Multi Structure Research Articles

Некоторые вопросы внедрения высоких технологий в предварительное расследование уголовных дел

Investigation of criminal cases is a complex multi-stage structure with various procedural participants. In this article, we will focus on two issues that are, in our opinion, the most relevant: the timing of the preliminary inquiry and the safety of the evidence obtained. The criminal procedural legislation only fragmentarily provides for the use of high technologies, especially at the stage of preliminary inquiry. Often a criminal case includes thousands of pages of text, printed and kept in the office of the investigator. Making copies from paper is time consuming. Hand-printed and signed texts of protocols, specifications and other documents may be falsified or destroyed. The introduction of blockchain technology into the preliminary inquiry stage can resolve these important aspects.

Bifunctional three-dimensional self-supporting multistage structure CC@MOF-74(NiO)@NiCo LDH electrode for supercapacitors and non-enzymatic glucose sensors

The bifunctional electrode materials for supercapacitors and non-enzymatic glucose sensors have attracted the researchers’ great interest due to their excellent electrochemical performance. In this work, three-dimensional self-supporting multistage structure CC@MOF-74(NiO)@NiCo LDH electrode has been successfully prepared through a facile hydrothermal and electrochemical deposition method. Benefiting from the unique three-dimensional flower-like multistage structure, the optimized CC@MOF-74(NiO)@NiCo LDH electrode exhibits an excellent specific capacitance of 9.73 F cm−2 and a superior rate capability of 77.65% at a high current density of 50 mA cm−2. Besides, the material has a superior capacitance retention rate of 84.09% after 5000 cycles. Furthermore, the fabricated CC@MOF-74(NiO)@NiCo LDH//CC@NiCo2O4 @NiFe LDH ASC device exhibits a high energy density of 22.85 Wh kg−1 and the power density of 1750 W kg−1 at the current density of 10 mA cm−2. Moreover, the as-prepared CC@MOF-74(NiO)@NiCo LDH shows an outstanding electrocatalytic performance in glucose detection, including a high sensitivity of 1699 μA mM−1 cm−2, a low detection limit of 278 nM (S/N = 3) and a wide linear range of 10 μM–1.1 mM and 1.5–9 mM. The electrode also has good long-term stability and remains 93.29% of the original current density after 35 days. The unique three-dimensional flower-like structure of MOF-74 and two-dimensional layered double hydroxides (LDHs) nanosheets structure provide a larger specific surface area and improve the conductivity of the MOF-74(NiO). Furthermore, the synergistic effect of the bimetal Ni-Co provides more active sites for electrochemical reactions and shortens the ion transport path. Accordingly, the fabricated CC@MOF-74(NiO)@NiCo LDH has great potential application prospects in the field of supercapacitors and non-enzymatic glucose sensors.

Ethylenediamine‐Modified Hollow Porous Nanospheres for Effective Removal of Chromium (VI)

AbstractThe synthesis of recyclable adsorbents with satisfactory adsorption properties is more beneficial to their value in environment‐related applications. Organic porous polymer has become a potential adsorption material because of its convenient and effective modifiability and relatively high specific surface area. Here, we report for the first time a novel synthesis of ethylenediamine‐modified hollow porous nanospheres (HPNs‐NH2) via hyper‐crosslinking mediated self‐assembly strategy using polylactide‐b‐polystyrene‐b‐polyglycidyl methacrylate (PLA‐b‐PS‐b‐PGM) triblock copolymers as precursors, followed by further ring‐opening of epoxy groups with ethylenediamine (EDA). Owing to the special multistage pore structure, high surface area and a large number of amino active sites, the obtained solid adsorbent HPNs‐NH2 showed high adsorption capacity (493 mg/g) for Cr(VI), and its adsorption performance can still be maintained at a high level after eight cycles. These obvious advantages indicated that HPNs‐NH2 is expected to play an important role in the treatment of hexavalent chromium in sewage.

