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This article reviews advanced process and electron device technology of integrated circuits, including recent featuring progress and potential solutions for future development. In 5 years, for pushing the performance of fin field-effect transistors (FinFET) to its limitations, several processes and device boosters are provided. Then, the three-dimensional (3D) integration schemes with alternative materials and device architectures will pave paths for future technology evolution. Finally, it could be concluded that Moore's law will undoubtedly continue in the next 15 years.

In this work, the closing process of aerial self-locking nuts with different materials was simulated using static analysis in Abaqus/Standard. The effects of different closing amounts of self-locking nuts with different types on the locking performance of self-locking nuts were investigated. In order to analyze the locking performance of self-locking nuts, the method was measured by using the maximum equivalent stress on the root of the third thread. Finally, the equivalent stress range of self-locking nuts of different materials and the closing size range of self-locking nuts of different types were obtained. The equivalent stress ranges of TC4, GH2132 and GH4169 self-locking nuts were 1060–1090 MPa, 664–712 MPa and 860–920 MPa, respectively. At the same time, the corresponding closing amount of M5-M10 self-locking nuts is 0.22–0.46 mm, 0.37–0.64 mm and 0.43–0.75 mm, respectively. (The simulation results show that the equivalent stress of different types of self-locking nuts with the same material shows the characteristics of layered distribution. The equivalent stress of the same type of self-locking nut increases with the increase of the closing amount. When the closing amount is the same, the smaller the type of the nut, the greater the equivalent stress. For the same of the equivalent stress, the closing amount increases with the increase of the type of self-locking nuts.) The conclusions can provide a reasonable theoretical reference for the closing process of aerial self-locking nuts with different materials.

In this work, the thermal stability issue of ultrathin Ti-based silicide (TiSix) in prospective dynamic random access memory (DRAM) peripheral 3D FinFET transistors was systematically studied. As-prepared TiSix/n+-Si contacts and ultrathin TiSix films with different annealing temperatures, were characterized by means of specific contact resistivity (ρc), sheet resistance measurement, X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). It is shown that the specific contact resistivity (ρc) for TiSix/n+-Si contacts gradually degrades with the increase of annealing temperature in the range 450–900 °C. In addition, it is revealed that though thick TiSi2 is conventionally known as thermal stable silicide, the agglomeration of ultrathin TiSix in the source/drain regions of 3D FinFETs still occurs after DRAM annealing typically at 750 °C for few hours. This agglomeration is thought to be responsible for the deterioration of ρc for TiSix/n+-Si contacts.

Calcium carbonate is promising thermochemical heat storage material for next-generation solar power systems due to its high energy storage density, low cost, and high operation temperature. Researchers have tried to improve energy storage performances of calcium carbonate recently, but most researches focus on powders, which are not suitable for scalable applications. Here, novel granular porous calcium carbonate particles with very high solar absorptance, energy storage density, abrasive resistances, and energy storage rate are proposed for direct solar thermochemical heat storage. The average solar absorptance is improved by 234% compared with ordinary particles. Both cycle stability and abrasive resistances are excellent with almost no decay of energy storage density over 25 cycles nor apparent particle weight loss over 24 h of continuous operation insides a planetary ball mill. In addition, the decomposition temperature is reduced by 2.8%–5.6% while the reaction rate of heat storage is enhanced by 80%–205% depending on the CO2 partial pressure. The decomposition process of doped granular porous CaCO3 particles is found to involve three overlapping processes. This work provides new routes to achieve scalable direct solar thermochemical heat storage for next-generation high-temperature solar power systems.

With the wide application of laser technology in laser processing and photoelectric detection, the measurement and display of the laser beam polarization has become an extremely important prerequisite. In this paper, we realize the laser polarization measurement tool based on the virtual instrument LabVIEW software platform. The set-up is designated to measure the Stokes parameters for an arbitrarily polarized beam, using the rotating waveplate method provided by the stepper motor, drive circuit, photodetector, and computer processing of the digitized electrical signal in the PCI expansion card. The Poincare sphere is used for the interpretation of the state of polarization (SOP) and degree of polarization (DOP). The working wavelength range is declared to be 400 – 1100 nm, the accuracy of DOP, azimuth measurement, and ellipticity are ±2%, 0.4°, and 0.4°, respectively.

The microencapsulation of volatile phase change materials is an important and challenging area for low-temperature thermal energy storage. Our previous studies have effectively addressed the challenge of long-term volatile core retention and also indicated that the quality of the obtained poly(urea-formaldehyde) microcapsules is highly affected by various process parameters, including reaction temperature, initial pH, reaction time, and homogenization speed. In this paper, the Taguchi orthogonal array has been employed to optimise controllable process parameters to identify the most synergistic combination, in order to maximise the payload, yield, and encapsulation efficiency. The Taguchi signal-to-noise ratio results substantiated that the most efficient combination of parameters was 3 h reaction time, pH 3.5, 55 °C reaction temperature, and 1200 rpm homogenization speed. With this combination of parameters, microcapsules with superbly high payload of 95.2%, as well as a yield of 30.5% and encapsulation efficiency of 71.1% were amalgamated. In addition, Analysis of Variance (ANOVA) was also utilised to demonstrate the mean response magnitudes (% contribution) of each of the four controllable process parameters, in terms of contribution for the payload, yield, and encapsulation efficiency. Overall, it was indicated that the temperature is the most influential parameter at 83.1% contribution, followed by pH at 6.8%, reaction time at 5.2%, and homogenization speed at 4.9%. Such findings in this work postulate the fundamental insights into maximising the output of the formulation conditions, which in turn is aimed to minimise the time and cost of production of the microcapsules.

