Search

With the rapid development of machine learning, artificial intelligence technology has been widely applied across various domains of life. However, concerns regarding the privacy risks associated with machine learning have increased. In response to these concerns, the Personal Information Protection Law of the People's Republic of China was promulgated to regulate the collection, use, and transmission of private information. Despite this, machine learning requires a large amount of data, necessitating the development of privacy protection technologies that allow for the collection and processing of data under legal and compliant conditions. Split learning, a privacy-preserving machine learning technique that enables the training of distributed models among multiple participants without sharing raw data, has emerged as a research focus. It has been recognized that split learning is vulnerable to data privacy attacks, and various attacks along with corresponding defenses have been proposed. However, existing surveys have not discussed and summarized research on data privacy during the training phase of split learning. The comprehensive overview of data privacy attack and defense techniques in the training phase of split learning was offered. Initially, the definition, principles, and classifications of split learning were summarized. Subsequently, two common attacks in split learning, namely the raw data reconstruction attack and the label leakage attack, were introduced. The causes of these attacks in the training phase of split learning were then analyzed, and corresponding defenses were presented. Finally, future research directions in the area of data privacy for split learning were discussed.

[Objective] By studying the relationship between the operating parameters of the polishing machine, the motion patterns of rice grains, and the generation of broken rice rates, to seek the basis for optimal parameter control of the polishing machine. [Methods] By analyzing the motion process of rice grains in the polishing chamber, conducting full-factorial experiments, and applying Particle Image Velocimetry (PIV) to analyze the trajectory of rice grain movement, clarifiied the relationship between the motion status of rice grains, the rate of broken rice, and the rotational speed of the polishing machine as well as the opening degree of the pressure gate. [Results] When the pressure gate aperture was set to 20 mm, no coherent motion pattern wwas observed within the experimental range of machine speeds, rendering the rice polishing ineffective. In contrast, with a pressure gate aperture of 4 mm and machine speeds ranging from 600 to 1 400 revolutions per minute, the rice grains exhibited an alternating motion pattern characterized by a relatively small spiral angle and the occurrence of regions with varying velocities. Furthermore, under the condition of a pressure gate aperture of 8 mm and a machine speed of 1 400 r/min, the rice grains demonstrated an alternating motion pattern in regions of high and low velocities (with a velocity difference exceeding 3 m/s). In both of these scenarios, excessive friction and pressure leaded to a high rate of broken rice (exceeding 4%). In the remaining experimental conditions, characterized by appropriate pressure gate apertures and machine speeds, the rice grains exhibited a moderately sized spiral angle in alternating regions of high and low velocities (with a velocity difference of 2～3 m/s). This configuration resulted in a broken rice rate ranging from 2% to 4%, indicative of favorable polishing effects. [Conclusion] The motion patterns formed by rice grains and the resulting broken rice rates vary under different operating conditions. Under suitable opening degree of the pressure gate and rotational speed, rice grains exhibit appropriate motion patterns and achieve better polishing effects.

The Western Route of the South-to-North Water Diversion Project is the final link to be constructed for the four-horizontal three-vertical framework of China’s national water network. The adjustable water volume in the water source areas is a focal and challenging issue in the planning and demonstration of the Western Route. This study raised ten questions related to the adjustable water volume in the water source areas of the Western Route from the aspects of water resource background conditions and evolution trends, ecological and socio-economic water demands, scales of reservoirs and water conveyance projects, as well as impacts of water diversion on water resource development and utilization, aquatic ecological environment, hydropower, and navigation in the water source areas and their lower reaches. Based on a distributed hydrological model of the upper reaches of the Yangtze River, a simulation and analysis model for calculating the adjustable water volume in water source areas of the Western Route is established to quantitatively answer the ten questions raised. The main conclusions are as follows. First, under the premise of solely satisfying ecological and socio-economic water demands within and outside the river channels of the water source areas, a plan that combines upper and lower routes presents an average adjustable water volume of 1.59×1010 m³ over multiple years, while a plan for solely constructing a lower route can reach an average adjustable water volume of 1.74×1010 m³ by constructing the Gangtuo Reservoir for coordinated operation. Second, comprehensively considering the impacts of water diversion on water balance, hydropower, and navigation, as well as their acceptability in the water source areas, the adjustable water volume is between 1.22×1010 and 1.26×1010 m³. Third, in the long term, the plan should focus on connecting and integrating the water network in the southwestern region with the main framework and major streams of the national water network of China. This will reduce the impacts of water diversion by the Western Route Project, increase the overall water supply capacity of the project, and promote its adaptability to external conditions such as climate change.