Design and Performance Study of Clutch Disc Assembly of Wide-Angle, Large-Hysteresis, Multistage Damper

The clutch is an important component of the vehicle driveline system. One of its major functions is to attenuate or eliminate the torsional vibration and noise of the driveline system caused by the engine. Based on experiments of vibration damping under different vehicle conditions, the structure and functional principle of a clutch-driven disc assembly for a wide-angle, large-hysteresis, multistage damper is investigated in this study using an innovative combined approach. Furthermore, a systematic integration of key technologies, including wide-angle low-stiffness damping technology, large-hysteresis clutch technology, a novel split pre-damping structure technology, damping structure technology for component cushioning, and multistage damping structure technology, is proposed. The results show that the total torsional angle of the wide-angle large-hysteresis, multistage damper is more than twice that of the traditional clutch damper. The multistage damping design allows a better consideration of various damping requirements under different vehicle conditions, which can effectively address problems of severe idle vibrations and torsional resonance that occur under idled and accelerated conditions. Meanwhile, the use of a large-hysteresis structure and wear-resistant materials not only improves the vibration damping performance, but also prolongs the product service life, consequently resulting in multi-faceted optimization and innovative products.

Evaluation of microbial community shift on the spatial distribution in an innovative anoxic/aerobic device response to performance

Investigating microbial communities will facilitate the evaluation of the applicability of wastewater treating devices. A novel five-section anoxic/aerobic device was proposed and proved its feasibility as the biological unit in bio-ecosystems. Taxonomic diversity and microbial community shift across the sections of this device was investigated in this study. The special structure of this device enabled a gradual change in dissolved oxygen (DO) concentration across different sections. Distinct microbial communities were formed in the different sections. Samples from eight different positions of this device were collected to investigate the microbial community shift via 16S rRNA gene sequencing. Microbial diversity was abundant in all the sections of this device. The phyla Proteobacteria (54.86%), Chloroflexi (8.94%), Acidobacteria (7.72%), Bacteroidetes (5.97%), and Firmicutes (4.31%) were dominant in the anoxic block, whereas the phyla Proteobacteria (45.89%–71.99%), Bacteroidetes (11.88%–21.45%), Nitrospirae (0.57%–23.5%) were dominant in the aerobic block. Ammonia-oxidizing bacteria (genuas Nitrosomonas, 0.63%–8.32%) and nitrite-oxidizing bacteria (genus Nitrospira, 0.57%–14.33%) were abundant in the aerobic block. The shift in microbial communities corresponded with the trend in contaminant removal and DO conditions. The findings of this study revealed that this multi-section device has a diverse microbial community that efficiently removes pollutants. The multi-stage structure of aerobic block is suitable for the nitrification of ammonia in small-scale devices. This device has commercial applications in rural areas where low-strength wastewater needs to be treated.

Sisal-inspired design of ZnO nanoneedle multistage structure for efficient fog harvesting

The collection of available water resources from fog has caused widespread attention under the situation of water shortage.However, their practical deployment has been largely retarded because most microstructures have very weak air-binding ability and cannot catch droplets on a large scale.The key to fog harvesting is the process in which the fog quickly gathers into small droplets and the droplets roll off quickly.Hence, inspired by the structure of sisal, we designed and synthesized ZnO nanoneedle multistage structure on Cu mesh by two-step method of electric-field assisted growth. ZnO nanoneedle multistage structure is composed of countless gradient structures, and the tip of the gradient can easily capture small droplets, which enables faster droplet condensation. The results demonstrate that ZnO nanoneedle multistage structure has ultra-low adhesion due to high roughness and strong ability to confine air. Compared with other ZnO nanostructures, this design of the structure can promote the falling of water droplets and maintain the Cassie state model during fog harvesting, improving fog collection efficiency. The current design provides a promising method to multi-level structure into fog collectors, which offers a great opportunity to develop water harvesters for real-world applications.

Advanced FPGA Implementation of AES Algorithm

Along with the enhance in computation as well as information safe-keeping in cloud servers, the requirement for a devoted computer hardware accelerator with regard to encryption is arising to be able to decrease the processor work. Highly efficient Advanced Encryption Standard (AES) 128-bit implementation, that could be utilized as an accelerator. In this research paper resource optimization and higher throughput were obtained. Memory segmentation is actually carried out to be able to assign several ports for simultaneous information accessibility. When algorithm is in proceed and examined time delay and initiation time period of various procedures, with regard to every crucial route delay, a fresh multistage solitary initiation time period sub-pipelined structure is suggested for making the initiation time period to a single for smallest route latency. Consequently, almost all operations in AES could be started within a single clock cycle and also can easily accept input in each and every clock cycle. The suggested approach while examined on latest Field Programmable Gate Array (FPGA) XC7VX690T unit that offers a throughput of 104.06 Gbps at a highest frequency of 813MHz and also 1.23-ns route delay. The useful resource utilization is reduced whenever compared along with other alternatives. The suggested method offers 30.74Mbps efficiency on device, which usually was 27.13% much more compared to the best efficiency documented in an earlier research study

