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We report a search for a dark photon using $14.9$~fb$^{-1}$ of $e^+e^-$ annihilation data taken at center-of-mass energies from 4.13 to 4.60~GeV with the BESIII detector operated at the BEPCII storage ring. The dark photon is assumed to be produced in the radiative annihilation process of $e^+e^-$ and to predominantly decay into light dark matter particles, which escape from the detector undetected. The mass range from 1.5 to 2.9~GeV is scanned for the dark photon candidate, and no significant signal is observed. The mass dependent upper limits at the 90$\%$ confidence level on the coupling strength parameter $\epsilon$ for a dark photon coupling with an ordinary photon vary between $1.6\times 10^{-3}$ and $5.7\times10^{-3}$., Comment: 8 pages, 3 figures

In this work, eight types of poly (ether-ether-ketone) (PEEK)/Ni foam co-continuous phase composites (PEEK–Nis) were fabricated by hot pressing. Unfilled PEEK polymer was also prepared in two different methods: P-1 was prepared by the same method with PEEK–Nis, and P-2 was synthesised via extrusion. The tensile properties and fracture processes of PEEK–Nis were investigated and compared with those of unfilled PEEK polymer. Results showed that the stress–strain curves of PEEK–Nis exhibited elastic deformation, yielding and necking. Nickel foam could improve the tensile toughness and elongation-at-break of PEEK–Nis by increasing the number of edges or decreasing the pore quantities of Ni foam. The Young's moduli of PEEK–Nis were related only to metal content. The Young's moduli of PEEK–Nis increased with Ni volume content, and this relationship showed a secondary upward trend. The fracture surfaces of 10 kinds of materials after tensile tests were observed through scanning electron microscopy. Mirror, mist and hackle zones were found on the fracture surfaces of PEEK–Nis and the unfilled PEEK polymer. Morphological analysis showed that a crack could begin in one site and propagate within the material. However, the Ni prism structure could effectively decelerate crack propagation and even stop the crack, causing the crack to restart in the mirror zone. Two main parameters influence the tensile behaviours of PEEK–Nis including the quantity of Ni edge (or PPI value) and edge thickness. The Ni edge quantity of the foam played a positive role in the tensile behaviour of PEEK–Nis. However the effect of edge thickness has two side effects. In Ni foam, intergranular fracture replaced plastic fracture and degraded tensile performance if edge thickness exceeded 70 μm. Amongst all PEEK–Nis studied in this work, PEEK–NiA-1 exhibits the best performance and its tensile toughness was more than 1.6 times that of P-1.

A low-diffusion NiRePtAl coating ((Ni,Pt)Al outer layer in addition to a Re-rich diffusion barrier layer) was prepared on a Ni3Al-base single crystal (SC) superalloy via electroplating and gaseous aluminizing treatments, wherein the electroplating procedures consisted of the composite deposition of Ni-Re followed by electroplating of Pt. In order to perform a comparison with conventional NiAl and (Ni,Pt)Al coatings, the cyclic oxidation performance of the NiRePtAl coating was evaluated at 1100 and 1150 °C. We observed that the oxidation resistance of the NiRePtAl coating was significantly improved by the greater presence of the residual β-NiAl phase in the outer layer and the lesser outward-diffusion of Mo from the substrate. In addition, the coating with the Re-rich diffusion barrier demonstrated a lower extent of interdiffusion into the substrate, where the thickness of the second reaction zone (SRZ) in the substrate alloy decreased by 25 %. The mechanisms responsible for improving the oxidation resistance and decreasing the extent of SRZ formation are discussed, in which a particular attention is paid to the inhibition of the outward diffusion of Mo by the Re-based diffusion barrier.

The low-cycle fatigue (LCF) deformation mechanism and fatigue life of an Al-12Si alloy were investigated at different temperatures and strain rates. With increasing temperature, the fatigue life increases at first and then reduces, which is derived from the deformation mechanism. At the lower temperatures, the primary Si cracking induced by piling-up of dislocations dominates fatigue damage behaviors. Both of increasing temperature and reducing the strain-rate can restrain the phase cracking, thus increase fatigue life. However, with further increasing temperature, the micro-scale void caused by dislocation annihilation dominates the phase debonding behavior, leading to the decrease of fatigue life.

