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Three-dimensional (3D) hybrid of nanocarbons is a very promising way to the high-performance design of electrocatalysis materials. However, sp3-like defect structure, a combination of high strength and conduction of graphene and carbon nanotubes (CNTs) is rarely reported. Herein, 3D neural-like hybrids of graphene (from reduced graphene oxide) and carbon nanotubes (CNTs) have been integrated via sp3-like defect structure by a hydrothermal approach. The sp3-like defect structure endows 3D nanocarbon hybrids with an enhanced carrier transfer, high structural stability, and electrocatalytic durability. The neural-like structure is shown to demonstrate a cascade effect of charges and significant performances regarding bio-electrocatalysis and lithium-sulfur energy storage. The concept and mechanism of “sp3-like defect structure” are proposed at an atomic/nanoscale to clarify the generation of rational structure as well as the cascade electron transfer.

The determination of the ozone concentration in the atmosphere is an urgent need but most current methods are limited by large-scale equipment or complex procedures. Herein, a gas–liquid chemiluminescence (GL-CL) assay based on a portable GL-CL detector platform was reported for the fast and sensitive online determination of ozone. Graphene quantum dots (GQDs) and Triton X-100 were employed to synergistically enhance the CL intensity of chromotropic acid (CA)–ozone. The increase was about seven-fold upon the addition of GQDs and Triton X-100. The potential enhancement mechanism was also investigated. The speculated CL enhancement mechanism was that GQDs could catalyze dissolved oxygen in the CA solution to produce more free radicals in the presence of UV-light, and these radicals converted CA into more active compounds that could react with ozone and emit photons. The free radicals, active compounds and luminophores were protected from water quenching by micelles produced by dissolving Triton X-100 in water and as a result, CL was markedly enhanced. Most importantly, the response time of the GL-CL detector platform towards ozone was less than 0.5 s. Based on this outcome, a GL-CL assay for detecting atmospheric ozone was successfully developed with a linear range from 0.1 to 150 ppbv and a detection limit of 0.02 ppbv. This work provides a rapid and sensitive method for the online measurement of ozone, and has great potential in environmental applications; the potential applications of GQDs and Triton X-100 in the field of GL-CL have also been highlighted.

The existence of the spherical aberration of the thermal lens in the crystal has a certain regulatory effect on the distribution of laser modes. In this paper, using the impact of this aberration on the superposition area of TEM01 and TEM10 modes, we carry out an experimental study of a 1064 nm hollow beam and its nonlinear frequency conversion providing a 532 nm hollow beam. Using a plano-concave cavity structure, under 21.92 W pump power at 808 nm, a 1064 nm hollow beam with an output power of 4.01 W is generated. Based on this result, a 532 nm hollow beam with an output power of 1.08 W is obtained by intracavity frequency doubling with type I phase matching in an LBO crystal. The conversion efficiency is 26.9%.

A large human natural single‑chain fragment variable (scFv) phage library was constructed based on Cre‑LoxP recombination, and used to successfully identify antibodies against proprotein convertase subtilisin/kexin type 9 (PCSK9). The library was derived from 400 blood samples, 30 bone marrow samples, and 10 cord blood samples from healthy donors. Lymphocytes were isolated from each sample and cDNA was synthesized using reverse transcription‑quantitative PCR. Two‑step overlap PCR was then used for scFv synthesis using a LoxP peptide as the linker. The scFv gene was inserted into the phagemid vector pDF by enzymatic digestion and ligation, and then transformed into Escherichia coli (E. coli) SS320 to establish a primary antibody library in the form of scFvs. A primary antibody library consisting of 5x107 peripheral blood and umbilical cord blood sources, as well as a primary antibody library of 5x107 bone marrow samples were obtained. By optimizing the recombination conditions, the primary phage library was used to infect E. coli BS1365 strain (which expresses the Cre enzyme), and a human scFv recombinant library with a size of 1x1011 was obtained through Cre‑LoxP enzyme‑mediated heavy and light chain replacement and recombination. This constructed recombinant library was employed to screen for antibodies against recombinant PCSK9. After four rounds of selection, a fully human antibody (3D2) was identified with a binding affinity of 1.96±1.56ⅹ10‑10 M towards PCSK9. In vitro, the PCSK9/low‑density lipoprotein receptor (LDLR) pathway of Hep‑G2 cells was inhibited by 3D2 treatment, thereby increasing LDL uptake in these cells. In addition, combination treatment with 3D2 and statin was more effective at increasing LDLR levels than treatment with 3D2 or statin alone. Furthermore, 3D2 resulted in a 3‑fold increase in hepatic LDLR levels, and lowered total serum cholesterol by up to 61.5% in vivo. Taken together, these results suggest that the constructed human Cre‑LoxP scFv phage display library can be used to screen fully human scFv, and that 3D2 may serve as a candidate hypolipidemic therapy.

Design of materials with desired properties is currently laborious and heavily relies on intuition of researchers through a trial-and-error process. To tackle this challenge, we propose a novel regressional and conditional generative adversarial network (RCGAN) for inverse design of representative two-dimensional materials, the graphene and boron-nitride (BN) hybrids. RCGAN incorporates a supervised regressor network, thus overcoming the common technical barrier in the traditional unsupervised GANs, which cannot generate data when fed with continuous and quantitative labels. RCGAN can autonomously generate graphene/BN hybrids given any target bandgap values. These structures are distinguished from the ones used for training and exhibit high diversity for a given bandgap. Moreover, they exhibit high fidelity, yielding bandgaps within ∼10% MAEF of the desired bandgaps as validated by density functional theory (DFT) calculations. Analysis by the principle component analysis (PCA) and modified locally linear embedding (MLLE) reveals that the generator has successfully generated structures following the statistical distribution of the real structures. It implies the possibility of the RCGAN in recognizing physical rules hidden in the high-dimensional data. The novel strategy for designing regressional GAN architecture together with the successful application to inverse design of materials would inspire further exploration in research fields beyond materials.