In this paper, we propose a measurement system based on single autocorrelation technology and combined with LabVIEW software platform to realize the real-time online measurement of the femtosecond-laser pulse width. The system uses an experimental device based on the Mach–Zehnder interferometer, where the second-harmonic signal of femtosecond laser is obtained by the nonlinear effect of light and nonlinear material; the linear grayscale conversion, median filtering, and threshold segmentation are also applied to the second-harmonic signal. The image centroid, autocorrelation curve, and femtosecond-laser pulse width are obtained, using LabVIEW software. In the experiment, a seed laser source with a central wavelength of 800 nm is used as a test object, and the pulse width is measured to be equal to 261 fs.

Solar thermochemical CO2-to-fuel conversion via two-step redox cycles is a promising strategy to solve climate change and energy storage challenges simultaneously. However, ideal thermochemical materials possessing moderate operation temperature, high yield, good stability, and rapid kinetics operating under isothermal and near-isothermal conditions are still missing. Here, we propose Sr-doped SmMnO3 for moderate-temperature near-isothermal CO2-to-fuel conversions. A record-high isothermal cycle CO yield (376.1 μmol g−1) at no more than 1300 °C is reported based on Sm0.6Sr0.4MnO3. No obvious decay is observed during 14 cycles although grain sizes have increased to some extent. The weakened Mn–O bond induced by Sr doping helps to create more oxygen vacancies, and thus contributes to enhanced yield of both O2 and CO. The oxidation reaction is fast with a CO yield of 58.6 μmol g−1 in 15 minutes, which is 5.6 times as high as that of CeO2 under the same cycling conditions between 1300 °C and 1000 °C. Detailed kinetics for the oxidation step is unveiled based on the Sestak–Berggren model. In addition, SmxSr1−xMnO3 can capture full-spectrum solar energy with a solar absorptance of more than 86.6% in stark contrast to 13.5% for CeO2, making the required concentration ratio to drive reactions decrease by 33.4%. This work provides new materials for high yield and stable thermochemical CO2-to-fuel conversion under moderate-temperature near-isothermal conditions, and paves the way for the development of CO2 splitting techniques directly driven by low-concentration solar energy with high efficiencies.

Herein, a uniformly distributed SnS2/Co3S4 heterostructure nanosheet array was grown on carbon cloth (CC) fibers by a simple solvothermal method and an oil bath method. When the hierarchical SnS2/Co3S4@CC nanoarray composite is used as a binder-free anode for sodium-ion batteries, its charge and discharge capacity is stabilized at 910.1 mA h g−1 at a current density of 0.5 A g−1 after 100 cycles. Even under a high current density of 2 A g−1, after 760 long-term cycles, the reversible capacity is stable at 637.2 mA h g−1, and still has excellent cycle stability with capacity retention of 87.3%. This excellent performance can be attributed to the reasonable design of the arrayed-electrode structure and the in situ growth of Co3S4 nanoparticles on the heterointerface of matrix SnS2 nanosheets: the well-defined array structure can shorten the diffusion path of Na+ ions and effectively alleviates volume expansion under long-cycle performance; the hierarchical heterostructure of SnS2/Co3S4 nanosheets can expand the interface contact area, provide more active sites and effectively enhance the electrochemical kinetics for sodium storage. The excellent electrochemical performance brought by the rational design of the heterogeneous nanostructure arrays provides new possibilities for the practical application of energy storage in the future.

In this work, a selective wet etching process of Si to Si0.7Ge0.3 with TMAH solution to fabricate SiGe nanowires is systematically investigated. Initially, the 2.3% TMAH solution at 20 °C is applied for the as grown Si0.7Ge0.3/Si multilayers stack and a “rectangular” profile is achieved at the Si0.7Ge0.3 extremity due to its high selectivity. However, the reduction of Ge concentration due to the Ge interdiffusion caused by the high temperature anneal treatment will attain a reduced selectivity of Si to Si0.7Ge0.3 and a “rounding” Si0.7Ge0.3 extremity profile. Moreover, the profile of the upper Si0.7Ge0.3 extremity is clearly worse than the bottom one. This is because the Ge concentration of upper Si0.7Ge0.3 is 1.5% lower and the Ge interdiffusion of the upper Si0.7Ge0.3 is slightly worse. After increasing the TMAH concentration to 25%, both the upper and bottom Si0.7Ge0.3 extremity can achieve a “rectangular” extremity profile with an almost the same Si0.7Ge0.3 loss ~ 1.5 nm per side. Compared with 2.3% TMAH concentration, the Ge concentration of the etching off SiGe film can be reduced from lower than 29% to lower than 24% using the 25% TMAH solution at 20 °C. Therefore, the 25% TMAH solution at 20 °C is chosen as the optimal selective etching condition for the thermal treated Si0.7Ge0.3/Si multilayers stack samples. Finally, a vertical stacked double SiGe nanowire structure is successfully prepared by utilizing this optimal process condition. This indicates that it is a practicable technique for the selective wet etching of Si in fabricating SiGe nanowires.

We study a continuous-wave sum-frequency blue laser operating at 484 nm. The laser elaborated is based on the intracavity pumping technology. A 912 nm laser produced by an end-pumped Nd:GdVO4 crystal, using an 808 nm fiber-coupled laser diode, is employed to pump an Yb:YAG crystal in the cavity to achieve the simultaneous oscillations in 912 and 1030 nm lasers. An intracavity sum-frequency achieved in a type-I phase-matched BIBO crystal is used to obtain the 484 nm blue laser output. In our experiment, we apply a linear coaxial laser resonator structure. As a result, we obtain a sumfrequency blue laser output of 317 mW at a pump power of 25 W. The slope efficiency of the designed laser is 2.8%, and the beam quality factors are 1.34 in the X direction and 1.36 in the Y direction, respectively, with the power fluctuations about 3.8% within four hours.