Parallel Multi-Branch Model with Multi-Resolution Interaction for Human Pose Estiation

In recent years, human pose estimation has become a research hotspot in the field of computer vision, and has extensive application value in many fields, such as activity recognition [1], action detection, self-drving, etc. This paper tries a novel multi-stage network structure to complete the task of human pose estimation, and focus on improving the loss of spatial accuracy caused by repeated downsampling and upsampling. The network structure contains multiple resolution subnets. After the original resolution is learned in the first stage, a low-resolution branch will be generated in each subsequent stage, and these branches can learn feature representations in parallel. Through continuous multi-scale and multi-resolution fusion, necessary information interaction between subnets of different resolutions can be carried out to obtain richer feature maps and make the predicted key point heat maps more accurate. This paper uses COCO keypoint detection dataset to obtain the relevant results of pose estimation, which verifies the effectiveness of this network.

Thiourea-assisted one-step fabrication of a novel nitrogen and sulfur co-doped biochar from nanocellulose as metal-free catalyst for efficient activation of peroxymonosulfate

The N, S co-doped biochar (N, S-BC) with multistage pore structure was successfully synthesized from nanocellulose and thiourea by one-step pyrolysis, which could effectively activate peroxymonosulfate (PMS) to degrade sulfamethoxazole (SMX) in water. Moreover, the removal efficiency of SMX by this oxidation system was 2.3–3.1 times than that of other systems activated by common metal oxides (such as Fe3O4、Fe2O3, and MnO2). More importantly, the mechanism of the N, S-BC/PMS process was deduced by reactive oxygen species (ROS) quenching experiment and electron paramagnetic resonance (EPR) test, which exhibited that surface-bound free radicals and singlet oxygen (1O2) played an essential role in the SMX degradation. Surprisingly, the sulfate radical (SO4•-) and hydroxyl radical (•OH) produced in this system existed in a bound state on the surface of the carbon catalyst to react with SMX, rather than dispersed in the aqueous solution. This particular form of free radicals could resist the influence of background substances and pH changes in water, and maintain excellent SMX degradation efficiency under different water matrices and pH. This study provides a new insight into the application of carbon catalyst in actual water pollution control.

Grasshopper optimization algorithm optimized multistage controller for automatic generation control of a power system with FACTS devices

This paper uses a Grasshopper Optimization Algorithm (GOA) optimized PDF plus (1 + PI) controller for Automatic generation control (AGC) of a power system with Flexible AC Transmission system (FACTS) devices. Three differently rated reheat turbine operated thermal units with appropriate generation rate constraint (GRC) are considered along with different FACTS devices. A new multistage controller design structure of a PDF plus (1 + PI) is introduced in the FACTS empowered power system for AGC while the controller gains are tuned by the GOA. The superiority of the proposed algorithm over the Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) algorithms is demonstrated. The dynamic responses of GOA optimized PDF plus (1 + PI) are compared with PIDF, PID and PI controllers on the same system. It is demonstrated that GOA optimized PDF plus (1 + PI) controller provides optimum responses in terms of settling time and peak deviations compared to other controllers. In addition, a GOA-tuned PDF plus (1 + PI) controller with Interline Power Flow Controller (IPFC) exhibits optimal results compared to other FACTS devices. The sturdiness of the projected controller is validated using sensitivity analysis with numerous load patterns and a wide variation of parameterization. To further validate the real-time feasibility of the proposed method, experiments using OPAL-RT OP5700 RCP/HIL and FPGA based real-time simulations are carried out.