The competitive adsorption of 8-methylquinoline (8-MQL) and partially hydrogenated product, 4H-8-MQL, was studied by performing a combination of experiments and first-principles calculations over a selected Ru catalyst. A series of hydrogenation reactions were conducted with 8-MQL and 4H-8-MQL as initial reactants, respectively. 8-MQL exhibits stronger adsorption on catalyst surface active sites compared with 4H-8-MQL and the massive adsorption of 8-MQL hampers the further adsorption of 4H-8-MQL. The effects of temperature, pressure and solvent on the selectivity in 8-MQL hydrogenation were investigated as well. Full hydrogenation of 8-MQL to 10H-8-MQL was achieved within 120 min when the catalyst dosage increased from 5 wt% to 7 wt% under 160 °C and a hydrogen pressure of 7 MPa. The electronic charge of the N-heteroatom in 8-MQL and 4H-8-MQL was analyzed and the adsorption geometries of 8-MQL and 4H-8-MQL on the Ru(001) surface were optimized by DFT calculations to explain the competitive adsorption behaviors of 8-MQL and 4H-8-MQL.

Metalenses based on dielectric nanostructures operating in the transmission mode are of great practical significances. As large-area, multifunctional metalenses are increasingly demanded at higher volumes nowadays, the quality and efficiency of the nanofabrication processes for these lenses are made even more important. Yet, no fabrication is without defects or errors. By using finite-difference time-domain (FDTD) calculation method, we study, in simulation, a set of common fabrication-induced errors such as inclined sidewall, critical dimension (CD) bias and process defects, and analyze their influences on the optical performances of two types of metalenses – one made of amorphous silicon and the other of silicon nitride. The study concludes that the lens behavior generally relies on the resonant nature of the nanostructure array. While most types of defects discussed in this work linearly decrease the focusing efficiency, a few would also influence the quality of the focal spot. Potential solutions to mitigate the effect of the process-induced defects are also investigated. The study provides the particular knowledge to understand the actual metalens performance when fabricated.

Green-red (500nm-660nm) laser is widely used in laser projection, laser color display, lithography and laser communication. It is a relatively simple and effective method to obtain the green, orange and red laser from Pr3+:YLF crystal pumped by blue laser diode (LD). In this paper, the influence of output mirror with different transmittance and different curvature radius on the output power of green laser is analyzed. The green laser is achieved with the maximum output power of 960mW at 522nm, when the full pumping current is 2.269A, the absorption power of a-cut Pr3+:YLF crystal is 7.44W.

An evaluation model for optimizing system parameters was established in this study using longitudinal-mode pre-lase selection technology. By solving the rate equation and calculating the evaluation function, we determined the evaluation efficiency of a single-longitudinal-mode operation using this scheme. The optimal condition for the characteristics of the single-longitudinal Q-switched laser was also analytically calculated in detail. We observed that the evaluation function derived using the two-step signal of the Q-switch modulation time and other resonator parameters significantly influenced the output characteristics of the single-longitudinal-mode Q-switched laser operation. Furthermore, the experimental results were consistent with the simulations.

Ni-rich cathode material LiNi0.6Co0.2Mn0.2O2 with the advantage of relative high capacity, low cost and high safety has been realized mass industrial production. To maximize the electrochemical performance of LiNi0.6Co0.2Mn0.2O2, it is highly necessary to gain insight into the inherent laws of precipitation process and precisely control the characterization of secondary and primary particle of precursor. Herein, the evolution of structure, morphology, D50, tap density, {010} facts for Ni0.6Co0.2Mn0.2(OH)2 precursor and the electrochemical performance of corresponding cathode modulated by ammonia during hydroxide precipitation are investigated. The particle size, D50, tap density and morphology are charged with the increase of reaction time under different of ammonia concentration. When the feeding time is larger than 32 h, the steady state of the continuous precipitation is reached. The higher amount of ammonia leads to the formation of precursor crystal with higher percentage of (001) plane and cathode with better electrochemical performance. The understanding of the evolution of precursor and electrochemical performance of Ni-rich cathode modulated by ammonia during hydroxide precipitation would provide new a guiding significance for the controllable preparation of other lithium transition metal oxide materials.

A dual-wavelength continuous-wave laser with direct intra-cavity pumping using a 879 nm laser diode that utilizes Nd:GdVO4 and Nd:YVO4 crystals, is presented. To the best of our knowledge, this system completely eliminates the gain competition between the 912 nm and 1064 nm transitions for the first time. A theoretical model is introduced to describe this intra-cavity pumped dual-wavelength laser. The lasing threshold of the 912 nm Nd:GdVO4 laser is presented by considering the ground-state reabsorption loss effect. A total output power of 1.33 W at dual-wavelength operation with an absorbed pump power of 7.91 W is experimentally achieved. The individual output power for the 912 nm and 1064 nm emissions were 0.43 W and 0.9 W, respectively. Both wavelengths operate in TEM00 mode with a total slope efficiency >20%.

