Effect of Longitudinal Fluctuations of 3D Weizsäcker-Williams Field on Pressure Isotropization of Glasma.

We investigate the effects of boost invariance breaking on the isotropization of pressure in the glasma, using a 3+1D glasma simulation. The breaking is attributed to spatial fluctuations in the classical color charge density along the collision axis. We present numerical results for pressure and energy density at mid-rapidity and across a wider rapidity region. It is found that, despite varying longitudinal correlation lengths, the behaviors of the pressure isotropizations are qualitatively similar. The numerical results suggest that, in the initial stage, longitudinal color electromagnetic fields develop, similar to those in the boost invariant glasma. Subsequently, these fields evolve into a dilute glasma, expanding longitudinally in a manner akin to a dilute gas. We also show that the energy density at mid-rapidity exhibits a 1/τ decay in the dilute glasma stage.

Responses of nickel bioavailability and toxicity of Prorocentrum Donghaienses to dissolved organic matter (DOM) fractions incubated in urea.

Urea, nickel (Ni) and dissolved organic matter (DOM) from land varied with different sources have a great impact on the offshore ecosystem. The heterogeneity of Ni bioavailability and toxicity of Prorocentrum donghaiense influenced by DOM fractions incubated in urea was investigated in this study. On the occasion, chlorophyll (Chl a) concentration, growth rate, and photosynthesis parameters were monitored to track changes occurring in the test organism. Chl a concentration and photosynthesis parameters in the treatment of hydrophilic DOM (HPI) with Ni-free was significantly higher than that in the control treatment, and similar data were shown in the treatment of hydrophobic DOM（HPO）with the low Ni environment (0.17µmol L-1). However, the opposite phenomena were observed in the treatments of HPO with the higher Ni environment (over 170µmol L-1). Moreover, the EC50 of Ni for P.donghaiense incubated in HPO was relatively lower than that in HPI and control treatment, which implied that HPO elevated the toxicity of Ni. Therefore, the varied DOM compositions because of different origins, as a chelating agent and potential nutrient source in coastal waters, shows the significantly different bioavailability and toxicity of Ni with the increasing inputs of urea, which in turn influences the dynamics of phytoplankton.

Transition Radiation as a Probe of the Chiral Anomaly.

A fast charged particle crossing the boundary between chiral matter and vacuum radiates transition radiation. Its most remarkable features-the resonant behavior at a certain emission angle and the circular polarization of the spectrum-depend on the parameters of the chiral anomaly in a particular material or matter. Chiral transition radiation can be used to investigate the chiral anomaly in such diverse media as the quark-gluon plasma, Weyl semimetals, and axionic dark matter.

Optical gears in a nanophotonic directional coupler.

Gears are rotating machines, meshing with each other by teeth to transmit torque. Interestingly, the rotating directions of two meshing gears are opposite, clockwise and counterclockwise. Although this opposite handedness motion has been widely investigated in machinery science, the analogue behavior of light remains undiscovered. Here, we present a simple nanophotonic directional coupler structure which can generate two light beams with opposite handedness of polarization states-optical gears. Due to the abrupt phase shift effect and birefringence effect, the angular momentum (AM) states of photons vary with the propagation distance in two adjacent waveguides of the coupler. Thus, by the choice of coupling length, it is able to obtain two light beams with opposite handedness of polarization, confirming the appearance of optical gears. The full control in the handedness of output beams is achieved via tuning the relative phase between two orthogonal modes at the input port. Optical gears thus offer the possibility of exploring light-matter interactions in nanoscale, opening up new avenues in fields of integrated quantum computing and nanoscale bio-sensing of chiral molecules.

On chip chirality-distinguishing beamsplitter.

The chirality of photons plays a fundamental role in light-matter interactions. However, a limiting factor in photonic integrated circuits is the lack of a miniaturized component, which can distinguish the chirality in a low cost and integrated manner. Herein we numerically demonstrate a chirality-distinguishing beamsplitter that can address this challenge. It consists of an integrated polarization rotator and a linear polarization beamsplitter, which together can fulfill the task of distinguishing and splitting left- and right-handed quasi-circularly polarized modes on a chip with an ultra-broadband operation range from 1.45 µm to 1.65 µm. Owning to the reciprocity, the device can emit photons with selectable spin angular momentum depending on the chosen feeding waveguide. The device is compatible with complementary metal-oxide semiconductor technology and it may open up new avenues in the fields of on-chip nano-photonics, bio-photonics and quantum information science.

Electromagnetic fields and anomalous transports in heavy-ion collisions-a pedagogical review.