Electrochemical water splitting by electrocatalyst is one of the most promising ways for generating and utilizing hydrogen energy, and it is critical to effectively mitigate the serious energy crisis and environmental pollution. However, the widely application of electrocatalysis technology is still limited by its low conversion efficiency and high cost. For this purpose, developing electrocatalyst materials with high activity, low cost and well stability are critical to solve the above limitions. As an inexpensive and readily available two-dimensional material, molybdenum disulfide is considered as a promising candidate to replace noble metal catalysts due to its good catalytic activity for electrocatalytic hydrogen evolution, which realize the industrial application. However, the inert basal plane and low electrical conductivity of pristine MoS2 limit the further improvement of its electrocatalytic performance. In this review, starting from the mechanism of water electrolysis and the inherent feature of molybdenum disulfide electrocatalysts, the latest research progress of various modification strategies to improve the catalytic performance of MoS2 was summarized. Moreover, the intrinsic mechanism of different modification strategies in the catalytic reaction process was highlighted and their respective drawbacks were indicated. Finally, it was pointed out that the current molybdenum disulfide catalyst should be further developed towards a combination of multiple modification measures, theoretical guidance for experiments, and rapid and effective synthesis.

The effect of microwave pretreatment of sesame seeds on the flavor, sensory quality, nutrition, and safety of sesame oil was systematically studied to provide a theoretical foundation for the application of microwave for aroma enhancement in sesame oil. Sesame oil samples were hydraulically pressed from sesame seeds microwaved at different powers (0, 180, 360, 540, 720 and 900 W) for 6 min. A total of 91 aroma active compounds were identified in sesame oil by solvent-assisted flavor evaporation and headspace solid-phase microextraction combined with gas chromatography-olfactometry-mass spectrometry. The total concentration of heterocyclic compounds including pyrazines, pyrroles, pyridines, thiazoles, thiophenes, and furans in sesame oil were positively correlated with microwave power, while the total concentration of carbonyl compounds including aldehydes, ketones, and esters increased initially and decreased later with an increase in microwave power. The intensities of roasted sesame-like, nutty, burnt and smoky aromas, and the bitter taste of sesame oil gradually increased, while the intensities of earthy, woody, and green odors decreased. The oil yield of microwave-pretreated sesame seeds (30.02%–31.93%), which was higher than that of raw sesame seeds (24.89%), was positively correlated with microwave power. Microwave pretreatment increased the nitrogen solubility index (NSI, from 11.7% to 18.07%) of sesame meal and the concentration of tocopherol in sesame oil (from 392.18 to 462.92 mg/kg). The highest NSI and tocopherol content appeared after 540 and 700 W microwave pretreatment, respectively. The concentrations of sesamin (13.01–15.78 mg/100 g), heterocyclic amines (HCAs, 33.19–143.88 ng/g), and polycyclic aromatic hydrocarbons (PAHs, 0.40–9.03 ng/g) in sesame oil were positively correlated with microwave power. The concentrations of PAHs and HCAs in sesame oil did not exceed the Chinese national standard limit. In summary, appropriate microwave pretreatment can provide sesame oil with a rich flavor, improve its nutritional value and oxidation stability, and increase the utilization value of sesame meal protein. Therefore, microwave pretreatment is highly advantageous and promising for application in aroma enhancement in sesame oil l and high-value utilization of sesame meal protein.

To solve the wear problem of stamping dies in high-speed machining，cathodic multi-arc ion plating is often used to improve surface properties，and the surface quality of cathode multi-arc ion plated coating is one of main factors affecting the life of stamping dies.In this paper，the effects of the DC bias voltage，flow rate of nitrogen and arc current on the surface quality of CrAlN coating were studied by the orthogonal experiments.The significance of the effects of DC bias voltage，flow rate of nitrogen and arc current on the surface quality of the CrAlN coating was analyzed by the extreme-range method and variance method.Results showed that the surface quality of the CrAlN coating was affected most significantly by the flow rate of nitrogen，and the DC bias voltage also influenced the number of large particles on the surface of the CrAlN coating.When the DC bias voltage was 160 V，the nitrogen flow rate was 1 600 mL/min，and the arc source current was 120 A，the as-prepared coating possessed the minimum number of large particles on the surface (42.5 per 10，000 μm2) and the optimal surface quality.

