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With the rapid development of semiconductor chip circuit integration and miniaturization, especially the high integration of microwave chips, it has become critical to realize the surface microwave field imaging for such chips. In this paper, a new method of microwave field imaging for chip surface is proposed based on scanning probe microscopy. We analyse the echo signal and extract the peak-to-peak values to characterize the microwave field intensity on the chip surface by building a theoretical model of the microwave signal coupling. Using a high-precision scanning stage based on a piezoelectric ceramic tube, we realize the imaging of microwave field. The experimental results show that the imaging method can complete the chip surface microwave field imaging, which is important to support the optimization of semiconductor chip manufacturing process, fault analysis and new material research, and promote the development and progress of the semiconductor industry.

High precision current measurement is very important for the calibration of various high-precision equipment and the measurement of other precision detection fields. A new current sensor based on diamond NV color center magnetic measurement method is proposed to realize the accurate measurement of current. This new current method can greatly improve the accuracy of current measurement. Experiments show that the linearity of the current sensor based on diamond NV color center can reach up to 33 ppm, which is superior to other current sensors and solves the problem of low linearity. When the range of input current is 5-40 A, the absolute error of calculated current is less than 51 µA, and the relative error is 2.42 × 10-6 at 40 A. Combined with the research content and results of the experiment, the application of the current sensor in the field of current precision measurement is prospected.

The flow structure of a cavity with a length-to-depth ratio of 2:1. In this experiment, the particle image velocimetry (PIV) technique was used to experimentally research the front and rear wall inclined cavity configurations with different inclinations. The experiments were carried out in a recirculating water tank. The configurations with front and rear wall inclination angles of 26°, 45°, and 56° were compared at the same incoming flow velocity. A total of seven different configurations are given for the comparison of several variables. In addition, the flow velocity, Reynolds stress and turbulence intensity values were measured and analyzed for all configurations. Correlation analysis is used to reveal the shear layer evolution process, and the outcomes indicate that the wall inclination changes the shape and size of the shear layer. The coherent structures of shear layers with different cavity shapes are identified in combination with appropriate proper orthogonal decomposition (POD). Different shapes of the cavity configuration may vary the size of the shear layer. The calculation of turbulence intensity also shows that the cavity configuration with the largest inclination angle has the largest cavity turbulence intensity at the centreline cross-section.

We have designed a gripper for scanning microwave microscopy (SMM) based on atomic force microscopy, which is optimized for impedance-matching structures and high-frequency microwave loss. The gripper is simple in construction and highly integrated. The return loss near the target operating frequency of 20 GHz is less than −30 dB. The minimum detected power reach −40 dBm with the order of nW. The microwave scanning image of the sample surface structure was experimentally tested, showing that the gripper can be applied to microwave scanning imaging. The research results have contributed to the development of SMM.

It is necessary to set UAV hovering points before programming the trajectory of a UAV patrol inspection transmission tower body and accessories such as fittings and insulators. The choice of the hover point will affect the work safety and inspection efficiency of the UAV. Therefore, a 500kV UHV AC double-drum tower and UAV three-dimensional simulation model are established and Electromagnetic field is emulated at first. Finally, UAV hovering points are determined by considering the simulation results and functional parameters of UAV. The research method is of great significance for the determination of 3D trajectory Hovering Point Determination Method of UAV Patrol Inspection Transmission Tower.

The scintillators capable of neutron detection are being the research hotspot recently. In this manuscript, we investigated the possibility of cerium-doped gadolinium aluminium gallium garnet (GAGG: Ce) crystal to achieve neutron gamma discrimination through pulse shape discrimination (PSD) method. PSD is a method based on the principle that the waveforms of scintillation light differ for different particles. The experiments show that it’s hard for single GAGG crystal to distinguish the neutron from the gamma-ray. Therefore, a composite crystal made of gamma-sensitive crystal and GAGG crystal was furtherly developed. Using the 252Cf neutron source, the composite is proven to be capable of discriminating the neutrons from the gamma-ray and the corresponding FOM is 3.33.

