A nano-radian precision absolute local slope measurement method for X-ray reflectors.

Ultra-precise reflectors in the advanced light source facilities urgently call for local slope error measurements with nano-radian precision. However, the existing methods currently utilized in the long trace profiler systems struggle to meet the requirements. In this paper, we present a weak-value amplification enhanced absolute local slope measurement scheme, in which the surface height difference between two adjacent points can be measured directly with precision on the pico-meter level. As a result, the absolute local slope measurement reaches a record precision level of 9.7 nrad (RMS) with a small lateral separation of 0.5 mm. Comparing to the existing methods, our scheme is more disturbance-resistant, more compact and cost-effective. The local curvature measuring capability is also validated with two synchronously parallel local slope measurement paths, between which the separation is set as 2mm. A local curvature measurement is obtained with precision of 3.4 × 10-6m-1 (RMS) and its corresponding slope variation is 6.8 nrad. Our method exhibits important application prospects in the field of ultra-precise surface fabrication inspection.

[Genetic analysis of a Chinese pedigree affected with Mucopolysaccharidosis type â ¢A].

OBJECTIVE: To explore the clinical and genetic characteristics of a patient with hypertrophic cardiomyopathy as the initial manifestation of Mucopolysaccharidosis type Ⅲ A (MPS Ⅲ A). METHODS: A female patient with MPS Ⅲ A who was admitted to the Affiliated Hospital of Jining Medical University in January 2022 and her family members (seven individuals from three generations) were selected as the study subjects. Clinical data of the proband were collected. Peripheral blood samples of the proband was collected and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing. Heparan-N-sulfatase activity was determined for the disease associated with the variant site. RESULTS: The proband was a 49-year-old woman, for whom cardiac MRI has revealed significant thickening (up to 20 mm) of left ventricular wall and delayed gadolinium enhancement at the apical myocardium. Genetic testing revealed that she has harbored compound heterozygous variants in exon 17 of the SGSH gene, namely c.545G>A (p.Arg182His) and c.703G>A (p.Asp235Asn). Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be pathogenic (PM2_Supporting +PM3+PP1Strong+PP3+PP4; PS3+PM1+PM2_Supporting +PM3+PP3+PP4). Sanger sequencing confirmed that her mother was heterozygous for the c.545G>A (p.Arg182His) variant, whilst her father, sisters and her son were heterozygous for the c.703G>A (p.Asp235Asn) variant. Determination of blood leukocyte heparan-N-sulfatase activity suggested that the patient had a low level of 1.6 nmol/(g·h), whilst that of her father, elder and younger sisters and son were all in the normal range. CONCLUSION: The compound heterozygous variants of the SGSH gene probably underlay the MPS ⅢA in this patient, for which hypertrophic cardiomyopathy is an associated phenotype.

Dual-task convolutional neural network based on the combination of the U-Net and a diffraction propagation model for phase hologram design with suppressed speckle noise.

In this paper, a dual-task convolutional neural network based on the combination of the U-Net and a diffraction propagation model is proposed for the design of phase holograms to suppress speckle noise of the reconstructed images. By introducing a Fresnel transmission layer, based on angular spectrum diffraction theory, as the diffraction propagation model and incorporating it into U-Net as the output layer, the proposed neural network model can describe the actual physical process of holographic imaging, and the distributions of both the light amplitude and phase can be generated. Afterwards, by respectively using the Pearson correlation coefficient (PCC) as the loss function to modulate the distribution of the amplitude, and a proposed target-weighted standard deviation (TWSD) as the loss function to limit the randomness and arbitrariness of the reconstructed phase distribution, the dual tasks of the amplitude reconstruction and phase smoothing are jointly solved, and thus the phase hologram that can produce high quality image without speckle is obtained. Both simulations and optical experiments are carried out to confirm the feasibility and effectiveness of the proposed method. Furthermore, the depth of field (DOF) of the image using the proposed method is much larger than that of using the traditional Gerchberg-Saxton (GS) algorithm due to the smoothness of the reconstructed phase distribution, which is also verified in the experiments. This study provides a new phase hologram design approach and shows the potential of neural networks in the field of the holographic imaging and more.

BnERF114.A1, a Rapeseed Gene Encoding APETALA2/ETHYLENE RESPONSE FACTOR, Regulates Plant Architecture through Auxin Accumulation in the Apex in Arabidopsis.

