Central Asia is currently a semiarid‐arid region, dominated by the Westerlies. It is important to understand mechanisms of climate and precipitation changes here, as water availability in the region ...is crucial today and in the future. High‐resolution, absolutely‐dated oxygen isotope (δ18O) records of stalagmites from Kesang Cave characterize a dynamic precipitation history over most of the past 500,000 years. This record demonstrates, for the first time, that climate change in the region exhibits a processional rhythm with abrupt inceptions of low δ18O speleothem growth at times of high Northern Hemisphere summer insolation followed by gradual δ18O increases that track decreases of insolation. These observations and interpretations contrast with the interpretation of nearby, but higher elevation ice core records. The absolutely‐dated caveδ18O shifts can be used to correlate the regional climate variability by providing chronological marks. Combined with other paleoclimate records, the Kesang observations suggest that possible incursions of Asian summer monsoon rainfall or related moisture into the Kesang site and/or adjacent areas during the high insolation times may play an important role in changing orbital‐scale hydrology of the region. Based on our record, arid climate will prevail in this region for the next several millennia, providing that anthropogenic effects do not supersede natural processes.
Key Points
Speleothem records characterize 500 ka precipitation history in Central Asia
Climatic patterns in the Westerlies region are dominated by a precession rhythm
Asian Monsoon incursions may explain the hydrological change on precession scale
A measurement of electron antineutrino oscillation by the Daya Bay Reactor Neutrino Experiment is described in detail. Six 2.9-GWth nuclear power reactors of the Daya Bay and Ling Ao nuclear power ...facilities served as intense sources of ν¯e’s. Comparison of the ν¯e rate and energy spectrum measured by antineutrino detectors far from the nuclear reactors (∼1500–1950 m) relative to detectors near the reactors (∼350–600 m) allowed a precise measurement of ν¯e disappearance. More than 2.5 million ν¯e inverse beta-decay interactions were observed, based on the combination of 217 days of operation of six antineutrino detectors (December, 2011–July, 2012) with a subsequent 1013 days using the complete configuration of eight detectors (October, 2012–July, 2015). The ν¯e rate observed at the far detectors relative to the near detectors showed a significant deficit, R=0.949±0.002(stat)±0.002(syst). The energy dependence of ν¯e disappearance showed the distinct variation predicted by neutrino oscillation. Analysis using an approximation for the three-flavor oscillation probability yielded the flavor-mixing angle sin22θ13=0.0841±0.0027(stat)±0.0019(syst) and the effective neutrino mass-squared difference of |Δmee2|=(2.50±0.06(stat)±0.06(syst))×10−3 eV2. Analysis using the exact three-flavor probability found Δm322=(2.45±0.06(stat)±0.06(syst))×10−3 eV2 assuming the normal neutrino mass hierarchy and Δm322=(−2.56±0.06(stat)±0.06(syst))×10−3 eV2 for the inverted hierarchy.
Sharp faceted interfaces are often observed between compound precipitates and matrix phases, which are remarkably different in their lattice parameters. Multiple orientation relationships (ORs) ...corresponding to various faceted interfaces tend to coexist in one alloy. A near row matching (NRM) approach is proposed for a systematic investigation of ORs corresponding to potential preferred interfaces. Unlike a common practice to search for misorientations corresponding to low sigma grain boundaries associated with matching periodicity in three dimensions (3D), this approach directly searches for ORs that permit local 2D periodic good matching structures in preferred interfaces. The calculation method consists of two simple steps to evaluate matching within and between rows of lattice points. The method has been applied to a Mg
2
Sn/Mg system. Ten of the forty-four predicted facets agree with the experimental observations, for the cases that the preferred facets can be described (approximately) by low index planes of the precipitates. The predictions can cover all known observations, if limited high index planes are included as candidates. Each observed facet is characterized with a periodic pattern of good matching sites (GMSs) in localized regions. NRM is a necessary condition for the existence of a periodic GMS pattern. The agreement between the calculation results and experimental results confirms the important role of periodic matching in the development of preferred interfaces and their corresponding ORs. It also demonstrates the usefulness of geometric matching study for quantitative predictions of potential preferred interfaces.