Low-temperature synthesis of Nb3Sn thin-film cavity is of great significance in the field of superconducting radio frequency (SRF). The bronze process can grow only stable Nb3Sn phase at 700 °C, so it is considered to be the most promising process for low-temperature synthesis of Nb3Sn thin-film cavity. We successfully fabricated the worldwide first Nb3Sn thin-film cavity by bronze process. We technically solved the key problems of precursor preparation, characterized and analyzed the uniformity of the Nb3Sn film, and tested the performance of the cut-out samples and the whole cavity of the Nb3Sn film. It is obtained that the Q 0 value of the cavity at 4.2 K is about 1.2 × 109, which is greater than the performance of the bulk-niobium cavity under the same conditions. This result means that the preparation of Nb3Sn by bronze process has the great potential to more practical copper-based Nb3Sn thin-film cavity, which is expected to achieve a substantial improvement in the performance of SRF cavity and comprehensive engineering applications.

A high-precision microwave detection technology using atoms is an essential foundation in future communication technologies. In this study, improvement of microwave detection sensitivity by atoms is realized. First, an open-loop resonator is designed based on finite element simulation and subsequently fabricated; then, the microwave electric field intensity is measured with and without the resonator, based on the electromagnetically induced transparency Autler–Townes effect. The microwave electric field with different input power is measured, and the improvement achieved with the resonator is verified. The optimal detection sensitivity is improved from 2.14(5) to 0.73(4)V m−1, and the sensitivity is improved by a factor of approximately 2.9. These results provide a practical reference for the application of high-precision detection of microwave electric fields with atoms and atomic microwave communication in the future.

P2-type layered oxides have been considered as promising cathode materials for Na-ion batteries, but the capacity decay resulting from the Na+/vacancy ordering and phase transformation limits their future large-scale applications. Herein, the impact of Li-doping in different layers on the structure and electrochemical performance of P2-type Na0.7Ni0.35Mn0.65O2 is investigated. It can be found that Li ions successfully enter both the Na and transition metal layers. The strategy of Li-doping can improve the cycling stability and rate capability of P2-type layered oxides, which promotes the development of high-performance Na-ion batteries.

In this paper, an optical fiber length measurement system based on phase modulated pulse time-of-flight method is proposed. The fiber length is calculated by measuring the flight time of the phase-modulated pulse in the fiber under test. To improve the signal-to-noise ratio of the system, the interference structure of Mach-Zehnder hybrid Sagnac assisted by phase-generated carrier(PGC) technique is utilized to effectively eliminate the parasitic Rayleigh scattering noise along the optical fiber. Finally, the balance of long measurement distance and high measurement precision is achieved in the system, and the measurement resolution of 0.2 meter is realized within the measurement range of 100 kilometers.

Two-dimensional (2D) Janus materials have attracted significant attention due to their asymmetrical structures and unique electronic properties. In this work, by using the first-principles calculation based on density functional theory, we systematically investigate the electronic properties of 6 types of Janus-XGa2 Y/Graphene van der Waals heterostructures (vdWHs). The results show that the Janus-XGa2 Y/Graphene vdWHs are connected by weak interlayer vdW forces and can form n-type Schottky contact, p-type Schottky contact or Ohmic contact when the spin–orbit coupling (SOC) is not considered. However, when considering SOC, only the SeGa2S/G and G/SeGa2S vdWHs show n-type Schottky contact, and other vdWHs show Ohmic contacts. In addition, the Schottky barriers and contact types of SeGa2S/Graphene and Graphene/SeGa2S vdWHs can be effectively modulated by interlayer distance and biaxial strain. They can be transformed from intrinsic n-type Schottky contact to p-type Schottky contact when the interlayer distances are smaller than 2.65 Å and 2.90 Å, respectively. They can also be transformed to Ohmic contact by applying external biaxial strain. Our work can provide useful guidelines for designing Schottky nanodiodes, field effect transistors or other low-resistance nanodevices based on the 2D vdWHs.

