Theoretical analyses and experimental studies of the mechanisms of melting film formation are performed. The results show that frictional heating is the dominant mechanism because temperature behaves in the manner pr...Theoretical analyses and experimental studies of the mechanisms of melting film formation are performed. The results show that frictional heating is the dominant mechanism because temperature behaves in the manner predicted by the theory of frictional heating. A study of the active technology for anti-skid is also made. Conclusions indicate that adjusting tire pneumatic pressure can improve the control stability and the travelling safety of an ice-automobile.展开更多
In this paper, the authors make a summary of current situation of research on the Auto Anti-Collision, briefly introduce the components and functions of the NSACA Simulation Platform and bring forward the project to r...In this paper, the authors make a summary of current situation of research on the Auto Anti-Collision, briefly introduce the components and functions of the NSACA Simulation Platform and bring forward the project to realize the simulation of an Automatic Anti-Collision control, based on the NSACA Simulation Platform. Finally give typical examples from a great deal of simulating tests and analyze them.展开更多
Various force disturbances influence the thrust force of linear motors when a linear motor （LM） is running. Among all of force disturbances, the force ripple is the dominant while a linear motor runs in low speed. I...Various force disturbances influence the thrust force of linear motors when a linear motor （LM） is running. Among all of force disturbances, the force ripple is the dominant while a linear motor runs in low speed. In order to suppress the force ripple, back propagation（BP） neural network is proposed to learn the function of the force ripple of linear motors, and the acquisition method of training samples is proposed based on a disturbance observer. An off-line BP neural network is used mainly because of its high running efficiency and the real-time requirement of the servo control system of a linear motor. By using the function, the force ripple is on-line compensated according to the position of the LM. The experimental results show that the force ripple is effectively suppressed by the compensation of the BP neural network.展开更多
To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on sprea...To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on spreading and interleaving is addressed. It will exploit the frequency diversity across the subcarriers and provide the robustness to narrow-band interference, by spreading the coded bit streams within each sub-band and interleaving across all sub-bands. Simulating results show that the spreading and interleaving provide about 5 dB to 10 dB advantages over the conventional multiband orthogonal frequency-division multiplexing ultra-wideband system in signal-to-interference ratio. Spreading and interleaving is an effective cure for enhancing the robustness to narrowband interference.展开更多
Anti-Mullerian Hormone (AMH) is a dimeric glycoprotein with a molecular weight of 140 kD, encoded by a gene on the short arm of chromosome and a member of the transforming growth factor-beta (TGF-<em>β</em&g...Anti-Mullerian Hormone (AMH) is a dimeric glycoprotein with a molecular weight of 140 kD, encoded by a gene on the short arm of chromosome and a member of the transforming growth factor-beta (TGF-<em>β</em>) superfamily. The expression of AMH is markedly different in males and females, both in concentration and temporality. In males, Sertoli cells maintain a high concentration of AMH in utero which peaks shortly after birth and then drops precipitously at puberty. In females, granulosa cells produce very low levels of AMH in utero followed by a transient spike in the neonatal period. Concentrations of the hormone then rise steadily through adolescence to a peak in the mid-twenties and subsequently decline until becoming undetectable in menopause. The study aimed to understand how Clinicians and Clinical Embryologists used anti-mullerian hormone (AMH) test to assess ovarian reserve, direct patient selection and treatment regimens and guide in vitro fertilization (IVF) cycle management in all registered fertility hospitals in a West African country, Ghana. A web-based survey (questionnaire) using google forms was performed to solicit responses from all IVF hospitals that are registered with the Fertility Society of Ghana (FERSOG). This questionnaire consisted of fifteen (15) broader questions, ten (10) of which assessed the clinics’ use of AMH. Responses were screened for quality to verify that only one (1) survey was completed by each IVF centre. The study was conducted during May and June 2020 at the In Vitro Fertilization (IVF) Department of the Airport Women’s Hospital (AWH) in Accra, Ghana. Results are reported as the proportion of IVF cycles represented by a particular answer choice. Survey responses were completed from 15 IVF centres, representing 2504 IVF cycles performed annually. A good majority (73.3%) [1835 IVF cycles] of the respondent IVF hospitals reported to use AMH as a first line test and 93.3% reported it as the best test for evaluating ovarian reserve. Another 66.7% reported that AMH results were extremely relevant to clinical practice. However, in contrast, for predicting live birth rate, 60% reported age as the best predictor in their practice. Overall, our results indicate that AMH is considered a first line test for assessing ovarian reserve and is relevant to the clinical practice of majority of Assisted Reproductive Technologies (ART) providers in Ghana.展开更多
Traditional intercept probability model has some drawbacks and can not meet the demands of command and control system. Aiming at this problem, a new calculation method based on search theory, terminal control area dis...Traditional intercept probability model has some drawbacks and can not meet the demands of command and control system. Aiming at this problem, a new calculation method based on search theory, terminal control area distribution function of anti-ship missile, target distribution function and missile's radar scan feature is proposed. Under the condition of common target distribution, an intercept probability model for present point attacking is determined. The simulation verifies its effectiveness and establishes the selecting model for aiming point when enemy ships evade in high speed.展开更多
Hydration cracks of magnesia-spinel bricks in cement industry have been serious problems for both refractory producers and refractory users for a long time.When magnesia-spinel bricks are kept for more than 6months,th...Hydration cracks of magnesia-spinel bricks in cement industry have been serious problems for both refractory producers and refractory users for a long time.When magnesia-spinel bricks are kept for more than 6months,the bricks tend to have reaction with water or moisture and result in cracks and loss on their structural strength. Those bricks cannot be used anymore and cause substantial loss for the related parties. In 2013,the Siam Refractory Industry Co.,Ltd.,Thailand,successfully developed and applied a special nano-technology to create ＂Anti-Hydration Magnesia-Spinel Bricks ＂ for cement industry which can have the storage time more than two years even in high humidity areas. The cement producers can ensure that all bricks still have good properties as the new ones.展开更多
基金1This project is supported by National Natural Science Foundation of China ( No.59475033)
文摘Theoretical analyses and experimental studies of the mechanisms of melting film formation are performed. The results show that frictional heating is the dominant mechanism because temperature behaves in the manner predicted by the theory of frictional heating. A study of the active technology for anti-skid is also made. Conclusions indicate that adjusting tire pneumatic pressure can improve the control stability and the travelling safety of an ice-automobile.
