Information Leakage Rate of Optical Code Division Multiple Access Network Using Wiretap Code.

Secrecy capacity is usually employed as the performance metric of the physical layer security in fiber-optic wiretap channels. However, secrecy capacity can only qualitatively evaluate the physical layer security, and it cannot quantitatively evaluate the physical layer security of an imperfect security system. Furthermore, secrecy capacity cannot quantitatively evaluate the amount of information leakage to the eavesdropper. Based on the channel model of an optical CDMA network using wiretap code, the information leakage rate is analyzed to evaluate the physical layer security. The numerical results show that the information leakage rate can quantitatively evaluate the physical layer security of an optical CDMA wiretap channel, and it is related to transmission distance, eavesdropping position, confidential information rate and optical code.

Graphene-enhanced polarization-insensitive all-optical wavelength conversion based on four-wave mixing.

All-optical wavelength conversion technology based on four-wave mixing (FWM) effect is a promising development need of the modern high-speed optical signal processing system. In this work, we report on the polarization insensitive four-wave mixing based on graphene for all optical wavelength conversion. To overcome the polarization sensitivity of FWM, a dual-pump configuration was proposed based on the combination of graphene and the optical fibers. Our experimental results illustrate that by using the dual pump configuration, the FWM-based wavelength conversion efficiency, can be enhanced by graphene with about 8 dB when the state of polarization of the two pumps are parallel. This proposed all-optical wavelength converter based on graphene may provide a new approach for the next generation optical communications and signal processing.

All-optical signal processing in few-layer bismuthene coated microfiber: towards applications in optical fiber systems.

Two-dimensional (2D) bismuthene can find its wide potential applications due to its appealing optical and electronic properties. Especially, bismuthene exhibits layer-count dependent direct bandgaps and strong light-matter interaction, enabling its applications in all-optical signal processing area that can overcome the bottle-neck in existing electrical signal processing. However, light-bismuthene interaction based on main stream optical fiber systems and its application in all-optical signal processing is relatively less investigated. In this work, few-layer bismuthene, synthesized with facile solution processing method, is coated onto a piece of microfiber. The experimental results show that this device can operate as an optical Kerr switcher and a four-wave-mixing-based wavelength converter under different configuration. The results including wavelength applicability, information bandwidth, eye diagrams in combination with bit-error rate (BER) performance and stability measurements confirm its feasibility in optical fiber systems. To the best of our knowledge, it is first prototypic device reported in this work for bismuthene in all-optical signal processing optical fiber systems.

Black phosphorus quantum dot based all-optical signal processing: ultrafast optical switching and wavelength converting.

As a unique two-dimensional material, few-layered black phosphorus (BP) nanosheets have shown promising applications in electronics and optoelectronics. Black phosphorus quantum dots (BPQDs) have attracted attention due to the unique properties of BP combined with the edge effects. In this paper, we report on the all-optical application of BPQD based on its nonlinear Kerr effect. BPQDs were synthesized using a liquid exfoliation method combined with probe sonication and bath sonication. BPQD deposited on the microfiber as an optical device was demonstrated as the Kerr switcher with extinction ratio of 20 dB and four-wave mixing based wavelength converter with -40 dB conversion efficiency. These findings suggest that BPQD-based novel nonlinear photonics devices could be further developed in the applications of next generation high-speed optical communication.

Dual surface structured light vision system based on multidimensional parameter coding.

A dual surface structured light vision system based on the theory of multidimensional parameter coding is proposed in this paper that can provide a new high-performance and adaptive encoding robot vision perception system. Specifically, the dual surface structured light consists of an auxiliary light source and a principal structured light. Scene images from the auxiliary structured light determine the parameters of the principal structured light. The vision process system can adaptively encode the principal structured light according to types and numbers of parameters. The image formed by the encoded principal structured light can reflect the depth change details of the target object and guide the robot to locate the target object quickly and accurately. The simulation and industrial experiments show that the dual surface structured light vision system has wider application scenarios and higher accuracy than the traditional structured light vision system. According to different industrial scenes, the positioning accuracy of the vision system can reach 0.1 mm to 20 µm in 0.8 s.