Click-through rate(CTR) prediction is an important task in the recommendation system.Its goal is to predict the pro-bability of a user clicking on an advertisement or item.Feature embedding and feature interacting are critical for prediction performance.Therefore,the ideas of many click-through rate prediction models are optimized based on these two aspects.However,most of the work only focus on one of the aspects,and almost all models do not distinguish features in feature interacting.The same embedding and interacting method are used when crossing the same feature with other features,which hinders the improvement of model performance.In order to solve this problem,the automatic super-field-aware feature embedding and interacting(Auto-SEI) model is proposed.Firstly,it assigns each sub-field to a super-field,and obtains the feature embedding according to the grouping,then selects appropriate interacting method for the feature pair to obtain the cross feature,and finally makes prediction.In Auto-SEI model,the division of sub-field and the selection of interacting methods are parameterized as an architecture search problem,and the neural architecture search(NAS) algorithm is used to compress the search space and make selections.A large number of experiments are conducted on three real large-scale data sets and the results show the excellent performance of the Auto-SEI model on the task of click-through rate prediction.

Objective: This experiment is to judge the comprehensive quality of Hunan bacon. Methods: The contents of 8 biogenic amines in Hunan bacon were determined by HPLC-UV. The contents of moisture content, peroxide value and nitrite were measured. Results: The facts showed the total amount of biogenic amines was 127.22~166.24 mg/kg, which were mainly composed of cadaverine, putrescine, spermine and tyramine. The content of histamine was 0.43~10.24 mg/kg while the content of tyramine was 2.11~57.60 mg/kg. As for the physical and chemical indicators, the moisture content in the sample ranged from 13%~23%, the detection range of peroxide value was 0.014 2~0.035 0 g/100 g, with the nitrite content ranging from 2.15 to 7.50 mg/kg. Conclusion: The content of biogenic amines in Hunan bacon products is lower than the European Union and US FDA standard. All physical and chemical indexes meet the national standard.

Objective To investigate the status quo and influencing factors of knowledge, attitude and practice (KAP) of hyperuricemia health management in community medical staff, and to put forward improvement strategies for enhancing the community health management of hyperuricemia. Methods A mixed methodology of both qualitative and quantitative research was employed in the study. In August 2022, the convenience sampling method was adopted to conduct a questionnaire survey on the knowledge and practice of hyperuricemia health intervention among 193 medical staff in Guangzhou community health service centers, to understand the knowledge and health management behavior of primary medical staff on hyperuricemia health management. Objective sampling method was used to conduct semi-structured interviews with 14 community medical workers to understand the status quo of community health management of hyperuricemia. Results The results of quantitative study showed that the knowledge and practice scores of community medical staff on health management of hyperuricemia were (73.60 ± 10.06) . There was a significant positive correlation between knowledge, attitude and practice of hyperuricemia management (P < 0.01) . Age, education background, occupation and participation in hyperuricemia management training were the influencing factors of health management knowledge, attitude and practice scores (P < 0.05) . The qualitative study found that the community focused on treatment rather than prevention of hyperuricemia health management, lacked effective incentive mechanism and did not realize quality division of labor cooperation within the team, and residents were not very active in participating in hyperuricemia health management activities. Conclusion The knowledge of hyperuricemia management of community health care workers was at a medium level, and the attitude towards hyperuricemia health intervention was positive, but the behavioral score was not ideal, the breadth and depth of community hyperuricemia health management services were insufficient, and the cooperation of residents was low. In the future, it is necessary to strengthen the training and practical guidance for community health care workers in hyperuricemia health management, optimize the functional deployment of community health management teams, enrich the connotation of health management services, and improve the level of community hyperuricemia health management. [ABSTRACT FROM AUTHOR]