In this study, based on the intra-cavity pumped dual-wavelength theoretical model, a reabsorption effect is introduced into a quasi-three-level laser, and a new theoretical model of a dual-wavelength laser with reabsorption effect is presented. Through experiments, the output characteristics of no gain competition 912 nm and 1064 nm dual-wavelength lasers with Nd:GdVO4 and Nd:YVO4 are presented for the first time. Results showed that at an incident pumping power of 38.9 W, the total output power was generally higher than at 3.6 W (1.4 and 2.2 W at 912 nm and 1064 nm, respectively) and the overall optical-to-optical efficiency was > 17%. The fluctuations in the output powers of the 912 nm and 1064 nm lasers were 1.62 and 2.18%, respectively. However, the fluctuation in the total output power was only 0.28% at a pumping power of 27.7 W. The laser mode was TEM00, and the measured M2 values for 912 nm and 1064 nm lasers were 1.35 and 1.28, respectively, under a pumping power of 30 W.

Graphene has shown great potentials for new-generation photodetectors in view of its outstanding optical and electrical properties, especially its ultra-broad range absorption. Most of graphene(Gr)/Si hybrid two-dimensional(2D)-three-dimensional(3D) photodetectors, which offer a perspective on future application in integrated optoelectronics, are still however enabled the excellent detection on visible light. Herein, we reported a self-powered Gr/Si Schottky heterojunciton with a high sensivity to communication light of 1.55 μm wavelenght by using graphene film as active area. The resultant photodetectors showed a high-speed response speed up to 5.0 μs, togther with a responsivity approaching 39.5 mAW−1, which are comparable with previous graphene-based photodetectors and superior to previous Gr/Si heterojunction. The high-performance of the schottky heterojunction can be ascribed to featuring a built-in field facilitating to separate photocarriers. Combined our results with the methodology of devcie fabrication, can be utilized as pathway for large-area integration of 1.55 μm communication light photodetectors.

Based on quasi-conformal mapping approach, we propose a two-dimensional broadband and low-loss planar lens in the acoustic regime, which can be realized using gradient-index sub-wavelength artificial structures with hard boundary. In this design, QCM is employed in the acoustic regime to convert a parabolic form into a planar one, which makes the resultant material approximately isotropic through minimizing the anisotropic factor. It is found that the planar lens can show the same performance as its parabolic counterparts over a broadband range of frequency. Moreover, the lens is fabricated via 3D printing technology and measured experimentally, which gives identical results with the theoretical prediction. The proposed technique could be extended to realize different acoustic devices and applied for a series of practical applications.

The brain deforms during neurosurgery, resulting in a decrease in the accuracy of the image guided neurosurgery system (IGNS). In this study, a wireless transmission-based brain shift compensation system (WBSCS) is implemented. The system consists of a laser range scanner for acquiring a cortical surface, and a mobile workstation equipped with a brain deformation correction software platform. The brain tissue deformation correction software platform includes a three-dimensional visualisation module, a calibration module, a brain tissue extraction module, a meshing module, a boundary condition acquisition module, a finite element calculation module, a preoperative image update module, and a communication module. The system exchanges data with the IGNS through wireless communication. The authors used five pigs to test the system. Results of experiments show that the system can compensate for brain deformation. It worked with IGNS to provide brain-shift-compensation-based guidance, improving the accuracy of the IGNS.

In this paper, the effect of injected energy on low energy single longitudinal mode (SLM) pre-lase Q-switched is analyzed and the optimization procedure is shown in detail. Here, taking the Pr:YLF laser as an example of low energy laser, and the parameters of Pr:YLF laser by using pre-lase have been shown. Compared with normal Q-switched laser, the single pulse energy reaches 60.16% and the pulse width exceeds 39.73% when the same maximum energy is injected and SLM is achieved in pre-lase. The analysis results show that pre-lase is suitable for low energy laser to obtain SLM and there be an optimal performance to achieve the optimal energy output.

The output characteristics of a narrow linewidth, no-gain competition, dual-wavelength solid-state laser using an intra-cavity pumped method are reported. This system consists of an intra-cavity pumped Nd:YVO4 laser emitting at 1064 nm, using a 912 nm Nd:GdVO4 laser. A Fabry-Perot etalon is used to compress the linewidth that located at the common cavity of 912 nm and 1064 nm laser. Theoretical analysis and experimental verification were carried out. When the pump power is 32.8 W, the output of 912 nm and 1064 nm theoretical value is 0.036 W and 0.046 W, and the experimental value is 0.017 W and 0.016 W, respectively. The change trend of the theoretical simulated output power value was the same as the actual measured value in the experiment. In addition to this, the experimental measurement shows when the etalon with an angle of 15?, corresponding minimum linewidths were 0.284 nm and 0.627 nm, respectively.

Background Radiofrequency ablation and microwave ablation are frequently prescribed for thoracic cancer. However, few writers have been able to draw on any systematic research into the differences between the two ablation methods. Methods A literature search was carried out using Embase, PUBMED, Web of Science, Cochrane Library, and CNKI databases, with additional searches carried out manually using terms associated with thoracic cancer and thermal ablation. Then we used Google Scholar for a complementary search. Data were extracted from studies of patients that underwent radiofrequency ablation or microwave ablation, and the investigator carried out efficacy evaluation and follow up. The data obtained from the literature were summarized and analyzed using Cochrane Revman software Version 5.3 and SPSS 22.0. Results There were seven comparative studies, but no randomized studies identified for data extraction; 246 patients received radiofrequency ablation therapy and 319 controls received microwave ablation. There was no significant difference in the six-month, one-year, two-year, and three-year survival rates, and adverse reactions were found in the two treatments. For patients' long-term survival rate, the two treatments can achieve a similar survival time. Conclusion In the treatment of thoracic cancer, microwave ablation can achieve the same efficacy as radiofrequency ablation.