Controlling multiple-dipole interactions mediated by nanophotonic structures and their application in W state generation.

We investigate cooperative behavior of three and four quantum emitters coupled to a common nanophotonic structure. We theoretically demonstrate that strong dipole-dipole interaction is attainable for emitter distances on the order of the operating wavelength in a couple of judiciously designed systems, including epsilon-near-zero parallel plate waveguide, SOI microring resonator, and silicon microshell/silica core structure. We also show that a high-purity W state can be generated with high efficiency in such systems, making them promising candidates for the generation of long-range quantum entanglement between multiple qubits.

Enhanced spontaneous emission of quantum emitter in monolayer and double layer black phosphorus.

We theoretically demonstrate that the spontaneous emission rate (SER) of quantum emitter is greatly enhanced in the proximity of single or double layers of black phosphorus (BP). The maximum enhancement factor is on the order of 106, about 3 times larger than that of graphene, due to the large photonic density of states near BP. We also study how the transition frequency, the BP doping level, the distance between emitter and BP, the existence of substrate underneath BP, and the orientation of transition dipole moment influence the SER. With properly designed parameters, both high SER of emitter and low propagation losses of BP surface plasmon polaritons can be achieved in the quantum system, making it a promising candidate for mid-infrared single-photon generation.

Ultrafast all-optical flip-flop based on passive micro Sagnac waveguide ring with photonic crystal fiber.

Ultrafast all-optical flip-flop based on a passive micro Sagnac waveguide ring is studied through theoretical analysis and numerical simulation in this paper. The types of D, R-S, J-K, and T flip-flop are designed by controlling the cross-phase modulation effect of lights in this special microring. The high nonlinearity of the hollow-core photonic crystal fiber is implanted on a chip to shorten the length of the ring and reduce input power. By sensible management, the pulse width ratio of the input and the control signal, problems of pulse narrowing, and residual pedestal at the out port are solved. The parameters affecting the performance of flip-flops are optimized. The results show that the all-optical flip-flops have stable performance, low power consumption, high transmission rate (up to 100 Gb/s), and response time in picosecond order. The small size microwaveguide structure is suitable for photonic integration.

The analysis of all-optical logic gates based with tunable femtosecond soliton self-frequency shift.

A type of tunable femtosecond soliton logic gate based on fiber Raman Self-Frequency Shift (SFS) is studied in this paper. The Raman SFSs of femtosecond solitons governed by the Newton's cradle mechanism in logic gate are analyzed with an Improved Split-Step Fast Fourier Transform (ISSFFT) algorithm. The impact factors of the solitonic pulse frequency shift and temporal time shift, which are included the Third-Order Dispersion (TOD) effect, are investigated. The existing theoretical equation of SFS is modified into a new expression for this type of soliton logic gate. A lower switching power and the small size of the soliton logic gate device is designed to realize the logic functions of AND, NOT, and XOR. The results demonstrate that the logic gate based on SFS is belonged to the asynchronous system and can be achieved with Milli-Watt switching power and good extinction ratio. ISSFFT is effective and accurately to analyze higher-order dispersive and nonlinear effects in the logic gates.

HGCMorph: joint discontinuity-preserving and pose-learning via GNN and capsule networks for deformable medical images registration.