Water-absorbent resins have attracted widespread attention in the field of environmental treatment due to their ability to adsorb metal ions. The article utilizes corn straw and kaolin as raw materials, and acrylate and acrylamide as polymerization monomers to prepare cellulose-based superabsorbent resin through an aqueous solution polymerization method. The cellulose-based superabsorbent resin was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The synthesized superabsorbent resin was utilized for the adsorption study of Cd2+ in simulated wastewater. The results showed that the cellulose-based superabsorbent resin exhibited excellent adsorption capacity for Cd2+. When the solution pH value was 6, the resin dosage was 0.10 g, and the adsorption time was 200 min, the effective removal rate of the superabsorbent resin for Cd2+ could reach 93.57%. The resin demonstrated good desorption performance for Cd2+ in dilute hydrochloric acid solution, with a desorption rate of 88.73%. The resin also exhibited good reusability, maintaining a Cd2+ removal rate of 79.12% after eight cycles of repeated adsorption. The cellulose-based superabsorbent resin possesses recyclable and regenerative capabilities, with good stability in repeated adsorption, and has potential value for the treatment of industrial wastewater containing Cd2+. [ABSTRACT FROM AUTHOR]

The formation mechanism and influencing factors of fold defects at the medium plate edge were studied by detecting and analyzing edge folding samples. It is found that the plate edge folding phenomenon results from the transformation of slab lateral side to plate surface during the broadside rolling process. The microstructure observed at the fold defects is composed of iron oxide and a decarburization layer formed at high temperature in the plate surface before rolling. Finite element numerical simulation of the rolling process confirms that the folding defects are mainly caused by the transformation of lateral side. The influences of slab defects,rolling procedures,broadening passes and reduction on the plate fold defects were obtained by rolling experiments. Experimental results show that rolling spread leads to the fold edge defects,which do not depend on the quality of the slab. In the process of rolling,the folding of lateral side transfers to the plate surface and changes to be edge seam defects. The distance of folding to the edge increases with the increment of broadside rolling passes and reduction.

Neural topic models in unsupervised machine learning methods have been widely used to automatically mine the text for latent semantics. However, the limited length of short text and the scarcity of information available for inference in the text makes it difficult for the model to correctly identify ambiguous words with insufficient context. Therefore, a label-conditional neural topic model for semantic analysis of short texts is proposed. The model adopts a variational auto-encoder architecture, which introduces the label information of the text as a semantic identifier at the topic category level on the topic distribution of the encoder output to guide the model to filter words that are not semantically relevant to the current topic, condense the semantics, and identify the exact word meanings of ambiguous words in the topic context to guide the model to infer discrete consistent topic. To address the data characteristics of statistically significant bias of topic semantic distribution during the application of short texts, PolyLoss is introduced in the model training process, and the imbalance of short text category distribution is modeled by adjusting Taylor polynomial coefficients. The experimental results show that the model can not only greatly improve the quality of short-text topic modeling, and generate coherent and diverse topics, but also effectively improve the performance of downstream tasks. [ABSTRACT FROM AUTHOR]

A kind of image analysis algorithm combining on-line analysis and off-line analysis was proposed: SVM was adopted to detect conjunctions images, and saliency map was used to check image of damaged belt during on-line analysis phase; Image processing methods such as thinning and regional analysis were used to detect joints twitching and classify a variety of injuries during off-line analysis phase. The conveyer belt detection system could analyze X image of conveyor belt in real time and detect damage accurately via applying these algorithms. The experiments and field deployments verify effectiveness of the proposed image analysis algorithm.

In this paper, a new nonanuclear terbium cluster {Tb9 (L)4 (μ4-OH)2 (μ3-OH)8 (μ2-OCH3)4 (NO3)8 (H2O)8} (OH)·2H2O(1) was synthesized by 2,6-dimethoxyphenol (HL) and Tb(NO3)2·6H2O. The cluster was characterized via XRD, elemental analysis, infrared spectrum and thermogravimetric analysis. The magnetic property were also studied. X-ray single-crystal diffraction analysis indicates that the cluster is orthorhombic, the space group is I222, the crystal cell parameters are a = 1. 532 8 (3) nm, b = 1. 796 9 (4) nm, c = 1. 863 5 (4) nm, α = β = γ = 90°, V = 5. 132 6 (19) nm³. The nonanuclear skeleton formed by metal centers in the cluster that connected by μ4-OH and μ3-OH presents an interesting hourglass like topology. The central Tb ion has a slightly twisted tetragonal pyramid geometry, while the other Tb ions have a slightly deformed dodecahedral configuration. Magnetic investigations reveal that the weak antiferromagnetic interactions between adjacent metal ions exist in cluster 1, but no obvious slow magnetic relaxation behavior is shown due to the rapid magnetic quantum tunneling effect. [ABSTRACT FROM AUTHOR]

