugs quality control are limited. So, we carried out a research of general reaction: synthesis of 3 “- N-demonomethyl - Erythromycin, 3 “- N-demonomethyl - Clarithromycin, 3 “- N- demonomethyl - Roxithromycin and 3 “- N-demonomethyl- Azithromycin by using Erythromycin, Clarithromycin, Roxithromycin and Azithromycin as the raw material respectively. Using 1HNMR, 13CNMR and MS identified those impurities structures. Our methods have many advantages: raw materials cheap, getting easily, safely and stability, high yield and good purity, and it also can use for quality control of Erythromycin derivatives and new drug development based on 3“-N-demonomenthyl macrolide compounds.
Copolymerization of P-Hydroxybenzoic Acid and Poly (Butylene Succinate): Effect of Catalysts
Authors: Bian Angting , Yang Fan , Liu Jiuhua , Wang Yanping
Published: October 2019

P-Hydroxybenzoic acid (HBA) and poly (butylene succinate) (PBS) were chosen to synthesize aromatic/aliphatic copolyester HBA/PBS. The effect of catalyst on the structure and properties of copolymers was studied. It is shown that HBA can have transesterification reaction with PBS and some HBA was easy to self-polymerize to form insoluble and infusible homopolyester. Tetrabutyl titanate is more effective than zinc acetate as catalyst. The reaction time has a certain impact on the polymerization reaction. The longer reaction time was, the more HBA/PBS copolyesters were obtained.
Anisotropic Self-Defocusing in Knbo3: Fe Crystal
Authors: He Zhenni , Zhang Xiaohua , Zhang Chunping
Published: October 2019

All the characteristics of the self-defocusing and “position dispersion” in KNbO3:Fe crystal are experimentally investigated. The results show that the scattering from KNbO3:Fe crystal is mainly due to the photo-induced lensing.
Effects of Different Nitrogen and Irrigation Amount on Growth, Evapotranspiration and Water and Nitrogen Use Efficiency of Jatropha Curcas L.
Authors: Li Jie , Ling Zhen
Published: October 2019

In order to study the effects of different nitrogen and irrigation water patterns on water and nitrogen use efficiency of Jatropha curcas L., three water levels (W1:100% ET (ET as evapotranspiration), W2:80% ET, W3:60% ET), and three nitrogen application levels (N1:0g.kg-1, N2:0.4g.kg-1, N3:0.8g.kg-1) were designed. The results showed that compared with T1, each organ and total dry matter of Jatropha curcas L. decreased in T2 and T3. Besides, nitrogen application significantly increased each organ and total dry matter of Jatropha curcas L. Compared with W1N3(high water and nitrogen content), W2N2 treatment saved 20% water and 50% nitrogen fertilizer. Its irrigation water uses efficiency and total amount of nitrogen uptake in per plant increased by 26% and 64.88%. Therefore, W2N2 treatment is the best irrigation and nitrogen application pattern for the growth, the use efficiency of water and nitrogen of Jatropha curcas L.
The Neurotoxicity of Ethanol and The Underlining Mechanisms
Authors: Du Shasha , Shi Huahua , Zhao Yan
Published: October 2019

After ingestion, ethanol is mainly metabolized in the liver, eventually producing ATP and end products such as carbon dioxide and water. Because it is both water- and fat-soluble, it is easy to pass through the blood-brain barrier and affect the function of the nervous system. Overconsumption of alcohol or alcohol abuse is associated with various diseases including neurocognitive disorders. This article reviews the neurotoxicity of ethanol and discusses its possible molecular mechanisms.
The role of friction in cylindrical projectile impact on fabric structure
Authors: Guo Dafeng
Published: October 2019

A three-dimensional finite element analysis model for plain weave fabric was created. Impact of a rigid cylindrical projectile on a square fabric clamped along its four edges were simulated using commercially available software LS-DYNA. To reveal the role of friction in ballistic impact, comparative study was conducted in which projectile velocity, boundary condition, and material property are kept the same but friction between projectile and fabric and between yarns themselves are varied systematically. Results from the study show that the friction between projectile and fabric has little effect on fabric energy absorption but the friction between yarns themselves has apparent effect. Fabric has larger impact energy absorption capacity when friction coefficient between yarns are smaller. Smaller friction between yarns delays initiation of yarn failure, increases the duration of interaction between projectile and fabric and thus increases impact energy absorption capacity of fabric structure.
Effect of spatial structure on rutting performance of asphalt mixture based on wheel tracking test
Authors: Feng Jianhua , Gong Xing , Zhang Baozhong , Liu Weidong
Published: October 2019