In this work, we investigated the effect of formaldehyde-induced autofluorescence using multiphoton and confocal microscopy. Porcine aorta, brain, kidney, and ventricle were processed, sliced, and immersed in 10% neutral buffered formalin at ambient temperature for different length of time. Our preliminary results show that the inducedautofluorescence in brain and ventricle tissue increases through time, whereas for aorta and kidney it remains nearly the same.

Polarization light microscopes are powerful tools for probing molecular order and orientation in birefringent materials. While a multitude of polarization light microscopy techniques are often used to access steady-state properties of birefringent samples, quantitative measurements of the molecular orientation dynamics on the millisecond time scale have remained a challenge. We propose polarized shearing interference microscopy (PSIM), a single-shot quantitative polarization imaging method, for extracting the retardance and orientation angle of the laser beam transmitting through optically anisotropic specimens with complex structures. The measurement accuracy and imaging performances of PSIM are validated by imaging a rotating wave plate and a bovine tendon specimen. We demonstrate that PSIM can quantify the dynamics of a flowing lyotropic chromonic liquid crystal in a microfluidic channel at an imaging speed of 506 frames per second (only limited by the camera frame rate), with a field-of-view of up to $350\times350 \mu m^2$ and a diffraction-limit spatial resolution of $\sim 2\mu m$. We envision that PSIM will find a broad range of applications in quantitative material characterization under dynamical conditions.

We develop a theoretical model of multimode rate equation that accurately describes mode evolution mechanism of prelase Q-switched Pr3+:YLF single longitudinal mode (SLM). We find that it is important to consider the effect of gain difference when calculating the mode competition time accurately. We identify that there is an optimal parameter for the two step signal of acoustic-optic modulator which determines the stability of SLM output. Then, a visible light direct oscillation Q-switched SLM Pr3+:YLF laser at 639.5 nm is obtained, and the experimental results is agree with the simulation very well.

A diode-pumped passively Q-switched intracavity Raman laser is experimentally investigated, in which a c-cut Nd:GdVO4 crystal is used as a self-Raman medium and a c-cut Nd:YVO4 crystal is only used as a Raman medium. Simultaneous laser pulse outputs at 1096, 1176, 1177 nm corresponding to the first-Stokes light at 259, 882 and 890 cm−1 are acquired. 1128 nm light corresponding the second-Stokes light at 259 cm−1 is obtained and occupies the majority of the output power. The Stimulated Raman Scattering at 259 cm−1 takes place in both the GdVO4 and the YVO4 crystals. With an incident pump power of 7.74 W and a pulse repetition frequency of 30.5 kHz, the average output powers at 1096, 1128, 1176 and 1177 nm are 47.6, 446, 27 and 44.2 mW, respectively.

In this work, two new types of structurally stable two-dimensional (2D) carbon nitrides are predicted by first-principles calculations. They are derived by extracting two adjacent atomic layers from cubic diamond or hexagonal diamond and then substituting the unsaturated C atoms with N atoms. The formed 2D diamond-like carbon nitrides are named as 2D c-C2N2 and 2D h-C2N2. First-principles calculations on their structural stability, electronic, mechanical, and thermal properties were performed. It is revealed that they are semiconductors with a direct band gap of ∼4.43 eV for c-C2N2 and an indirect band gap of 3.70 eV for h-C2N2. Their Young's modulus reaches as high as 1.08 TGa for c-C2N2 and 1.06 TGa for h-C2N2, both of which are comparable to that of graphene. The c-C2N2 shows a thermal conductivity of 41200 W/m·K while the h-C2N2 has a thermal conductivity of 49500 W/m·K at 80 K. These values are several times of those of graphene and diamond at the same temperature. This research provides theoretic perspectives for exploring novel 2D carbon nitrides with extraordinary properties. Once experimentally realized, they would open widespread applications in electronics, optoelectronics, heat management, and mechanical structures.

IntroductionFor sciatica caused by lumbar disc herniation (LDH), the standard surgical technique is conventional microdiscectomy. In recent years, minimally invasive techniques (eg, percutaneous transforaminal endoscopic discectomy (PTED), paraspinal minitubular microdiscectomy (PMTM)) have gained increasing interest. PTED and PMTM are considered alternative minimally invasive techniques for the treatment of LDH. Due to insufficient evidence, the differences in efficacy between PTED and PMTM have been debated. A pragmatic, multicentre, non-inferiority, randomised controlled trial has been designed to determine the efficacy and cost-effectiveness of PTED versus PMTM for the treatment of LDH.Methods and analysisA total of 280 patients (18–70 years) presenting with significant symptoms of sciatica and failure after 3 months of conservative treatment will be recruited. Patients must have an indication for surgery based on MRI demonstrating LDH with nerve root compression. Patients will be randomised to PTED or PMTM treatment. The primary outcome is Oswestry Disability Index scores. Secondary outcomes include Visual Analogue Scale scores, Short Form 36 health survey scores, physical examination, length of hospital stay, costs and complications. Outcomes will be measured the day following surgery, at 1 week, and at 1, 3, 6, 12 and 24 months after surgical treatment. Physical examination will be conducted at 1 week, 1 month and 12 months after surgery. The non-inferiority margin for the primary outcome is 5.Ethics and disseminationEthical approval has been granted by the Ethics Committee of Fujian Medical University Union Hospital, Fuzhou, China (2018YF010-02). Results of the research will be published in an international peer-reviewed scientific journal and disseminated through presentation at scientific conferences.Trial registration numberChiCTR1800015727; Pre-results.