Since the data-centric sensing task focuses more on the data reliability,many cluster-based communication protocols were failed to analyze the reliability of the sensing task. The RBD （reliability block diagram） was used to model the data reliability of cluster-based wireless sensor networks （WSN）. The value of reliability was adopted into the cluster formation scheme. Then the malfunctioning node （MN） that could affect the data reliability is defined and analyzed. A detecting scheme was proposed to detect the MN and the friendly node （FN） is used to mitigate its negative effects. Based on the above analysis,the REECP （reliable energy-efficient cluster-based protocol） was proposed. Simulation results demonstrate REECP can prolong the effective lifetime of the network and mitigate the error propagation in data aggrega-tion of sensing tasks,reinforcing the reliability of WSNs with cluster-based communication protocols.

The study was to determine the nutritional value of Rhynchocypris oxycephalus. The general nutritional composition, amino acid composition and mineral content of Rhynchocypris oxycephalus were measured by biochemical methods, and evaluated the nutritional value of Rhynchocypris oxycephalus comprehensively. The results showed that the content of crude protein, crude fat, water and crude ash in Rhynchocypris oxycephalus muscle were 15.80%, 1.34%, 78.02% and 1.50%, respectively. A total of 18 amino acids were detected, the content of TAA, EAA and DAA was 12.67%, 4.79%, 4.94%, respectively. Rhynchocypris oxycephalus muscle was rich in magnesium, zinc, iron, selenium and other mineral elements, especially zinc and selenium content was higher than most freshwater fish. The study indicates that Rhynchocypris oxycephalus is a nutrient-rich fish with high development value. [ABSTRACT FROM AUTHOR]

Rumen microorganisms determine the optimal utilization rate of nutrients, and Prevotella is one of the most representative bacteria in the rumen biological system. Prevotella is involved in food digestion and metabolism of complex forms of nutrients such as cellulose and protein, and can cooperate with other forms of bacteria in the digestive tract of body. It promotes the biodegradation of some forms of nutrients by enzymes. The paper summarizes the research results of Prevotella at home and abroad, summarizes its classification and growth conditions, and focuses on the role of Prevotella in digestion and metabolism in rumen of ruminants. Prevotella can assist the digestion and metabolism of cellulose by indirect use of enzymes, play an important role in the process of protein degradation. It can also degrade plant polysaccharides, can be affected by dietary structure, feeding environment and other factors. The article aims to explore the role and mechanism of Prevotella in nutrient metabolism in the rumen of ruminants, thereby improving animal production performance. [ABSTRACT FROM AUTHOR]

The presence of oxygen inhibition effect in radical photopolymerization leads to incomplete curing in the surfaces and affects the final performance of cured material. In this work, the insensitivity of thiol-acrylate system to oxygen was introduced into the upconversion particles assisted near-infrared photopolymerization (UCAP) to overcome the oxygen inhibition effect of acrylate system. The effects of the UCPs concentration, the structure and content of thiol monomers on the oxygen inhibition degree were systematically studied by combining thiols with (meth) acrylate monomers. The ATR-FTIR were used to characterize the polymerization kinetics of monocomponent (meth) acrylate and thiol-acrylate systems in UCAP. The double bond conversion at different depths of the cured material was characterized by Confocal Raman Microscopy. The results show that in the mixed system of secondary mercaptan PE-1 and acrylate monomer EM2261 with 2. Owt% UCPs and 50%-SH molarity, the maximum double bond conversion of 82% was obtained on the surface and over 90% in the deep layer, the oxygen inhibition degree of the surface layer were effectively reduced. [ABSTRACT FROM AUTHOR]

There are only a handful references to China or Chinese people in Shakespeare's works. However, the people in his era, from the monarchs at the top to the peddlers and porters at the bottom of the society, plus scientists, navigators, geographers, dramatists, and poets, were keenly interested in expanding overseas trade, discovering new continents, opening up new sea routes, and establishing contact with China in particular. Studies show that Shakespeare's Twelfth Night is closely related to the British desire for and construction of the contact with China during the Elizabethan era, as evidenced by the royal family's letters to the Chinese emperor, British trade and diplomacy, the opening of new sea routes and the drawing of new maps, the performance in Cecil's house warming and so on. As a playwright, Shakespeare was influenced by Elizabeth I's "Cathy Venture" plan in search for "China". [ABSTRACT FROM AUTHOR]