Rutting of asphalt pavement is one of major patters premature damage modes experienced during the service period of pavement. Aggregate characteristics, especially aggregate gradation can affect the rutting performance of asphalt pavement. In order to investigate the influence of spatial structure on rutting performance, the volumetric indices such as VV, VMA and VCA were employed to characterize the spatial structure of asphalt mixture, and five different gradations of asphalt mixtures with three types of aggregate skeleton structure were prepared to conduct rutting measurement by wheel tracking test. It is demonstrated that aggregate particle size of 4.75-9.5mm can affect forming aggregate skeleton structure and rutting performance. Rutting depth at a certain period of time are concerned with VV and types of aggregate skeleton structure, and the VCAratio equal to one can be used as critical value to evaluate the types of aggregate skeleton structure. It is also indicated that fine aggregate can decrease the value of VMA and excellent stability in high-temperature of asphalt mixture should match suitable VMA. This study provides a significant reference for asphalt design and choice of aggregate gradation.
Influence of parasitic phases on the magnetic properties of BiFeO3 powders
Authors: Zhao Sen , Wang Guping , Zheng Rui , Liu Yanping
Published: October 2019

Single phase BiFeO3 nanoparticles were successfully prepared by sol-gel method. The influence of annealing temperature and precursor drying process on phase purity, microstructures and magnetic properties of BiFeO3 powders were explored. The precursor was pre-dried at 70 °C for 6 hours and then heated at 100 °C for 12 hours. The single-phase BiFeO3 powders were successfully obtained by annealing the dried samples at 500°C for 1 hour. However, powder X-ray diffraction reveals the presence of parasitic phase Bi2Fe4O9 or iron oxide under other preparation conditions. With the increase of annealing temperature, the content of parasitic phase Bi2Fe4O9 increases while the grain size, particle size, morphology and distribution uniformity of BiFeO3 also change. When the precursor solution was dried directly at 100°C and then annealed at 500 °C for 1 hour, the parasitic phase of Fe1.966O2.963 appeared. The particles exhibit sphere-like morphology covered with small BiFeO3 grains. With the increase of drying time, the surface grains changed and the content of parasitic phase Fe1.966O2.963 increased. FTIR and EDS confirm the existence of BiFeO3. UV-VIS measurements show that the optical band gap of BiFeO3 nano-powders decrease with the increase of the content of these two parasitic phases. In this paper, effects of these parasitic phases on the magnetic properties of BiFeO3 have been studied in detail. Results show that the ferromagnetic behavior of the powders could be attributed to the Fe1.966O2.963 parasitic phases. The parasitic phase of Bi2Fe4O9 in the powders does not change the room temperature magnetic properties of BiFeO3. Both the single phase BiFeO3 and the Bi2Fe4O9 incorporated powders exhibit bulk antiferromagnetic behavior.
Review of research on dynamic characteristics and seismic behavior of pc composite box-girder bridge with corrugated steel webs
Authors: Li Zhicong , Zhao Wenzhong , Zhang Chao , Wan Shui
Published: October 2019

The PC composite box-girder bridge with corrugated steel webs, as a new type of bridge structure, has obvious advantages in structure and distinct mechanics characteristic. So it has been widely applied in the engineering field. However, we have been lack of Research on the dynamic characteristics and seismic performance of the bridge. Based on a large number of documents, this paper expresses some research about the dynamic characteristics and seismic performance of the PC composite box-girder bridge with corrugated steel webs from four aspects: dynamic characteristics Analysis, dynamic characteristics test, influence factors of dynamic characteristics, and seismic performance analysis, and proposes that we should pay more attention to the theoretical analysis in the dynamic characteristics and monitoring of actual bridges to lay a solid foundation for the development of this new kind of bridge.
Development and Testing of Fast Responsive Bi-Enzyme Time - Temperature Indicator
Authors: Li Qiang , Duan Min , Li Wen , Dai Dai Yue , Hao Jia , Li Ren
Published: October 2019

In order to directly indicate the change of the quality of temperature sensitive products, such as food and medicine, during transportation and storage, the time-temperature indicator (TTI) was researched. It has cumulative effect on the time and temperature in the transport process and also can be used to monitor the environmental temperature changes. Based on the novel glucose oxidase and horseradish peroxidase double enzyme reaction system, a new time-temperature indicator was developed. The suitable storage conditions and the composition of double enzyme asof the TTI reaction system were studied. In conclusion, the time-temperature indicator with obvious color change is applied to the packaging of cold products during the transportation and storage process.
Spectroscopic Diagnostic and Electrical Characteristic of a Converging-Diverging Plasma Torch at Low Pressure Condition
Authors: Sun Chengqi , An Liantong , Gao Yang
Published: October 2019