This article theoretically investigates the impact of charges at the ferroelectric/interlayer interface on the depolarization field of ferroelectric FET (FeFET) with metal/ferroelectric/interlayer/Si gate structure. The interfacial charges include fixed charges and trapped/detrapped charges. We find that the positive or negative interfacial charges (~1013 cm−2) can align the directions of the depolarization field and corresponding polarization in the ferroelectric. This article may provide insight into the device design of FeFET.

The present work proposed a novel two-stage carbon dioxide hydrate-based vapor-compression refrigeration system. The proposed system applied pure carbon dioxide hydrate as the primary refrigerant and arranged both of hydrate formation and dissociation at the low-pressure stage. The thermodynamic and economic models were developed and then performances of the proposed system using load-levelling storage and full storage operations were evaluated and compared with those of a conventional carbon dioxide single-stage vapor-compression refrigeration system, which is treated as the baseline and with no energy storage. The simulation results indicate that the design capacity of the proposed system using full storage is the largest among the three systems, but with lowest operation cost, and with the incentivization of electricity prices ratio of on and off-peak this cost savings would raise significantly. Noted that the bill structure reveals the load-levelling storage system saves most on the water consumption. Due to the dominant expenditure on the two compressors, compare with the baseline system, the initial capital cost of the full storage system was 75.5% higher, whereas that of the levelling-load storage system was only 21.5% higher. Finally, this paper discussed the economic feasibility on the initial capital cost for the proposed system and developed an indication map to predict the profit years in case of that the new system using load-levelling storage operation replaces the baseline system assuming a system lifetime of 15 years under different electricity prices ratios.

Bionic electronic synapses with weight-modulation properties are promising alternative candidates when compared with traditional CMOS based neuromorphic hardware when building at-scale neural networks for efficient neuromorphic computing. In this Letter, due to the partial polarisation switching of multi-domain properties in polycrystalline Zr-doped HfO2 (HZO) ferroelectric materials, a capacitor-based bionic synapse was proposed, which showed multi-level capacitance modulation characteristics. By switching the voltage-controlled polarisation, the capacitance was gradually modulated via the variation of net polarisation vectors in the HZO layer. The potentiation and depression properties can be achieved with better linearity, symmetry and multiple states. This Letter laid the groundwork for realising the high-density integration neuromorphic computing system by using ferroelectric capacitors as the bionic synapse.

A coupled approach between the conventional computational fluid dynamics platform COMSOL and an in-house-developed direct numerical simulation code DigiDiss is presented to study the dissolution kinetics of an irregular-shaped particle in a stirred cuvette. The complex flow dynamics from COMSOL were imported into DigiDiss as an initial flow condition. A digitised 3D particle structure scanned and reconstructed by X-ray micro-tomography was used in the dissolution simulation. A quantitative assessment of the simulation results was made using as a reference experimental data and a theoretical calculation based on the shrinking spherical model with different flow velocity profiles near the particle. The comprehensive agreement demonstrates the coherence of the simulation method in reproducing the experimental behaviour and is seen as a step closer towards developing a computer software design aide to help with formulation development.

2 μm/3 μm laser has been extensively applied to the fields of medical treatment, communication and detection. In this paper, the genetic algorithm is innovatively used to solve the fiber power transmission equation, which improves the accuracy of simulation results. According to the simulation results, a dual-wavelength Er3+:ZBLAN fiber laser based on composite Fabry-Perot (F-P) cavity was designed and constructed. A stable continuous dual-wavelength output was obtained with a pump power of 50 W. The center wavelengths were 2.79 μm and 1.59 μm, respectively, the maximum output powers were 8.19 W and 2.8 W, respectively, the slope efficiencies were 17.7% and 7.17%, respectively, and the stability of the wavelengths in 2 h were 4.6% and 3.1%, respectively.

In this work, SiGe Fin formation technique using shallow trench isolation (STI) first or STI last strategy for the high mobility channel FinFET device is systematically investigated. A 20 nm width and 35 nm height high crystalline quality of the Si0.7Ge0.3 Fin formation for STI first scheme is demonstrated by utilizing a new developed Si Fin etching, Si Fin recess and SiGe selective epitaxial growth process. For the STI last strategy, a novel chemical mechanical planarization (CMP) treated three-layer SiGe strain relaxed buffer (SRB) is successfully fabricated and a 50 nm high crystal quality and atomically smooth surface Si0.5Ge0.5 layer on this SRB is attained. Moreover, a spike annealing is employed to avoid the Si0.5Ge0.5 Fin oxidation during STI densification with an acceptable STI etching rate. However, both a spike annealing and a lower temperature of traditional furnace at 850 °C or 750 °C suffer micro-trench issue during the Fin reveal process. Therefore, a new developed process, named as STI recess first, is developed to resolve both thermal instability and micro-trench issue at the same time. A minor Si0.5Ge0.5 Fin loss with a sharp Si0.7Ge0.3 SRB/Si0.5Ge0.5 interfaces for STI last scheme is realized by utilizing this new developed STI recess first process.

A dual-wavelength laser operating at 912 nm/1030 nm for the first time using a compact intracavity cascade pumping structure is set up The laser system model was designed and built for testing. The proposed system employs a coaxial linear cavity structure and uses a fiber-coupled 808 nm laser diode (LD) end-pumped Nd:GdVO4 crystal to obtain a 912 nm laser, which then pumped Yb:YAG crystal directly in the cavity to produce a 1030 nm laser. When the LD pump power at 808 nm is 25 W, a 0.97 W laser at 912 nm and a 1.33 W laser at 1030 nm are obtained, respectively. The corresponding optical to optical conversion efficiency is 9.2%. The beam quality factors M2 of 912 nm and 1030 nm lasers at maximum output power is measured to be 1.19 and 1.23.