Two-dimensional (2D) graphitic carbon nitrides (2D GCNs) are a rising class of 2D polymeric materials. Compared with graphene, they have many attractive merits, such as their great semi-conductivity and photo-catalyticity. Despite much progress in studying their various properties, their thermal properties have been given little attention. In this work, thermal conductivities of three kinds of 2D GCNs, heptazine-based g-C3N4 (HEP), triazine-based g-C3N4 (TRI), and 2D polyaniline g-C3N (PANI), were computationally investigated by non-equilibrium molecule dynamics (NEMD) simulations based on both Tersoff and ReaxFF potentials, which offer comprehensive understanding of their thermal properties. It was found that the PANI was predicted to show extrapolated bulk thermal conductivities of 810 W/(m⋅K) and 461.9 W/(m⋅K) by the Tersoff and ReaxFF potentials, respectively. The HEP and TRI have much lower bulk thermal conductivities, ranging from 14.1 to 119 W/(m⋅K). Nevertheless, they are still much higher than those of traditional polymers. The ReaxFF potential also shows that carbon–nitrogen bonds are stiffer than those modeled by the Tersoff potential, resulting in higher phonon harmonicity, and longer phonon mean free paths.

We report a new type of responsive polymer film which is composed of pure poly(vinylidene fluoride) (PVDF) and is prepared using a simple solution-casting method. This responsive PVDF film possesses an anisotropic spatial distribution of the α phase and β phase, resulting in a fast response rate, high sensitivity, and robust responsiveness to organic vapors. Experimental and computational studies illustrate that α-phase PVDF exhibits a much stronger swelling ability in acetone vapor than β-phase PVDF. Anisotropic swelling induces internal stresses, offering a driving force for macroscopic shape transformation. This newly unveiled mechanism endows the material with new functionalities for fabricating devices such as a magnetically controlled soft tumbler and a chemi-mechanical sensor. Furthermore, crystal phase anisotropy in the PVDF film can be easily programmed into origami patterns by direct laser writing (DLW) for driving reversible three-dimensional (3D) shape transformation of the film.

Theory and experiment of Tm: YAG 2 μm double-pulse laser output based on the two-step signal of acousto-optic Q-switch is presented for the first time. As pump power of 10 W, a Q-switched Tm: YAG double-pulse laser is achieved with output energy of 3.6 mJ at 2014.16 nm and repetition rate of 100 Hz. The pulse width of the first pulse is 416 ns, and that of the second is 407 ns. The interval between the two pulses is 1 ms. The beam quality is M2x = 1.39 and M2y = 1.34.

This paper presents a high repetition rate and high power 1.57 μm and 3.84 μm multiple optical parametric oscillator based on a single MgO:APLN crystal and pumped by a pulsed 1.064 μm MOPA laser for the first time. In the experiment, with a repetition rate of 200 kHz, a maximum average output powers of 6.5 W at 1.57 μm and 4.3 W at 3.84 μm were obtained under 49 W of 1064 nm pump power, corresponding to optical–optical conversion efficiencies of 13.3% and 8.8%, respectively. The pulse widths were 12.8 and 11.2 ns for 1.57 μm and 3.84 μm, respectively, at the maximum output power.

Carbon fiber reinforced polymers (CFRP) are a widely used composite material applied in both commercial and industrial utilization. Based on the heat conduction theory, a theoretical model for the temperature rise of braided CFRP irradiated by long pulse laser is established in this work, and the time required for the maximum temperature rise of CFRP (with different thicknesses) to be acted by long pulse laser with different energy densities and pulse widths is simulated. At the same time, the temperature rise experiment and damage morphology of a long pulse laser with braided CFRP were carried out. The theoretical simulation results are in good agreement with the experimental results, which verifies the correctness of the theoretical model. The results of this paper will provide a theoretical basis for laser processing of CFRP.

In the design and development of liquid breeder blankets, a number of duct geometries are considered, such as the multiple channel, U-turn duct and T-shaped duct. In the presence of the magnetic field, the motion of electrically-conducting liquid metal leads to Megnetohydrodynamic phenomena, as results of the liquid metal flow profile changes inside the flow channels and additional pressure drop of liquid breeder blankets. A three-dimensional liquid-metal (LM) magnetohydrodynamic (MHD) flows in a U-turn duct with large aspect ratio of the duct cross-section of the connecting channel and in a U-turn conduit with manifold in the connecting region is studied, respectively. Here, the effects of the electrical conductivity of the separating wall in the manifold and different Hartmann numbers on the flow features are considered. Since the 3-D currents are induced due to the complicated geometrical flow path, the electrical conductivity of the separating wall plays a key role in the distribution of mass flow rate among the parallel ducts in manifold. Thus, in the present study, the distribution of the mass flow rate is analyzed for different electrical conductivity of the structural walls. Furthermore, since the aim of the optimal design of liquid-metal blanket is to achieve a proper velocity distribution and reduce the pressure drop caused by the flow opposing Lorentz force, the investigation of the effect of the duct geometry on the pressure distribution in this study is significant.