The North China Plain (NCP) is a region with high level of seismic hazard. Previous Global Positioning System measurements, however, have shown a near absence of present‐day crustal deformation. ...Using updated Global Positioning System data covering three blocks of the eastern China, we discover that interseismic deformation in the NCP takes place in an ~1,100 km wide left‐lateral shear zone of roughly east‐west orientation. The 6.0 ± 1.3 mm/yr interseismic left‐lateral shear over the NCP results in contemporary deformation that is eventually accommodated by earthquake ruptures of right‐lateral strike‐slip along the north‐northeast trending faults and anticlockwise block rotates. We suggest that rapid eastward motion of the rigid South China block, with respect to the rigid Amurian block, has created a left‐lateral shear couple to twist the nonrigid NCP to form the contemporary deformation.
Key Points
North China Plain is a region with high‐level of earthquake hazard but absence of detectable crustal deformation
Interseismic deformation of the NCP takes place in an ~1,100 km wide left‐lateral shear zone of roughly east‐west orientation
Permanent right‐lateral slips and block rotates on the NNE‐trending faults accommodate the left‐lateral transient shearing
This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 ...m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18) cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43) cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) relative to the flux predicted with the Huber-Mueller (ILL-Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.
This study investigated the air pollution characteristics of synoptic-scale circulation in the Beijing megacity, and provided quantitative evaluation of the impacts of circulation patterns on air ...quality during the 2008 Beijing Summer Olympics. Nine weather circulation types (CTs) were objectively identified over the North China region during 2000–2009, using obliquely rotated T-mode principal component analysis (PCA). The resulting CTs were examined in relation to the local meteorology, regional transport pathways, and air quality parameters, respectively. The FLEXPART-WRF model was used to calculate 48-h backward plume trajectories for each CT. Each CT was characterized with distinct local meteorology and air mass origin. CT 1 (high pressure to the west with a strong pressure gradient) was characterized by a northwestern air mass origin, with the smallest local and southeasterly air mass sources, and CT 6 (high pressure to the northwest) had air mass sources mostly from the north and east. On the contrary, CTs 5, 8, and 9 (weak pressure field, high pressure to the east, and low pressure to the northwest, respectively) were characterized by southern and southeastern trajectories, which indicated a greater influence of high pollutant emission sources. In turn, poor air quality in Beijing (high loadings of PM10, BC, SO2, NO2, NOx, O3, AOD, and low visibility) was associated with these CTs. Good air quality in Beijing was associated with CTs 1 and 6. The average visibilities (with ±1σ) in Beijing for CTs 1 and 6 during 2000–2009 were 18.5 ± 8.3 km and 14.3 ± 8.5 km, respectively. In contrast, low visibility values of 6.0 ± 3.5 km, 6.6 ± 3.7 km, and 6.7 ± 3.6 km were found in CTs 5, 8, and 9, respectively. The mean concentrations of PM10 for CTs 1, 6, 5, 8, and 9 during 2005–2009 were 90.3 ± 76.3 μg m−3, 111.7 ± 89.6 μg m−3, 173.4 ± 105.8 μg m−3, 158.4 ± 90.0 μg m−3, and 151.2 ± 93.1 μg m−3, respectively. Analysis of the relationship between circulation pattern and air quality during the emission control period suggests that CTs are the primary drivers of day-to-day variations in pollutant concentrations over Beijing and its vicinity. During the Olympics period, the frequency of CT 6 was twice that of the mean in August from 2000 to 2009. This CT had northerly transport pathways and favorable meteorological conditions (e.g. frequent precipitation) for clean air during the Olympics. Assuming that relationships between CTs and air quality parameters in the same season are fixed in different years, the relative contributions of synoptic circulation to decreases in PM10, BC, SO2, NO2, NOx, CO, and horizontal light extinction during the Olympics were estimated as 19 ± 14%, 18 ± 13%, 41 ± 36%, 12 ± 7%, 10 ± 5%, 19 ± 11%, and 54 ± 25%, respectively.
