29 research outputs found

    Cryogenic spectroscopy of ultra-low density colloidal lead chalcogenide quantum dots on chip-scale optical cavities towards single quantum dot near-infrared cavity QED

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    We present evidence of cavity quantum electrodynamics from a sparse density of strongly quantum-confined Pb-chalcogenide nanocrystals (between 1 and 10) approaching single-dot levels on moderately high-Q mesoscopic silicon optical cavities. Operating at important near-infrared (1500-nm) wavelengths, large enhancements are observed from devices and strong modifications of the QD emission are achieved. Saturation spectroscopy of coupled QDs is observed at 77K, highlighting the modified nanocrystal dynamics for quantum information processing.Comment: * new additional figures and text * 10 pages, 5 figure

    Genetic Implication of a Novel Thiamine Transporter in Human Hypertension

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    ObjectivesThis study coupled 2 strategies—trait extremes and genome-wide pooling—to discover a novel blood pressure (BP) locus that encodes a previously uncharacterized thiamine transporter.BackgroundHypertension is a heritable trait that remains the most potent and widespread cardiovascular risk factor, although details of its genetic determination are poorly understood.MethodsRepresentative genomic deoxyribonucleic acid (DNA) pools were created from male and female subjects in the highest- and lowest-fifth percentiles of BP in a primary care population of >50,000 patients. The peak associated single-nucleotide polymorphisms were typed in individual DNA samples, as well as in twins/siblings phenotyped for cardiovascular and autonomic traits. Biochemical properties of the associated transporter were evaluated in cellular assays.ResultsAfter chip hybridization and calculation of relative allele scores, the peak associations were typed in individual samples, revealing an association between hypertension, systolic BP, and diastolic BP and the previously uncharacterized solute carrier SLC35F3. The BP genetic association at SLC35F3 was validated by meta-analysis in an independent sample from the original source population, as well as the International Consortium for Blood Pressure Genome-Wide Association Studies (across North America and western Europe). Sequence homology to a putative yeast thiamine (vitamin B1) transporter prompted us to express human SLC35F3 in Escherichia coli, which catalyzed [3H]-thiamine uptake. SLC35F3 risk-allele homozygotes (T/T) displayed decreased erythrocyte thiamine content on microbiological assay. In twin pairs, the SLC35F3 risk allele predicted heritable cardiovascular traits previously associated with thiamine deficiency, including elevated cardiac stroke volume with decreased vascular resistance, and elevated pressor responses to environmental (cold) stress. Allelic expression imbalance confirmed that cis variation at the human SLC35F3 locus influenced expression of that gene, and the allelic expression imbalance peak coincided with the hypertension peak.ConclusionsNovel strategies were coupled to position a new hypertension-susceptibility locus, uncovering a previously unsuspected thiamine transporter whose genetic variants predicted several disturbances in cardiac and autonomic function. The results have implications for the pathogenesis and treatment of systemic hypertension

    Examining the generalizability of research findings from archival data

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    This initiative examined systematically the extent to which a large set of archival research findings generalizes across contexts. We repeated the key analyses for 29 original strategic management effects in the same context (direct reproduction) as well as in 52 novel time periods and geographies; 45% of the reproductions returned results matching the original reports together with 55% of tests in different spans of years and 40% of tests in novel geographies. Some original findings were associated with multiple new tests. Reproducibility was the best predictor of generalizability—for the findings that proved directly reproducible, 84% emerged in other available time periods and 57% emerged in other geographies. Overall, only limited empirical evidence emerged for context sensitivity. In a forecasting survey, independent scientists were able to anticipate which effects would find support in tests in new samples

    Realizing Quantum Controlled Phase Gate Through Quantum Dot in Silicon Photonic Crystal Waveguide

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    Scheme to realize controlled phase gate through single quantum dot in slow-light silicon photonic crystal waveguide is proposed. Enhanced Purcell factor and ?-factor lead to high gate fidelity over broadband frequencies compared to cavity-assisted system

    Experimental Investigation on the Static Performance of Stud Connectors in Steel-HSFRC Composite Beams

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    In this research, high strength fiber reinforced concrete (HSFRC) was used to replace the normal strength concrete (NSC) in steel-concrete composite beams to improve their working performance, which might change the static performance of stud connectors. Firstly, push-out tests were conducted to investigation on the static performance of stud connectors in steel-HSFRC composite beams and compared with steel-NSC composite beams. Studs of 8 sizes, 13 mm, 16 mm, 19 mm and 22 mm in diameter and 80 mm and 120 mm in height were adopted to study the influence of stud dimension. The test phenomenon shown that the crack resistance of HSFRC was better than that of NSC, and there were some splitting cracks on NSC slabs whereas no visible cracks on HSFRC slabs when specimens failed. Next, the load-slip curves of studs were analyzed and a typical load-slip curve was proposed which was divided into four stages. In addition, the effects of test parameters were analyzed according to the characteristic points of load-slip curve. Compared with NSC slab, HSFRC slab could provide greater restraining force to the studs, which improved the shear capacity and stiffness of studs while suppressed the ductility of studs. The shear capacity, stiffness and ductility of studs would significantly increase with the increasement of stud diameter and the studs with large diameter were more suitable for steel-HSFRC composite beams. The stud height had no obvious influence on the static performance of studs. Finally, based on the test results, the empirical formulas for load-slip curve and shear capacity of stud connectors embedded in HSFRC were developed which considered the influence factors more comprehensively and had better accuracy and applicability than previous formulas

    A survey on quantum information technology

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    Organic Geochemistry and Hydrocarbon Generation Characteristics of Shale of the Fourth Member of Yingcheng Formation in the South Shuangcheng Fault Depression, Songliao Basin

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    In order to evaluate the potential for oil and gas resources in the deep fault depression of the Northern Songliao Basin, shale from the fourth member of the Yingcheng Formation (K1yc4) in the South Shuangcheng Fault Depression was selected as an example. The organic geochemical characteristics such as abundance, type and maturity from experiments on low-maturity source rock samples, the hydrocarbon generation conversion rate, hydrocarbon generation amount and hydrocarbon generation period of the shale from K1yc4 were evaluated via the chemical kinetics method. The hydrocarbon generation threshold of shale from K1yc4 in the South Shuangcheng Fault Depression was analyzed by examining the organic matter (OM) in shale core samples from K1yc4. Based on the thermal simulations to an approximate buried depth of 750 m, the maximum oil-generation stage corresponds to an approximate buried depth of 1380 m. The amounts of generated oil and gas from the shale in K1yc4 are approximately 2.417 Ă— 108 t and 0.546 Ă— 1011 m3, respectively. The shale in K1yc4 generated crude oil mainly during the sedimentary period of the Qingshankou Formation, Yaojia Formation and Nenjiang Formation, and mainly generated natural gas during the sedimentary period of the Nenjiang Formation. In the South Shuangcheng Fault Depression, the high parts of the local structure are the favorable areas for oil and gas exploration of K1yc4 in the sag zone, which could be used for the combined production of shale oil, tight sandstone oil and conventional oil
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