文摘In this paper, the authors make a summary of current situation of research on the Auto Anti-Collision, briefly introduce the components and functions of the NSACA Simulation Platform and bring forward the project to realize the simulation of an Automatic Anti-Collision control, based on the NSACA Simulation Platform. Finally give typical examples from a great deal of simulating tests and analyze them.
基金National Natural Science Foundation of China(No. 60474021)
文摘Various force disturbances influence the thrust force of linear motors when a linear motor （LM） is running. Among all of force disturbances, the force ripple is the dominant while a linear motor runs in low speed. In order to suppress the force ripple, back propagation（BP） neural network is proposed to learn the function of the force ripple of linear motors, and the acquisition method of training samples is proposed based on a disturbance observer. An off-line BP neural network is used mainly because of its high running efficiency and the real-time requirement of the servo control system of a linear motor. By using the function, the force ripple is on-line compensated according to the position of the LM. The experimental results show that the force ripple is effectively suppressed by the compensation of the BP neural network.
基金the National "863" High Technology Research Program of China (2005AA123320)Universities Natural Science Research Project of Jiangsu Province (05KJB510101).
文摘To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on spreading and interleaving is addressed. It will exploit the frequency diversity across the subcarriers and provide the robustness to narrow-band interference, by spreading the coded bit streams within each sub-band and interleaving across all sub-bands. Simulating results show that the spreading and interleaving provide about 5 dB to 10 dB advantages over the conventional multiband orthogonal frequency-division multiplexing ultra-wideband system in signal-to-interference ratio. Spreading and interleaving is an effective cure for enhancing the robustness to narrowband interference.
文摘Anti-Mullerian Hormone (AMH) is a dimeric glycoprotein with a molecular weight of 140 kD, encoded by a gene on the short arm of chromosome and a member of the transforming growth factor-beta (TGF-<em>β</em>) superfamily. The expression of AMH is markedly different in males and females, both in concentration and temporality. In males, Sertoli cells maintain a high concentration of AMH in utero which peaks shortly after birth and then drops precipitously at puberty. In females, granulosa cells produce very low levels of AMH in utero followed by a transient spike in the neonatal period. Concentrations of the hormone then rise steadily through adolescence to a peak in the mid-twenties and subsequently decline until becoming undetectable in menopause. The study aimed to understand how Clinicians and Clinical Embryologists used anti-mullerian hormone (AMH) test to assess ovarian reserve, direct patient selection and treatment regimens and guide in vitro fertilization (IVF) cycle management in all registered fertility hospitals in a West African country, Ghana. A web-based survey (questionnaire) using google forms was performed to solicit responses from all IVF hospitals that are registered with the Fertility Society of Ghana (FERSOG). This questionnaire consisted of fifteen (15) broader questions, ten (10) of which assessed the clinics’ use of AMH. Responses were screened for quality to verify that only one (1) survey was completed by each IVF centre. The study was conducted during May and June 2020 at the In Vitro Fertilization (IVF) Department of the Airport Women’s Hospital (AWH) in Accra, Ghana. Results are reported as the proportion of IVF cycles represented by a particular answer choice. Survey responses were completed from 15 IVF centres, representing 2504 IVF cycles performed annually. A good majority (73.3%) [1835 IVF cycles] of the respondent IVF hospitals reported to use AMH as a first line test and 93.3% reported it as the best test for evaluating ovarian reserve. Another 66.7% reported that AMH results were extremely relevant to clinical practice. However, in contrast, for predicting live birth rate, 60% reported age as the best predictor in their practice. Overall, our results indicate that AMH is considered a first line test for assessing ovarian reserve and is relevant to the clinical practice of majority of Assisted Reproductive Technologies (ART) providers in Ghana.
文摘Traditional intercept probability model has some drawbacks and can not meet the demands of command and control system. Aiming at this problem, a new calculation method based on search theory, terminal control area distribution function of anti-ship missile, target distribution function and missile's radar scan feature is proposed. Under the condition of common target distribution, an intercept probability model for present point attacking is determined. The simulation verifies its effectiveness and establishes the selecting model for aiming point when enemy ships evade in high speed.
文摘Hydration cracks of magnesia-spinel bricks in cement industry have been serious problems for both refractory producers and refractory users for a long time.When magnesia-spinel bricks are kept for more than 6months,the bricks tend to have reaction with water or moisture and result in cracks and loss on their structural strength. Those bricks cannot be used anymore and cause substantial loss for the related parties. In 2013,the Siam Refractory Industry Co.,Ltd.,Thailand,successfully developed and applied a special nano-technology to create ＂Anti-Hydration Magnesia-Spinel Bricks ＂ for cement industry which can have the storage time more than two years even in high humidity areas. The cement producers can ensure that all bricks still have good properties as the new ones.
