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An atomistic kinetic Monte Carlo coupled with the embedded-atom method is used to simulate film growth and morphology evolution of a Cu–Zn–Sn precursor of Cu2ZnSnS4 solar cells by single-step electrodeposition. The deposition and diffusion events of three different metallic atoms are described by the simulation. Moreover, the multibody Cu–Zn–Sn potential is used to calculate diffusion barrier energy. The effects of process factors, including temperature and electrode potential, on the cross-section morphology and surface roughness are explored, while keeping the elemental composition ratios constant. The lowest roughness with the smoothest morphology is obtained at the optimal parameters. The distribution and transformation behaviors of cluster sizes are investigated to describe the alloy film growth process. Furthermore, the comparison between deposition events and diffusion events reveals that deposition events depend primarily on individual deposition rates of different metallic atoms, but diffusion events are mainly dependent on the interaction of metallic atoms. The film morphology evolution is visualized by three-dimensional configuration with increasing numbers of atoms, which suggests a competing mechanism between nucleation and growth of the thin film alloy.
Arid central Asia plays an important role in global climate dynamics, but large uncertainties remain in our understanding of the region's hydroclimate variability during the Late Quaternary. Here we present a new, high-resolution record of lacustrine sediment grain-size and element chemistry from Ebinur Lake, which was used to infer lake conditions and related climate changes in the study region between ca. 39.2 and 3.6 ka. End-member modeling analysis of grain-size data and PCA of elemental data show that lake level fluctuated dramatically from 39.2 to 34.0 ka. Subsequently, Ebinur Lake experienced a high stand from 34.0 to 28.0 ka, under humid climate conditions. The subsequent period, from 28.0 to 12.0 ka, was characterized by lake regression under dry climate conditions, whereas afterward (12.0–3.6 ka), considerably higher lake levels and humid conditions again prevailed. Millennial-scale abrupt climate changes, such as Heinrich events (H3 and H1) and the Younger Dryas, which are documented in the North Atlantic region, are also detected in the sediment record from Ebinur Lake. Comparisons with other sediment records from arid central Asia generally support the claim that climate change in this region was influenced mainly by variations in North Atlantic sea surface temperatures, through the westerlies.
We report a roll-to-roll dry processing for making low cost and high performance electrodes for lithium-ion batteries (LIBs). Currently, the electrodes for LIBs are made with a slurry casting procedure (wet method). The dry electrode fabrication is a three-step process including: step 1 of uniformly mixing electrode materials powders comprising an active material, a carbonaceous conductor and the soft polymer binder; step 2 of forming a free-standing, continuous electrode film by pressing the mixed powders together through the gap between two rolls of a roll-mill; and step 3 of roll-to-roll laminating the electrode film onto a substrate such as a current collector. Compared with the conventional wet slurry electrode manufacturing method, the dry manufactural procedure and infrastructure are simpler, the production cost is lower, and the process eliminates volatile organic compound emission and is more environmentally friendly, and the ability of making thick (>120µm) electrodes with high tap density results in high energy density of final energy storage device. A prototype LIBs of LiNi0.6Mn0.2Co0.2O2 (NMC622)/graphite also has 230 Wh/ kg energy density.
In this paper, a novel NiFe-LDH@ZnO composite was prepared by using a facile two-step process upon nickel foam (NF) substrate. The morphologies and chemical compositions of the samples were characterized by SEM, EDS, XRD and XPS. Photocatalytic degradation of Rhodamine B dye was tested with the samples NiFe-LDH@ZnO@NF, ZnO@NF and NiFe-LDH under the same conditions. The experimental results revealed that the NiFe-LDH@ZnO@NF composite exhibited excellent photocatalytic performance, i.e., 1.4 and 2.5 times higher than that of pure ZnO and NiFe-LDH, respectively. The reason was that the NiFe-LDH@ZnO@NF composite provided a possibility to effectively inhibit the recombination of the photogenerated electron-hole pairs, and therefore enhanced the photocatalytic efficiency. This composite is expected to have potential applications in wastewater treatment field.