A new anode nozzle with converging-diverging shape designed for low pressure condition used to produce the plasma jet. The emission spectroscope diagnostic method is applied to calculate the electron temperature by Ar I neutral species’ Boltzmann plots. The efficiency and voltage-current characteristic of the plasma torch were studied. The results showed that with the increase of the current intensity the electron temperature increase a lot. With the increase of the input power the efficiency of the plasma gun rise a little bit and the electric characteristic of the plasma gun is dependent on the content of hydrogen.
Characteristic Analysis of TCM External Treatment of Chloasma
Authors: Liu Tianyuan , Bai Ming , Liu Baosong , Miao Mingsan
Published: October 2019

Chloasma is a common skin disease among female patients.Due to its slow development, long course of disease, extremely high recurrence rate and other characteristics, it has a huge impact on the female population, seriously affecting the physical health of female patients and easily causing a series of psychological pressure or diseases.Therefore, by searching and sorting out the literature, this paper analyzes the literature on external treatment of chloasma with traditional Chinese medicine on cnki, and discusses the mechanism and main treatment methods of external treatment of chloasma with traditional Chinese medicine. According to this, a total of 54 articles related to “chloasma” and “external treatment” were counted on cnki, and various TCM external treatment methods involved in the literature were analyzed.
Analysis on The Application Prospect of Staghorn Glue in Uterine Dysplasia
Authors: Wang Can , Liu Tianyuan , Bai Ming , Miao Mingsan
Published: October 2019

To explore the application prospect of Chinese medicine deerhorn glue in uterine dysplasia.Methods :The association rule analysis and factor analysis of the included standard Chinese medicine were conducted using the journal literature collected by cnki as the data source, and the tools of Excel 2013, SPSS Modeler 14.1 and SPSS Statistics 19.0.Results : Among the 106 prescriptions included in the inclusion criteria, 38 high-frequency drugs with the frequency of >10 were used, among which angelica sinensis (84 times, 79.25%), rehmannia rehmannii (73 times, 68.87%), dota cuscuta (72 times, 67.92%) and medlar fruit (46 times, 43.40%) were the most common. The drugs for the treatment of uterine dysplasia were mainly wen (691 times, 54.50%), ping (310 times, 24.25%), wuwei (937 times, 42.80%), guijing (977 times, 30.09%) and kidney (771 times, 23.74%). The most commonly used drugs were tonic drugs for deficiency (803 times, 63.28%) and drugs for activating blood circulation and removing blood stasis (169 times, 13.32%). In association rule analysis, 14 combinations with the highest association intensity were found, and 9 common factors were extracted from factor analysis. Conclusion: Treatment of uterine dysplasia more to make up for virtual medicine is given priority to, such as Chinese angelica, rehmannia glutinosa, etc.), the clinical use of compatibility of promoting blood circulation to remove blood stasis pill (herba leonuri, salvia miltiorrhiza), temperature in medicine, medicinal choosing GanWen, liver and kidney by the combination of drugs such as medicine, antler glue from sexual flavour to the efficacy of application, etc., in accordance with its statistical results, it has great development prospects, treatment can be further explored.
Synthesis, characterization and bioactivities of the new 3-acetyl-2,5-disubstituted-1,3,4-oxadiazolines
Authors: Zhang Jie , Qiang Genrong , Shen Tianhua , Pan Lifang , Xu Lijuan , Song Qingbao
Published: October 2019

A series of heterocyclic compounds 3-acetyl-2,5-disubstituted-1,3,4-oxadiazolines (2a-2g) were prepared with hydrazones and acetic anhydride. The products were characterized by 1H-NMR, 13CNMR, IR and elemental analysis. Furthermore, these compounds were tested for their bioactivities of anti-Staphylococcus aureus, HIV-1 RT (Human Immunodeficiency Virus Type 1 Reverse Transcriptase) and proliferative. However, there were no compounds showed promising activities with S. aureus, HIV-1 RT, HT-29 cells and HT-1080 cells.
Study on Aging Treatment Temperature of a Special Aluminum brass
Authors: Zhang Dongya , Li Yi , Hou Zhiqiang , Feng Kun , Zhu Pengxiao , Xu Guo
Published: October 2019