We demonstrate a method for thermal detection that is the sensitivity 6.2 mK Hz−1 2, which uses the frequency lock closed-loop scheme to track Zeeman-split resonance of nitrogen-vacancy (NV) centers in diamond. The NV diamond surface acts as a temperature measurement sensor to transfer the temperature variation as D(T) parameter change to lead to the movement of the energy levels to detect the temperature. By frequency modulation technology and closed-loop feedback locking technology, automatic temperature detection and step signal reading are realized, with a resolution of 7.6 mK. It is found that the closed-loop output is basically unchanged, while the open-loop output has an error signal proportional to the laser fluctuation. The closed-loop feedback technique can improve the stability and resolution of the system and provides a method for measuring the actual temperature detection. Such a demonstration marks a vital advance in transitioning the NV thermometer from a laboratory system to a functional device for detecting temperature fields in a practical environment.

In order to efficiently grasp the tritium behavior in advanced core–shell breeding materials, this study adopts a route of injecting tritium out-of-pile to deal with the problems of fewer platforms, long periods, and high costs for traditional neutron irradiation-tritium release experiments. Here, tritium adsorption and desorption experiments were carried out with Li4TiO4–Li2TiO3 core–shell breeding materials before and after long-term heating up to 30 days. The purpose is to study whether the structural changes caused by long-term heating will affect the adsorption and desorption behavior of tritium on the sample surface. The results show that the lack of chemically adsorbed water caused by long-term heating will significantly weaken the tritium adsorption capacity of the sample, but will not affect the desorption behavior of Ar, 1% H2 + Ar and water vapor on tritium, so all samples show a very low tritium retention.

Accuracy and speed have always been a measure of the performance of object detection algorithms. The current algorithms have reduced the detection speed on the basis of increasing a certain accuracy due to their complex structure. In response to this problem, this paper uses the RepVGG network to improve the original YOLOv3 structure, which uses a diversified branch structure to enhance the network feature extraction ability during training and transforms the training model into an equivalent VGG-like topology network model during inference. In addition, we use ASFF to deal with the problem of mutually restricted scales. Experiments show that compared with the original algorithm, the improved algorithm increases mAP by 0.51 on the VOC data set, and at the same time the speed increases by 10%.

The Nb3Sn thin film cavity, having the potential to be operated at a higher temperature and higher gradient compared to the cavity made from bulk niobium, is one of the most promising key technologies for the next-generation radio-frequency superconducting accelerators. In our work, several 1.3 GHz single-cell TESLA-shaped Nb3Sn thin film cavities, coated by the vapor diffusion method, were tested at Peking University and Institute of Modern Physics, Chinese Academy of Sciences. It was observed that the performance of the Nb3Sn thin film cavities in the tests without the slow cooling down procedure and the effective magnetic field shielding was significantly improved by using a low temperature baking at 100 °C for 48 hours. Although the peak electric field of the cavity remained unchanged, the rapid drop of the unloaded Q value (Q 0) with the increasing accelerating field (Q-slope) was effectively eliminated, resulting in an improvement of the Q 0 in the intermediate field region by ∼ 8 times. Furthermore, under better test conditions with the shielded magnetic field less than 5 mG and the slow cooling down procedure in the temperature range of 25–15 K, the Q 0 was still improved by about 20%. Our study shows that the low temperature baking can be an effective supplement to the effective post-treatment for the Nb3Sn thin film cavity.

A method of detecting the single channel triaxial magnetic field information based on diamond nitrogen-vacancy (NV) color center is introduced. Firstly, the incident angle of the bias magnetic field which can achieve the equal frequency difference optically-detected magnetic resonance (ODMR) spectrum of diamond NV color center is calculated theoretically, and the triaxial magnetic information solution model is also constructed. Secondly, the microwave time-controlled circuit module is designed to generate equal timing and equal frequency difference microwave pulse signals in one channel. Combining with the optical detection magnetic resonance technology, the purpose of sequentially locking and detecting the four formant signals on one side of the diamond NV color center (m s = –1 state signal) is achieved, and the vector magnetic field information detection is accomplished by combining the triaxial magnetic information solution model. The system can obtain magnetic field detection in a range of 0 mT–0.82 mT. The system’s magnetic noise sensitivity is 14.2 nT/Hz1/2, and the deviation angle errors of magnetic field detection θx and θy are 1.3° and 8.2° respectively.