A method is presented to determine the focal lengths of thermal lenses and the beam waist of an intracavity-pumped dual-wavelength narrow-linewidth laser in the laser gain medium. In this method, two thermal lenses are introduced in the laser system, and the thermo-stable resonator is investigated after confirming the radius of the wave surface of a Gaussian beam R or spot size value ω based on σ and π circles. The transformation circle theory is used in this analysis, and the relationship between the fundamental-mode spot size in two gain mediums and the thermodynamic factor 1 / f t is obtained. The effect of the thermal lens on the output power is also measured and analyzed. Finally, a thermo-stable resonator for an intracavity-pumped narrow-linewidth dual-wavelength laser is developed by analyzing the dynamic stability zone with the two thermal lenses.

Carbon nanotubes (CNTs) and graphene are thought to be building bricks for next-generation thermal management devices due to their ultra-high thermal conductivities. However, in practical applications they do not exhibit their full potentials due to issues from interfaces, dopants, and functional groups. Thus, deep understanding of these effects on the thermal conductivities is needed. Molecular dynamics (MD) simulation can provide such insights into these material systems. However, prediction capability is limited by a narrow choice of chemical elements in traditional equilibrium MD potentials. Herein, non-equilibrium MD (NEMD) simulations were implemented to study the thermal conductivities of CNTs and graphene by using ReaxFF potentials (Reax-03, Reax-12, and Reax-15), all of which enable a wider choice of the element category. In the simulations, CNT and graphene have maximum lengths of 400 nm. The length-dependent thermal conductivities were studied in those systems. The ReaxFF potentials predicted higher thermal conductivities and longer phonon mean free paths than the traditional AIREBO potential. The geometry and location of G-peaks shown in the phonon density of states calculated by the Reax-03 and Reax-12 potentials were similar to the results obtained from the AIREBO potential. In contrast, a wider G-peak was obtained from the Reax-15 potential. The phonon dispersion curves based on each potential showed that Reax-03 and Reax-12 can predict accurate out-of-plane modes when compared with experiments. The Gruneisen parameters of the ZA mode based on the Reax-03 and Reax-12 potentials are smaller than those based on the AIREBO potential, indicating a lower anharmonicity of lattice vibrations. Radical distribution functions from the Reax-03 and Reax-12 potentials showed a higher lattice stiffness and longer phonon mean free paths (MFPs) than those obtained from the AIREBO potential. These results illustrate the capability of ReaxFF in predicting thermal conductivities of low dimensional carbon allotropes and their derivatives for advanced heat management.

Rechargeable lithium-sulfur batteries are deemed to be a promising energy supply to next-generation high energy power system, yet dissolution of lithium polysulfides in the electrolyte leads to poor cycling performance. Here, we report an approach to assemble graphene and polydopamine double-wrapped porous carbon/sulfur (GN-PD-PC-S) for lithium-sulfur batteries. Remarkably, the double-wrapping graphene and polydopamine further help confine the sulfur and polysulfides inside the mesopores and micropores of porous carbon. Moreover, the hierarchical porous structures provide a conductive network for electron transfer and facilitate the effective accommodation of the volume change of sulfur. The GN-PD-PC-S cathode presents an excellent cycling stability of 821 mAh g−1 after 100 cycles, with a favorable high-rate capability of 496 mAh g−1 at a current density of 2 A g−1. Our results indicate the importance of chemically synergistic effect of polymer and carbon in the electrode system for achieving high-performance electrodes in rechargeable lithium-sulfur batteries.

A continuous-wave 1.57 and 3.84 μm intracavity multiple optical parametric oscillator based on a single MgO:APLN crystal is reported for the first time. The synchronized dual-wavelength laser is obtained by using a folded-type double cavity, which consists of a 1064-nm resonator and a multiple optical parametric oscillator. With T = 10% at 1.47 and 3.3 μm output couplers, maximum output powers of 3.13 W at 1.57 μm and 0.85 W at 3.84 μm are obtained, corresponding to slope efficiencies of 6.8% and 1.9%, respectively. The power stabilities are better than 1.8% and 3% at the maximum output power in half an hour.

BACKGROUND Long non-coding RNAs (lncRNAs) have been confirmed to play an important role in the development and progression of diseases. Ankylosing spondylitis (AS) is a chronic inflammatory systemic disease and it is hard to be found in early time. The purpose of this study was to investigate the role of lncRNA-AK001085 in the diagnosis of AS. MATERIAL AND METHODS The expression of lncRNA-AK001085 was detected by quantitative real-time polymerase chain reaction (qRT-PCR) analysis. The relationship between its expression and clinicopathologic characteristics was also analyzed. Meanwhile the correlation between lncRNA-AK001085 expression and diseases activity indexes was estimated. In addition, the value of it in the diagnosis of AS was explored through establishing receiver operating characteristic (ROC) curve. RESULTS Serum lncRNA-AK001085 expression was decreased in patients with AS compared with healthy individuals. And its expression was proved to be influenced by ever cigarette smoker, exercise level and occupational activity level. Besides, the correlation of the expression of lncRNA-AK001085 and disease activity indexes (BASDI, ASDAS, ESR, CRP) were all negative, which suggested that the lncRNA-AK001085 was significantly lower in patients with a high disease activity score. It might showed that the expression of lncRNA-AK001085 affected the activity of AS. CONCLUSIONS LncRNA-AK001085 was down-regulated in AS patients and it could be an independent diagnostic indicator.