Aging treatment of ZCuZn25Al6Fe3Mn3 was conducted by muffle furnace. We studied the variation of the microstructure and properties of ZCuZn25Al6Fe3Mn3 with the increase of aging temperature. We discovered that the microstructure consists of an equiaxed β phase + a star-like Fe phase + a finely distributed phase of the dispersed phase. No distributed phase was observed when the aging temperature was low. As the aging temperature rises, the punctate phase appears, and the number of punctate phases is the highest at 500 °C . Above 500 °C, continue to raise the temperature, point-like phase aggregation grows into granular phase. As the aging temperature rises, the hardness of the alloy rises first and then decreases, the weight loss of the alloy decreases first and then rises. At 500°C, the hardness of the alloy is the highest, reaching 263 HV, and the weight loss is the smallest, about 0.3990 g.Observing the wear morphology, the wear mechanism under dry friction conditions is known as abrasive wear and adhesive wear. The optimum aging treatment process for ZCuZn25Al6Fe3Mn3 is 500 °C × 2 h air cooling.
Research on Dss-I Polymer Probe Based on Schiff Base Dss Probe
Authors: Wang Hongjia , Han Tongyu , Shu Qinghai , Shi Rui , Lu Baoping , Du Junyi
Published: October 2019

4, 4’- diamino diphenyl sulfone and salicylaldehyde as the main raw material, can be synthesized DSS-I polymer probe based on Schiff base. The DSS-I polymer probe have a similar property with DSS probe, and UV and fluorescence responses to F- and CN- were observed. Although UV color effect weakened, but they have strong fluorescence characteristics, and the fluorescent color is in some changes.
Interface Decoration Of N-Doped Carbon Nanotube with Fe For Enhancing Oxygen Catalytic Activity
Authors: Yang Jian , Guo Heng , Xiang Fei
Published: October 2019

Oxygen electrocatalytic reactions, including oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are extremely important in energy storage and conversion technology. The ORR is happened in cathode electrode in fuel cells or metal air batteries when discharging, the OER is occurred in anode electrode in water splitting or rechargeable metal air batteries when charging. Currently, the high-performance catalyst developed for ORR still relies on platinum (Pt) and its alloys. On the other hand, ruthenium (Ru) oxides were demonstrated to be high performance electrocatalysts for OER. However, their scarcity, limited stability, and aggregation limited the development of electrochemistry energy storage and conversion. Herein, we synthesize a series of transition metal nanoparticles embedded in nitrogen doped carbon nanotubes (M-CNT) and further decorating the interface of N-CNT with Fe element for enhancing oxygen catalytic activities. The results show that the type of transition metal determine the morphologies of N-CNT and the catalytic performance in ORR and OER. After further modification by introducing Fe element, the Fe-CNT based catalyst displays a superior ORR activity, even surpasses that of Pt/C, the Ni-CNT based catalyst with Fe decoration also showes a significant enhancement in OER. This work provides a feasible strategy to develop highly efficient oxygen catalysts with low-cost, earth-abundant transition metal elements via further decoration.
Monitoring steel corrosion by using the combination of ultrasonic guided wave and acoustic emission
Authors: Shi Fengjiao , Wang Junzeng , Cui Wensheng , Qin Lei
Published: October 2019

Corrosion of steel bars in reinforced concrete structure will reduce the bearing capacity of the structure, which will cause damage to the structure and cause great casualties and economic losses. In this paper, the same specimen was monitored by using the ultrasonic guided wave (UGW) and acoustic emission (AE). The variation trend of the cumulative number of acoustic emission impacts and the amplitude variation trend of ultrasonic guided waves were obtained in the process of monitoring steel corrosion. By analysing the curve of cumulative number of impacts and the curve of the amplitude of ultrasonic guided wave changing with time, it can be accurately obtained that the corrosion of steel reinforcement can be divided into three stages, so that the feasibility of monitoring the corrosion process of steel reinforcement can be verified by ultrasonic guided wave and acoustic emission.
Simulation of temperature field and stress field of v-groove butt joint
Authors: Han Liang
Published: October 2019

The APDL language of ANSYS software is used to write program to realize the moving load of weld heat source. The thermal-elastic-plastic finite element method for multi-layer and multi-pass welding process was used to simulate the temperature and stress fields of the V-groove Q235 steel plate butt joint with a thickness of 12 mm. It is concluded that in the welding process, the maximum temperature field does not appear at the center of the heat source, but around the heat source. The farther the free end is from the weld zone after welding, the larger the deformation is. After welding, the overall stress on the upper surface of the weld is larger than that on the middle and lower surface of the weld. Post-weld stress mainly concentrates at the bottom of the weld, i.e. the bottom of the V-shaped opening, and tends to increase from small to large in the direction of thickness.