Plant architecture is crucial for rapeseed breeding. Here, we demonstrate the involvement of BnERF114.A1, a transcription factor for ETHYLENE RESPONSE FACTOR (ERF), in the regulation of plant architecture in Brassica napus. BnERF114.A1 is a member of the ERF family group X-a, encoding a putative 252-amino acid (aa) protein, which harbours the AP2/ERF domain and the conserved CMX-1 motif. BnERF114.A1 is localised to the nucleus and presents transcriptional activity, with the functional region located at 142-252 aa of the C-terminus. GUS staining revealed high BnERF114.A1 expression in leaf primordia, shoot apical meristem, leaf marginal meristem, and reproductive organs. Ectopic BnERF114.A1 expression in Arabidopsis reduced plant height, increased branch and silique number per plant, and improved seed yield per plant. Furthermore, in Arabidopsis, BnERF114.A1 overexpression inhibited indole-3-acetic acid (IAA) efflux, thus promoting auxin accumulation in the apex and arresting apical dominance. Therefore, BnERF114.A1 probably plays an important role in auxin-dependent plant architecture regulation.

How can urban parks be planned to maximize cooling effect in hot extremes? Linking maximum and accumulative perspectives.

How to maximize the cooling effect of urban parks in hot extremes has been closely linked to well-beings of citizens. Few studies have quantified urban parks' cooling effect in hot extremes from both maximum and accumulative perspectives. Here, we explored 65 urban parks' cooling effect based on spatially continuous cooling curves using multiple satellite images of Greater Xi'an (34°06' ∼34°34' N, 108°33' ∼109°15' E), one of China's metropolises with frequent hot extremes during July and August in 2019 summer. From maximum perspective, the urban parks cool down as far as 151.4 m, and covering 63.62 ha area, circa five times their own area in hot extremes; from accumulative perspective, the average cooling intensity is 0.78 °C along the whole continuous cooling distance spectrum, accumulated as 153.87 °C•m. And the urban parks show stronger accumulative cooling effect in hot extremes than the relative moderate temperatures. The cooling range could be maximized in large parks with dense trees, also in complex-shaped parks with strong interaction with surrounding environment. Small parks such as neighborhood parks located in the densely populated area are with maximum efficiency, cooling down about nine times their own area, which could serve as highly efficient cooling networks. Enhancing vegetation growth and coupling both blue and green infrastructures are always effective to increase accumulative cooling intensity in hot extremes. Our findings provide nature-based solutions (NBS) to counteracting heat stresses from the intense and frequent hot extremes in the future, also helpful for energy saving in the continuing climate change scenario.

U-Net convolutional neural network-based modification method for precise fabrication of three-dimensional microstructures using laser direct writing lithography.

In this paper, a modification method based on a U-Net convolutional neural network is proposed for the precise fabrication of three-dimensional microstructures using laser direct writing lithography (LDWL). In order to build the correspondence between the exposure intensity distribution data imported to the laser direct writing system and the surface profile data of the actual fabricated microstructure, these two kinds of data are used as training tensors of the U-Net convolutional neural network, which is proved to be capable of generating their accurate mapping relations. By employing such mapping relations to modify the initial designed exposure intensity data of the parabolic and saddle concave micro-lens with an aperture of 24µm×24µm, it is demonstrated that their fabrication precision, characterized by the mean squared error (MSE) and the peak signal-to-noise ratio (PSNR) between the fabricated and the designed microstructure, can be improved significantly. Specifically, the MSE of the parabolic and saddle concave micro-lens decreased from 100 to 17 and 151 to 50, respectively, and the PSNR increased from 22dB to 29dB and 20dB to 25dB, respectively. Furthermore, the effect of laser beam shaping using these two kinds of micro-lens has also been improved considerably. This study provides a new solution for the fabrication of high-precision three-dimensional microstructures by LDWL.

Characterization of tribenuron-methyl-induced male sterility in Brassica juncea L.