The cyclic deformation and damage behaviors of Al-Si piston alloys are comprehensively studied. It is found that the fatigue cracks mainly initiate from broken primary Si at low temperature and phase/matrix interface debonding at higher temperature. The transgranular crack propagation can be found for all the temperatures and the grain is obviously reduced after low-cycle fatigue at higher temperature. Furthermore, a hysteresis energy-based life prediction model was developed and utilized. Based on the model, the optimum fatigue life was found at intermediate temperature. A strategy for fatigue property optimization was proposed: increasing W0 at low temperature and increasing β at high temperature, to enhance the fatigue life during entire service temperatures with the ultrasonic melt treatment. In this way, the remarkable improvement of the fatigue properties may be achieved. Keywords: Al-Si alloys, Low cycle fatigue, Fatigue crack initiation, Temperature, Property optimization

A new kind of analog integrator has been developed for a magnetic diagnostic system on the Experimental Advanced Superconducting Tokamak. Although the previous analog integrators are single-ended input, which has low common-mode rejection ratio (CMRR), a different kind of integrator, a difference integrator is introduced which has the same structure as a standard difference amplifier. The linear drift compensation method is used for determining the effective drift slope; then, the plasma control system uses the drift slope to rectify the integration signal in real time. To improve the maintainability and testability of the integrator system, a new integrator controller has been developed. The new controller uses an advanced reduced instruction set computing machine microcontroller and the lightweight IP protocol stack to realize the network control. The tests show that the upgraded integrator works well, its CMRR is high up to 125 dB when the common voltage is 1.5 V, and the processed integration drift is about 10 mV in 1000 s of integration when the time constant is 20 ms. The performance is much better than the previous integrator.

The high-performance Al12Si4Cu3NiMg alloy with massive transition elements has been developed recently for piston of diesel engines. The influences of microstructures on the tensile and low-cycle fatigue (LCF) behaviors were investigated with conventional and in situ testing technologies in this study. Upon the tensile loading, the microcracks initiate from the primary Si near the surface when the tensile stress reaches approximately 280 MPa (close to the tensile strength); then, the microcracks grow rapidly through eutectic Si and intermetallics (Al3CuNi) for the gravity casting (GC) alloy. With regard to the LCF, the microcracks initiate from the shrinkage pores regularly because of the localization of fatigue damage in the GC alloy. The shrinkage pores, usually accompanied by the brittle intermetallics (Al3CuNi), typically exhibit more complex geometry. The lamellar Al3CuNi provides a preferred path for the crack propagation after fatigue crack initiation. The ultrasonic melt treatment (UT) was used to optimize the microstructures and reduce casting defects (shrinkage pores), thereby resulting in improvement in tensile and LCF properties. For the UT alloy (pore-free), the microcrack initiates from some coarser primary Si rather than from the shrinkage pores because of the accumulation of micro-scale plastic deformation. Furthermore, higher resistance of crack propagation can also be realized with refinement of microstructures in the UT alloy. Increase in crack initiation and propagation resistances is the main reason for improvement in the LCF life of the UT alloy.

Ferroelectric flux-closure domains have attracted great attention due to their potentials in high density data storage. For their future applications, it is important to understand their evolution with different factors, such as misfit strain. In this work, a flux-closure domain consisting of a vertical 180° domain wall with two symmetric a domains in both ends (“I” type closure) was observed in nearly unstrained SrTiO3/PbTiO3 multilayers by aberration corrected Transmission Electron Microscopy, which was speculated to be mainly induced by the strong depolarization field near the interface. With the tensile strain increasing, the small a domains in “I” type flux-closures grow gradually and eventually change to the well-known “V” type flux-closures. On the basis of a combination of experimental results and phase field simulations, the phase diagram of the stabilized domain arrays versus the strains in PbTiO3 films are established. These results provide significant information on understanding the formation mechanism of flux-closure domains and shed light on their controlled growth. In addition, it paves a way to reduce the economic cost in their commercial applications because the SrTiO3 substrate is easy to synthesize and much cheaper than scandate substrates.

Oil absorption by macroporous absorbents has been recognized as an easy, efficient, economical and environment-friendly method in such fields as oil pollution control, oil-water separation, and solidification of liquid fuels/hazardous. In this study, Carbonized asphalt-melamine sponge (CAMS) was prepared by the combination of dip-coating melamine sponge with asphalt/water emulsion and then mild carbonization at 500 °C. The produced CAMS presented high oil-absorption capacity and good recyclability, water-repellence, fire resistance, flexible compressibility and low density. Its chloroform absorption capacity can reach 246 g g−1, significantly higher than that of most of other reported oil absorbents. CAMS is verified as oil-absorbent material with great commercial development potentials that can be massively produced via green and economic process, using no organic solvents or harmful solutions while lowering manufacture costs.