Topological materials with exotic quantum properties are promising candidates for quantum spin electronics. Different classes of topological materials, including Weyl semimetal, topological ...superconductor, topological insulator and Axion insulator, etc., can be connected to each other via quantum phase transition. For example, it is believed that a trivial band insulator can be twisted into topological phase by increasing spin-orbital coupling or changing the parameters of crystal lattice. With the results of LDA calculation and measurement by angle-resolved photoemission spectroscopy (ARPES), we demonstrate in this work that the electronic structure of SrSn2As2 single crystal has the texture of band inversion near the critical point. The results indicate the possibility of realizing topological quantum phase transition in SrSn2As2 single crystal and obtaining different exotic quantum states.
We study the process e^{+}e^{-}→Λ_{c}^{+}Λover ¯_{c}^{-} at twelve center-of-mass energies from 4.6119 to 4.9509 GeV using data samples collected by the BESIII detector at the BEPCII collider. The ...Born cross sections and effective form factors (|G_{eff}|) are determined with unprecedented precision after combining the single and double-tag methods based on the decay process Λ_{c}^{+}→pK^{-}π^{+}. Flat cross sections around 4.63 GeV are obtained and no indication of the resonant structure Y(4630), as reported by Belle, is found. In addition, no oscillatory behavior is discerned in the |G_{eff}| energy dependence of Λ_{c}^{+}, in contrast to what is seen for the proton and neutron cases. Analyzing the cross section together with the polar-angle distribution of the Λ_{c}^{+} baryon at each energy point, the moduli of electric and magnetic form factors (|G_{E}| and |G_{M}|) are extracted and separated. For the first time, the energy dependence of the form factor ratio |G_{E}/G_{M}| is observed, which can be well described by an oscillatory function.
Objective
ATPase family, AAA domain containing 2 (ATAD2) has been found overexpressed in various cancer types and correlated with malignant status and poor prognosis. However, little is known about ...the clinical significance of ATAD2 in gastric cancer patients. The aim of this study was to explore the clinical and prognostic significance of ATAD2 in gastric cancer.
Methods
The mRNA and protein levels expression of ATAD2 were detected in clinical tissue samples by qRT-PCR and immunohistochemistry, respectively. We examined the ATAD2 protein expression by immunohistochemistry. Furthermore, we analyzed the association between ATAD2 expression and clinicopathological features including prognosis in 166 gastric cancer samples.
Results
In our results, ATAD2 mRNA and protein were highly expressed in gastric cancer samples. ATAD2 overexpression was correlated with advanced clinical stage, tumor depth, lymph node metastasis, and distant metastasis. According to the survival analysis, ATAD2 protein overexpression was a poor independent prognostic factor for gastric cancer patients.
Conclusions
In summary, ATAD2 could serve as a prognostic biomarker for gastric cancer patients.
A series of Ni-free Zr55Ti3HfxCu32-xAl10 (x = 0, 1, 2, 3, 4, 5 at. %) bulk metallic glasses (BMGs) were developed by copper mold suction-casting. The effect of partially substituting Cu by Hf was ...investigated in terms of glass-forming ability (GFA), mechanical properties, and corrosion behavior. As a result of the partial substitution, the GFA of Hf-bearing amorphous alloys were significantly enhanced as compared to Zr55Ti3Cu32Al10 BMGs. Hf addition also enlarged the supercooled liquid region from 55 K to 70 K. The critical diameter was found to increase from 4 mm to 8 mm for x = 3. The corresponding compressive yield strength was over 1800 ± 21 MPa with a large plastic strain above 2.60 ± 0.10%. Electrochemical tests indicated that the lowest corrosion current density was 1.6 ± 0.1 × 10−8 A/cm2 for the alloy with x = 5 in H2SO4 solution, thereby yielding a superior corrosion resistance.
•Partial substitution of Hf with Cu greatly enhanced the GFA of BMGs.•The Hf-bearing BMGs show a higher σy of 1800 ± 21 MPa and a large εp of 2.60 ± 0.10%.•The lowest icorr of BMGs is 1.6 ± 0.1 × 10−8 A/cm2 in H2SO4 solution.
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