On approach towards the end of technology roadmap, a revolutionary approach towards the nanowire transistors is favorable due to the full control of carrier transport. The transistor design moves toward vertically or laterally stacked Gate-All-Around (GAA) where Si or SiGe can be used as channel material. This study presents a novel isotropic inductively coupled plasma (ICP) dry etching of Si1−xGex (0.10 ≤ x ≤ 0.28) in SiGe/Si multilayer structures (MLSs) with high selectivity to Si, SiO2, Si3N4 and SiON which can be applied in advanced 3D transistors and Micro-Electro-Mechanical System (MEMS) in future. The profile of SiGe etching for different thicknesses, compositions and locations in MLSs using dry or wet etch have been studied. A special care has been spent for layer quality of Si, strain relaxation of SiGe layers as well as residual contamination during the etching. In difference with dry etching methods (downstream remote plasma), the conventional ICP source in situ is used where CF4/O2/He gas mixture was used as the etching gas to obtain higher selectivity. Based on the reliability of ICP technique a range of etching rate 25–50 nm/min can be obtained for accurate isotropic etching of Si1−xGex, to form cavity in advanced 3D transistor processes in future.

Aiming at the problem of mining coal resources under the Yuxing Mine Ecological Park in Inner Mongolia, China, we adopted a continuous mining and continuous backfilling (CMCB) cemented-fill mining method; based on the systematic description of the mining and backfilling craft of the CMCB mining process, comprehensive use of theoretical analysis, numerical simulation, and similar simulation test methods to analyze the control mechanism of overlying strata. By establishing the mechanical model of roof movement for the CMCB mining, the roof deflection curve equation is deduced, and the roof instability criterion is put forward based on the maximum tensile stress criterion. Numerical simulation showed that the stress curve at the shallow part of the roof fluctuates up and down in a “w” shape, the stress curve of the upper surrounding rock sinks slowly, and the coal pillars and filling bodies are alternately loaded during the staged mining process to jointly limit the movement of the overlying strata. The similar simulation test results showed that the roof has no structural damage, the roof cracks are not obvious, and the overlying strata control effect is good. On site tests showed that the CMCB mining method can effectively limit the movement of the overlying rock in the stope, control the surface subsidence of the ecological park, and increase the recovery rate of coal resources. It can provide a reference for the development of coal resources and ecological protection in a fragile environment.

This paper analyzes the high-quality communication network based on 5G, uses the support of big data, artificial intelligence and virtual reality technology, uses the Internet of Things technology to optimize the supply chain, better integrates online and offline data, and realizes the e-commerce marketing mode of online and offline resource sharing. The countermeasures and suggestions of e-commerce in 5G era are discussed. The application of VR technology based on 5G communication is bound to become the key of the emerging e-commerce platform. The paper presents influence and strategy of 5G technology on E-commerce marketing and operation mode.

Compared with the traditional centralized power transaction mode, the distributed power transaction in the microgrid has the advantages of high transaction efficiency, low transaction cost and high privacy, while the characteristics of the block-chain, such as decentralization, transparency, openness and immutability, are highly consistent with the distributed power transaction mode. This paper proposes a blockchain-based microgrid distributed power trading mechanism that provides consumers with the opportunity to contribute to the grid through renewable energy. By integrating a smart microgrid, the system will remain functional during isolation from the national grid, while allowing energy within the system to be consumed nearby. Through aggregation agents in the microgrid and infrastructure such as smart electricity meters, participants can share the generated energy for profit. Moreover, all the transformations are carried out under the condition that the preset conditions are satisfied. Due to the characteristics of blockchain, no participant can change the data, making the system more reliable.

The major obstacle to treat cervical squamous cell carcinoma (CSCC) is the high prevalence of metastasis, which severely affects 5-year survival rate and quality of life for cancer patients. The DEAD-box helicase family has been reported to be a critical mediator in the development and metastasis of various cancers. DEAD-box helicase 19A (DDX19A) is a member of the DEAD-box helicase family; however, its functional role in CSCC is unclear. In this study, bioinformatics analysis of clinical samples from public databases demonstrated that the expression of DDX19A was elevated in CSCC tissues and that high expression of DDX19A was positively correlated with metastasis and poor clinical outcome. Functionally, we found that DDX19A promoted CSCC cell migration and invasion in vitro and lung metastasis in vivo. Mechanistically, overexpression of DDX19A increased NADPH oxidase 1 (NOX1) expression, enhanced reactive oxygen species (ROS) production, and induced the migration and invasion of CSCC cells. Rescue experiments revealed that DDX19A-induced CSCC functional alterations were dependent on NOX1 and that DDX19A-promoted CSCC metastasis was abrogated upon the inhibition of ROS. Our results demonstrated that DDX19A could promote CSCC metastasis by inducing NOX1-mediated ROS production and that blockage of the NOX1/ROS axis might serve as a potential therapeutic target for patients with DDX19A-overexpressed CSCC.

