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In order to calculate the damage probability of antiaircraft gun weapon system more accurately, the shooting errors were separated according to error sources. The time community (correlation) of the shooting error components caused by the same error source was analyzed. For antiaircraft gun weapon systems with common fire control subsystem and with independent fire control subsystem, the space community (repetitiveness) of the shooting error components was analyzed. The generation method of weak correlated error series was given. Based on the above, the damage probability calculation method by Monte Carlo method was given. The contrastive study was made between the Monte Carlo method based on time and space community analysis of errors and those existing methods. [ABSTRACT FROM AUTHOR]

Introduced the finite element strength reduction method to the risk assessment for groundwater inrush from coal seam floor. On the basis of analyzing the groundwater inrush criterion of finite element calculation, the meaning of coal floor safety coefficient Fs1 was clarified. And the implementation approach of finite element strength reduction method in FLAC3D was introduced briefly. At last, the feasibility of this method using in groundwater inrush risk assessment was proved by a calculation of a case. The ratio of the actual rock mechanicals parameters to breaking mechanicals parameters after strength reduction can be seen as the safety coefficient. The numerical results indicate that the depth of fractured floor is about 15 m in the example's panel and the safety coefficient is 1.38. The safety coefficient reduces with the advance of the working face, the increase of the face length and in-situ stress. Two different water inrush paths are demonstrated by the strength reduction method. Safety coefficient Fs1 is more credible because it considers more factors than the traditional water bursting coefficient. [ABSTRACT FROM AUTHOR]

Landsat Thematic Mapper (TM) image was used to estimate Moso bamboo forest biomass, and six atmospheric calibration methods (FLAASH model, 6S model, and DOS1-4 models) were adopted to analysis the effects of atmospheric calibration on the remote sensing estimation of Moso bamboo forest biomass. All the six calibration methods could effectively reduce the atmospheric impacts on TM spectral responses. The relationships between NDVI and Moso bamboo forest biomass under the calibration by the six calibration methods were improved. Great differences were observed in the relationships of Moso bamboo forest biomass with NDVI, II , and MI when using the same calibration methods, suggesting that atmospheric calibration should be made for studying the biophysical significance of vegetation indices. The Landsat TM data corrected with DOS3 model had the highest correlation coefficient with Moso bamboo forest biomass, but there were no significant differences in the correlation coefficients after corrected with the six calibration methods, which indicated that atmospheric calibration might be not required if a single TM image was used for biomass estimation with multiple linear regression model. [ABSTRACT FROM AUTHOR]

For the boring of non-circular shapes, a revolving electromagnetic actuation mechanism composed of electromagnetic stator and electromagnetic rotor was developed. The main component of the rotor is a flexure-hinged based flexible body. There are four pole-pairs coils in the stator supplying actuation currents. The micro displacement between the stator and rotor can be controlled by changing the currents applied on the pole-pairs coils. With the linearization of the actuation force near static action point, a linear relationship between control current and the actuation force is constructed, and the synchronizing control method of the electromagnetic actuation mechanism is illuminated. With the two-factor analysis of the linearization error of the actuation force, the influences of control current and micro displacement to the linearization error of the actuation force were studied, which would contribute to improve the control accuracy of radial micro displacement of the mechanism. The calibration of the mechanism indicates the relationship between the micro displacement and control current has linear characteristics in the wanted micro displacement dimension. The simulation tests show that the turning radius of the rotor changes with the control current proportionally. [ABSTRACT FROM AUTHOR]

Artificial neural networks were introduced in the area of curve grinding. The prediction model of surface roughness in curve grinding based on back propagation (BP) algorithm was proposed. There are some disadvantages in BP algorithm, such as low rate of convergence, easily failing into local minimum point and weak global search capability. In order to settle these problems, a genetic algorithm was used to train BP neural network to replace classical learning algorithms. An evolutionary neural network learning algorithm was founded. The results of simulations and experiments show that the evolutionary neural network based genetic algorithm can effectively overcome the problem of falling into local minimum point. This method can get higher accuracy of predictions. [ABSTRACT FROM AUTHOR]