High tensile strength and optical clarity are unique properties of the cornea. These features are dictated by the three-dimensional architecture of corneal lamellae. Therefore, understanding the microscopic details of the cornea’s structural organization may contribute to the development of artificial cornea for the treatment of corneal diseases. In this study, the combination of forward second harmonic generation (SHG) microcopy and fast Fourier-transform based image analysis was used to characterize the depth-dependent superstructure of chicken corneal stroma. Our results show that from the surface, adjacent lamellae of anterior chicken cornea lamella rotate in a counterclockwise direction, and the same rotational helicity is observed in left and right corneas. Furthermore, the overall average rotational pitch of lamellae is 0.92 ± 0.11 degree/µm which persists for 176 ± 14 µm in the anterior stroma. As depth further increased, the rate of lamellar rotation decreases. Upon reaching posterior stroma, lamellar orientation remains constant. Throughout the stroma, collagen lamellae in chicken rotate a total of 169 ± 21 degrees. The lack of lamellar rotation in posterior stroma suggests that packing efficiency cannot be used to explain the helicity of depth-dependent rotation of anterior stroma. In addition, although the right cornea has a higher rotational pitch (0.95 ± 11 vs 0.90 ± 10 degrees/µm) and thinner anterior stroma (173 ± 13 vs 179 ± 14 µm) than the left cornea, the two effects cancel each other out and result in similar total angular rotation of anterior stroma (161 ± 23 and 165 degrees ± 21). Finally, our observation of a total angular rotation of 169 ± 21 degrees shows that within experimental error, chicken cornea lamellae rotate around 180 degrees or half of a complete turn. Additional studies are needed to arrive at an explanation of chicken superstructure in three dimensions.

It is known that the interlayer van der Waals (vdW) interactions will decrease the thermal conductivity of graphene. Single layer graphene (SLG) has the highest thermal conductivities, double layer graphene (DLG) would decrease to about half of the thermal conductivity of SLG. The graphite was measured to have a thermal conductivity of about 2000 W/m-K. Some research shows that graphite differs from SLG within a factor of 2, and DLG has almost the same thermal conductivity with graphite. In theoretical aspect, how to simulate the vdW interaction between graphene layers is a long existing problem. It is only until recently that the vdW interaction is still an active topic in first principle calculations. The popular methods include the Grimme’s DFT-D, vdW-DF and vdW-DFT-R methods. The vdW-DFT-R method was further optimized to increase accuracy by Hamada and was found to predict the most accurate interlayer distance between AB-stacked graphene in our recent study. The motivation of this work is to investigate the effect of vdW interaction on the thermal conductivity of multiple layer graphene from principles. We will calculate firstly the phonon dispersion relations of multiple layer graphene with the vdW interaction included. The obtained phonon properties and force constants will be combined with the ShengBTE method to calculate the thermal conductivity. The results show how vdW interaction causes the dimensional crossover of graphene thermal conductivity.

The dual-active-bridge (DAB) converter attracts more and more attentions due to its ability of bidirectional power transmission and high conversion efficiency. The adoption of high-frequency transformer provides galvanic isolation, but also brings the possibility of de bias. In this paper, the causes of de bias have been analyzed comprehensively and relevant calculation methods are derived in details. With the calculation methods, the dc bias magnetizing current can be predicted considering the inconsistency of semiconductor switches and driver signals. In other words, if the maximum permitted dc bias of the transformer is given, the range of the inconsistency of semiconductor switches and driver signals can be obtained which helps guide the selection of semiconductor devices and design of the transformer. Therefore, the extra flux balancing method can be avoided and the overall cost and volume will be reduced further. Additionally, the simulation and experimental results show great agreement with the theoretical analysis.

It is well-known that the atomic-scale and nano-scale configuration of dopants can play a crucial role in determining the electronic properties of materials. However, predicting such effects is challenging due to the large range of atomic configurations that are possible. Here, we present a case study of how deep learning algorithms can enable bandgap prediction in hybridized boron–nitrogen graphene with arbitrary supercell configurations. A material descriptor that enables correlation of structure and bandgap was developed for convolutional neural networks. Bandgaps calculated by ab initio calculations, and corresponding structures, were used as training datasets. The trained networks were then used to predict bandgaps of systems with various configurations. For 4 × 4 and 5 × 5 supercells they accurately predict bandgaps, with a R2 of >90% and root-mean-square error of ~0.1 eV. The transfer learning was performed by leveraging data generated from small supercells to improve the prediction accuracy for 6 × 6 supercells. This work will pave a route to future investigation of configurationally hybridized graphene and other 2D materials. Moreover, given the ubiquitous existence of configurations in materials, this work may stimulate interest in applying deep learning algorithms for the configurational design of materials across different length scales.

We report all-Si metasurface based polarizing bandpass filter (PBF) fabricated on 12 inch wafer, employing CMOS-compatible 193nm ArF DUV immersion lithography and ICP etch. The fabricated metasurface PBF work on dual short wave infrared bands.

Pseudomorphic GeSn/Ge multiple-quantum-well p-i-n photodiodes were studied at 2 μm range. Direct current and radio frequency measurements were performed to investigate the electrical and optical property of GeSn/Ge MQWs for photo detection and electro-absorption modulation.

We demonstrate ultralow loss AlN single-mode channel waveguide and AlN electro-optic (EO) modulators in CMOS compatible AlN-on-insulator photonic circuits. Propagation loss was measured to be ∼0.42 dB/cm at 1550 nm and ∼2.36 dB/cm at 905 nm. A push-pull MZI modulator with arm length of 2.8 cm exhibits V of ∼21 V at 1550 nm and ∼12.9 V at 1064 nm, and modulation speed of ∼140 MHz, limited by the resistive-capacitive delay. A dual-ring modulator exhibits extension ratio of ∼12 dB and high modulation speed of ∼4 GHz because of its small footprint as compared with the MZI modulator.