Thermal energy storage is essential whenever there is a mismatch between the supply and consumption of energy. When the air conditioning system is applied in transport, a great challenge occurred due to frequent fluctuations of cooling load which causes comfort degradation and even healthy concern. In this study, we evaluate charging performance including charging time, transient charging rate, overall energetic and exegetic efficiency of the designed device under different operating conditions. Evolutions of PCM temperature with processing time both in the axial and radial directions are also investigated. What’s more, the dynamic exergy efficiency is studied for the first time to assess the optimal charging depth and charging time. The experimental results show that the charging time can be reduced by 49% and 28% by dropping the charging temperature from 15 to 11 °C and increasing the inlet air velocity from 0.70 to 1.20 m/s. The designed energy storage device has flexible charging rates with the maximum value of 1.3 kJ/s, high thermal efficiencies at 87% and overall exergy efficiencies up to 70%. Both the drop of the inlet air temperature and the rise of the inlet air velocity contribute to the energy efficiency. The analysis of dynamic exergy efficiency shows that the maximum exergy efficiency can reach around 90% with the optimal charging time varying from 10 to 52 min. The corresponding optimal charging depth varies between 46% and 58% under the studied conditions. These findings could provide guidelines for the design and optimization of PCM energy storage device specifically when it is used in the transport field.

Liquid Air Energy Storage (LAES) stands out among other large-scale energy storage technologies in terms of high energy density, no geographical constraints, low maintenance costs, etc. However, the LAES has a relatively lower round trip efficiency, 50–60%, which is a big disadvantage. One of the main reasons is the lower liquid air yield, ∼70%, which is far from 100% due to the lack of cold energy during air liquefaction. Thus, in this paper, cold energy released during liquified natural gas (LNG) regasification is recovered and stored with pressurized propane, which is used to help air liquefaction in the LAES (denoted as LAES-LNG-CS). The LNG regasification process works independently of the LAES thanks to cold storage. Effects of various working conditions on the LAES-LNG-CS system are studied and three operation periods (off-peak, peak and full hours) of the LNG regasification process are considered. Comparisons are made between the LAES-LNG-CS and standalone LAES systems. The results show that the LAES-LNG-CS system could achieve a liquid air yield up to ∼89% and the power consumption per unit mass of liquid air is reduced by ∼32%, compared with the standalone LAES system. What’s more, the system exergy efficiency of the standalone LAES is improved by ∼28% as the air charging pressure is at 8 MPa under studied conditions. Year-round performance study indicates that the round trip efficiency of the LAES-LNG-CS is in the range of 78–89%. Therefore, the proposed LAES-LNG-CS offers a good option for the future development of the LAES system.

Compressed air energy storage (CAES) is one of the most promising large capacity energy storage technologies and this technology which was used only for demand side management, it has not attained the status of an economic model due to its poor round-trip efficiency. However, in the emerging renewable power scenario, this technology has received a new interest among the scientists. In this paper, a comprehensive thermodynamic analysis is performed for conventional and modified configurations that enhances the round-trip efficiency appreciably. The results reveal that when the compressed air is kept at isothermal temperature at atmospheric condition, the mass of air stored in the tank will be high which will reduce the size of the storage tank appreciably for the given capacity. Further, the possibility of generating cool energy along with power generation during the expansion of compressed air from the atmospheric temperature is also addressed. Though this configuration yields a poor round-trip power efficiency, if the heat of compression and cool energy generated during expansion are utilized for other applications, then the overall polygeneration efficiency is very high. However, if the objective is to maximize the round-trip power efficiency then the compressed air in the storage tank to be heated by the stored heat along with the external heat source. The main conclusions drawn from this work will be of great help by providing guidelines for the future development of a high-efficiency Isothermal CAES (ICAES) system for enhanced power generation/combined with the concept of polygeneration.

In this work, a novel three-layer SiGe strain relaxed buffer/strained Si0.5Ge0.5 layer stacking structure is systematically investigated. The novel three-layer graded SiGe strain relaxed buffer, whose Ge concentration increased from bottom to top by roughly 10% with an in situ annealing after each layer grown, can effectively constrain the threading dislocation in the strain relaxed buffer layer. Moreover, a chemical mechanical planarization process can be applied to the strain relaxed buffer to further improve its surface roughness. A high crystal quality and atomically smooth surface Si0.5Ge0.5 layer can be successfully realized on the novel chemical mechanical planarization-treated three-layer SiGe strain relaxed buffer. This strategy can attain at least 50 nm and 0.6% compressive strained Si0.5Ge0.5 layer and its quantification of the strain level is confirmed by utilizing the scanning moire fringe imaging technique. It can be seen that this novel structure can provide a better mobility and larger width for the FinFET or nanowire SiGe channel device.

With the wide application of laser technology in various fields, how to quickly and quantitatively evaluate the characteristic parameters of laser spot becomes a hot issue in laser technology research. In this paper, based on the virtual instrument LabVIEW platform, the image is captured by USB camera, the NI-IMAQdx module is used for programming.Through image acquisition, gradation transformation, filtering processing, threshold segmentation and edge detection, the pseudo-color transformation display, centroid, long and short axis values and ellipticity of laser spot intensity are obtained, the corresponding display level is 0–256, and the working wavelength range is 400 nm–1100 nm, which satisfies the testing and analysis requirements in most current environments.

Nanosecond and sub-nanosecond ultrashort pulse have good applications in medical cosmetology, microstructure machining, scientific research, etc. Using stimulated Brillouin scattering(SBS) to compress the pulse width of ten nanoseconds to one nanosecond or even picosecond which is a technical way that is economical and easy to implement. This article uses a compact single-cell structure device to pass a Nd:YAG laser-pulse with 8.05ns and 145mJ through FC-40. An ultrashort pulse with 1.35ns and 94.5mJ was obtained. The pulse width after compression was measured within 4 h, and the pulse width stability was better than 5%.

The laser source with 3 μm/2 μm output wavelength has many application prospects in clinical medicine, photoelectric countermeasure, and scientific research measurement. An Er3+ doped ZBLAN fiber laser with output wavelength of 2 .8 μm and 1 .6 μm is experimentally studied. By setting the pump power to 5 W, a continuous dual-wavelength output with a central wavelength of 2.803 μm and 1.61 μm is obtained and the corresponding maximum output power is 362.4 mW and 108.6 mW. The slope efficiency is 12.1% and 4.94% respectively. What’s more, the slope efficiency is 12.1% and 4.94% respectively, and the fluctuation rates of peak power of the two wavelengths are 9.7% and 2.1% within 4 h which indicate that the laser has relatively good stability.