Significant heterosis has been documented in Brassica juncea L. that are grown as agriculturally important oilseeds, vegetables and condiments crops. Male sterility induced by chemical hybridizing agents is an important pollination control system in hybrid crop breeding. Herein, we show that tribenuron-methyl (TBM), a sulfonylurea herbicide, is an effective male gametocide in B. juncea when used at a very low dosage. In the present study, foliar application of various rates of TBM induced a significant increase in pollen sterility in B. juncea (90.57-100%). TBM-treated plants exhibited reductions in size of floral organ and yield components; however, lower dose of TBM (0.075 g a.i. ha-1) did not cause a significant reduction in seed yield per plant. Tapetum cells of TBM-treated plants were hypertrophied and degenerated earlier, and abnormal meiosis was observed at the meiotic stage. A significant decrease of acetohydroxyacid synthase (AHAS) activities was detected in buds of plants treated with 0.10 g a.i. ha-1 TBM, and RT-qPCR analysis showed that TBM exposure perturbed AHAS expression in small buds, which support that TBM induces male sterility in B. juncea by targeting AHAS expression. Our results suggest that TBM could be used as an efficient chemical hybridization agent in B. juncea, which has practical implications for the application of hybrid breeding in B. juncea.

Ultrasensitive Molecular Detection by Improving the Mode Energy of Graphene Plasmons for Surface Enhanced Infrared Absorption Spectroscopy.

Ultrasensitive detection of molecules by graphene plasmons based surface enhanced infrared absorption spectroscopy (SEIRAS) has attracted considerable research interest in recent years. However, SEIRAS still suffers from low enhancement. Herein, we investigated the crucial factors that determined the enhancement of graphene plasmons based SEIRAS. Through numerical calculations, it found that the enhancement of SEIRAS can be significantly improved by increasing the absorptance of graphene plasmons and the electron relaxation time of graphene. It revealed that such results were related to the mode energy of graphene plasmons. High absorptance and long electron relaxation time would result in high mode energy, which would in turn induce large local electric field to enhance the SEIRAS signal. Moreover, it showed that the resonant center of a molecular vibrational mode can be accurately extracted from the Rabi splitting spectra obtained by sweeping the Fermi energy of graphene. Our study could provide a guidance to improve the enhancement of graphene plasmons based SEIRAS for ultrasensitive molecular detection.

Mechanism of propagating graphene plasmons excitation for tunable infrared photonic devices.

The mechanism of propagating graphene plasmons excitation using a nano-grating and a Fabry-Pérot cavity as the optical coupling components is studied. It is demonstrated that the system could be well described within the temporal coupled mode theory using two phenomenological parameters, namely, the intrinsic loss rate and the coupling rate of a graphene plasmonic mode, and their analytical expressions are derived. It is found that the intrinsic loss rate is solely determined by the electron relaxation time of graphene, while independent of the field distributions of the modes. Such result originates from the negligible magnetic field energy of the graphene plasmonic mode. The coupling rate is governed by the optical coupling components parameters, and varies periodically with the Fabry-Pérot cavity length. By modulating the two rates, quality factors and absorption rates can be adjusted. Furthermore, it is revealed that low refractive index of the Fabry-Pérot cavity material is vital to the enlargement of tunable band, and the underlying physics is discussed. Such plasmon excitation configuration is insensitive to light incident angle and could serve as a platform for many tunable infrared photonic device, such as surface-enhanced infrared absorption spectroscopies, infrared detectors and modulators.

The all-optical modulator in dielectric-loaded waveguide with graphene-silicon heterojunction structure.

All-optical modulators based on graphene show great promise for on-chip optical interconnects. However, the modulation performance of all-optical modulators is usually based on the interaction between graphene and the fiber, limiting their potential in high integration. Based on this point, an all-optical modulator in a dielectric-loaded waveguide (DLW) with a graphene-silicon heterojunction structure (GSH) is proposed. The DLW raises the waveguide mode, which provides a strong light-graphene interaction. Sufficient tuning of the graphene Fermi energy beyond the Pauli blocking effect is obtained with the presented GSH structure. Under the modulation light with a wavelength of 532 nm and a power of 60 mW, a modulation efficiency of 0.0275 dB µm-1 is achieved for light with a communication wavelength of 1.55 µm in the experiment. This modulator has the advantage of having a compact footprint, which may make it a candidate for achieving a highly integrated all-optical modulator.

Three-dimensional conformal graphene microstructure for flexible and highly sensitive electronic skin.

