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1.
Sci Rep ; 12(1): 7353, 2022 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-35513465

RESUMEN

The pollution problem caused by surplus livestock manure nutrient is becoming more and more serious; thus, analyzing characteristics of the temporal and spatial patterns of livestock manure nutrient and assessing the risks are extremely important. The pollution coefficient method was used to figure out the spatiotemporal variation characteristics of the nitrogen (N) and phosphorus (P) emissions of livestock manure nutrient in soil of the Yangtze River Delta from 1980 to 2018. High-risk areas for livestock manure pollution were determined by matching degree assessment between livestock manure nutrient supply and crop nutrient requirements. Clustering and principal component analysis were applied to select main control factors. The results found that the total discharge and manure N and P loads in animal manure nutrient showed an overall trend of increasing first and then decreasing in the Yangtze River Delta in the soil from 1980 to 2018. The center of manure N and P loads shifted from the central region to the northeastern and southwestern regions. There were four typical patterns for manure N emissions, the main control factors were meat production and primary industry. Meanwhile, the main control factors for the four typical patterns of manure P emissions were meat production and cultivated land area. This research provides a theoretical basis for the sustainable development of the livestock breeding industry and is of significance for promoting a balance between planting and breeding in the Yangtze River Delta.


Asunto(s)
Ganado , Estiércol , Agricultura/métodos , Animales , China , Estiércol/análisis , Nitrógeno/análisis , Nutrientes , Ríos , Suelo
2.
Opt Express ; 28(3): 3215-3225, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-32121994

RESUMEN

Counter-propagating parametric conversion processes in non-linear bulk crystals have been shown to feature unique properties for efficient narrowband frequency conversion. In quantum optics, the generation of photon pairs with a counter-propagating parametric down-conversion process (PDC) in a waveguide, where signal and idler photons propagate in opposite directions, offers unique material-independent engineering capabilities. However, realizing counter-propagating PDC necessitates quasi-phase-matching (QPM) with extremely short poling periods. Here, we report on the generation of counter-propagating single-photon pairs in a self-made periodically poled lithium niobate waveguide with a poling period on the same order of magnitude as the generated wavelength. The single photons of the biphoton state bridge GHz and THz bandwidths with a separable joint temporal-spectral behavior. Furthermore, they allow the direct observation of the temporal envelope of heralded single photons with state-of-the art photon counters.

3.
Light Sci Appl ; 8: 70, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31645918

RESUMEN

Optical metasurfaces open new avenues for the precise wavefront control of light for integrated quantum technology. Here, we demonstrate a hybrid integrated quantum photonic system that is capable of entangling and disentangling two-photon spin states at a dielectric metasurface. Via the interference of single-photon pairs at a nanostructured dielectric metasurface, a path-entangled two-photon NOON state with circular polarization that exhibits a quantum HOM interference visibility of 86 ± 4% is generated. Furthermore, we demonstrate nonclassicality andphase sensitivity in a metasurface-based interferometer with a fringe visibility of 86.8 ± 1.1% in the coincidence counts. This high visibility proves the metasurface-induced path entanglement inside the interferometer. Our findings provide a promising way to develop hybrid-integrated quantum technology operating in the high-dimensional mode space in various applications, such as imaging, sensing, and computing.

4.
Sci Adv ; 5(1): eaat1451, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30613766

RESUMEN

Future quantum computation and networks require scalable monolithic circuits, which incorporate various advanced functionalities on a single physical substrate. Although substantial progress for various applications has already been demonstrated on different platforms, the range of diversified manipulation of photonic states on demand on a single chip has remained limited, especially dynamic time management. Here, we demonstrate an electro-optic device, including photon pair generation, propagation, electro-optical path routing, as well as a voltage-controllable time delay of up to ~12 ps on a single Ti:LiNbO3 waveguide chip. As an example, we demonstrate Hong-Ou-Mandel interference with a visibility of more than 93 ± 1.8%. Our chip not only enables the deliberate manipulation of photonic states by rotating the polarization but also provides precise time control. Our experiment reveals that we have full flexible control over single-qubit operations by harnessing the complete potential of fast on-chip electro-optic modulation.

5.
Lipids Health Dis ; 17(1): 70, 2018 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-29618361

RESUMEN

BACKGROUND: The aim of this study was to investigate the prevalence changes of hyperlipidemia and hyperglycemia from 2009 to 2016 and the effectiveness of yearly physical examinations to hyperlipidemia and hyperglycemia prevention in Chengdu. METHODS: A total of 794 residents (499 males) who have undergone annual health check-ups for 8 consecutive years (from 2009 to 2016) in Chengdu, a city in southwest China were selected as the follow-up group, 7226 residents in 2009 and 75,068 residents in 2016 who underwent health examinations in the same hospital were chosen to be the contemporary control group. The concentration of fasting serum triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol(LDL-C), high density lipoprotein cholesterol (HDL-C) and glucose were measured and compared among these groups. RESULTS: There was a clear rise in the prevalence of hypercholesterolemia and hyperglycemia from 2009 to 2016 (p < 0.05). The follow-up group didn't show difference in levels of serum lipids and glucose compared with the general population after an 8-years' consecutive physical examination (p > 0.05), the follow-up cohort in the 8th year exhibited significant increases in serum total cholesterol and glucose compared with the 1st year (p < 0.05). CONCLUSION: The prevalence of hypercholesterolemia and hyperglycemia were increased significantly from 2009 to 2016. Annual physical examination didn't show a positive effect in the prevention of hypercholesterolemia and hyperglycemia. Health education should be improved to ensure the fulfillment of the preventive objective of yearly physical examination.


