Influence of different cover ratios on Gas-particle flow characteristics of a centrally-fuel-rich primary air burner: experiment and simulation

AbstractThe flow field for different cover ratios within a three-level conical ring concentrator of a centrally-fuel-rich swirl coal combustion burner has been studied both experimentally and numerically. A particle dynamics anemometer measurement system was employed in the study to measure velocity and particle volume flux after the outlet of third-level ring. And the numerical simulations were used to calculate the flow field in the conical ring region. In each cross-section, after the outlet of third-level ring, concentration ratio for each cover ratio is always larger than 2. With conical ring concentrator in the primary air tube, the coal concentration can be concentrated to a suitable range. In the cross-sections 0.5<x/D<4.0, as cover ratio increases, concentration ratio decreases and resistance coefficient increases

Reinstatement of long-term memory following erasure of its behavioral and synaptic expression in Aplysia.

Long-term memory (LTM) is believed to be stored in the brain as changes in synaptic connections. Here, we show that LTM storage and synaptic change can be dissociated. Cocultures of Aplysia sensory and motor neurons were trained with spaced pulses of serotonin, which induces long-term facilitation. Serotonin (5HT) triggered growth of new presynaptic varicosities, a synaptic mechanism of long-term sensitization. Following 5HT training, two antimnemonic treatments-reconsolidation blockade and inhibition of PKM--caused the number of presynaptic varicosities to revert to the original, pretraining value. Surprisingly, the final synaptic structure was not achieved by targeted retraction of the 5HT-induced varicosities but, rather, by an apparently arbitrary retraction of both 5HT-induced and original synapses. In addition, we find evidence that the LTM for sensitization persists covertly after its apparent elimination by the same antimnemonic treatments that erase learning-related synaptic growth. These results challenge the idea that stable synapses store long-term memories

SiteFinding-PCR: a simple and efficient PCR method for chromosome walking

In this paper, we present a novel PCR method, termed SiteFinding-PCR, for gene or chromosome walking. The PCR was primed by a SiteFinder at a low temperature, and then the target molecules were amplified exponentially with gene-specific and SiteFinder primers, and screened out by another gene-specific primer and a vector primer. However, non-target molecules could not be amplified exponentially owing to the suppression effect of stem–loop structure and could not be screened out. This simple method proved to be efficient, reliable, inexpensive and time-saving, and may be suitable for the molecules for which gene-specific primers are available. More importantly, large DNA fragments can be obtained easily using this method. To demonstrate the feasibility and efficiency of SiteFinding-PCR, we employed this method to do chromosome walking and obtained 16 positive results from 17 samples

Multi - mechanism coalescence design and matrix expression of logic action sequences of the over-turn nursing robot Part II: Gesture-state in sets and matrix

As is expressed in Part I, Functions and coalescence design of the over-turn nursing robot, the performance and requirements have been put forward with systematic design of several mechanisms. Here, in order to control and function well the over-turn nursing robot, the three-dimensional and five-dimensional Euclidean space with the real number were adopted in terms of sets for gesture of the bedridden person and the corresponding state of the robot, respectively. The matrix method was employed to define and describe the gestures-robot performance and its transition path. The gesture-state sequence matrix not only accurately and clearly expressed the gesture series, state sequence and their corresponding relations, but also laid a theoretical and technical foundation for the path planning from the current gesture to the target one. The control and operation of 7 states and 5 gestures were done to realize the automation and intelligent over-turning safely, comfortably and conveniently

Multi - mechanism coalescence design and matrix expression of logic action sequences of the over-turn nursing robot Part I: Functions and coalescence design

In order to effectively solve the problem in over-turn of a bedridden person with the assistance of external force, a double bed face- three embedded leave over-turn nursing robot with the flexible compensation was put forward, with the abstraction of the bedridden person as an organism. This robot, on the basis of concept gesture of the person in bed and the state of the robot supporting and proving the gesture with the actions and combination of the two bed faces, held the complete function of over-turn nursing with 7 states corresponding to 5 gestures of the bedridden person obeying the fundamental requirements of safety, rapidity, and comport. The design method of "PS-MM-KD" was proposed for multi-mechanism coalescent system with related specific tasks induced from the original problems with Systems Engineering. Mechanics and Mechanisms, then applied in the concrete sub-system design followed by analysis and verification of both the scheme and the sub-systems in the design, using the Kinematics and Dynamics, implementing the gears, chain wheel, slewing mechanism, screw nut and mortise and tenon joint type clutch mechanism design successfully. Based on those above, a "two-bed face/three-leaf embedded flexible compensation nursing robot" was designed adopting to all ages, people of various kinds of body geometry. PLC, sensor and logic algorithm were used to carry out the control and operation of 7 state-5 posture sequences for realization of the automation and intelligent over-turning in safety, comfort, and convenience

Are men dominant? Evidence of differences between physical activity and quality of life among older adults in China

