| 111. |
- Tang, Hu, et al.
(författare)
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Boron-Rich Molybdenum Boride with Unusual Short-Range Vacancy Ordering, Anisotropic Hardness, and Superconductivity
- 2020
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Ingår i: Chemistry of Materials. - : AMER CHEMICAL SOC. - 0897-4756 .- 1520-5002. ; 32:1, s. 459-467
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Tidskriftsartikel (refereegranskat)abstract
- Determination of the structures of materials involving more light elements such as boron-rich compounds is challenging and technically important in understanding their varied compositions and superior functionalities. Here we resolve the long-standing uncertainties in structure and composition about the highest boride (termed MoB4, Mo1-xB3, or MoB3) through the rapid formation of large sized boron-rich molybdenum boride under pressure. Using high-quality single-crystal X-ray diffraction analysis and aberration-corrected scanning transmission electron microscopy, we reveal that boron-rich molybdenum boride with a composition of Mo0.757B3 exhibits P6(3)/mmc symmetry with a partial occupancy of 0.514 in 211 Mo sites (Mol), and direct observations reveal the short-range ordering of cation vacancies in (010) crystal planes. Large anisotropic Young's moduli and Vickers hardness are seen for Mo0.757B3, which may be attributed by its two-dimensional boron distributions. Mo0.757B3 is also found to be superconducting with a transition temperature (T-c) of 2.4 K, which was confirmed by measurements of resistivity and magnetic susceptibility. Theoretical calculations suggest that the partial occupancy of Mo atoms plays a crucial role in the emergence of superconductivity.
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| 112. |
- Wan, Bo, et al.
(författare)
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Permian hornblende gabbros in the Chinese Altai from a subduction-related hydrous parent magma, not from the Tarim mantle plume
- 2013
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Ingår i: Lithosphere. - 1941-8264 .- 1947-4253. ; 5:3, s. 290-299
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Tidskriftsartikel (refereegranskat)abstract
- In the Chinese Altai, on the northern side of the Erqis fault, the similar to 10-m-wide Qiemuerqieke gabbro is composed almost entirely of hornblende and plagioclase. Its relative crystallization sequence is olivine, hornblende, plagioclase, and it shows a narrow compositional range in SiO2 (48.7-50.2 wt%), MgO (6.33-8.54 wt%), FeO (5.27-6.46 wt%), Na2O (3.06-3.71 wt%), and K2O (0.26-0.37 wt%). These contents result in a high Mg# value (68-72) and a low K2O/Na2O ratio of similar to 0.1. It has (Sr-87/Sr-86)(i) ratios of 0.70339-0.70350, epsilon(Nd(t)) values of 4.8-6.0, and zircon epsilon(Hf(t)) of 11.4-15.8; these values demonstrate a mantle-derived source, and a whole-rock delta O-18 of similar to 6.7 parts per thousand suggests a mantle wedge origin. The presence of magmatic hornblende suggests a relatively high water fugacity, and the crystallization temperature (715-826 degrees C) calculated using Ti-in-zircon thermometry is considerably lower than that of a normal mafic melt but consistent with an origin from a water-bearing magma. The gabbro has a secondary ion mass spectrometry zircon U-Pb age of 276.0 +/- 2.1 Ma, which is coeval with the 275 Ma mantle plume in the northern Tarim craton, but the Qiemuerqieke petrological and geochemical data do not indicate an abnormally high mantle temperature or a deep mantle signature, which would commonly characterize a mantle plume source. Our results integrated with published data support a model of juvenile crustal growth by a subduction-related process.
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| 113. |
- Wang, Fang, et al.
(författare)
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Emerging contaminants: A One Health perspective
- 2024
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Ingår i: Innovation. - 2666-6758. ; 5
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Forskningsöversikt (refereegranskat)abstract
- Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary health. Despite global efforts to mitigate legacy pollutants, the continuous introduction of new substances remains a major threat to both people and the planet. In response, global initiatives are focusing on risk assessment and regulation of emerging contaminants, as demonstrated by the ongoing efforts to establish the UN's Intergovernmental Science-Policy Panel on Chemicals, Waste, and Pollution Prevention. This review identifies the sources and impacts of emerging contaminants on planetary health, emphasizing the importance of adopting a One Health approach. Strategies for monitoring and addressing these pollutants are discussed, underscoring the need for robust and socially equitable environmental policies at both regional and international levels. Urgent actions are needed to transition toward sustainable pollution management practices to safeguard our planet for future generations.
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| 114. |
- Wang, Thanh, 1979-, et al.