Asunto(s)
Hiperglucemia/epidemiología , Hiperlipidemias/epidemiología , Lípidos/sangre , Examen Físico/métodos , Adulto , Factores de Edad , Anciano , Glucemia/análisis , China/epidemiología , Femenino , Humanos , Hiperglucemia/diagnóstico , Hiperglucemia/prevención & control , Hiperlipidemias/diagnóstico , Hiperlipidemias/prevención & control , Masculino , Persona de Mediana Edad
6.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 49(6): 924-928, 2018 Nov.
Artículo en Chino | MEDLINE | ID: mdl-32677406

RESUMEN

OBJECTIVE: To explore the interference of exogenous insulin therapy on insulin detection test by electrochemical luminescence immunoassay (ECLIA). METHODS: Insulin level was determined by ECLIA. According to the requirements of EP7-A2 of American Society for Clinical Laboratory Standards Institute Standards, paired difference experiment was conducted to evaluate the interference of 8 kinds of exogenous insulin on insulin detection, dose effect experiment was conducted to determine the relationship between exogenous insulin concentration and interference degree. RESULTS: When the interfering substance concentrations were ≤250 µU/mL, Gansulin NⓇ, Gansulin RⓇ, Humulin RⓇ,Novolin RⓇ and LantusⓇ all showed linear positive interference, while LevemirⓇ showed a linear negative interference in high concentrations insulin and non-interfering in low concentrations insulin, HumalogⓇ and Novo RapidⓇ showed non-interference in insulin detection. CONCLUSIONS: The use of different exogenous insulin may have different interference on insulin measurement, which need laboratorians and physicians notice to avoid misdiagnosis.

7.
Phys Rev E ; 95(4-1): 043304, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28505730

RESUMEN

In this work, we propose a general approach for modeling mass transfer and reaction of dilute solute(s) in incompressible three-phase flows by introducing a collision operator in lattice Boltzmann (LB) method. An LB equation was used to simulate the solute dynamics among three different fluids, in which the newly expanded collision operator was used to depict the interface behavior of dilute solute(s). The multiscale analysis showed that the presented model can recover the macroscopic transport equations derived from the Maxwell-Stefan equation for dilute solutes in three-phase systems. Compared with the analytical equation of state of solute and dynamic behavior, these results are proven to constitute a generalized framework to simulate solute distributions in three-phase flows, including compound soluble in one phase, compound adsorbed on single-interface, compound in two phases, and solute soluble in three phases. Moreover, numerical simulations of benchmark cases, such as phase decomposition, multilayered planar interfaces, and liquid lens, were performed to test the stability and efficiency of the model. Finally, the multiphase mass transfer and reaction in Janus droplet transport in a straight microchannel were well reproduced.

8.
Phys Rev Lett ; 107(3): 033902, 2011 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-21838358

RESUMEN

We report the first experimental observation of quantum Talbot effects with single photons and entangled photon pairs. Both the first- and second-order quantum Talbot self-images are observed experimentally. They exhibit unique properties, which are different from those produced by coherent and incoherent classical light sources. In particular, our experiments show that the revival distance of two-photon Talbot imaging is twice the usual classical Talbot length and there is no net improvement in the resolution, due to the near-field effect of Fresnel diffraction, which is different from the case of previous proof-of-principle quantum lithography experiments in the far field.

9.
Opt Lett ; 35(8): 1166-8, 2010 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-20410954

RESUMEN

High-visibility Nth-order ghost imaging with thermal light has been realized by recording only the intensities in two optical paths in a lensless setup. It is shown that the visibility is dramatically enhanced as the order N increases, but longer integration times are required owing to the increased fluctuations of higher-order intensity correlation functions. It is also demonstrated that the required integration time for a good image depends on the partition ratio of the intensities on the two detectors and the complexity of the object.

10.
Opt Lett ; 34(5): 695-7, 2009 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-19252596

RESUMEN

We report the first (to our knowledge) experimental demonstration of lensless ghost imaging with true thermal light. Although there is no magnification, the method is suitable for all wavelengths and so may find special applications in cases where it is not possible to use lenses, such as with x rays or gamma rays. We also numerically show that some magnification may be realized away from the focal plane, but the image will always be somewhat blurred.

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