We present that the guided surface magneto-plasmons (SMPs) can be finely tailored and truely stopped at specific location in a class of non-reciprocal graded waveguide system. By examining the dispersion properties of SMPs, the one-way propagating wave stops eventually at the band edge in the proposed waveguide system, where the group velocity vanishes. Meanwhile, the stopped location can be readily tuned by an external static magnetic field. Numerical calculations on the group velocity of propagating SMPs and the spatial field distribution are employed to verify the formation of hotspots. The impact of intrinsic absorption as well as fabrication disorder involved in the realistic waveguide structure is also investigated. The results may suggest an effective method for fast modulation on wave harvesting and energy concentration through external magnetic field.

The stable zones of the first three low-order modes of the LD end-pumped laser dynamically controlled by spherical aberration are proposed. Considering the temperature dependence of thermal conductivity, an aberration factor representing spherical aberration is calculated. Based on the multiples of the thermal focal lengths of the fundamental mode, TEM01 and TEM10, their dynamic stable zones were confirmed. An asymmetrical LD end-pumped Nd:YVO4 laser wavefront information measurement experiment was performed. The primary spherical aberration, the beam quality factor and the output power were measured, and their changes with the pumping power were analyzed to determine the dynamic stable zone. The experimental results agree well with the theoretical simulations.

Optical color filters are widely applied in many areas including display, imaging, sensing, holography, energy harvest, and measurement. Traditional dye-based color filters have drawbacks such as environmental hazards and instability under high temperature and ultraviolet radiation. With advances in nanotechnology, structural color filters, which are based on the interaction of light with designed nanostructures, are able to overcome the drawbacks. Also, it is possible to fabricate structural color filters using standard complementary metal-oxide-semiconductor (CMOS) fabrication facilities with low cost and high volume. In this work, metasurface-based subtractive color filters (SCFs) are demonstrated on 12-inch (300-mm) glass wafers using a CMOS-compatible fabrication process. In order to make the transmissive-type SCF on a transparent glass wafer, an in-house developed layer transfer process is used to solve the glass wafer handling issue in fabrication tools. Three different heights of embedded silicon nanopillars (110, 170, and 230 nm) are found to support magnetic dipole resonances. With pillar height and pitch variation, SCFs with different displayed colors are achieved. Based on the resonance wavelength, the displayed color of the metasurface is verified within the red-yellow-blue color wheel. The simulation and measurement results are compared and discussed. The work provides an alternative design for high efficiency color filters on a CMOS-compatible platform, and paves the way towards mass-producible large-area metasurfaces.

The previous experimental study illustrated that a direct laser scribing on polyimide (PI) induced layered graphene, which opened a new door of producing graphene associated materials. However, the underlying conversion mechanism is unknown, especially from theoretical perspectives. In this paper, we performed molecular dynamics (MD) simulation of this mechanism under extreme conditions of high pressure and temperature which mimic those generated by laser induction. We investigated this process using the ReaxFF potential in a nanosecond time scale. We found out that at a pressure of ∼3 GPa and temperature of >2400 K generated from NVT processes, layered graphene clusters were crystallized from PI without metal catalysts, which is consistent with previous experimental results. However, if simulated under NPT processes with a pressure of 27 MPa, the PI was decomposed into small molecules, and no graphene layers were observed. Furthermore, by analyzing the number of the carbon rings and the pair distribution function of them we quantified the crystallinity of the graphene clusters. Through tracing the emission of the small molecules such as H 2 O, N 2 , H 2 , CO we propose possible reaction paths for both of the NVT and NPT processes.

This paper proposes a blue LD pumping Pr:YLF crystal acousto-optic Q-switched double pulse laser with 639 nm red light output. The output principle of the Pr:YLF double pulse laser is demonstrated, and a four level differential rate equation model is established to describe the distribution of the double pulse sequence at a high repetition frequency. When the laser repetition frequency is 10 kHz, the double step signal generator, as the modulator of the acousto-optic Q-switching, turns on the Q-switching twice in one pumping period, and obtains the maximum output power of 144 mW, pulse energy of 7.1μJ and the output of visible light double pulse with the pulse interval of 20 μs.

The dual-wavelength alternating output laser using double laser gain mediums and single electro-optic (EO) Q-switched crystal with the same EO Q-switched voltage is obtained. A rate-equation model is developed, accounting for dual-wavelength alternating output laser based on the same EO Q-switched voltage. In numerical simulation, the relationship between loss and gain value in each cavity is compared as the criterion for selecting the same Q-switched voltage. Using this method, the dual-wavelength alternating output laser of 1319 nm and 1064 nm, the pulse widths of 15.88 ns and 14.58 ns, and the energies of 42.37 mJ and 43.6 mJ respectively, is stably achieved under the same Q-switched voltage of 1000 V with the maximum pump current of 90 A and 70 A, respectively.

This letter presents a visible light direct oscillation Q-switched single-longitudinal-mode Pr:YLF laser output at 639.5 nm by using the Q-switching pre-lase technology combined with the Fabry–Perot etalon. The experimental results show that the single-longitudinal-mode oscillation can be generated in a low-energy injection state. The proposed laser overcomes the problem associated with the Q-switched Pr:YLF laser, which cannot produce high-efficiency single longitudinal mode owing to the high loss of inserted elements. With the proposed laser, a Q-switched single-longitudinal-mode pulsed laser output has been achieved with 3.94 μJ energy and 81.1 ns pulse duration at a repetition of 10 kHz. The spectral linewidth of single-longitudinal-mode pulse laser was approximately 33 MHz.