(författare)
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Summer-winter concentrations and gas-particle partitioning of short chain chlorinated paraffins in the atmosphere of an urban setting
- 2012
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 171, s. 38-45
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Tidskriftsartikel (refereegranskat)abstract
- Short chain chlorinated paraffins (SCCPs) are semi-volatile chemicals that are considered persistent in the environment, potential toxic and subject to long-range transport. This study investigates the concentrations and gas-particle partitioning of SCCPs at an urban site in Beijing during summer and wintertime. The total atmospheric SCCP levels ranged 1.9-33.0 ng/m(3) during wintertime. Significantly higher levels were found during the summer (range 112-332 ng/m(3)). The average fraction of total SCCPs in the particle phase (ϕ) was 0.67 during wintertime but decreased significantly during the summer (ϕ = 0.06). The ten and eleven carbon chain homologues with five to eight chlorine atoms were the predominant SCCP formula groups in air. Significant linear correlations were found between the gas-particle partition coefficients and the predicted subcooled vapor pressures and octanol-air partition coefficients. The gas-particle partitioning of SCCPs was further investigated and compared with both the Junge-Pankow adsorption and K(oa)-based absorption models.
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| 115. |
- Wang, Ying, et al.
(författare)
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Epoxy composite with high thermal conductivity by constructing 3D-oriented carbon fiber and BN network structure
- 2021
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 11:41, s. 25422-25430
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Tidskriftsartikel (refereegranskat)abstract
- As electronic devices tend to be integrated and high-powered, thermal conductivity is regarded as the crucial parameter of electronic components, which has become the main factor that limits the operating speed and service lifetime of electronic devices. However, constructing continuous thermal conductive paths for low content particle fillers and reducing interface thermal resistance between fillers and matrix are still two challenging issues for the preparation of thermally conductive composites. In this study, 3D-oriented carbon fiber (CF) thermal network structures filled with boron nitride flakes (BN) as thermal conductive bridges were successfully constructed. The epoxy composite was fabricated by thermal conductive material with a 3D oriented structure by the vacuum liquid impregnation method. This special 3D-oriented structure modified by BN (BN/CF) could efficiently broaden the heat conduction pathway and connected adjacent fibers, which leads to the reduction of thermal resistance. The thermal conductivity of the boron nitride/carbon fiber/epoxy resin composite (BN/CF/EP) with 5 vol% 10 mm CF and 40 vol% BN reaches up to 3.1 W m(-1) K-1, and its conductivity is only 2.5 x 10(-4) S cm(-1). This facile and high-efficient method could provide some useful advice for the thermal management material in the microelectronic field and aerospace industry.
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| 116. |
- Wang, Ying, et al.
(författare)
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Epoxy Composites with High Thermal Conductivity by Constructing Three-Dimensional Carbon Fiber/Carbon/Nickel Networks Using an Electroplating Method
- 2021
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Ingår i: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 6:29, s. 19238-19251
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Tidskriftsartikel (refereegranskat)abstract
- Heat dissipation problem is the primary factor restricting the service life of an electronic component. The thermal conductivity of materials has become a bottleneck that hinders the development of the electronic information industry (such as light-emitting diodes, SG mobile phones). Therefore, the research on improving the thermal conductivity of materials has a very important theoretical value and a practical application value. Whether the thermally conductive filler in polymer composites can form a highly thermal conductive pathway is a key issue at this stage. The carbon fiber/carbon felt (CF/C felt) prepared in the study has a three-dimensional continuous network structure. The nickel-coated carbon fiber/carbon felt (CF/C/Ni felt) was fabricated by an electroplating deposition method. Three-dimensional CF/C/Ni/epoxy composites were manufactured by vacuum-assisted liquid-phase impregnation. By forming connection points between the adjacent carbon fibers, the thermal conduction path inside the felt can be improved so as to improve the thermal conductivity of the CF/C/Ni/epoxy composite. The thermal conductivity of the CF/ C/Ni/epoxy composite (in-plane KO is up to 2.13 W/(m K) with 14.0 wt % CF/C and 3.70 wt % Ni particles (60 min electroplating deposition). This paper provides a theoretical basis for the development of high thermal conductivity and high-performance composite materials urgently needed in industrial production and high-tech fields.
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| 117. |
- Wang, Zhanyun, et al.
(författare)
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Enhancing Scientific Support for the Stockholm Convention’s Implementation : An Analysis of Policy Needs for Scientific Evidence
- 2022
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 56:5, s. 2936-2949
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Tidskriftsartikel (refereegranskat)abstract
- The Stockholm Convention is key to addressing the global threats of persistent organic pollutants (POPs) to humanity and the environment. It has been successful in identifying new POPs, but its national implementation remains challenging, particularly by low- and middle-income Parties. Concerted action is needed to assist Parties in implementing the Convention’s obligations. This analysis aims to identify and recommend research and scientific support needed for timely implementation of the Convention. We aim this analysis at scientists and experts from a variety of natural and social sciences and from all sectors (academia, civil society, industry, and government institutions), as well as research funding agencies. Further, we provide practical guidance to scientists and experts to promote the visibility and accessibility of their work for the Convention’s implementation, followed by recommendations for sustaining scientific support to the Convention. This study is the first of a series on analyzing policy needs for scientific evidence under global governance on chemicals and waste.
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| 118. |
- Wen, Wanqing, et al.