In this paper, zircon U–Pb geochronology, major and trace elements, and Sr–Nd isotope geochemistry of the Baiyanghe dolerites in northern West Junggar of NW China are presented. The U–Pb dating of zircons from the dolerites yielded ages of 272.2±4 Ma and 276.7±6.2 Ma, which indicate the emplacement times. The dolerites are characterized by minor variations in SiO2 (46.89 to 49.07 wt%), high contents of Al2O3 (13.60 to 13.92 wt%) and total Fe2O3 (11.14 to 11.70 wt%), and low contents of MgO (2.67 to 3.64 wt%) and total alkalis (Na2O+K2O, 5.1 to 5.97 wt%, K2O/Na2O = 0.37–0.94), which indicate affinities to metaluminous tholeiite basalt. The REE pattern ((La/Sm)N = 2.25–2.34, (La/Yb)N = 7.42–8.36), V–Ti/1000 and 50*Zr–Ti/50–Sm discrimination diagrams show that these rocks are OIB-type. The high contents of Zr and Ti indicate a within-plate tectonic setting, and samples plot in the ‘plume source’ field shown on the Dy/Yb(N) versus Ce/Yb(N) diagram. The positive εNd(t) values (+7.09 to +7.48), high initial 87Sr/86Sr ratios (0.70442 to 0.70682) and depletions of Nb and Ta elements in the samples can be explained by the involvement of subducted sediments. In summary, it is possible that the Baiyanghe dolerites were derived from an OIB-like mantle source and associated with a mantle plume tectonic setting. Therefore, our samples provide the youngest evidence for the existence of a mantle plume, which may provide new insights into the Late Palaeozoic tectonic setting of West Junggar.
To assess the feasibility, reliability and validity of reflection spectroscopy (RS) to assess skin carotenoids in a racially diverse sample.
Study 1 was a cross-sectional study of corner store customers (n 479) who completed the National Cancer Institute Fruit and Vegetable Screener as well as RS measures. Feasibility was assessed by examining the time it took to complete three RS measures, reliability was assessed by examining the variation between three RS measures, and validity was examined by correlation with self-reported fruit and vegetable consumption. In Study 2, validity was assessed in a smaller sample (n 30) by examining associations between RS measures and dietary carotenoids, fruits and vegetables as calculated from a validated FFQ and plasma carotenoids.
Eastern North Carolina, USA.
It took on average 94·0 s to complete three RS readings per person. The average variation between three readings for each participant was 6·8 %. In Study 2, in models adjusted for age, race and sex, there were statistically significant associations between RS measures and (i) FFQ-estimated carotenoid intake (P<0·0001); (ii) FFQ-estimated fruit and vegetable consumption (P<0·010); and (iii) plasma carotenoids (P<0·0001).
RS is a potentially improved method to approximate fruit and vegetable consumption among diverse participants. RS is portable and easy to use in field-based public health nutrition settings. More research is needed to investigate validity and sensitivity in diverse populations.
In the past few years, our group worked on the area of transformation from the two-dimensional (2-D) nanocrystalline films to one-dimensional (1-D) nanomaterials by using thermal oxidation. In this paper, we overview the research work on the controllable growth processes, transformation phenomena, growth mechanisms and applications. In general, the preparation process includes the following steps: 1) prepare a pure metal nanocrystalline film via a pulse electro – deposition; 2) grow variant 1-D nanomaterials, such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), and 1-D metal oxide nanoneedles involving ZnO, CuO and Fe3O4, etc. by using this film as catalyst. This process exhibits the following features: 1) the 1-D nanomaterials grow according to “base growth” model and no residual catalyst exists at the tip of the products; 2) the diameter of the 1-D nanomaterials can be controlled by controlling grain sizes of the 2-D films through adjusting pulse electro-deposition parameters; 3) it is more easily to get the 1-D nanomaterials with large area, uniform, vertical alignment and good shape on the substrates. We propose a “solid state based-up diffusion growth mechanism” for growth of the 1-D metal oxide nanoneedles, and “base growth model” for the 1-D carbon nanomaterials. The physical properties, such as Field emission and magnetics, of the 1-D metal oxide nanoneedles were studied, which showed desired values. In addition, we couple the ZnO nanoneedles with NiO, TiO2, graphene, Au nanoparticles, etc. for enhancing photocatalytic properties in the areas of environmental purification.