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the DArk Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of $4.3\sigma$. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out., Comment: 11 pages, 13 figures, published in Phys. Rev. Lett. Add one more digit for first three columns in Table S2

Thermal evaporation was used to prepare the Al doped Mg2Si film on Si substrates. The influences of the structure, morphology, Raman spectrum, and electrical resistivity of Mg2Si film with Al doping were investigated using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), four-point probe (FPP), Raman spectroscopy, and surface profiler. The results of XRD indicate that after Al is doped, the intensity of Mg2Si diffraction peak is enhanced and the grain size become larger. FESEM results indicate that after Al is doped, Mg2Si grains aggregate into clusters, and the internal structure of the thin films is dense. Raman results showed that after Al is doped, a redshift happened at the Raman characteristic peak near 256cm-1. FPP results show that the electrical resistivity of Mg2Si thin films decrease after doping Al.

The microstructure, tensile and fatigue strengths of the high-strength 35CrMo steel with quenched and tempered (QT) and hot-rolled (HR) states were investigated. There is not a commonly linear relation between tensile and fatigue strengths, namely, the HR steel with higher tensile strength has lower fatigue strength, which is mainly attributed to microstructural inhomogeneity of the steel and different damage mechanisms under fatigue and tensile loads. In this work, an estimation method of fatigue strength for steels with dual phase is suggested.

For the purpose of keeping a plasma in steady state and avoiding instabilities, the experimental advanced superconducting tokamak (EAST) plasma control system (PCS) needs more diagnostic data produced by the EAST distributed subsystems to perform its complex control algorithms. To solve the transmission problem of all these data, a real-time communication system based on the messaging, real time, and grid real time operating system and reflective memory (RFM) network is designed. It is expected to enable the data acquisition (DAQ) systems of various EAST subsystems to be able to transfer the diagnostic data to the PCS in real time through the RFM network as the data are acquired. Then, the PCS can use these available data to carry out the necessary calculations according to the control algorithms and send the commands to the subsystems in every control cycle. To reach this goal, a small real-time communication system, adapted from the prototype of the EAST vacuum DAQ system (sampling rate of 10 KHz), was built for a performance test. In this test, the vacuum DAQ system transferred the acquired data to the PCS within the control cycle of $100~\mu \text{s}$ , which tentatively meets the abovementioned requirements. The test was performed for 1000 s to get a stable and reliable result, which is described in detail in this paper as well as plans for future work.

The as-casted compacted graphite irons (CGIs) with different microstructures were opted to investigate the relation between tensile and fatigue strengths as well as the correspondingly influencing mechanisms. The results show that the fatigue strength increases first and then decreases with increasing the tensile strength. The fatigue strength is mainly determined by the area percentage ratio of ferrite to graphite and the strength of ferrite, while the tensile strength is basically dominated by the pearlite area percentage, resulting in the non-synchronous relation above. Finally, based on these investigations, a prediction model for the fatigue strength of CGI is proposed.

The microstructure, tensile strength, high-cycle fatigue property and corresponding damage mechanisms of compacted graphite iron at room temperature (25 °C), 400 °C and 500 °C, were investigated. It is found that the fatigue strength increases at first and then decreases with the increase of the testing temperature. At 25 °C, the fatigue crack mainly initiates from graphite debonding and propagates along the graphite clusters. At 400 °C, the fatigue crack initiation is influenced by oxidation; the fatigue strength may be improved by dynamic strain aging. At 500 °C, the oxidation becomes more serious and the oxide layer accelerates the crack to propagate along the matrix. At the same time, the phenomenon of grain boundary softening, one of the reasons resulting in the reduction of fatigue strength, appears. Then, the model of damage mechanism was proposed according to the propagation behavior of fatigue crack at high temperatures, and the quantitative relationship between the fatigue strength and the ratio of the interphase corrosion depth to the critical crack length was established. This investigation may enrich the fundamental understanding on the damage mechanism of compacted graphite iron.