The development of more efficient and reliable absorption/adsorption refrigeration for air conditioners (ACs) and chillers is of great interest due to the increasing demand of these cooling devices...

Microencapsulated phase change material (MPCM) slurry has proven to have potential in elevating the overall performance of a photovoltaic/thermal (PV/T) module as a working fluid. In order to make full use of the superiority of MPCM slurry and further improve energy and exergy efficiencies of the PV/T module, the effects of MPCM concentration and melting temperature under a wide inlet fluid velocity range were explored based on a three-dimensional numerical model of coupled heat transfer in this study. The results show that both the energy and exergy efficiencies increased with the concentration. A lower melting temperature resulted in higher energy efficiency, whereas a higher melting temperature is helpful for exergy efficiency improvement. The slurry with an excessively low melting temperature (e.g. 27 °C) even led to lower exergy efficiency than pure water. The melting temperature needs to be precisely tailored to make a compromise between energy and exergy efficiencies. In comparison with pure water, the improvement in energy efficiency provided by the slurry was further enhanced at a lower inlet velocity, while the improvement in exergy efficiency was optimized by adjusting the inlet velocity to a certain value. The maximum improvement in energy efficiency provided by the slurry was 8.3%, whilst that in exergy efficiency was 3.23% in this work. From the above, the superiority of MPCM slurry can be further promoted by selecting suitable material properties and operating parameters. The authors would like to acknowledge the financial support of the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom (Grant Nos. EP/N000714/1 and EP/N021142/1), National Natural Science Foundation of China (Grant Nos. 51606135 and 51776142) and Natural Science Foundation of Hubei Province (Grant No. 2016CFB156).

Phase change materials (PCMs) are generally integrated into matrix materials to form shape-stabilized composite heat storage materials (HSMs) used for high temperature thermal energy storage applications. The conventional fabrication of composite HSMs is prevalently implemented at quite high temperatures, which is energy-intensive and narrows down the range of applicable PCMs because of thermal decomposition. Therefore, this paper establishes a novel fabrication approach to accomplish highly dense matrix to encapsulate PCMs at extremely low temperatures, based on the recently developed cold sintering process. The feasibility of the proposed approach was demonstrated by a case study of NaNO3/Ca(OH)2 composite HSMs. It was observed that the Ca(OH)2 matrix formed dense microstructure with obvious sintered boundaries and successfully encapsulated NaNO3 as PCM. The HSMs maintained stable macroscopic shape after hundreds of thermal cycles, and exhibited an energy storage efficiency of 59.48%, little leakage of PCM, and good thermal stability. Mechanical tests indicated that the HSMs possessed excellent mechanical properties when the sintering pressure is over 220 MPa. The discharging time of stored heat was presented through infrared thermography, and the heat storage capacity measured for the composite HSMs was over four times as high as those of typical solid storage materials of sensible heat, which demonstrated their excellent heat storage performances. The HSMs can be used in the form of packed bed or parallel channel with multi-layered heat storage, which is beneficial for efficiently utilizing solar heat and improving the performance of current energy storage system. This study therefore provides a novel route for energy-saving and low-carbon fabrication of shape-stabilized composite HSMs.

Liquid air energy storage (LAES) is a novel proven technology that can increase flexibility of the power network, obtaining revenue through energy price arbitrage. To assess the economic potential of a variety of energy storage options, this study develops a cost research framework for LAES, which is also applicable to other energy storage technologies. For the calculation of Levelized Cost of Storage (LCOS), it is essential to evaluate the electricity purchasing cost and the total electricity generated. However, they are often estimated by simply assuming an average electricity price and an annual operating cycle in the previous studies. In this paper, a price arbitrage algorithm is developed, according to which decisions are made at each time step whether to charge, discharge or stand by. Thus, the electricity purchasing cost as well as the amount of electricity generated by the storage unit is determined and the LCOS of the energy storage system is calculated. Results show that the LCOS for a 25MW/125MWh LAES system is in the range 191-590 £/MWh, depending on different round-trip efficiencies and different costs set in three scenarios. If the round-trip efficiency is assumed to be 60%, the LCOS would in the range 191-294 £/MWh under the three scenarios.

The rapid increase in application of intermittent renewable energy generation has stimulated the development of energy storage system to guarantee a stable supply in electricity grid. As a large-scale storage technology, Liquid Air Energy Storage (LAES) technology has attracted many attractions in recent years due to it offers many unique advantages including high energy density, mature technologies based and geographical-constraint free. However, current LAES has relatively low round trip efficiency (less than 60%) and still needs improvement. In the LAES, the recovered cold energy from the liquid air is insufficient to cool the compressed air to the lowest temperature with the shortage of ~18% and liquid air yield does not achieve the maximum in the charging process; external free cold sources would be needed to further increase the liquid air yield, and the round trip efficiency could easily break through 60%. This paper proposes an innovative LAES system integrated with LNG regasification process, the objectives in this established work are to improve the product yield of liquid air and enhance the overall roundtrip efficiency. Sensibility analysis and exergy efficiency analysis of charging process and discharging process at LAES are discussed. Meanwhile, the comparisons of system performance are made between traditional LAES system and LAES with LNG regasification system (LAES-LNG) at same operating parameters. Through the LAES-LNG system, more liquid air is generated. Results show that relatively higher round trip efficiency could be obtained, with 15-35% enhancement compared with the current LAES. Also, liquid air yield obtains a significant improvement to 0.87.