The Shen-Guang II Upgrade (SG-II-U) laser facility consists of eight high-power nanosecond laser beams and one short-pulse picosecond petawatt laser. It is designed for the study of inertial confinement fusion (ICF), especially for conducting fast ignition (FI) research in China and other basic science experiments. To perform FI successfully with hohlraum targets containing a golden cone, the long-pulse beam and cylindrical hohlraum as well as the short-pulse beam and cone target alignment must satisfy tight specifications (30 and
rms for each case). To explore new ICF ignition targets with six laser entrance holes (LEHs), a rotation sensor was adapted to meet the requirements of a three-dimensional target and correct beam alignment. In this paper, the strategy for aligning the nanosecond beam based on target alignment sensor (TAS) is introduced and improved to meet requirements of the picosecond lasers and the new six LEHs hohlraum targets in the SG-II-U facility. The expected performance of the alignment system is presented, and the alignment error is also discussed.
In high power laser facility for inertial confinement fusion research, final optics assembly (FOA) plays a critical role in the frequency conversion, beam focusing, color separation, beam sampling and debris shielding. The design and performance of FOA in SG-II Upgrade laser facility are mainly introduced here. Due to the limited space and short focal length, a coaxial aspheric wedged focus lens is designed and applied in the FOA configuration. Then the ghost image analysis, the focus characteristic analysis, the B integral control design and the optomechanical design are carried out in the FOA design phase. In order to ensure the FOA performance, two key technologies are developed including measurement and adjustment technique of the wedged focus lens and the stray light management technique based on ground glass. Experimental results show that the design specifications including laser fluence, frequency conversion efficiency and perforation efficiency of the focus spot have been achieved, which meet the requirements of physical experiments well.
We find that firms headquartered in U.S. counties with higher levels of social capital incur lower bank loan spreads. This finding is robust to using organ donation as an alternative social capital measure and incremental to the effects of religiosity, corporate social responsibility, and tax avoidance. We identify the causal relation using companies with a social-capital-changing headquarters relocation. We also find that high-social-capital firms face loosened nonprice loan terms, incur lower at-issue bond spreads, and prefer public bonds over bank loans. We conclude that debt holders perceive social capital as providing environmental pressure that constrains opportunistic firm behaviors in debt contracting.
An effective multiplex real-time polymerase chain reaction (PCR) assay for the simultaneous detection of three major pathogens, Nosema bombycis Nägeli (Microsporidia: Nosematidae), Bombyx mori nucleopolyhedrovirus (Baculoviridae: genus Alphabaculovirus) (NPV), and Bombyx mori densovirus (Parvoviridae: genus Iteravirus) (DNV), in silkworms (Bombyx mori (Linnaeus); Lepidoptera: Bombycidae) was developed in this study. Polymerase chain reaction and real-time PCR tests and basic local alignment search tool searches revealed that the primers and probes used in this study had high specificities for their target species. The ability of each primer/probe set to detect pure pathogen DNA was determined using a plasmid dilution panel, in which under optimal conditions the multiplex real-time PCR assay showed high efficiency in the detection of three mixed target plasmids with a detection limit of 8.5×103 copies for N. bombycis and Bombyx mori NPV (BmNPV) and 8.5×104 copies for Bombyx mori DNV (BmDNV). When the ability to detect these three pathogens was examined in artificially inoculated silkworms, our method presented a number of advantages over traditional microscopy, including specificity, sensitivity, and high-throughput capabilities. Under the optimal volume ratio for the three primer/probe sets (3:2:2=N. bombycis:BmNPV:BmDNV), the multiplex real-time PCR assay showed early detection of BmNPV and BmDNV by day 1 post inoculation using DNA templates of the three pathogens in various combinations from individually infected silkworms; the early detection of N. bombycis was possible by day 3 post inoculation using the DNA isolated from the midgut of N. bombycis-infected silkworms.