The real-time data acquisition system is designed for providing POlarimeter-INTerferometer (POINT) diagnostic data to P-EFIT in real-time. The digital phase detector of POINT can provide real-time Faraday rotation angle data and density phase shift output which can be used in plasma control. P-EFIT, a code based on parallel computation in Graphic Processing Unit and the EFIT framework, is developed for EAST plasma control. Now P-EFIT includes a new algorithm for real-time plasma current profile reconstruction with POINT diagnostic data. The new real-time data acquisition system has been designed based on a reflective memory (RFM) network and the LabVIEW real-time operating system. It can be divided into three modules: data acquisition, data pre-processing and real-time data transmission. The data acquisition module receives a message containing the plasma shot information from the data acquisition console (according to the rules of the EAST data acquisition system) and then acquires the POINT diagnostic data after signal conditioning. The data pre-processing module primarily converts the raw data into a valid physical signal thus reducing the workload of P-EFIT. The EAST Plasma Control System has a well-established RFM network from which P-EFIT is able to get all the data it needs. This means that the data transmission module must first choose the RFM network to transfer processed data in real-time, and then P-EFIT can perform a new equilibrium reconstruction iteration with the most recent data from the data transmission module and the last equilibrium result. The data transmission frequency is 20 kHz, which satisfies the requirements of the P-EFIT real-time plasma current profile reconstruction.

The electromagnetic interference (EMI) around the Experimental Advanced Superconducting Tokamak (EAST) device is very harsh during plasma discharge experiment. In order to reduce the effect of EMI and enhance signal to noise ratio (SNR), a fiber-optic high speed isolator has been designed. Each channel of the isolator has a transmitter unit connected via fiber-optic cable to the receiver unit. A transmitter unit which consists of a 6th order Bessel low-pass anti-aliasing filter, an analog-to-digital converter (ADC), a Field Programmable Gate Array (FPGA), a serializer and an optical transceiver, while a receiver unit comprises an optical transceiver, a deserializer, a FPGA, a digital–to-analog converter (DAC) and a 6th order Bessel low-pass filter. Data from the ADC is serialized by the serializer using 8b/10b encoding before transmission, and 10b/8b decoding was used by the deserializer in the receiver unit. A prototype of this isolator has been realized and tested. The test results show that the transmission bandwidth of analog signal is up to 10 MHz, the transmission delay is typically 500 ns, the transmission distance is up to 250 m and the output noise is less than 5 mV, which can meet the requirements of EAST experimental campaigns.

For EAST experiments, the plasma control system (PCS) needs a lot of diagnostic data produced by the distributed subsystems of EAST to meet the requirements of steady-state plasma control. But due to the factors of different sampling frequencies of the subsystems and the signal distortion caused by long distance transmission, it’s difficult for the PCS alone to acquire all the diagnostic data in each control cycle. So the real-time data sharing system is designed to solve the problem of real-time data transmission between the PCS and the subsystems so as to realize data sharing among the distributed EAST systems. In consideration of the required transfer speed and data volume, a “multiple networks” structure composed of a reflective memory (RFM) network and a Gigabit Ethernet network is used to build this system. To work with this multi-network structure, Red Hat MRG Realtime (Messaging, RealTime, and Grid) operating system (OS) is adopted, as it can provide deterministic response time. This system is responsible for transferring the diagnostic data collected by the data acquisition (DAQ) systems of the various distributed subsystems to the PCS and data server. The PCS receives the data through the RFM network in each PCS control cycle (defined as 100 microseconds) while the data server receives the data through the Ethernet network in every time-slice (defined in the DAQ program). All the relevant diagnostic data are to be available to the PCS through the data sharing system, though the PCS has the ability to choose some specified data according to its own needs during the plasma control. Likely, the above advantages for the PCS also apply for any EAST subsystems connected to the RFM network. In this paper, the details of the real-time data sharing system are described and the future work is also discussed.

The thermo-mechanical fatigue (TMF) behaviors and corresponding damage mechanisms of Al-Si piston alloy were investigated in the temperature ranges of 120–350 °C and 120–425 °C in this study. For TMF cyclic stress response behavior, the rapid cyclic softening occurs in the initial stage and then the cyclic stress maintains stable at lower strain amplitudes; but the cyclic stress displays gradual decrease up to the final failure at higher strain amplitudes. For TMF damage behavior, the cracks mainly initiate from the broken primary silicon in the temperature of 120–350 °C range, and commonly nucleate from the boundary between primary Si and matrix in the temperature of 120–425 °C range. For both cases, creep may have obvious influence and result in the formation of many micro-voids, but the oxidation may only have a little effect. A new energy-based model for low-cycle fatigue (LCF) and TMF life prediction was proposed based on the hysteresis energy with strain rate modification, considering both fatigue and creep damages. The predicted results agree well with the experimental ones for the Al-Si piston alloy.