According to the necessity of non-circular piston pinhole and actuality of machining, a piezoelectric actuator driven micro-displacement mechanism was put forward to achieve the feeding of boring tool. On the basis of geometric features of piston pinhole and the characteristics of piezoelectric actuators, which have infinite resolution, high stiffness, high frequency and its sensor function, a piezoelectric voltage feed back control system was put forward. Meanwhile, a feed-forward controller in open-loop disturbance channel and a repetitive controller were also introduced into the system. As a result, the robustness and tracking precision of the system are bettered. It is shown by experiments that 3-micron machining accuracy can be achieved. [ABSTRACT FROM AUTHOR]

During the process of fault diagnosis for computer numerically controlled (CNC) machine, the diagnostic rules describing the fault symptom are all diagnostic expert's experience. They are much random. This paper uses the Sugeno fuzzy model for fault auto diagnosis of CNC machine, and realizes fuzzy synthesis of different diagnostic expert's diagnostic conclusion. Sugeno model can eliminate random properties of expert's diagnostic conclusion and assure the accuracy of diagnostic conclusion. The method can be used to realize auto diagnosis of CNC machine based on diagnostic expert system, and the diagnostic conclusion is accurate and reliable. [ABSTRACT FROM AUTHOR]

The single-channel control micro energy pulse source whose switch element is MOSFET has inherent drawback. There exists an uncertain gap voltage during the pulse interval, which prolongs the discharge time and decreases the surface accuracy seriously. Moreover it drives up the average voltage and results in the misoperation of the control unit. Based on the analysis of the waveshape collected in machining, a dual channel MOSFET micro energy pulse power source was designed to make the gap voltage fall down to zero in order to eliminate the uncertain gap voltage. According to the switch characteristics of the MOSFET, reasonable circuit parameters were used, and the theoretical waveshape was calculated. From the waveshape picked during experiment, it shows that the practical waveshape and the theoretical waveshape areanastomotic, and the pulse width can be contracted to sub microsecond. By means of comparison experiment, it shows that the surface texture is improved remarkably, and the course of machining becomes trouble free machining. And the dimension accuracy and surface accuracy of the workpiece increase dramatically. [ABSTRACT FROM AUTHOR]

Aiming at the collision in 5 axis numerical control (NC) machining free-form surfaces using non-ball mill, a new method to automatically generate the tool posture without collision was proposed. It checks collision by calculating the shortest distance between tool-axis and surrounding surface. Based on the maximum avoidance value, the tool position is modified to get the tool posture without collision. The validity of the proposed method was confirmed by machining an impeller. [ABSTRACT FROM AUTHOR]

Experiments on dressing resin and copper bonded diamond grind wheels by means of continuous wave CO2 laser were carried out. The diamond wheel topographies before and after laser scanning were observed by VH-800 series three-dimension digital microscope. The mechanism of removing bond materials was analyzed. The wheel profiles before and after dressing were observed. The results of laser dressing under different process parameters were compared. The experimental results show that it is feasible that application of laser technologies to dress diamond wheel. By properly selecting laser heating parameters and dressing conditions, high-quality dressing can be achieved. [ABSTRACT FROM AUTHOR]

Based on the shortest distance between the cylinder cutter axis and surrounding surface, the maximum gouging was obtained by comparing with the radius of cutter. A new algorithm to calculate the shortest distance between free-form curve and free-form surface was proposed. Based on geometric condition, a normed space projection method is used to obtain the extreme distance. At the same time, the bounder distance between the curve and the surface is fully considered to ensure correctness and convergence property. The algorithm provides important theory basis for the interference detection between the tool and the surface in NC machining with high efficiency and accuracy. [ABSTRACT FROM AUTHOR]

Based on the laser intervening theory, the displacement measurement laser was used to measure the convex curve and the varying ovality curve of a car piston. An aggressive analysis method was used to process the cross section curve data. A five points two-power center based moving average method was used to process the convex curve. The proposed non-contace in-site measurement is important for the online error compensation of piston skirt. [ABSTRACT FROM AUTHOR]