In a high-sensitivity atomic magnetometer, increasing the temperature of the vapor cell causes higher polarized atomic density, which enhances the intensity of the output signal. Therefore, it is essential to precisely control the temperature of the vapor cell. Based on the principle of electric heating and reverse magnetic cancellation, miniature weak magnetic electric heating chips of single-layer and double-layer structure are designed. By measuring the magnetic flux density at different distances and currents, it can be proved that the chips suppress the magnetic field. The experiment results show that the double-layer chip is better than the single-layer chip in respect of magnetic suppression and temperature response. The magnetic flux density introduced by the current at 5 mm from the chip is 0.0722 nT mA−1. These results show that a high-precision heating method for the atomic vapor cell can be realized by the double-layer meander structure, which provides a simple and fast electric heating scheme for atomic polarization.

The internal anti-parallel Schottky barrier diode threshold voltage of SiC metal-oxide-semiconductor field-effect transistor (MOSFET) modules is less than that of their body diodes, which prevents the use of the body diode voltage drop to measure junction temperature. In this paper, a thermal resistance test of the SiC MOSFET module is proposed based on the onstate voltage drop as a temperature-sensitive electrical parameter. Measurements are performed with the method and its feasibility evaluated. The on-state voltage drop temperature sensitivity under different gate voltages and the repeatability of the on-state voltage drop parameters before and after electric power heating in the thermal resistance tests are studied. The on-state voltage drop is measured under a high gate voltage and the accuracy of junction temperature measurement improves when the grid voltage remains the same during heating and measurement.

Considering the problem of measuring the peak junction temperature of a double-chip module with temperature inhomogeneity, we use a double-chip parallel model to analyze peak junction temperature measurement error for the traditional electrical method. An improved test method is proposed that is based on the small current–voltage drop method—specifically the dual current test method employing an extended-dimension calibration curve library. This method realizes a match of the calibration current with the test current by expanding the dimension database, eliminates errors of temperature measurements, and finally obtains the peak junction temperature of the module. The measurement result is close to the set temperature of the model, thereby verifying its accuracy.

The purpose of this study was to prepare microencapsules containing L. bulgaricus QY2 by using pulluan, sucrose and whey protein as wall material and to evaluate the survival of the encapsulated L. bulgaricus QY2. Pullulan, sucrose and whey protein were selected to optimize the compound protective agent, L9 (33) orthogonal test design was carried out to determine the activity of L. bulgaricus QY2. Through the analyses that can reflect the core material for encapsulant protection indicators such as survival rate and vitality of L. bulgaricus QY2. When the microcapsule wall material was composed of 2 wt% pullulan, 10 wt% sucrose and 10 wt% whey protein, the survival rate of L. bulgaricus QY2 was the highest. In addition, the L. bulgaricus QY2 microcapsule combination of pullulan at 1 wt%, sucrose at 10 wt% and whey protein at 10 wt% had the highest activity.