We demonstrate a highly stretchable electronic skin (E-skin) based on the facile combination of microstructured graphene nanowalls (GNWs) and a polydimethylsiloxane (PDMS) substrate. The microstructure of the GNWs was endowed by conformally growing them on the unpolished silicon wafer without the aid of nanofabrication technology. Then a stamping transfer method was used to replicate the micropattern of the unpolished silicon wafer. Due to the large contact interface between the 3D graphene network and the PDMS, this type of E-skin worked under a stretching ratio of nearly 100%, and showed excellent mechanical strength and high sensitivity, with a change in relative resistance of up to 6500% and a gauge factor of 65.9 at 99.64% strain. Furthermore, the E-skin exhibited an obvious highly sensitive response to joint movement, eye movement and sound vibration, demonstrating broad potential applications in healthcare, body monitoring and wearable devices.

[Progress of Detection Technology of Ultra-Broadband THz Time-Domain Spectroscopy].

Terahertz Time-Domain Spectroscopy (THz-TDS) is one of the effective coherent detection techniques. It has been widely applied in materials, chemistry, biology, security and other fields due to its capabilities such as high signal-to-noise ratio (SNR), broadband detection, working at room temperature, time resolved measurement and others. Limited by the spectrum bandwidth of THz radiation and detection techniques, the measuring range of the traditional THz-TDS system is generally less than several THz, thus the spectral information of high frequencies cannot be obtained. In order to expand its application, there is an urgent need for the development of ultra-broadband (≥10 THz) THz-TDS detection techniques. This paper reviews the development and applications of main detection techniques in ultra-broadband THz-TDS. The advantages and disadvantages of these techniques are also analyzed.

[Current Status and Recent Advances in Research and Application of THz Technology in Articular Cartilage Detection].

Osteoarthritis is a common arthritis disease caused by cartilage tissue damage and degeneration, which is one of the large epidemics that affect human health. The early detection of the pathological changes of articular cartilage can greatly improve the cure rate of disease, but the relevant clinical diagnosis technology has not been developed. In recent years, the applications and researches of terahertz technology are increasingly valued and it has drawn great attention in the field of medicine. Compared with traditional methods, the terahertz radiation is low-energy and non-ionizing whose spectral-fingerprinting capability is well-known in the biological world. Meanwhile, THz technology has a great potential in diagnosis of articular cartilage early degeneration. This paper briefly introduces the physiological and pathological conditions of the articular cartilage, the current clinical techniques of articular cartilage detection. It mainly summarizes the terahertz technology used for detecting articular cartilage, including detection of animal and human cartilage respectively. At last, the challenges and development prospects of terahertz technology in articular cartilage detection are discussed.

Scaling phenomenon of graphene surface plasmon modes in grating-spacer-graphene hybrid systems.

We investigate the excitations of graphene surface plasmon waves in grating-spacer-graphene hybrid systems. It is demonstrated that the resonant absorption rate is scaling invariant as the geometric parameters of the hybrid system are scaled, and this phenomenon is nearly unaffected by the dispersions of the optical parameters of graphene and the grating material. We present an analytical model to calculate the absorption rate and elucidate that the scaling invariant phenomenon originates from the scalabilities of the graphene surface plasmon modes. This study could benefit the development of graphene plasmonic devices at infrared and terahertz frequencies.

Multi-focus plasmonic lens design based on holography.

Multi-focus plasmonic lens with metallic nanoslits of variant widths have great potential applications in optical interconnection, integrated optics and nanophotonics. But the design method with simulated annealing algorithm or Yang-Gu algorithm requires complex calculation and multi focuses are limited to be set on the same output plane. In this paper, we propose a design method based on holography. The desired light field distribution and the incident plane wave can be treated as object wave and reference wave, respectively. So the calculation is relative simple and multi focuses can be located in different output plane. Numerical simulation of multi-focus lens design is performed through finite-difference time-domain (FDTD) method and the result confirms the feasibility of our method.

Surface enhanced Raman scattering substrate with metallic nanogap array fabricated by etching the assembled polystyrene spheres array.