(författare)
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Genome-wide association studies in East Asians identify new loci for waist-hip ratio and waist circumference
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Sixty genetic loci associated with abdominal obesity, measured by waist circumference (WC) and waist-hip ratio (WHR), have been previously identified, primarily from studies conducted in Europeanancestry populations. We conducted a meta-analysis of associations of abdominal obesity with approximately 2.5 million single nucleotide polymorphisms (SNPs) among 53,052 (for WC) and 48,312 (for WHR) individuals of Asian descent, and replicated 33 selected SNPs among 3,762 to 17,110 additional individuals. We identified four novel loci near the EFEMP1, ADAMTSL3, CNPY2, and GNAS genes that were associated with WC after adjustment for body mass index (BMI); two loci near the NID2 and HLA-DRB5 genes associated with WHR after adjustment for BMI, and three loci near the CEP120, TSC22D2, and SLC22A2 genes associated with WC without adjustment for BMI. Functional enrichment analyses revealed enrichment of corticotropin-releasing hormone signaling, GNRH signaling, and/or CDK5 signaling pathways for those newly-identified loci. Our study provides additional insight on genetic contribution to abdominal obesity.
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| 119. |
- Wong, Fiona, et al.
(författare)
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Dioxin-like activities, halogenated flame retardants, organophosphate esters and chlorinated paraffins in dust from Australia, the United Kingdom, Canada, Sweden and China
- 2017
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 168, s. 1248-1256
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Tidskriftsartikel (refereegranskat)abstract
- The concentrations of organic flame retardants (FRs) and dioxin-like activities in dust collected from five countries were investigated. The correlations between the concentrations of the different groups of FRs and dioxin-like activities were examined. Chlorinated paraffins (CPs, C-9 to C-31) were found in the highest concentration (median Sigma CP 700 mu g/g, range 280-4750 mu g/g), followed by organophosphate esters (median Sigma 13OPEs 56 mu g/g, range 21-110 mu g/g), halogenated flame retardants (median Sigma(17)HFRs 3.3 mu g/g, range 0.87-14 mu g/g) and polybrominated diphenyl ethers (median Sigma 17PBDEs 2.8 mu g/g, range 0.46-11 mu g/g). There were no significant differences in concentrations of the FRs among the countries but differences in PBDE and CP congener profiles were found. BDE209 predominated in dust from Australia, the UK, Sweden and China, ranging from 50 to 70% of total PBDEs. The lowest percentage of BDE209 was found in the dust from Canada, representing only 20% of total PBDEs. For CPs in dust from Sweden, the long-chain CPs (especially C-18 congeners) predominated, while for other countries, medium-chain CPs (especially C-14 congeners) predominated. The dioxin-activities of the dusts ranged from 58 to 590 pg CALUX-TEQ/g, and had a median of 200 pg CALUX-TEQ/g. There were significant positive correlations between concentrations of PBDEs and CPs with dioxin-like activities. The dioxin-like activity may be due to the presence of polychlorinated or polybrominated dioxin/furans (PBDD/DFs) or polychlorinated naphthalenes (PCNs) in the dust. The PBDD/DFs are known impurities and degradation product of the penta-BDE mixture, and PCNs are known impurities of CPs which exhibit dioxin-like activities.
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| 120. |
- Xiao, Xiaozhou, et al.
(författare)
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Optomagnetic biosensors : Volumetric sensing based on magnetic actuation-induced optical modulations
- 2022
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Ingår i: Biosensors & bioelectronics. - : Elsevier. - 0956-5663 .- 1873-4235. ; 215
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Tidskriftsartikel (refereegranskat)abstract
- In comparison to alternative nanomaterials, magnetic micron/nano-sized particles show unique advantages, e.g., easy manipulation, stable signal, and high contrast. By applying magnetic actuation, magnetic particles exert forces on target objects for highly selective operation even in non-purified samples. We herein describe a subgroup of magnetic biosensors, namely optomagnetic biosensors, which employ alternating magnetic fields to generate periodic movements of magnetic labels. The optical modulation induced by the dynamics of magnetic labels is then analyzed by photodetectors, providing information of, e.g., hydrodynamic size changes of the magnetic labels. Optomagnetic sensing mechanisms can suppress the noise (by performing lock-in detection), accelerate the reaction (by magnetic force-enhanced molecular collision), and facilitate homogeneous/volumetric detection. Moreover, optomagnetic sensing can be performed using a low magnetic field (<10 mT) without sophisticated light sources or pickup coils, further enhancing its applicability for point-of-care tests. This review concentrates on optomagnetic biosensing techniques of different concepts classified by the magnetic actuation strategy, i.e., magnetic field-enhanced agglutination, rotating magnetic field-based particle rotation, and oscillating magnetic field-induced Brownian relaxation. Optomagnetic sensing principles applied with different actuation strategies are introduced as well. For each representative optomagnetic biosensor, a simple immunoassay strategy-based application is introduced (if possible) for methodological comparison. Thereafter, challenges and perspectives are discussed, including minimization of nonspecific binding, on-chip integration, and multiplex detection, all of which are key requirements in point-of-care diagnostics.
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