Choline and betaine are essential nutrients involved in one-carbon metabolism and have been hypothesised to affect breast cancer risk. Functional polymorphisms in genes encoding choline-related one-carbon metabolism enzymes, including phosphatidylethanolamine N-methyltransferase (PEMT), choline dehydrogenase (CHDH) and betaine-homocysteine methyltransferase (BHMT), have important roles in choline metabolism and may thus interact with dietary choline and betaine intake to modify breast cancer risk. This study aimed to investigate the interactive effect of polymorphisms in PEMT, BHMT and CHDH genes with choline/betaine intake on breast cancer risk among Chinese women. This hospital-based case–control study consecutively recruited 570 cases with histologically confirmed breast cancer and 576 age-matched (5-year interval) controls. Choline and betaine intakes were assessed by a validated FFQ, and genotyping was conducted for PEMT rs7946, CHDH rs9001 and BHMT rs3733890. OR and 95 % CI were estimated using unconditional logistic regression. Compared with the highest quartile of choline intake, the lowest intake quartile showed a significant increased risk of breast cancer. The SNP PEMT rs7946, CHDH rs9001 and BHMT rs3733890 had no overall association with breast cancer, but a significant risk reduction was observed among postmenopausal women with AA genotype of BHMT rs3733890 (OR 0·49; 95 % CI 0·25, 0·98). Significant interactions were observed between choline intake and SNP PEMT rs7946 (Pinteraction=0·029) and BHMT rs3733890 (Pinteraction=0·006) in relation to breast cancer risk. Our results suggest that SNP PEMT rs7946 and BHMT rs3733890 may interact with choline intake on breast cancer risk.
Psychiatric disorders such as schizophrenia and major depressive disorder
(MDD) are likely to be caused by multiple susceptibility genes, each with
small effects in increasing the risk of illness. Identifying DNA variants
associated with schizophrenia and MDD is a crucial step in understanding
the pathophysiology of these disorders.
To investigate whether the SP4 gene plays a significant
role in schizophrenia or MDD in the Han Chinese population.
We focused on nine single nucleotide polymorphisms (SNPs) harbouring the
SP4 gene and carried out case–control studies in 1235
patients with schizophrenia, 1045 patients with MDD and 1235 healthy
controls recruited from the Han Chinese population.
We found that rs40245 was significantly associated with schizophrenia in
both allele and genotype distributions (Pallele = 0.0005, Pallele = 0.004 after Bonferroni correction; Pgenotype = 0.0023, Pgenotype = 0.0184 after Bonferroni correction). The rs6461563
SNP was significantly associated with schizophrenia in the allele
distributions (Pallele = 0.0033, Pallele = 0.0264 after Bonferroni correction).
Our results suggest that common risk factors in the SP4
gene are associated with schizophrenia, although not with MDD, in the Han
The effect of Zn, as an adjunct to antibiotics, on the treatment of severe pneumonia in young children is still under debate; therefore, we performed a meta-analysis to evaluate the therapeutic role of Zn for severe pneumonia in children younger than 5 years. PubMed, Cochrane library and Embase databases were systematically searched from inception until October 2015 for randomised-controlled trials (RCT) that assessed the effect of Zn as an adjunct to antibiotics for severe pneumonia. Random-effects model was used for calculating the pooled estimates, and intention-to-treat principle was also applied. Nine RCT involving 2926 children were included. Overall, the pooled results showed that adjunct treatment with Zn failed to reduce the time to recovery from severe pneumonia (hazard ratios (HR)=1·04; 95 % CI 0·90, 1·19; I2=39 %; P=0·58), hospital length of stay (HR=1·04; 95 % CI 0·83, 1·33; I2=57 %; P=0·74), treatment failure (relative risk (RR)=0·95; 95 % CI 0·79, 1·14; I2=20 %; P=0·58) or change of antibiotics (RR=1·07; 95 % CI 0·79, 1·45; I2=44 %; P=0·67). In addition, continuous outcomes were consistent while meta-analysed with standard mean difference, and all outcomes remained stable in intention-to-treat analysis. No significant differences were observed in the two groups between death rate, adverse events or recovery times of severe pneumonia indicators. Our results suggested that adjunct treatment with Zn failed to benefit young children in the treatment of severe pneumonia. Considering the clinical heterogeneity, baseline characteristics of children, definition of severe pneumonia and Zn supplement way should be taken into consideration in future research. This study was registered at PRESPERO as CRD42015019798.