Compacted graphite iron (CGI) is a typical engineering material with double phases, of which graphite morphology largely determines its mechanical performances. Although microstructural effects have been widely investigated, quantitative relations between mechanical properties and microstructures are still limited. In this study, a micro-scale damage cohesive finite element model (CFEM) was reconstructed and identified based on the tensile properties and damage characteristics of CGI, and then the effects of graphite including distribution, size, volume fraction and morphology on tensile behaviors were investigated. The agreement of yield strength and fracture mechanism between experimental and simulation results shows that the developed methods, combining the digital image-based technique (DIT) and CFEM, can be used to simulate CGI effectively. Furthermore, the quantitative relations between yield strength and microstructures were established. It is found that graphite distribution and volume fraction affect the yield strength much more compared with graphite size and morphology. Specifically, interesting results were found that yield strength does not monotonically change with volume fraction and aspect ratio of graphite, but reaches a maximum value under an optimal graphite size, which is in contrast to the traditional results. The established quantitative relations between microstructures and tensile properties of cast alloys can be utilized to design and manufacture the metallic composite with optimal mechanical properties.

High-temperature performance is a key factor to concern for the application of cast Al–Si alloys. The evolution of microstructures and mechanical properties of a multiphase Al–Si–Cu–Mg–Ni–Ce alloy during tension in a temperature range from 25 °C (ambient temperature) to 425 °C was investigated. The results show that the main strengthening precipitates of the alloy are θ′ and Q phases. They are stable at 25–250 °C, while dissolve rapidly above 250 °C during tension. The damage initiates and propagates in the form of cracking of brittle phases. The fracture mechanism transforms from quasi-cleavage to coexistence of quasi-cleavage and dimple as temperature increases. The Ce-bearing phase Al20Ti2Ce promotes the damage occurrence below 350 °C while hinders crack propagation at 425 °C. The ultimate tensile strength (UTS) and yield strength (YS) decrease as the tensile temperature increases. The decreasing rate of UTS can be divided into three stages which is associated with the decreasing rate of strengthening precipitates. An empirical constitutive equation is proposed to describe the relationship between UTS and tensile temperature. It provides a good estimation for both cast and wrought Al alloys and the predicted strengths are in good agreement with the experimental results.

Fatigue failure is the most common failure mode of structural materials. In this study, the high-cycle fatigue properties at different temperatures, fracture surface morphologies and corresponding damage mechanisms of a widely used vermicular graphite cast iron RuT450 were investigated. It is found that the fatigue strength values are 150 MPa, 143 MPa and 108 MPa for room temperature, 400 °C and 500 °C, respectively. The decrease rate of fatigue strength is affected by the change of morphology. At high temperature, the proportion of pearlite decreases and graphite becomes blunt. In general, the cracks initiate from the graphite phase boundary and propagate through the pearlite lamellae. In addition, according to the change of matrix micro-structure and crack growth processes under different temperature conditions, and by the quantitative analysis of micro-structure, the effect of temperature can be transformed into related parameters of matrix. Based on the changes, a fatigue strength prediction model for vermicular graphite cast iron at different temperatures was proposed, which predicts the trend well.

The influences of temperature on the microstructure evolution, tensile properties, especially low-cycle fatigue (LCF) behaviors and damage mechanisms of Al-Si piston alloy have been investigated in this paper. The results show that the alloy exhibits cyclic softening at high-temperature. Fatigue cracks usually initiate from primary silicon phase and preferentially grow along particles in a slightly zigzag path at relatively low temperature. With temperature increasing, however, the ductile tearing fracture through micro-cracks can be found. In order to evaluate the fatigue life, considering the temperature and loading conditions, a comprehensive 3-parameter model based on hysteresis energy has been proposed; at a constant temperature the fatigue life can be controlled by two parameters, i.e., the intrinsic fatigue toughness W 0 (the resistance to crack propagation) and the fatigue cracking exponent β (the resistance to fatigue cracking), which dominate the LCF damage mechanisms (from fatigue-induced particle cracking to rapid fatigue crack growth). For the current Al-Si alloy, the combined effect of W 0 , β and temperature T can lead to an optimal fatigue life at a critical temperature. This model provides a new clue for optimizing and designing the high-temperature materials.