One-step facile fabrication of hydrophobic SiO2 coated super-hydrophobic/super-oleophilic mesh via an improved Stöber method to efficient oil/water separation

To achieve effective oil/water separation, one-step facile fabricated hydrophobic SiO2 coated super-hydrophobic/super-oleophilic mesh (FSSM) via an improved Stöber method. Apparent contact angle was characterized by a contact angle meter (CA). SEM, FTIR and XPS were used to characterize the surface morphology and chemical composition of FSSM, individually. The super-hydrophobicity of the membrane was conferred by the multistage rough structure and low surface energy substances produced by the hydrolysis and polycondensation reactions of TEOS, DTMS and TMODS. Meanwhile, the effect of the proportion for silane coupling agents DTMS and TMODS on the hydrophobicity from claiming stainless steel network surfaces was investigated. The results showed that when DTMS: TMODS = 1:9 (n: n), the maximum apparent contact angle of FSSM was 153.3°, while the apparent contact angle of oil was 0°. The C, O and Si elements on the surface of FSSM increased by approximately 21%, 9% and 20% respectively. The FSSM can efficiently separate different oil/water mixtures (about 96%). Furthermore, FSSM showed excellent anti-corrosion (pH from 0 to 14) and remarkable reusability (about 40 cycles) and durability (exposure test at atmosphere for 35 days). The advantages of easy manufacture, stability and low cost of FSSM make it expected to be widely used in the field of oil-water separation.

Multi-stage collaborative efficiency measurement of sci-tech finance: network-DEA analysis and spatial impact research

Sci-tech and finance plays an increasingly important role and have become an important driving force in economic development. In China, the problem of insufficient financial support for sci-tech innovation is important to enterprises. According to the internal relationship between different stages of Sci-tech and the finance system, this paper is aimed at exploring the efficiency measurement method between sci-tech and finance systems. Firstly the multi-stage collaborative structure of sci-tech finance is built, where the system of sci-tech is divided into three stages including the R&D stage, transformation stage of sci-tech achievements and industrialization stage, and the financing channel is the input of the finance system into the sci-tech system at different stages. The measurement method of the multi-stage collaborative efficiency between sci-tech and finance systems is put forward by the framework of network DEA. Then, taking China as an example, we collect the information of 30 provinces and cities from 2009 to 2016 and measure the efficiency of each system and the collaborative efficiency of the both. The efficiency’s spatial correlation is tested by means of Moran index. Finally, the influencing factors of the collaborative efficiency are analyzed based on the spatial econometric regression model, which considers the financing channels and human capital. To sum up, there are significant differences in the sci-tech finance collaborative efficiency among regions in China. Among them, the collaborative efficiency of Beijing, Shanghai and Jiangsu ranks in the top three. Comparing the different stages of the sci-tech system, the commercialization stage is a weak link in many regions of China. Human capital and financing channels of sci-tech finance have different degrees of positive impact on the sci-tech finance collaborative efficiency. Among them, human capital plays a greater role in promoting the sci-tech finance collaborative development.

Application of Direct-driven Multistage Supercharging Technology in Water Jet Propulsion Devices

In order to solve the problems of complex transmission and low power density of water jet propulsion devices, a direct-driven multistage supercharging structure suitable for such devices is designed, and the computational fluid dynamics (CFD) method is used for numerical calculation and verification analysis. The results show that the designed structure can improve the performance of water jet propulsion devices, which is of great significance to the integrated development of such devices.

A Full-Ocean-Depth Sampler for Hadal Microbes Based on Multistage Membrane Filters With In-Situ Preservation

Abstract In order to obtain high-quality microbial samples from the hadal zone, which has a depth of over 6,000 m, a full-ocean-depth sampler with the function of in-situ filtration and preservation was developed. A flow pump and several membrane filters were used for in-situ filtration under the sea. With a multistage filtering structure, the microbes can be initially screened according to their sizes. To avoid the degradation of microbial ribonucleic acid (RNA), a special structure was designed to inject the RNAlater solution into the samples immediately after the filtration. The sampler was tested in our laboratory and deployed during Mariana TS-15 in 2019. It was installed on a hadal lander of Shanghai Ocean University and deployed at MBR02 (11.371°N, 142.587°E, 10,931 m) in the Mariana Trench. A total of 20 L of in-situ seawater was filtered, and membranes with pore sizes of 3 and 0.2 μm were preserved. The study is expected to provide important support for the establishment of a hadal microbial gene pool.