At present, the aging population is one of China's basic national concerns, and physical exercise offers endless potential to cope with it. However, the life expectancy of men in China is generally lower than that of women, and the health status of older men is more worrying. Could it be that differences in physical exercise cause the difference in life expectancy between older men and women? This study analyzes the exercise regimen of older men and women and its influence on their quality of life. Approximately 200 respondents aged over 60 were investigated using the SF-36 and exercise questionnaires. Our findings revealed the following: (1) The scores of seven dimensions of life quality of older men were significantly lower than those of older women (p &lt; 0.001), but there was no significant difference only in physiological function (p &gt; 0.05); (2) The exercise frequency and persistence of older men were significantly lower than those of older women (p &lt; 0.001), but there was no significant difference in exercise time (p &gt; 0.05); and (3) All eight indices of quality of life of older men were positively correlated with the four indices of exercise (0.250 &lt; R &lt; 0.597). Our study offered the following conclusions: (1) The health of older men who lack physical exercise is poor. From the perspective of healthy aging, older men are a vulnerable group that deserves more attention. (2) Within an appropriate range, the more older men participate in physical activity programs, the more conducive they are to improved health. (3) This study focuses on promoting physical exercise for older adults and suggests organizing them to participate in sports activities as an important measure to promote healthy aging in China

Family and social class differences in sports behavior motivation among college students: An empirical study based on the latent class model

ObjectiveThis article aims to explore the potential categories of college students’ sports behavior motivation and the differences between different family social classes on potential categories.ParticipantsIn total, 1,092 college students were investigated in this study.MethodsThis article used the “College Students’ Sports Behavior Motivation Questionnaire” to survey 1,092 college students using the whole group sampling method. The potential profile analysis method was applied to classify the types of college students’ sports behavior motivation and further analyze the characteristics of different family social classes and sports behavior motivation.ResultsCollege students’ sports behavior motivation types can be divided into the following four categories: “low motivation type” (0.82%), “healthy appearance type” (11.45%), “healthy fun type” (37.36%), and “high motivation type” (50.37%). The higher the family’s social class, the more the sports behavior motivation of college students tends to be healthy appearance, health, fun, and high motivation. The lower the family social class, the more motivational sports behavior of college students tends to be low motivation. The better the perception of health, the higher the probability that college students belong to the high-motivation type. The fewer chronic diseases that college students have are associated with a healthy appearance and high motivation.ConclusionThere is a certain relationship between the type of college students’ sports behavior motivation and their family social class. Therefore, in school physical education, we should open all kinds of sports activities according to college students’ sports behavior motivation needs and focus on college students with lower family social class in order to intervene precisely on their motivation for sports behaviors, improve participation, and promote the overall health of college students

Online synchronous inspection and system optimization of flexible food packaging bags by using machine vision and sensing technique

Flexible food packaging in the market is increasingly favored, and its quality is essential and indispensable for safety and convenience.  However, quality inspection still stays in the manual stage, or partially manual inspection remains, in production, leading low efficiency, lack and even false inspection, hardly meeting the requirements of the modern output.  This paper proposes and optimizes the design of an automatic detection system with intelligence for flexible food packaging bag, which can effectively be adopted to check the quality of packaging trademark patterns, fillers, and sealing quality.  The inspection system runs with two-stage structure, machine vision, pressure sensing and synchronization to improve efficiency and ensure the normal production beat. Simplex Method is adopted to determine the best synchronous speeds online to achieve the best expectation. Comparison has been made between the manual inspection and our automatic operation, the sample of 10000 was statistically analyzed and results have shown that two workers were saved and the correctness rate of inspection raised up to 999.8‰

Multiple evaluations, risk assessment, and source identification of heavy metals in surface water and sediment of the Golmud River, northeastern Qinghai-Tibet Plateau, China

The water quality of the Golmud River is essential for environmental preservation and economic growth of Golmud city and Qarhan Salt Lake in China. Thirty-four samples of surface water and sediment from seventeen places in the Golmud River and thirty-two dustfall samples in the Qaidam Basin were collected. The concentrations of heavy metals (HMs) were measured; water quality, risk assessment, and multiple source analysis were applied. Concentrations of HMs in water were Zn &gt; Cu &gt; Ni &gt; As &gt; Pb &gt; Cd &gt; Hg, and in sediment were Ni &gt; Zn &gt; Pb &gt; As &gt; Cu &gt; Cd &gt; Hg. In water, the Nemerow pollution index (NP) values indicated that most of the sampling points seemly were seriously polluted; other water quality assessment results suggested no pollution. In sediment, the concentrations of 27% HMs exceeded the background values of soil in Qinghai; 48% exceeded the Earth crust background values, which were As, Hg, and Cd. The single factor index method (Pi), geological accumulation index (Igeo), and contamination factor (CF) revealed that As pollution is serious, followed by Hg and Cd; the pollution load index (PLI) and modified pollution index (mCd) values indicated that 64% and 57% of samples were polluted. NP values are shown serious pollution. The ecological risk results demonstrated a low risk in water and a medium risk in sediment. The average total hazard quotient values in sediment and water for adults and children revealed low non-carcinogenic risks. Carcinogenic risk indicated Ni in water and sediment, and As in sediment may be involved in cancer risk. Multivariate statistics showed that the HMs mainly came from nature, and human activities will also impact them. The upper continental crust values indicated that As and Hg have high background values. The saline dust storm was one of the essential sources of HMs, especially Hg. Various provenances constituted the material cycling of HMs in the surface environment