A intracavity cascading pumped dual-wavelength output Nd:YAG/Yb:YAG laser is demonstrated for the first time. The system adopts a coaxial composite cavity structure, and using an all-solid-state Nd:YAG laser operating at 946 nm as intracavity pump source, a 1160 mW 946 nm laser and a 43 mW 1030 nm laser were obtained with 1.39 W absorbed pump power. The fluctuation of the output power was better than 5% in the given 30 min. The corresponding beam quality factors M2 are 1.25 and 1.27.

Thermal energy storage (TES) has a crucial role to play in conserving and efficiently utilising energy, dealing with mismatch between demand and supply, and enhancing the performance and reliability of our current energy systems. A competitive TES technology requires a number of scientific and technological challenges to be addressed including TES materials, TES components and devices, and integration of TES devices with energy networks and associated dynamic optimization. This paper concerns mainly about TES materials challenges with a specific focus on using shape stable composite phase change materials (CPCMs) for medium and high temperature application. The paper first briefly reviews the state-of-the-art development of materials research for thermal energy storage. The focus is then on CPCMs for medium to high temperatures applications, covering materials screening, formulation based on molecular modelling validated at a different length scale through experiments, formulation based on chemical and physical compatibility, and manufacture of material modules via innovative use of conventional powder technology. The properties of the materials and materials modules are characterised and analysed with an aim to establish property-structure relationships. This includes a particularly interesting aspect of the motion of PCM and nanoscale objects with the PCMs for heat transfer enhancement during thermal cycling, which explains the mechanisms of the encapsulation of PCMs in the composite.

A high theoretical capacity of approximately 1400 mA h g-1 makes SnO2 a promising anode material for sodium-ion batteries (SIBs). However, large volume expansion, poor intrinsic conductivity, and sluggish reaction kinetics have greatly hindered its practical application. The controlled creation of oxygen vacancy (OV) defects allows the intrinsic properties of SnO2 to be effectively modulated, but related work concerning SIBs is still lacking. In this Minireview, the mechanism of failure of SnO2 electrodes is discussed and an overview of recent progress in the general synthesis of OV-containing SnO2 materials and the feasible detection of OVs in SnO2 is presented. The use of OV-containing SnO2 -based anode materials in SIBs is also reviewed. Finally, challenges and future opportunities to engineer OVs for semiconductor oxides are examined.

With the deepening of electric power system reformation and the enhancement of distributed energy permeability, distributed energy in power generation and sales side of effective configuration is facing opportunities and challenges. The traditional centralized power trading mode is centralized trading, which has many problems such as low transparency, high cost, low efficiency and unreliable data, so it’s unable to adapt to the large-scale distributed power trading scenario. In this context, this paper proposes a distributed power trading mechanism based on blockchain asynchronous consensus mechanism, analyzes the compatibility between blockchain technology and distributed power trading mode, carries out research on the asynchronous consensus mechanism, designs the blockchain-based distributed power trading system architecture and process method and carries out trial application to improve the consensus efficiency of the system consensus. Meanwhile, the mechanism could solve the trust problem in the process of distributed power trading, and ensure the transparency and fairness of distributed power trading.

Phase change materials (PCMs) are regarded as one of the most promising candidates for thermal energy storage due to possessing large energy storage densities and maintaining nearly a constant temperature during charging/discharging processes. However, the intrinsically low thermal conductivity of PCMs has become a bottleneck for rapid energy transport and storage. Here, we present a strategy to achieve ultrafast solar and thermal energy storage based on biomorphic SiC skeletons embedded NaCl-KCl molten salts. A record-high thermal conductivity of 116 W/mK is achieved by replicating cellular structure of oak wood, leading to an ultrafast thermal energy storage rate compared with molten salts alone. By further decorating TiN nanoparticles on SiC skeletons, the solar absorptance is enhanced to be as high as 95.63 % via exciting broadband plasmonic resonances. Excellent thermal transport and solar absorption properties enable designed composites to have bifunctional capabilities of harvesting both thermal energy and solar energy very rapidly. This work opens a new route for the design of bifunctional energy storage materials for ultrafast solar and thermal energy storage.

The energy industry needs to take action against climate change by improving efficiency and increasing the share of renewable sources in the energy mix. On top of that, refrigeration, air-conditioning, and heat pump equipment account for 25-30% of the global electricity consumption and will increase dramatically in the next decades. However, some waste cold energy sources have not been fully used. These challenges triggered an interest in developing the concept of cold thermal energy storage, which can be used to recover the waste cold energy, enhance the performance of refrigeration systems, and improve renewable energy integration. This paper comprehensively reviews the research activities about cold thermal energy storage technologies at sub-zero temperatures (from around 􀀀 270 ◦C to below 0 ◦C). A wide range of existing and potential storage materials are tabulated with their properties. Numerical and experimental work conducted for different storage types is systematically summarized. Current and potential applications of cold thermal energy storage are analyzed with their suitable materials and compatible storage types. Selection criteria of materials and storage types are also presented. This review aims to provide a quick reference for researchers and industry experts in designing cold thermal energy systems. Moreover, by identifying the research gaps where further efforts are needed, the review also outlines the progress and potential development directions of cold thermal energy storage technologies. The authors would like to acknowledge the funding support from SJ-NTU Corporate Lab. This work was partically funded by the Ministerio de Ciencia, Innovación y Universidades de España (RTI2018-093849-B-C31 - MCIU/AEI/FEDER, UE), and the Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación (AEI) (RED2018-102431-T). The authors at the University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2017 SGR 1537). GREiA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. This work is partially supported by ICREA under the ICREA Academia program.