Laser-assisted synthesis of cobalt@N-doped carbon nanotubes decorated channels and pillars of wafer-sized silicon as highly efficient three-dimensional solar evaporator

The Co@NCNTs/Si pillars with channels is assemble to a suitable pure water gathering device, which is applied in seawater desalination and sewage purification to produce pure water by utilizing solar energy. High-efficiency utilization of solar energy to generate water vapor is popular, recyclable, and environmentally friendly for seawater desalination and sewage purification, helping to alleviate the global water shortage crisis. Here, we report an efficient and simple method to prepare a three-dimensional (3D) evaporator for steam generation by harnessing the power of the sun. This evaporation is composed of one-dimensional (1D) cobalt embedded and nitrogen doped carbon nanotubes (Co@NCNTs) and 3D silicon pillars array structure (Si pillars). The Co@NCNTs/Si pillars shows a wide light absorption range provided by carbon nanotubes and a long light absorption path because of the silicon pillars. The surface temperature of the sample rises rapidly in 1.5 min and exceed 80 °C under solar illumination of one sun. The water evaporation can be high as 1.21 kg m−2 h−1 under one sun irradiation (1 kW/m2) with the energy efficiency up to 82.4%. This scalable Co@NCNTs/Si pillars can prepare pure water from seawater and sewage, where the removal rate of ions in seawater and pollutants in sewage is similar to 100%. Based on our research, this multistage three-dimensional structure is a simple and efficient novel photothermal material for extensive seawater desalination and sewage purification.

Multi-stage internally-cooled membrane-based liquid desiccant dehumidifiers: Driving-force based insights into structural improvement

Membrane-based liquid desiccant dehumidification (MLDD), as a promising technology for temperature and humidity control, suffers from a degradation of effectiveness when handling large air flows in industrial sectors. Existing methods such as multi-stage dehumidifying and internally cooling provide a solution to solve this issue, but their implementation in the large-scale systems is somehow challenging due to the difficulty in sealing ducts, and their mechanisms for enhancing effectiveness have not yet been clarified in depth. This paper aims to apply a tractable multi-stage internally-cooled structure for improving the MLDD effectiveness at an acceptable cost and to uncover the underlying mechanisms from the perspective of the driving forces for heat and mass transfer. A dimensionless finite-difference model is first developed to capture the physical fields of the multi-stage internally-cooled membrane-based liquid desiccant dehumidifier (MI-MLDD). The MI-MLDD is then compared with the single-stage adiabatic one (SA-MLDD) in terms of the effectiveness, maldistribution and thermodynamic limits of driving forces. Four structural improvement methods including increasing stages and layers in the unlimited-size and fixed-size schemes are proposed to further improve the MI-MLDD effectiveness. Their enhancing mechanism is explained by introducing six dimensionless parameters that denote the intensity, distribution and maximum driving forces of heat and mass transfer respectively. Besides, the specific cooling capacity is defined to evaluate the energy efficiency variation of dehumidifiers caused by different effectiveness improvement methods. Compared to the SA-MLDD, the MI-MLDD increases the sensible and latent effectiveness by up to 64% and 18% due to the mitigated maldistribution and the increased minimum local driving forces, even as the air-to-solution flow ratio exceeds 2.4. The unlimited-size scheme improves the MI-MLDD effectiveness more significantly than the fixed-size one due to a linear increase in the number of heat and mass transfer units. The specific cooling capacity could reach the maximum value at the condition where the MI-MLDD operates without unfunctional contact areas. These findings highlight the potential of MI-MLDD for handling the large flow air with the improved performance.

A Novel Low-Power Notch-Enhanced Active Filter for Ultrawideband Interferer Rejected LNA

In this article, a novel low-power notch-enhanced active filter is presented using the feedback notch-enhanced (FNE) technique. The active notch filter is proposed based on an area-saving second-order $LC$ series resonator. The passive devices’ loss can be effectively eliminated by the generated dc power-independent negative resistance by inserting a current feedback transistor. Moreover, the capacitive source degeneration (CSD) technique is proposed to boost the filter $Q$ by shifting the series resonant frequency to the negative-resistance region. To demonstrate the feasibility and practicability of the proposed notch filter, a 3.1–10.6-GHz IEEE 802.11a interferer rejected low-noise amplifier (IR-LNA) is fabricated in a 0.13- $\mu {\hbox {m}}$ CMOS process. The multistage structure, consisting of a common-gate (CG) stage with a dual-resonance load and a cascode stage with the proposed active notch filter, is employed for wideband input matching, gain flatness, and interferer rejection (IR) simultaneously. The measurements show that the IR-LNA provides a maximum of 16.05-dB power gain, 2.08–3.70-dB noise figure (NF) in the desired band, and a maximum of 40.9-dB IR ratio (IRR) at 5.77 GHz, with a power consumption of 10.2 mW, while the active notch filter only consumes 456- $\mu {\hbox {A}}$ current.