Yajiang County, located in the middle reaches of Yalong River in western Sichuan Province, is dominated by the landform of middle mountain-alpine valley, with frequent geological disasters. The risk assessment of landslide disasters in the upper reaches of Yajiang County is carried out on the basis of overlay analysis of logistic regression (LR) and certainty factor (CF) to ensure people's life and property security. The results show that the landslides are prone to occur in the hard rock interbedded with soft rock zone, with an altitude of 2 500-3 000 m, relative height above river of 600-900 m, gradient of 30-45° and distance of 0-200 m from river system. The high and very high risk areas in the upper reaches of Yajiang County account for 46.75% of the total area, and 65.91% of the total landslide occurrences, indicating the dense distribution of landslides and high damage degree, which is consistent with the field survey results. The Xiala Town mostly belongs to very high and high risk area, Waduo Township mostly medium risk area, and Murong Township and Pubarong Township mostly low and very low risk area. The assessment results have high accuracy through verification of inspection points and ROC curve, and thus can serve as a reasonable plan basis for disaster prevention and mitigation, river development and utilization in the study area. [ABSTRACT FROM AUTHOR]

Objective To analyze the sensitivity and specificity of neuroelectrophysiological monitoring and warning criterion in the spinal cord cavernous malformations surgery. Methods A total of 64 patients with spinal cord cavernous malformation underwent surgical treatment were collected from November 2012 to March 2016. All patients underwent intraoperative monitoring of motor-evoked potential (MEP) and somatosensory - evoked potential (SEP). Multimodal monitoring combined MEP amplitude decreased ≥ 80% with SEP was performed to predict the postoperative neurological function defect of patients. McCormick grade as "gold standard" was used to calculate sensitivity, specificity, positive predictive value and negative predictive value. Results The sensitivity, specificity, positive predictive value and negative predictive value were 75% (15/20), 78.57% (33/42), 62.50% (15/24) and 86.84% (33/38), respectively. Conclusions Intraoperative MEP combined with SEP monitoring can effectively predict the occurrence of new neurological deficits after operation. MEP amplitude reduction ≥ 80% can be used as the operation warning criterion. [ABSTRACT FROM AUTHOR]

With the joint efforts of Yang Lingui, Nie Zhenzhao, Du Juan, Zhang Chong, Li Weimin and Qiao Xueying, Shakespeare Studies Series was published by the Commercial Press in April, 2020. This gigantic work includes 5 volumes The Research on Shakespeare's Tragedies in China, The Research on Shakespeare's Comedies in China, The Research on Performance and Adaptation of Shakespeare in China, The Research on Performance and Adaptation of Shakespeare in China, Anthology of World Shakespearean Criticism. Editors review the history of Shakespeare studies in China and show us the typical research of Chinese and Western Shakespeare criticism. The work is a landmark in the history of studies of Shakespeare and foreign literature in China. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lumbosacral transitional vertebra is a commonly seen congenital spinal deformity, and the changes in the muscle innervation pattern and the sensory dermatomes of the lumbosacral nerve roots have been reported, but the changes and its guidance significance for the surgeries of lumbar disc herniation have not been clarified systematically. OBJECTIVE: To explore the possibility of changes in the muscle innervation pattern and the sensory dermatomes of the lumbosacral nerve roots when there is a lumbosacral transitional vertebra. METHODS: The study was in accordance with the ethical requirements of Affiliated HospitaI of Binzhou Medical University, and the subjects and their families signed the informed consents. The medical records of 321 patients with single segment lumbar disc herniation who underwent surgical treatment were analyzed retrospectively. Lumbosacral transitional vertebrae were present in 38 of 321 patients (11.8%). There were 26 cases of sacral lumbarization and 12 cases of lumbar sacralization. Among these 26 patients with sacral lumbarization, 23 had hemiated discs at L5/S1(La) compressing the S1 (L6) nerve root. Of the 12 patients with lumbar sacralization, 8 had herniated discs at L3/4 compressing the L4 nerve root. In the 283 normally configured patients, 138 had herniated discs at L5/S1 compressing the S1 nerve root, 95 had herniated discs at L4/L5 compressing the L5 nerve root, and 47 had herniated discs at L3/L4 compressing the L4 nerve root. The preoperative symptoms of S1 nerve root compression in the patients with sacral lumbarization and of 4 nerve root compression in the patients with lumbar sacralization were compared with those of L4, L5 or S1 nerve root compression in the patients with normal configuration. RESULTS AND CONCLUSION: (1) The distribution of motor function depression caused by S1 nerve root compression was significantly different between sacral lumbarization patients group and normal group (P < 0.05). (2) The distribution of motor function depression caused by L4 nerve root compression was also significantly different between lumbar sacralization patients group and normal group (P < 0.05). (3) The motor function depression caused by S1 nerve root compression in sacral lumbarization patients was similar to that of the L5 nerve root compression in the normal configuration, while the motor function depression caused by L4 nerve root compression in lumbar sacralization patients was similar to that of the L5 nerve root compression in the normal configuration. The analysis of the sensory dermatomes also showed similar results. (4) Our results suggest that the function of lumbosacral nerve roots changes in patients with transitional vertebrae. The S1 nerve roots in patients with sacral lumbarization tend to serve the usual function of L6 nerve roots (nerve roots move up), and the L4 nerve roots in patients with lumbar sacralization tend to serve the usual function of L5 nerve roots (nerve roots move down). [ABSTRACT FROM AUTHOR]