This chapter discusses the roles and applications of different thermal energy storage technologies for both supply-side and demand-side energy management through integration. The supply-side management covers solar power generation, grid-scale electrical power conversion and storage, and industrial waste heat recovery. The demand-side management includes district heating, district cooling, and domestic heating and cooling. Typical examples are given in each of the cases with a focus on system integration. Special attention is also paid to potential commercial operations.

In order to explore the stability of coal pillar and the characteristics of roof movement during the process of roadway backfill mining (RBM), the 301 backfilling test working face of Ordos Chahasu coal mine is taken as the background. Based on the expansive pressure arch theory, the evolution process of the stope expansive pressure arch in RBM is studied; by establishing a mechanical model for the stability of coal pillars, the interactions between the height, width, and the maximum number of branches are obtained. When the width and height of the branch are both 5 m, the optimal number of the branches is obtained. Then, by establishing a mechanical model for the subsidence of the immediate roof, the process of the immediate roof subsidence is divided into three stages, namely, the formation stage of the local pressure arch, the merge stage of the pressure arch, and the expansion stage of the pressure arch. In addition, using the numerical method, the alternate bearing process of coal pillars and filling bodies and the change of the maximum supporting stress are studied, and the evolution of the pressure arch bearing structure above the stope and the staged subsidence characteristics of the roof are analyzed. The on-site test showed that the coal pillar has a good stability during the mining process. The maximum stress of the coal pillar is 16.5 MPa, and the maximum stress of the filling body is 9 MPa. The maximum settlement of the immediate roof is 102 mm, indicating that the roof control effect is good. This research will play an important role on engineering practice.

According to the working characteristics of Metal Oxide Varistor (MOV) in series capacitors, the architecture of MOV’s leakage current monitoring device using for EHV or UHV series capacitors was studied in this paper. The method of extracting and correcting resistive current of each MOV based on main capacitor current was proposed. Furtherly the MOV’s leakage current monitoring device and power supply based on current transformer was developed. The finite element model of the series capacitors was established and the electric field intensity and potential distribution after installing the monitoring device were simulated and analyzed. The application of MOV monitoring device was firstly implemented in China, and the leakage current data of under MOV’s operation were obtained, which provides reference for the development of condition monitoring technology of series capacitors in the future.

In this paper, the introduction technique of high mobility Si0.5Ge0.5 channel on bulk-Si substrate and its FinFET device preparation are explored in detail. First, a vertical Si0.5Ge0.5 fin formation on a slightly tapered SiGe strain relaxed buffer (SRB) can be attained by developing an optimized two-step etching process with HBr/O2/He plasma. Moreover, a SiN liner is introduced to further improve the thermal stability of the SiGe SRB/Si0.5Ge0.5 fin during a low temperature STI densification annealing. As a result, no obvious Si0.5Ge0.5 oxidation and Ge diffusion are observed. After the SiGe SRB/Si0.5Ge0.5fin structure is successfully prepared, a Si0.5Ge0.5 channel pMOS FinFET device is fabricated. Its drive current IDS of 123 μA/μm under |VDS| = |VGS| = 0.8 V, Ion/Ioff ratio of ∼3e4 and subthreshold slope of 120 mV/dec are demonstrated. The above results show that these newly developed processes can be a practical technique for the preparation of high mobility FinFET device.

2.79 μ m-band pulsed laser has important application prospects in medicine, military, etc. In this paper, the pulse operation of Er, Cr: YSGG laser Q-switched by piezoelectric crystal La3Ga5SIO14(LGS) is realized, and high-energy output under nanosecond pulse is obtained. In the experiment, LGS crystal was used as the de-voltage Q-switching element. At a repetition frequency of 10 Hz, the obtained pulse width was 27.4 ns, the corresponding single pulse maximum output energy was 136 mJ, and the dynamic–static energy conversion efficiency was 75.6%; The output beam quality factor M2 obtained by self-made spot analysis software in the x and y directions are 1.34 and 1.40, respectively.

Phase change materials (PCMs) based thermal energy storage techniques are promising to bridge the gap between thermal energy demand and intermittent supply. However, the low specific heat capacity (Cp) and thermal conductivity of PCMs preclude the simultaneous realization of high energy density and high power density thermal charging/discharging. Here, concurrent enhancement of Cp and thermal conductivity are demonstrated to be possible based on SiO2 nanoparticles decorated LiNO3/NaCl eutectics inlaid in three-dimensional (3D) hierarchical ultralight silicon carbide (SiC) foams. The average Cp is 4.86% higher than that of pure PCMs due to the high surface energy and interfacial thermal resistance induced by weak interaction between SiO2 nanoparticles and eutectics, as confirmed by molecular dynamics (MD) simulations. The thermal conductivity of composites achieves an ultrahigh value of 2.78 W·m−1·K−1, which is 259% of LiNO3/NaCl, accompanied with a large phase change enthalpy of 331.9 kJ/kg. Continuous heat transport paths provided by ultralight SiC foams have dominant contributions to the enhancement of thermal conductivity, although the presence of SiO2 nanoparticles deteriorates it slightly. In addition, the full-spectrum solar absorptance is enhanced from 25.2% to 76.3%. Rapid thermal transport and enhanced solar absorptance of composites enable heat charging rate to rise by 150% compared with SiO2 nanoparticles decorated eutectics. This work provides a strategy for the realization of high energy density and power density compatible thermal energy storage technology.

With the development of science and technology in China, it enriches the teaching methods of higher vocational colleges and creates a good learning environment for students. In order to send more comprehensive talents to the country in order to further promote the pace of national development, college education has been concerned by people from all walks of life. In order to improve the teaching quality of colleges and universities, cloud computing vocational education information technology has been widely used in the field of higher vocational education.