This paper describes a new genus Liaous, with L. shaiwensis He and Chen n. gen. n. sp. as the type species, from the Xinyuan Formation of Anisian age in Ziyun, southern Guizhou, China. The phylogenetic tree revealed by the parsimony analysis shows that Liaous is closely allied to both Mentzelia Quenstedt, 1871 and Paramentzelia Xu, 1978 of the subfamily Mentzeliinae. A new classification scheme for the Spiriferinoidea is also proposed based on a phylogenetic tree of the superfamily indicated by parsimony analysis. The Spiriferinoidea includes three families and nine subfamilies. Three new subfamilies—Madoinae He and Chen, new subfam., Qinghaispiriferininae He and Chen, new subfam., and Triadispirinae He and Chen, new subfam. are proposed. Liaous shaiwensis He and Chen n. gen. n. sp. is found in the Posidonia wengensis-Liaous shaiwensis (P-L) paleocommunity, which is dominated by r-strategists (i.e., organisms defined by a fauna with a high dominance and small body sizes) and has a low diversity and high dominance. The P-L paleocommunity therefore has little similarity to its coeval communities from the Anisian Stage of South China and instead it appears more similar to the Lower Triassic shelly faunas in community structures. This paleocommunity is interpreted to have inhabited a relatively deep, low-energy, dysaerobic offshore basin/slope setting with the influence of episodic storms.
X-ray powder diffraction data, unit-cell parameters, and space group for beta-methyl vinyl phosphate (MAP), C29H27N2O10P, are reported [a = 17.293(4) Å, b = 6.142(6) Å, c = 14.464(8) Å, α = γ = 90°, β = 112.048(0)°, unit-cell volume V = 1424.19 Å3, Z = 2, and space group P21]. All measured lines were indexed and are consistent with the P21 space group. No detectable impurity was observed.
Because farmers’ markets include a variety of fruits and vegetables, shopping at farmers’ markets would likely improve diet quality among low-income consumers, as well as promote sustainable direct farm-to-consumer business models. However, not much is known about how to promote farmers’ market shopping among low-income consumers. Therefore, the purpose of the present paper was to examine barriers to and facilitators of shopping at farmers’ markets and associations between shopping at farmers’ markets and self-reported dietary behaviours (fruit and vegetable, sugar-sweetened beverage and fast-food consumption) and BMI.
Cross-sectional analyses of associations between farmers’ market shopping frequency, awareness of markets, access to markets, dietary behaviours and BMI.
Department of Social Services, Pitt County, eastern North Carolina, USA.
Between April and July 2013, Supplemental Nutrition Assistance Program (SNAP) participants (n 205) completed a quantitative survey.
Barriers to shopping at farmers’ markets included does not accept SNAP/electronic benefit transfer, out of the way and lack of transportation. Farmers’ market shopping was associated with awareness of farmers’ markets (estimate =0·18 (se 0·04), P<0·001). Fruit and vegetable consumption was positively associated with farmers’ market shopping (estimate =1·06 (se 0·32), P=0·001).
Our study is one of the first to examine SNAP participants’ farmers’ market shopping, distance to farmers’ markets and dietary behaviours. Barriers to shopping at farmers’ markets and increasing awareness of existing markets should be addressed in future interventions to increase SNAP participants’ use of farmers’ markets, ultimately improving diet quality in this high-risk group.
We consider a distributed optimization problem over a multi-agent network, in which
the sum of several local convex objective functions is minimized subject to global
convex inequality constraints. We first transform the constrained optimization
problem to an unconstrained one, using the exact penalty function method. Our
transformed problem has a smaller number of variables and a simpler structure than
the existing distributed primal–dual subgradient methods for constrained
distributed optimization problems. Using the special structure of this problem, we
then propose a distributed proximal-gradient algorithm over a time-changing
connectivity network, and establish a convergence rate depending on the number of
iterations, the network topology and the number of agents. Although the transformed
problem is nonsmooth by nature, our method can still achieve a convergence rate,
iterations, which is faster than the rate,
, of existing distributed subgradient-based methods. Simulation
experiments on a distributed state estimation problem illustrate the excellent
performance of our proposed method.