Objective.This study aims to enhance medical image registration by addressing the limitations of existing approaches that rely on spatial transformations through U-Net, ConvNets, or Transformers. The objective is to develop a novel architecture that combines ConvNets, graph neural networks (GNNs), and capsule networks to improve the accuracy and efficiency of medical image registration, which can also deal with the problem of rotating registration.Approach.We propose an deep learning-based approach which can be utilized in both unsupervised and semi-supervised manners, named as HGCMorph. It leverages a hybrid framework that integrates ConvNets and GNNs to capture lower-level features, specifically short-range attention, while also utilizing capsule networks (CapsNets) to model abstract higher-level features, including entity properties such as position, size, orientation, deformation, and texture. This hybrid framework aims to provide a comprehensive representation of anatomical structures and their spatial relationships in medical images.Main results.The results demonstrate the superiority of HGCMorph over existing state-of-the-art deep learning-based methods in both qualitative and quantitative evaluations. In unsupervised training process, our model outperforms the recent SOTA method TransMorph by achieving 7%/38% increase on Dice score coefficient (DSC), and 2%/7% improvement on negative jacobian determinant for OASIS and LPBA40 datasets, respectively. Furthermore, HGCMorph achieves improved registration accuracy in semi-supervised training process. In addition, when dealing with complex 3D rotations and secondary randomly deformations, our method still achieves the best performance. We also tested our methods on lung datasets, such as Japanese Society of Radiology, Montgoermy and Shenzhen.Significance.The significance lies in its innovative design to medical image registration. HGCMorph offers a novel framework that overcomes the limitations of existing methods by efficiently capturing both local and abstract features, leading to enhanced registration accuracy, discontinuity-preserving, and pose-learning abilities. The incorporation of capsule networks introduces valuable improvements, making the proposed method a valuable contribution to the field of medical image analysis. HGCMorph not only advances the SOTA methods but also has the potential to improve various medical applications that rely on accurate image registration.

Novel Optical Kerr Switching Photonic Device Based on Nonlinear Carbon Material.

In the context of current communication systems, there is an urgent demand for more efficient and higher-speed optical signal processing technologies. Researchers are actively exploring new materials and devices to harness nonlinear optical phenomena, seeking advancements in this field. Nonlinear carbon materials, especially promising 2D materials, have garnered attention for their potential interaction with light and have become integral to the development of all-optical signal processing devices. This study focuses on utilizing a photonic device based on a nonlinear Au/CB composite material for optical Kerr switching. The application of Au/CB as a nonlinear material in the Kerr switch represents a noteworthy advancement, demonstrating its capability to modulate optical signals. By appropriately applying a pump light, the study achieves optical Kerr switching with an extinction ratio of approximately 15 dB in the fully off state of the signal light carrying a 10 GHz analog signal, marking a pioneering achievement in the field to the best of our knowledge. The experimental results, encompassing extinction ratios, signal control, and stability, not only validate the feasibility of this technology but also underscore its potential applicability within optical communication systems. The successful modulation and control of a 10 GHz analog signal showcase the practicality and effectiveness of the Au/CB-based optical Kerr switch. This progress contributes to the continuous evolution of optical Kerr switching, a crucial component in modern optical communication systems. Therefore, we believe that the Au/CB-based optical Kerr switch is an exceptionally promising and stable all-optical signal processing device. As the contemporary communication landscape evolves, the integration of this technology holds the potential to enhance the efficiency and speed of optical signal processing.

Does environmental regulation dividends inequality impact inclusive growth? Evidence from China.

Based on the panel data of 281 city level in China for the period of 2004-2016, this study uses the Cobb-Douglas production function to investigate the distribution of environmental regulation dividends and further adopts the threshold model to explore the impact of environmental regulation dividends inequality (ERDI) on inclusive growth (IG). Results indicate that the distribution structure of the environmental regulation dividends has improved, but the inequality between urban-rural residents is still apparent. Environmental regulation dividends inequality has a non-linear threshold effect on inclusive growth, which turns from a significant inhibition to a slight promotion after exceeding the threshold value. Grouping tests show that environmental regulation dividends inequality has a heterogeneous effect on cities with different resource endowments and leading industries and still inhibits inclusive growth of non-resource-based cities even if the inequality is higher than the threshold value. Mechanism analysis reveals that primary distribution and redistribution are the main channels through which environmental regulation dividends inequality inhibits and promotes inclusive growth when the inequality is below and above the threshold value, respectively. These conclusions have important implications for enhancing and distributing environmental regulation dividends to promote inclusive growth.

Effects of Different Surgical Procedures on the Therapeutic Effects, Prognosis, and Major Complications of Acetabular Fractures in the Elderly of China: A Systematic Review and Meta-Analysis.