This paper describes the plasma current profile reconstruction algorithms using POlarimeter-INTerferometer(POINT) measurements in GPU parallel equilibrium reconstruction code P-EFIT for EAST plasma control. Real-time POINT diagnostic data acquisition system is designed to satisfy the requirement for real-time reconstruction. The static time-slice and experimental simulation benchmark calculations using experimental magnetic plus POINT data of EAST discharge are conducted, which show that P-EFIT could provide reasonable plasma current and q profile in 0.7 ms in real-time with 65 × 65 spatial grid resolution. These results show that P-EFIT with POINT diagnostic could provide equilibrium reconstruction results for real-time plasma current and q profile control which will be applied in the near future.

Thermo-mechanical fatigue (TMF) failure is the major problem of the cylinder head subjected to combined variations in temperature and loading during operation. This study mainly focuses on the TMF property and the life prediction of vermicular graphite iron (VGI). The ferrite clusters can be easily found from the microstructure and fractography images. Compared with the TMF experimental data testing at 125–400 ℃ and 125–500 ℃, significant cyclic hardening occurs in the former and slight hardening does in the latter. Depending on the difference in the damage mechanism between TMF and iso-thermal low-cycle fatigue (LCF), based on the hysteresis energy, a life prediction method has been proposed at first. By the minimum amount of LCF and TMF tests, the present method can predict the TMF life rapidly, accurately and cheaply. And based on the difference in the fatigue crack propagation thresholds between pearlite and ferrite, the fracture mechanism of TMF was also discussed.

Ferroelectric a1/a2 domain structure has great potentials in high dielectric capacitors and tunable microwave devices. Understanding its structure is crucial to better control the domain configurations for future applications. In this paper, PbTiO3 thin films with variant thicknesses are deposited on (110)-oriented GdScO3 substrates by Pulsed Laser Deposition (PLD) and investigated by using conventional transmission electron microscopy (TEM) and Cs-corrected Scanning TEM. Contrast analysis and electron diffractions reveal that PbTiO3 films are domain oriented consisting of a1/a2 and a/c domain structure. The a1/a2 domains are found to distribute periodically and its width increases with increasing film thickness following square root rule. Cs-corrected STEM imaging demonstrates that the domain walls of a1/a2 domain structure have the rotation characteristic of 90° ferroelastic domain wall. The interchange of a1/a2 domains induces the formation of vertex domains composed of two 90° and one 180° domain walls. Strains are mainly concentrated on the domain walls. The formation of this complex domain configuration is discussed in terms of the effect of the misfit strain, film thickness and cooling rate. These results provide novel information about a1/a2 domain structures and are expected to shed some light on modulating a1/a2 ferroelectric domain patterns in the design of ferroelectric-based devices.

By analyzing the formation mechanisms of different types of dislocation patterns, one unified factor is developed to account for effects of slip mode and further explore the basic law of dislocation evolution in fatigued face-centered cubic (fcc) crystals. First of all, in the formation of persistent slip band (PSB) ladders, geometrically necessary dislocations (GNDs) accommodate the elastic/plastic strain gradients between the hard walls and soft channels and provide the long-range internal stresses required for the simultaneous compatible deformation of soft and hard regions. In typical wavy-slip materials, advanced dislocation patterns include the wall, cell and labyrinth structures. The formation of deformation band (DB) walls may be derived from the accumulation of GNDs. The appearance of labyrinth and cell structures should be related to the activation of critical and coplanar secondary slip systems, respectively. In typical planar-slip materials, the dislocation structures consist of the dipole arrays and stacking fault (SF) bands. The constant compression of the split distance between partials will lead to the conversion of the closely spaced dipole array to the SF bands, which indicates that both wavy-slip and planar-slip materials follow one unified evolution factor. This factor, labelled α in this work, may be described as the ratio of the annihilation distance of screw dislocations to the split distance between partials, which can characterize the slip mode. The higher the α value is, the easier will be the appearance of PSBs and various advanced dislocation patterns. With decreasing the α value, dislocation evolution gradually changes from 3D patterns to 2D structures.