A sensitive surface enhanced Raman scattering (SERS) substrate with metallic nanogap array (MNGA) is fabricated by etching of an assembled polystyrene (PS) spheres array, followed by the coating of a metal film. The substrate is reproducible in fabrication and sensitive due to the nanogap coupling resonance (NGCR) enhancement. The NGCR is analyzed with the finite difference time domain (FDTD) method, and the relationship between the gap parameter and the field enhancement is obtained. Experimental measurements of R6G on demonstrate that the enhancement factor (EF) of the MNGA SERS substrate is increased by more than two fold compared with the control sample.

[Spectral characteristics of white organic light-emitting devices based on phosphorescent system of three iridium chelates].

A white organic light-emitting device (WOLED) with a yellow phosphorescence material, bis[2-(4-tertbutylphenyl) benzothiazolato-N,C2 '] iridium (acetylacetonate) [(t-bt)2Ir(acac)], and two blue phosphorescence materials, iridium(Ill) bis (4', 6'-difluorophenylpyridinato) tetrakis(1-pyrazolyl) borate (FIr6) and bis[(4, 6-difluorophenyl)-pyridinato-N, C2 '] (picolinate) iridium (III) (FIrpic), were fabricated. Stable white emission was realized by using undoped ultrathin yellow emissive layer (EML), two doped blue EMLs together with the proper thickness of an interlayer confining the exciton. The WOLED performed pure white light emission with the Commissions Internationale de l'Eclairage (CIE) coordinates of (0.29+/-0.01, 0.34+/-0.01) from 6 to 14 V. Moreover, electroluminescence (EL) characteristics of the devices were also studied to verify the emissive mechanism from a phosphorescent system consisting of three iridium chelates. Also, the results showed that the triple-phosphor-element EMLs WOLED had lower efficiency roll-off owing to the stable recombination zone.

Broadband absorption enhancement in a-Si:H thin-film solar cells sandwiched by pyramidal nanostructured arrays.

A new thin-film solar cell structure with a broadband absorption enhancement is proposed. The active a-Si:H film is sandwiched by two periodic pyramidal structured layers. The upper dielectric pyramidal layer acts as matching impedance by gradual change of the effective refractive index to enhance the absorption of the active layer in the short wavelength range. The lower metallic pyramidal layer traps light by the excitation of Fabry-Perot (FP) resonance, waveguide (WG) resonance and surface plasmon (SP) mode to enhance the absorption in the long wavelength range. With the cooperation of the two functional layers, a broadband absorption enhancement is realized. The structure parameters are designed by the cavity resonance theory, which shows that the results are accordant with the finite-difference time-domain (FDTD) simulation. By optimizing, the absorption of the sandwich structure is enhanced up to 48% under AM1.5G illumination in the 350-900 nm wavelength range compared to that of bare thin-film solar cells.

General conformal transformation method based on Schwarz-Christoffel approach.

A general conformal transformation method (CTM) is proposed to construct the conformal mapping between two irregular geometries. In order to find the material parameters corresponding to the conformal transformation between two irregular geometries, two polygons are utilized to approximate the two irregular geometries, and an intermediate geometry is used to connect the mapping relations between the two polygons. Based on these manipulations, the approximate material parameters for TE and TM waves are finally obtained by calculating the Schwarz-Christoffel (SC) mappings. To demonstrate the validity of the method, a phase modulator and a plane focal surface Luneburg lens are designed and simulated by the finite element method. The results show that the conformal transformation can be expanded to the cases that the transformed objects are with irregular geometries.

Resolution and stability analysis of localized surface plasmon lithography on the geometrical parameters of soft mold.

We have recently shown that patterns with 30 nm line width and micrometer scale periodicity could be steadily fabricated by employing localized surface plasmons lithography based on a soft mold [Opt. Lett. 35, 13 (2009)]. In this paper, the dependence of the resolution (pattern periodicity), critical dimension, and electric field intensity on the geometrical parameters of the soft mold, such as ridge width, mold periodicity, ridge depth, and slope, have been systematically studied and analyzed. The relevant simulation results by finite-difference time-domain demonstrate that the critical dimension exhibits a perfect stabilization and the value of electric field intensity would be especially large, when the ridge depth is in the range from 100 to 270 nm and the slope angle is below 35°. Importantly, the optimal resolution and critical dimension can reach 100 and 17 nm, respectively, by reasonably designing the corresponding mold periodicity and ridge width, which indicates that the method is particularly suitable for obtaining patterns with high density and is extremely promising for bio-sensing and photonic crystals application.