Pickering emulsion-embedded hierarchical solid-liquid hydrogel spheres for static and flow photocatalysis

Pickering emulsion-based photocatalysis is considered to be a promising system due to its large active surface area and water/oil spatial separation capability for enrichment of substrates and products. In this work, a novel hierarchical structure composed of calcium alginate gel sphere wrapped ionic liquid-in-water Pickering emulsion with TiO2 in the water phase, which are stabilized by graphene oxide, is prepared via a facile one-step emulsion gelation method. Such subtle combination of Pickering emulsion, hydrogel and TiO2 with a multi-stage solid-liquid assemblage structure shows enhanced degradation activity of 2-naphthol into small molecular alkanes under simulated solar irradiation. The photodegradation activity is attributed to the ionic liquid as adsorption medium for 2-naphthol, and the high-efficient charge separation at graphene oxide/TiO2 interface superior to that of pure TiO2. More importantly, the as-prepared millimeter-sized assembled gel spheres can be directly used as the column filler to construct continuous flow photocatalytic system, maintaining the promising performance in removing pollutants from water with ~100% remove ability of 2-naphthol on stream. A charge transfer mechanism of the photocatalyst is proposed, i.e. photogenerated charges are separated in TiO2/graphene oxide p-n heterostructure at the interface of Pickering emulsion droplets.

Speech Enhancement Using Multi-Stage Self-Attentive Temporal Convolutional Networks

Multi-stage learning is an effective technique to invoke multiple deep-learning modules sequentially. This paper applies multi-stage learning to speech enhancement by using a multi-stage structure, where each stage comprises a self-attention (SA) block followed by stacks of temporal convolutional network (TCN) blocks with doubling dilation factors. Each stage generates a prediction that is refined in a subsequent stage. A fusion block is inserted at the input of later stages to re-inject original information. The resulting multi-stage speech enhancement system, in short, multi-stage SA-TCN, is compared with state-of-the-art deep-learning speech enhancement methods using the LibriSpeech and VCTK data sets. The multi-stage SA-TCN system's hyper-parameters are fine-tuned, and the impact of the SA block, the fusion block and the number of stages are determined. The use of a multi-stage SA-TCN system as a front-end for automatic speech recognition systems is investigated as well. It is shown that the multi-stage SA-TCN systems perform well relative to other state-of-the-art systems in terms of speech enhancement and speech recognition scores.

Работа образовательных и научных учреждений Санкт-Петербурга (Петрограда) в интересах военного производства в годы Первой мировой войны

During the First World War which quickly acquired the limits of an unprecedented military confrontation between the largest world powers all Russian resources were mobilized to work in the interests of military production for the first time. Scientific and educational institutions of various levels were involved in this work. In this article it is shown how this process took place in practice by the example of the capital of the Russian Empire, St. Petersburg (Petrograd). The mobilization of science during the First World War is understood as the intensification of research aimed at the development of the defense industry, energy and transport support for its activities, the supply of raw materials and the introduction of new technologies into production in order to provide the front with ammunition, weapons and military equipment and other military products, as well as the development of scientific principles for the organization of industry, agriculture, military medical service and the use of natural resources in wartime. This fully refers to educational institutions. During the war there appeared new forms of organizing the scientific and educational institutions work in the interests of military production. They included military-industrial committees, special meetings, various scientific societies, unions and meetings. Some of them obtained a very extensive and multi-stage structure and showed their effectiveness in a short time. The educational institutions of the city began to be even more actively involved in the sphere of military production. Their best representatives began to participate in research on military topics. Various educational institutions of Petrograd in close cooperation with the laboratories of military factories were increasingly involved in the development of complex technological processes at military production. In addition, the production divisions of various educational institutions of the city received tasks for the manufacturing military products, sometimes of the highest degree of complexity. During the war military orders for many educational institutions of the city became permanent.