Objective: Different surgical approaches were systematically evaluated to provide an evidence-based medical rationale for the application and promotion of acetabular fractures in the elderly of China. Methods: Randomized controlled trials (RCT) of different surgical methods in the treatment of elderly acetabular fractures were searched in the PubMed, EMBASE, ScienceDirect, Cochrane Library, China Knowledge Network Database (CNKI), China VIP Database, Wanfang Database, and China Biomedical Literature Database (CBM). The search time threshold was set from the time the database was created to the current time. Investigators obtained data independently, and the bias risk of each included writing was reviewed using the Cochrane Manual 5.1.0 criterion. The meta data was analyzed using RevMan 5.4 statistical package. Results: 6 RCT articles were included in the end. A total of 445 samples were analyzed by meta. All the six RCT literatures included in this meta-analysis reported the baseline status of patients, only 3 RCT mentioned "random assignment" without any explanation, and the rest did not mention "random" information. The five studies included all gave detailed intervention measures. The number and reasons of blind method and lost follow-up or withdrawal were not described in detail in 6 RCT articles. Through the meta-analysis excellent and good rate between the experimental group and the control group through 6 RCT studies, the heterogeneity test results were chi2 = 6.11, df = 4, P = 0.19 > 0.05, and I2 = 35%, without obvious heterogeneity at Z = 2.68 and P = 0.007. These results suggested that the total hip arthroplasty application has the same excellent rate as other surgical treatment methods, indicating that total hip arthroplasty has a significant effect on the treatment of elderly acetabular fractures. Through the meta-analysis hip-joint function score, the heterogeneity test results were chi2 = 56.16, df = 4, P < 0.00001, and I 2 = 93%, with obvious heterogeneity. The great difference was discovered in hip function score between total hip arthroplasty and other surgical methods, showing that total hip arthroplasty can greatly improve hip-joint function. Then, the incidence of hip complications between the experimental cases and the control cases was calculated by meta. The heterogeneity test results were chi2 = 3.17, df = 4, P = 0.53 > 0.05, and I 2 = 0%, without remarkable heterogeneity at Z = 3.05 and P = 0.002. This demonstrated that a significant difference was observed in the complication incidence, indicating that total hip arthroplasty displayed a lower incidence of hip-joint functional complications. Conclusion: Total hip arthroplasty has a good prognosis and a low complication rate in the treatment of acetabular fractures in the elderly. However, more studies and longer follow-ups are needed to further validate the findings of this study.

Pd-Catalyzed C-O Bond Formation Enabling the Synthesis of Congested N,N,O-Trisubstituted Hydroxylamines.

A Pd-catalyzed C-O cross-coupling of O-acyl hydroxylamines and tertiary or secondary alkyl electrophiles was reported without the cleavage of the rather fragile N-O bond. The described strategy provides direct access to congested N,N,O-trisubstituted hydroxylamines bearing an α-quaternary carbon center under mild conditions in high yields and features exclusively chemoselective C-O bond formation, a broad substrate scope, and excellent functional group tolerance. The synthetic potential of the cross-coupling was established via pharmaceuticals derivatizations and a series of postcatalytic modifications.

Speed regulation strategy and algorithm for the variable-belt-speed energy-saving control of a belt conveyor based on the material flow rate.

As an important transportation, the belt conveyor has been widely used and researched. It is urgent to solve the problem of energy saving and consumption reduction of belt conveyor. Aiming at reducing high energy consumption in the rated-speed operation of a belt conveyor, the present paper establishes an energy-saving belt-speed model of a belt conveyor using a polynomial regression-fitting algorithm and a small number of sample observations, and proposes a speed regulation strategy and particle swarm optimization-proportional-integral-derivative algorithm for the variable-belt-speed energy-saving control of a belt conveyor based on the material flow rate. The control strategy and algorithm adjust the running speed of the belt conveyor accurately according to changes in the material flow rate, thus reducing damage of frequent speed regulation to the belt conveyor and saving energy. Simulation analysis of a practical case shows that energy-saving belt-speed model, speed regulation strategy, and algorithm effectively reduce the energy consumption of a belt conveyor, and they thus have high application value in coal, ports, power, mine, metallurgy, chemical, and other industries. Further work in this field can be focused on the prediction of material flow rate of belt conveyor, the controllable adjustment duration of algorithm and the reduction of overshoot.

Long-term effects of combination of organic and inorganic fertilizer on soil properties and microorganisms in a Quaternary Red Clay.