The hot and dense matter generated in heavy-ion collisions may contain domains which are not invariant under P and CP transformations. Moreover, heavy-ion collisions can generate extremely strong magnetic fields as well as electric fields. The interplay between the electromagnetic field and triangle anomaly leads to a number of macroscopic quantum phenomena in these P- and CP-odd domains known as anomalous transports. The purpose of this article is to give a pedagogical review of various properties of the electromagnetic fields, the anomalous transport phenomena, and their experimental signatures in heavy-ion collisions.

All-optical controlling based on nonlinear graphene plasmonic waveguides.

We give the effective refractive index of graphene plasmonic waveguides with both linear and nonlinear effects based on the nonlinear cross-phase modulation, and address the effects of photo-induced refractive index change and absorption change. A non-resonant all-optical nonlinear graphene plasmonic switch with an ultra-compact size of 0.25 µm2 is proposed and numerically analyzed based on the dynamics of the photo-induced absorption change. The results show that the all-optical graphene plasmonic switch can realize a broad bandwidth over 5 THz, a potentially very high switching speed and an extinction ratio of 18.14 dB with the electric amplitude of the pump light of 1.5 × 107 V/m at the signal frequency of 28 THz. Our study could provide a possibility for future all-optical highly integrated optical components.

Tunable metamaterial-induced transparency with gate-controlled on-chip graphene metasurface.

We propose and numerically investigate a gate-controlled on-chip graphene metasurface consisting of a monolayer graphene sheet and silicon photonic crystal-like substrate, to achieve an electrically-tunable induced transparency. The operation mechanism of the induced transparency of the on-chip graphene metasurface is analyzed. The tunable optical properties with different gate-voltages and polarizations have been discussed. Additionally, the spectral feature of the on-chip graphene metasurface as a function of the refractive index of the local environment is also investigated. The result shows that the on-chip graphene metasurface as a refractive index sensor can achieve an overall figure of merit of 8.89 in infrared wavelength range. Our study suggests that the proposed structure is potentially attractive as optoelectronic modulators and refractive index sensors.

Research Progress on F-P Interference-Based Fiber-Optic Sensors.

We review our works on Fabry-Perot (F-P) interferometric fiber-optic sensors with various applications. We give a general model of F-P interferometric optical fiber sensors including diffraction loss caused by the beam divergence and the Gouy phase shift. Based on different structures of an F-P cavity formed on the end of a single-mode fiber, the F-P interferometric optical sensor has been extended to measurements of the refractive index (RI) of liquids and solids, temperature as well as small displacement. The RI of liquids and solids can be obtained by monitoring the fringe contrast related to Fresnel reflections, while the ambient temperature and small displacement can be obtained by monitoring the wavelength shift of the interference fringes. The F-P interferometric fiber-optic sensors can be used for many scientific and technological applications.

Vector nature of multi-soliton patterns in a passively mode-locked figure-eight fiber laser.

The vector nature of multi-soliton dynamic patterns was investigated in a passively mode-locked figure-eight fiber laser based on the nonlinear amplifying loop mirror (NALM). By properly adjusting the cavity parameters such as the pump power level and intra-cavity polarization controllers (PCs), in addition to the fundamental vector soliton, various vector multi-soliton regimes were observed, such as the random static distribution of vector multiple solitons, vector soliton cluster, vector soliton flow, and the state of vector multiple solitons occupying the whole cavity. Both the polarization-locked vector solitons (PLVSs) and the polarization-rotating vector solitons (PRVSs) were observed for fundamental soliton and each type of multi-soliton patterns. The obtained results further reveal the fundamental physics of multi-soliton patterns and demonstrate that the figure-eight fiber lasers are indeed a good platform for investigating the vector nature of different soliton types.

Compact filters and demultiplexers based on long-range air-hole assisted subwavelength waveguides.

Compact filters and demultiplexers based on long-range air-hole assisted subwavelength (LR-AHAS) waveguides have been proposed and numerically demonstrated. The tunable reflective filters possess the characters of high extinction ratio (17.5dB) and narrow bandwidth (10.1nm). The average demultiplexing bandwidth of a 1 × 3 wavelength demultiplexer based on LR-AHAS waveguide is 17.3 nm. The drop efficiencies can be significantly enhanced up to 60% by employing proposed filters in the structure. With distinguished wavelength-filtering/dropping characters and compact footprints, the proposed filters and demultiplexers could become the fundamental signal processing components in the LR-AHAS waveguides for large-scale photonic integrations.

Axial current generation from electric field: chiral electric separation effect.