Development of efficient two-photon initiators (2Pls) are critical to promote two-photon 3D printing speeds. On the basis of photodecarboxylation, two unimolecular 2Pls that contain coumarin moieties (as two-photon absorption chromophores) and oxime-ester groups (as initiation functional groups) were synthesized The investigation of the photophysical and photochemical behaviors of the oxime-esters were conducted via quantum-chemical calculations and experimental tests. The results indicated that the 2Pls exhibits a broad absorption band ranging from 400 to 500 nm. Under visible LED light irradiation, the investigated oxime-esters decomposed and formed active free radicals to effectively induce polymerization of acrylates. Interestingly, the photoinitiators exhibit a good photobleaching property. In two-photon polymerization tests with acrylate formulations, the oxime-ester derivatives can be used to build complex 3D microstructures with high spatial resolution. The possible photopolymerization mechanism was proposed according to the quantum chemical calculation results. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical & Electrical Engineering is the property of Mechanical & Electrical Engineering Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the problems of the wind-induced vibration of high-rise flashing column, the tuned mass damper (TMD) was researched to minimize the vibration, ensure safety operation and prolong service life. By numerical simulation, the top vibration energy decrement rate of the equipment with the TMD and optimal matching parameters of the TMD had been studied. The contours of the energy decrement rate were presented to solve the problem of limited running space of TMD. The results indicate that the TMD is feasible for wind-induced vibration control of high-rise flashing column, and that the top vibration energy reduces by 47.07% under optimal matching parameters, which has provided valuable preferences for practical application. [ABSTRACT FROM AUTHOR]

Fluid simulation based on the Smoothed Particle Hydrodynamics (SPH) plays an important role in the virtual reality, but it requires a lot of computing resources. The general methods are difficult to achieve the real-time requirement of fluid simulation based on SPH. The simulation of fluid consists of physical computing, collision detection and rendering and so on. The parallel computing based on GPU can speed up the computing and collision of particles and simulate the motion of fluid in realtime. In order to satisfy the realistic and real-time requirements, a novel fluid simulation method based on CPU-GPU hybrid acceleration is proposed, which consists of computing and rendering. The computing part of fluid simulation is accelerated by GPU, and the rendering part is accelerated by OpenMP running on CPU. The experiments show that the proposed hybrid acceleration method can significantly reduce the computing time in a fluid time step and complete rendering tasks more quickly. [ABSTRACT FROM AUTHOR]