Quaternary Red Clay (QRC) is the most common planting soil with low soil fertility and low crop yields in Southeast China, with low soil fertility and low crop yields. Many factors can impact the fertility and utilization efficiency of QRC. Here, we conducted a long-term fertilization experiment from 1984 to 2013. Five fertilization measures were carried out, including non-fertilization group; chemical Fertilizer group; 70% chemical and 30% organic fertilizer group; 50% chemical and 50% organic fertilizer group; 30% chemical and 70% organic fertilizer group. Soil organic matter (OM), total nitrogen (TN), total phosphorus (TP), total potassium (TK), soil microbial biomass carbon (SMBC) and nitrogen (SMBN), and soil enzymes activity were measured to evaluate the changes of soil. In addition, soil microorganisms were determined by high-throughput sequencing technology, and the dominant microbes were screened. The higher the proportion of organic fertilizer was, the higher the soil OM content was. The OM content of the non-fertilization group was the lowest. Similarly, SMBC and SMBN showed a consistent trend with OM content. Illumina sequence results showed that the application of organic fertilizer reduced the relative abundance of Chloroflexi, Acidobacteria and Nitrospirae, but increased Proteobacteria and Actinobacteria. The relative abundance of Acremonium and Mortierella were also greatly increased by different fertilization strategies. However, when high proportion of organic fertilizer was applied, the abundance of Acremonium and Mortierella decreased. Long-term balanced inorganic fertilization (NPK, 60%N:20%P:20%K) can effectively improve the quality and fertility of QRC. The effect of different fertilization strategies on fungi was greater than that on bacteria. The change of soil microorganism also proved the validity of inorganic fertilizer application.

Research on the energy-saving control strategy of a belt conveyor with variable belt speed based on the material flow rate.

Aiming at solving the problem of high energy consumption in the rated belt speed operation of a belt conveyor system when the material flow rate is reduced, the power consumption of the frequency converter, motor, and belt conveyor is analyzed, a power consumption model of the belt conveyor system is established, the relationship between the power consumption of the belt conveyor system and belt speed is obtained, and a energy-saving control strategy of the belt conveyor with variable belt speed based on the material flow rate is put forward. The energy consumption of the belt conveyor is analyzed for a practical case. Results show that the power consumption model is accurate and the control strategy effectively reduces energy consumption. The model has high application value in coal, ports, power, mine, metallurgy, chemical, and other industries.

Utilization Phase Transition Component Method to Prepare Specially Functionalized Nanoemulsion by Adding Resveratrol/Phenethyl Resorcinol Mixed Active Components and Application in Free Radicals Removal.

To explore the possibility of using a specially functionalized nanoemulsion for the removal of free radical, resveratrol and phenethyl resorcinol were employed to form resveratrol/phenethyl resorcinol mixed active components, and the removal efficiency of free radicals was evaluated. Original nanoemulsion and specially functionalized-nanoemulsion were characterized by DLS and EPR. The free radical scavenging ability of the mixed active components of resveratrol/phenethyl resorcinol was determined as a function of the mass ratio of resveratrol to phenethyl resorcinol, temperature, and ionic strength. In the results, the removal of free radicals by the resveratrol/phenethyl resorcinol nanoemulsion system was found to be more effective than the nanoemulsion alone. At a higher resveratrol ratio, more than 68% of free radicals could be removed. The efficiency was also found to increase with rising temperature. However, efficiency decreased with the increase in ionic strength. In conclusion, compared with conventional nanoemulsion, the combined utilization of nanoemulsion and the mixed active components of resveratrol/phenethyl resorcinol achieved better results for the removal of free radicals because of synergistic effect between nanoemulsion droplets and the mixed active components of resveratrol/phenethyl resorcinol, involving hydrophobic binding, hydrogen binding, and partitioning.

Virtual sources for a cosh-Gaussian beam.

On the basis of superposition of beams, a group of virtual sources that generate a cosh-Gaussian wave is identified. A closed-form expression is derived for this cosh-Gaussian wave, which, in the appropriate limit, yields the paraxial approximation for the cosh-Gaussian beam. From this expression, the paraxial approximation and the nonparaxial corrections of all orders for the corresponding paraxial cosh-Gaussian beam are determined.