We study a relativistic plasma containing charged chiral fermions in an external electric field. We show that with the presence of both vector and axial charge densities, the electric field can induce an axial current along its direction and thus cause chirality separation. We call it the chiral electric separation effect (CESE). On a very general basis, we argue that the strength of CESE is proportional to µ(V)µ(A) with µ(V) and µ(A) the chemical potentials for vector charge and axial charge. We then explicitly calculate this CESE conductivity coefficient in thermal QED at leading-log order. The CESE can manifest a new gapless wave mode propagating along the electric field. Potential observable effects of CESE in heavy-ion collisions are also discussed.

Long-range air-hole assisted subwavelength waveguides.

A novel air-hole assisted metal-dielectric-metal (MDM) waveguide is proposed and demonstrated. The configuration can be considered as a hybrid waveguide combining an MDM waveguide with a photonic crystal waveguide. The results reveal that the figure of merit of the proposed waveguide is as high as 6 × 10(8), the propagation length is 15.2 mm with the lateral mode width between 511.3 and 564.3 nm, and the waveguide isolation is over 36 dB with tiny center-to-center separation at the wavelength of 1.55 µm. In addition, we also demonstrate its broad optical bandwidth, highly efficient 90° and 120° direct bends, and low radiation loss of the metallic gaps. The above excellent features show that the proposed waveguide could be an ideal candidate for high-density photonic integrations, compared to long-range surface plasmon polariton waveguides and TE-mode MDM waveguides.

BCS-BEC crossover in 2D Fermi gases with Rashba spin-orbit coupling.

We present a systematic theoretical study of the BCS-BEC crossover in two-dimensional Fermi gases with Rashba spin-orbit coupling (SOC). By solving the exact two-body problem in the presence of an attractive short-range interaction we show that the SOC enhances the formation of the bound state: the binding energy E(B) and effective mass m(B) of the bound state grows along with the increase of the SOC. For the many-body problem, even at weak attraction, a dilute Fermi gas can evolve from a BCS superfluid state to a Bose condensation of molecules when the SOC becomes comparable to the Fermi momentum. The ground-state properties and the Berezinskii-Kosterlitz-Thouless (BKT) transition temperature are studied, and analytical results are obtained in various limits. For large SOC, the BKT transition temperature recovers that for a Bose gas with an effective mass m(B). We find that the condensate and superfluid densities have distinct behaviors in the presence of SOC: the condensate density is generally enhanced by the SOC due to the increase of the molecule binding; the superfluid density is suppressed because of the nontrivial molecule effective mass m(B).

Thalassiosira weissflogii grown in various Zn levels shows different ecophysiological responses to seawater acidification.

The presence of zinc (Zn), a vital element for algal physiological functions, coupled with the silicification of diatoms implies that it plays an integral role in the carbon and silicon cycles of the sea. In this study, we examined the effects of different pCO2 and Zn levels on growth rate, elemental compositions and silicification by Thalassiosira weissflogii. The results showed that under normal pCO2 (400 µatm), cultures of T. weissflogii were depressed for growth rate and silica incorporation rate, but encouraged for cellular silicon content, Si/C, Si/N, and sinking rate when Zn deficient (0.3 pmol L-1). However, cellular silicon and sinking rate of Zn-deficient and Zn-replete (25 pmol L-1) T. weissflogii were decreased and increased at higher pCO2 (800 µatm), respectively. Thus, acidification may affect diatoms significantly differently depending on the Zn levels of the ocean and then alter the biochemical cycling of carbon and silica.

Benefit-Risk Assessment of Dietary Patterns by Bioavailable Metals, Gut Microbes, and Their Interaction for Human Health.

The high-carbohydrate, low-fat, low-protein (HC-LFP) and low-carbohydrate, high-fat, high-protein (LC-HFP) diets are the main dietary patterns worldwide. The influence of dietary patterns on bioavailable metals, gut microbes, and their interaction is still unknown. A biomimetic digestive tract with full functions is constructed to transform the diets into chyme, and the gut microbes are cultured with the corresponding chyme. The diet species-specificity in bioavailable metal content and the positive and negative correlations between bioavailable metals and microbial reproductions are disclosed. The safe dosage and maximum consumption are 369.5 and 858.6 g/d and 268.6 and 3119.0 g/d for LC-HFP and HC-LFP, respectively. When replacing HC-LFP with LC-HFP for 21 days, the bioavailability of Fe and Cr is increased 83.2% and 268.4%, respectively; the reproductions of harmful and benefical microbes are significantly increased and decreased. The prevalences of obesity, inflammation, septicemia, and cancer are increased, and then the risk of dietary pattern shift is disclosed.