In this study, sodium alginate was used as the main embedding material, and sodium polyacrylate had been immobilized on sodium alginate with calcium ions as crosslinking agent for preparing a new type of lactic acid bacteria entrapment material. The aim of this study was to investigate the viability of Lactococcus lactis NCU1315 under simulated gastrointestinal conditions and the physical properties of the microcapsules and their protective effects on Lactobacillusto develop a feasible and stable method for preparing microbial particles. The hardness of Alg-1 and Alg-2 microcapsules varied with time in simulated gastric juice and showed significant difference at the second and third hour (P < 0.05, P < 0.01). The particle size of Alg-1 and Alg-2 microcapsules varied with time in simulated gastric juice and showed significant difference at the second and third hour (P < 0.05, P < 0.01). Alg-1 had no significant effect on the growth of NCU1315, but Alg-2 had inhibitory effect on the growth of Lactococcus lactis NCU1315. The survival rate of Lactococcus lactis in Alg-1 and Alg-2 microencapsulated groups was significantly higher than that in Free cell group at 24h, 48h and 72h (P < 0.05, P < 0.01). However, the survival rate of Lactococcus lactis in Alg-1 and Alg-2 microencapsulated groups decreased with time (P

Herein, we report a novel full printing process for fabricating chemiresistor gas sensor matrixes on photographic paper with an inkjet printer. Sensor matrices, which can increase a number of sensors significantly compared to a serial sensor array, were printed on one piece of A4 photographic paper. Each sensor matrix contains 36 interdigital electrodes in an area of less than 11 mm2, which greatly improves the density of the sensor. The basic architecture of the sensor matrix is electrodes that row and column intersecting. In order to insulate the row and column electrodes from meeting each other, an insulating layer needs to be fabricated at the point of intersection between the row and column electrodes. The insulation layer was produced by adjusting the number of printing passes and shape of the printing pattern of color pigment ink. Carbon black (CB) was used to form a chemosensitive composite by changing its resistivity with a specific polymer for the preparation of sensing material. In order to make the sensing material can be printed, it is necessary to disperse CB first. CB was dispersed in aqueous solution with sodium dodecyl sulfate added as a surfactant to lower the surface tension, which enabled printing of CB using an inkjet printer. Some polymers have certain adsorption characteristics for gases. According to the different gas properties, the adsorption characteristics are also different. By adding polyethylene glycol polymer to the CB layer, the response to four gases with different properties is improved. Compared with the drop coating, the full-printing sensors not only reduces the production time significantly, but also improves the gas response magnitude to ethanol by about three times. The results demonstrate that the developed sensor can be used as a low cost, disposable, and easily printable chemical sensor.

Currently, slip water fracturing fluid is widely used as a fracturing fluid for shale reservoirs. Non-ionic hydrophobic modified polyacrylamide (HM-PAM), partially hydrolyzed water-soluble hydrophobic associating polyacrylamide (HMWSP) and partially hydrolyzed anionic polyacrylamide (HPAM) solutions were modeled by molecular simulation software Materials Studio. The radius of gyration (Rg) and mean square displacement (MSD) of HPAM and HMWSP at different NaCl concentrations were calculated. From the simulation results, compared with HPAM and HM-PAM, HMWSP had a larger radius of gyration, a larger intrinsic viscosity number, and a larger hydrodynamic size, which would produce better drag reduction effects. Using acrylamide (AM), acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as basic raw materials, a hydrophobic associative drag reducer (HMWSP) was prepared by an inverse emulsion method. Infrared spectroscopy (FIIR) was used to characterize the synthesized products, and fluorescence chromatography was used to test the association of polymer solutions. Using a friction tester to test the drag reduction performance of the drag reducer, HMWSP has good resistance to salt reduction. HMWSP had good resistance reducing salt performance.

In the urban rail transit engineering, the construction of undercutting under the existing rail line is plagued by high construction risk and high monitoring accuracy requirements. Taking a station A in an urban rail transit project as an example, combined with the characteristics of the project, the monitoring scheme of vault settlement in the excavation section is formulated. In order to establish two sets of relatively independent elevation system and adopt the method of setting up independent station to measure the inverted ruler, the feasibility of this method is verified, and the sources of measurement error and control measures are analyzed. The actual results show that the method can meet the requirements of monitoring accuracy of vault settlement in the underground excavation section of subway station.