In order to conduct research on the in-cylinder spray and combustion of an electrically controlled high pressure common-rail diesel engine, taking one high pressure common-rail diesel engine as the research object, a multifunctional dynamic visual experimental device was designed, which was used to collect in-cylinder dynamic combustion process images. On this basis, the intake port of the diesel engine was improved, and the fresh air was replaced by industrial purity nitrogen, so that the real-time dynamic multiple spray images were collected under single cylinder misfiring conditions. The study illustrated that the multiple injections-pre- injection, main injection, and post injection-can be clearly observed, including at the injection time, spray cone angle, and in the atomization situation. The pre-injection occurred at the -25° crankshaft angle, and the duration was about 5° crank angle. At this stage, the quantity of fuel injection was less, and the atomization was not obvious. The main injection occurred at the -10° crankshaft angle, and the duration was about 10° crankshaft angle. There was a large amount of fuel ejected from the nozzle, and the penetration force was strong. The spray cone angle and a significant oil beam could clearly be observed, which expanded to the bottom of the piston "ω" crown in line. The post injection occurred at the 8° crankshaft angle, the injection duration was shorter, and the amount of fuel injection was less, however, the atomization effect was obvious because of the higher temperature of the cylinder at this stage. In addition, when the diesel engine ignited, the flame center formation and flame propagation process could be captured in real time under different working conditions. The fuel spray was not fully discrete and mixed with air partly at the initial in-cylinder ignition time, which was the so-called pre-mixing ignition and occurred at -15°- -4° crankshaft angle. Near the TDC, the flame quickly spread and filled the combustion chamber fully along with the air flowing. Compared with the in-cylinder combustion image under rated conditions, the ignition time under idling conditions was delayed about 5° crankshaft angle, the flame occupied area was smaller, and there was lower brightness. The study provided a lot of in-cylinder information and experimental measurement means for research on the in-cylinder spray and combustion of an electronically controlled common-rail diesel engine, and the spray and combustion simulation results could also be verified by these experiments. [ABSTRACT FROM AUTHOR]

To study the appropriate boundary transition section shape of terrain model for mountains-gorge bridge site, a kind of transition section curves was derived based on the theory of flow around cylinder with ideal fluid. According to the different shapes of the curve transition section with equivalent slope of 0.58 and the ramp transition section with included angle of 30°, an ideal two-dimensional platform terrain was used as the analysis model to comparatively analyze the flow separation behavior and the distribution characteristics of average wind field after airflow flowed along the two transition sections by CFD commercial software FLUENT. Furthermore, the total flow transition lengths of different curve transition section shapes were also compared. The results show that when airflow flows along the curve transition section with equivalent slope of 0.58, the distribution characteristics of wind velocity field after airflow flowed along it are much closer to the distribution characteristics of reference wind velocity field than those when airflow flows along the ramp transition section with included angle of 30°, and its total flow transition length is also the relative shortest. The research conclusions could provide some references for the complex terrain model studies on wind characteristics over the mountains-gorge bridge site by wind tunnel test and CFD methods. [ABSTRACT FROM AUTHOR]

To achieve the equilibrium atmosphere boundary layer in an empty flow field with SST k-ϖ turbulence model, the method of adding source terms to the turbulent kinetic energy transport equation and the specific dissipation rate transport equation respectively was adopted to make the inlet profiles of average wind and turbulence wind consistent with the turbulence model, the consistency of the average wind profiles, turbulent kinetic energy profiles and specific dissipation rate profiles at several different positions with and without considering the source terms were investigated respectively according to the corresponding CFD numerical example. The numerical result shows that when considering the source terms in the turbulence model, the average wind profiles, turbulent kinetic energy profiles and specific dissipation rate profiles at several different positions along the flow field are all maintained very well, which indicates that the equilibrium atmosphere boundary layer in the empty flow field is achieved satisfactorily. The study conclusion proposes a new idea or research method for modeling the equilibrium atmosphere boundary layer and also provides the further CFD simulations in structural wind engineering with theoretical and actual values. [ABSTRACT FROM AUTHOR]

To consider dynamic load while equivalent standard axle load conversion is carried out, two degree of freedom vehicle model is built to calculate power spectral density of dynamic load coefficient, and then distribution of dynamic load coefficient is calculated. Increasing degree of equivalent standard axles is calculated in theory while dynamic load is considered. The results of examples show that equivalent standard axle load shall be increased when dynamic load is considered for various kind of pavement: for asphalt pavement, while design deflection and tensile stress at the bottom of asphalt pavement is taken as index, 1% - 2% shall be increased for expressway and first class highway, 2% - 5% shall be increased for other classes highway; while tensile stress at the bottom of semi-rigid base is taken as checking index, 3% - 6% shall be increased for expressway and first class highway, 7% - 17% shall be increased for other classes highway; for cement concrete pavements, 15% - 25% shall be increased for expressway and first class highway, 35% -80% shall be increased for other classes highway. [ABSTRACT FROM AUTHOR]