Long-term stable, high accuracy, and visual detection platform for In-field analysis of nitrite in food based on colorimetric test paper and deep convolutional neural networks.

Nitrite is one of the most common carcinogens in daily food. Its simple, rapid, inexpensive, and in-field measurement is important for food safety, based on the requirements of the standard from Codex Alimentarius Commission and China. Using polyacrylonitrile (PAN) and thin layer silica gel (SG), p-aminophenylcyclic acid (SA) and naphthalene ethylenediamine hydrochloride (NEH), as carriers and chromogenic agents, respectively, PAN-NSS as nitrite color sensor is proposed. After fixing and protecting of SA and NEH with layer-upon-layer PAN, the validity period of the test paper can be prolonged from 7 days to more than 30 days. The reproducibility of PAN-NSS preparation is ensured by electrospinning. Combined with PAN-NSS, deep convolutional neural network (DCNN) and APP as a visual monitoring platform, which has the functions of rapid sampling, data processing and transmission, intuitive feedback, etc., and provides a fully integrated detection system for field detection.

Low-toxic, fluorescent labeled and size-controlled graphene oxide quantum dots@polystyrene nanospheres as reference material for quantitative determination and in vivo tracing.

Polystyrene (PS) is selected as a representative nanoplastic and persistent pollutant for its difficult degradation and wide application. The environmental risk assessment of PS is obstructed by the toxic dye-based fluorescent PS, which false positives could be induced by the leakage of dye. For high biocompatibility, low toxicity, hydrophilicity, good water dispersibility, strong fluorescent stability, graphene oxide quantum dots (o-CQDs) are selected and embedded into PS microspheres, i.e., o-CQDs@PS, by microemulsion polymerization and denoted as CPS. Meanwhile, the sizes of CPS, e.g., 100, 150, and 200 nm, could be controlled by optimizing the type and number of water-soluble initiators. The anti-interference, low toxicity, and in vivo fluorescent tracing of CPS are proven by the coexistence of metals (including Fe2+, Fe3+, K+, Ba2+, Al3+, Zn2+, Mg2+, Ca2+, and Na+) on the fluorescence intensity of CPS, the growth of Chlorella pyrenoidosa and Artemia cysts as aquatic phytoplankton and zooplankton cultured with CPS, and the transfer of CPS from water into brine shrimp. In the concentration range of 0.1-100 mg/L, CPS can be quantitatively determined, which is suitable for coastal water and wastewater treatment plants. Therefore, CPS with standard size is suitable as reference material of PS.

Fiber magnetic-field sensor based on nanoparticle magnetic fluid and Fresnel reflection.

A simple fiber sensor for magnetic field measurement based on nanoparticle Fe(3)O(4) magnetic fluid and relative Fresnel reflection is presented. The sensor includes only a light source, three couplers, two photodetectors, and two fiber sensing ends. Magnetic fields at different concentrations of magnetic fluid are measured. Magnetic fluid with high concentration can be used for the measurement of weak magnetic fields, while low concentration fluid is used for the measurement of strong magnetic fields. The temperature dependence of the sensor is also addressed.

Benefit-risk assessment of metal bioavailability in edible fungi by biomimetic whole digestive tracts with digestion, metabolism, and absorption functions.

As worldwide edible fungi, Lentinula edodes and Agaricus bisporus accumulate both essential and harmful metals. Metal bioavailability is important for metal benefit-risk assessment. A full functional model of digestive tracts (including digestion, metabolism, and absorption) is established. Under the digestive tract functions, the bioaccessible and bioavailable metals are released from edible fungi and absorbed by intestinal tract, respectively. Based on bioavailable metal contents in the intestine, safe dosage and maximum consumption are 43.52 g/d and 248.7 g/d for Agaricus bisporu, 20.59/328.9 g/d (for males/ female) and 132.9 g/d for Lentinus edodes; V, Co, Ni, Cu, Zn, Se, Cr, Cd and Pb in Agaricus bisporus and Lentinula edodes are absorbed mainly in the large intestine; Fe is mainly absorbed in small intestine; edible fungi species-specificity in metal bioavailability is observed for As and Mn, which are mainly absorbed by small and large intestine for Agaricus bisporus and Lentinus edodes, respectively; and then metal toxicity on small and large intestine is disclosed. Metal benefit-risk is assessed by the content of monolayer liposome-extracted metal in the chyme from small and large intestine, which is controlled by the gastrointestinal functions, metal and edible fungi species.