In this paper, the selective blocking ability of double crosslinking gel plugging agent was tested. The parallel core experiment was conducted by using the fractures with different permeability sizes in the chamber. We investigated the injection of gel in simulated fractures, the liquid distribution ratio, the breakthrough of pressure gradient, water plugging rate, oil plugging rate and erosion resistance with different size fractures. The selective plugging mechanism of double crosslinking gel plugging agent was analyzed.

The motion of a magnetic levitation structure can lead to low accuracy for magnetically suspended control moment gyros (MSCMG), artificial heart pumps or high precision stable platforms. Measuring this motion is important in orbital navigation and precision measurement technologies, but current methods are unable to measure it with high accuracy under a strong magnetic field around the magnetic levitation structure. Here, we present a method in which nitrogen–vacancy (NV) centers in diamond have been used as a sensor to detect the movement of the magnetic levitation structure. The NV quantum sensors probe the electric field around the suspension magnet induced by the magnet fluctuations. Based on the high sensitivity of 0.3 nT (√Hz)−1, the resolution of motion was about 5 nm. Also, the dynamic movement of the magnetic levitation system has been recorded in real-time with a potential resolution of ∼pm as the magnetic field sensitivity of NV center was improved to ∼pT. Our method offers a novel route to measure and feedback control the magnetic levitation system for MSCMGs in satellite attitude or for magnetic pumps in artificial heart applications.

Collective behavior, from murmurations to synchronized beating of heart cells, governs some of the most beautiful and important aspects of nature. Likewise, cooperation—the act of sacrificing personal benefits for the common good—is one of the pillars of social evolution, and it is the basis for the emergence of collective organized actions from single-cell organisms to modern human societies. Here we merge these two phenomena into a single model, considering an ensemble of networked oscillators, where each oscillator can be either a cooperator or a defector, and with only cooperators contributing to synchrony. At the same time, the value of the order parameter in the neighborhood of each oscillator is considered as an effective local temperature which determines the strategy updating procedure in the evolutionary game. The emergence of cooperation is thus intertwined with that of synchronization, producing a novel and fascinating dynamics which includes a double explosive transition.

One of the most crucial issues in facial beauty study is to find the traits, which determine the perceived attractiveness of a face. During the decades, many traits have been studied extensively, such as proportions, averageness, and symmetry. However, facial beauty seems to be more complex than these traits. In this paper, a face image is represented by a series of interpretable parameters, which are learnt by a CNN based 3DMM fitting algorithm. Based on the SCUT-FBP5500 dataset, we explore the relationship between those parameters and the human rated facial beauty scores. We observe that the pitch angle parameter has a strong correlation with the beauty score. In order to study the causal relationship between the pitch angle and facial beauty, face images with different pitch angles were generated as the stimuli and 39 volunteers were invited to a rating experiment. The results show that the change of the pitch angle has a significant effect on the perceived facial beauty. This finding may explain that head pose plays an important role in the self-portrait shot.

An microwave-cavity antenna was designed to manipulate the spin state in diamond. It consists of an Ω antenna and a microwave cavity with the thickness of 0.35mm and Q-value of 65. The microwave intensity increased 12 times than that of the Ω antenna. The size of homogeneity area is 25πmm2 and the heterogeneity is less than 2.3%. Hence, more spin structures in large-sized diamonds with high concentration can be homogeneous excited. As applied in the spin-based magnetometer, the sensitivity increased 13 times, and noise reduced to 0.5nT/Hz1/2. It proves a way to develop the high sensitive spin-based sensors.

The lifetime of the state in Cd populated via the Zr ( O, 4n) Cd reaction has been measured with the Recoil Distance Doppler Shift technique in combination with the Differential Decay Curve Method. By subtracting the contamination in the data, the mean lifetime of the =2 633 keV state was determined as 9.9 (12) ps. The value calculated in this study is in good agreement with the experimental systematics and was compared to the shell model calculations.

Here, we demonstrate a microwave (MW) cavity interference enhancement method to image nano-defects on the surface of metal waveguide. The MW cavity interference system mainly consisted of a MW coaxial resonant cavity with a nano-probe. The MW signals have been evenly divided into two channels. One was the reference signal inputted into the MW waveguide and coupled into the MW cavity via the probe. Also, the coupling strength depends on the distance between the probe and the MW waveguide. Another one was directly inputted the MW cavity to interfere with the reference signal, and was enhanced in the cavity. Then, the surface topography of the metal waveguide was mapped by calculating the enhanced signals. In our experiment, a weak signal of ∼1 pW coupled from the waveguide can be detected by a MW cavity with the quality factor of ∼209. As a proof of application, the topography of nano-defects on the surface of metal waveguide in an MW chip has been mapped with a resolution of ∼15 nm. We have proved that this is a high-resolution, easy-to-manufacture, low-cost, and real-time online monitoring approach for online assessment and screening chips. This potentially has broad applications in the fields of chip manufacturing, chip inspection, nano-structure detection, and so on.

Sacrificing personal benefits for a common good is at odds with the fundamental principle of Darwinian evolution: if only the fittest survives, then there should be no place for cooperation. But cooperative behavior actually abounds, and constitutes one of the most persistent and fascinating puzzles of nature. One solution to this puzzle is network reciprocity, where the collective dynamics of cooperators affords them protection against invading defectors. Commonly, however, such a competition does not unfold in isolation. Populations are often divided into sub-populations, with different evolutionary rules describing the interactions between them. Here we propose and study a paradigmatic model that captures the essence of this setup. Specifically, if two players belong to the same sub-population, they play the prisoner’s dilemma game. If not, they play either the harmony game, the snowdrift game, the stag-hunt game, or the prisoner’s dilemma game. Due to such an asymmetry in the interactions across sub-populations, a fascinating evolutionary dynamics sets up that greatly expands the survivability of cooperators. For instance, when the harmony game applies, cyclic dominance spontaneously emerges, wherein cooperators in one sub-population become predators of defectors in the other sub-population. One also may observe self-organized segregation, wherein both sub-populations maintain a mixed state of cooperators and defectors. As a general rule, we show that the lower the dilemma strength between sub-populations, the more abundant the cooperative strategy in the entire population. Results are confirmed by means of Monte Carlo simulations with pair approximation method, which reveals a rich plethora of novel and generally valid paths to cooperation.

To control the separation of flow past an airfoil with a simple jet mechanism, based on the Large Eddy Simulation from Favre, a suction-blowing combined jet is studied with holes placed on a NACA0012 airfoil’s upper surface and Re = 104 attack angle α = 6°. The results show the control mode of front-hole suction and back-hole blowing is effective. It can suppress the disturbance in the flow field and increase the lift-to-drag ratio of the airfoil at the same time.

Industrial prosperity is the focus of rural revitalization, and the agglomeration of agricultural products processing industry is the breakthrough of industrial prosperity. Agricultural product processing industry is an important symbol of modern agriculture and a key link in the construction of modern agriculture. Its development plays an increasingly important role in promoting farmers’ employment income, agricultural value-added and efficiency, and rural prosperity and development. At present, China’s economic development has entered a new normal, and the development of the agricultural product processing industry has also shown some new characteristics. In order to promote its sustainable and healthy development, we must deeply understand these characteristics, grasp the trend change, conform to the trend, seek benefits, avoid harm, and better improve the quality and level of development.

The development of practical applications of the magnetometer based on ensemble of nitrogen-vacancy centers has been impeded by the large size of the system. In this paper, we present an integrated and miniaturized magnetic field sensor with a volume of approximately 10 cm3. Compared to the previous design, with the fluorescence waveguide excitation and collection structure, both the optical excitation system and collection system are integrated into a compact device by combining the optical fiber, so that it can be a handheld sensing head. We demonstrated experimentally that this sensor head enables the optically detected magnetic resonance measurements with or without the external magnetic field. Subsequently, we verified that the magnetic-field sensitivity is approximately 67 , and projected the photon shot noise limited sensitivity to be 2.04 . This novel system has considerable performance regarding previous designs while greatly reducing dimensions.