The paper presented a new way for piston noncircular pin hole boring which uses a piezodriven displacement mechanism. In order to attain desired displacement of boring bar, the piezo actuator is mounted radially in the middle of the rotating bar of the mechanism. The working principle of the mechanism was analyzed, the model to compensate the hysteresis of the piezo actuator was established. A kind of control method combining the advantage of real time monitoring control and looking up a table control was proposed, the design method of rotating rigidity for one-axis flexure hinge was illustrated. A dynamic model of the mechanism was set up, the dynamic performance demonstrates that the initial conditions do not affect the stable output of the mechanism, which indicates that the piezodriven boring bar can get stable output and high displacement accuracy. The theoretical analysis confirms the validity of the proposed mechanism. [ABSTRACT FROM AUTHOR]

To improve the bi-directional associative memroy (BAM) performance, a modified model was used to enhance neural networks' memory capacity and error correction capability. The modified model (MBAM) is shown to be asymptotically stable. Theoretical analysis and experiment results demonstrate that the modified model performs much better than the original BAM in terms o{ memory capacity and the modified model not only can complete fault diagnosis correctly but also have fairly high error correction capability for disturbed input information sequence. Moreover, MBAM model is more convenient and effective for solving the problem of computer numerical control (CNC) electric system fault diagnosis. [ABSTRACT FROM AUTHOR]

Objective To study the promoting effect of Shenmai injection on myocardial angiogenesis in myocardial infarction(MI) rats. Methods Forty-one MI model rats were divided into model group, low and high-dose groups, with 10 rats each, and 11 rats in the positive group. Low and high-dose groups were treated with 1, 2 mol/kg of Shenmai injection injected intraperitoneally, positive group was treated with 2 mg/kg enalapril. HE staining was used to observe the pathological changes of myocardial tissue in each group. Immunohistochemical staining was used to observe the capillary density in the infarct area. Western blot was used to detect the relative expression of PI3K, AKT, p-AKT and VEGF protein. Results The pathological changes of the low and high-dose groups and the positive group were reduced. Compared with the sham operation group, the capillary density and arteriole density, the expression of PI3K and VEGF protein, and p-AKT/AKT in the model group were increased (P＜0.05). Compared with the model group, the capillary density and arteriole density, the expression of PI3K and VEGF protein, and p-AKT/AKT in the low and high-dose groups and the positive group were increased (P＜0.05). Conclusions Shenmai injection may promote myocardial angiogenesis in MI rats in a dose-dependent manner. It is speculated that the mechanism of this drug is related to the activation of PI3K/AKT signaling pathway.

Electrical discharge dressing (EDD) process is a non-traditional promising truing and dressing technology for superabrasive wheels. The process makes use of electrical energy to melt and vaporize the wheel bond, and make the abrasive grains stick from the grinding wheel. The development of lightning leader displays a stochastic discharge channel with branching and tortuous structure during EDD. It obviously has characteristic of self-similarity, which can be well described by fractals. A discharge channels simulation model based on the fraetal theory shows the thermal energy distribution of various discharge mediums on the diamond wheel. And various discharge mediums including kerosene-based oil, impressed air and misted deionized water, are applied on EDD bronze-bonded diamond grinding wheels. The surface topography of dressed diamond grinding wheel is observed by VHX-1000 three-dimensional digital microscope. The analyses indicate that the surface topography of dressed diamond grinding wheel is consistent with the feature of simulation discharge channel based on the fraetal theory. At the same time, the fractal simulation model of discharge channels is benefit to predict the wheel dressing microstructure and fressing quality. [ABSTRACT FROM AUTHOR]

The temperature of coated workpieces in intermittent grinding with cup wheel is investigated. The effective width of moving heat source is calculated under the condition of plane grinding with cup wheel; the shape of grinding block is simplified in order to use traditional heat source model; triangular and rectangular models are analyzed and compared. Energy partition ratio is analyzed on the basis of actual end-face temperature and one-dimensional heat conduction model, and the energy partition ratio is also obtained under different parameters. The feasibility of the temperature model is verified experimentally, and the influence of grinding parameters on the grinding temperature is also analyzed. The analysis results show that the grinding temperature rises with the increase of grinding depth, work-piece feed speed and wheel linear speed. [ABSTRACT FROM AUTHOR]

To understand the clinical characteristics and distribution of combined treatment of Chinese and western medicine in diabetes deaths, the hospitalization information of diabetes deaths from HIS system of 20 national 3A-grade general hospitals. Then the frequency statistics and association rules analysis were used to analyze the general information, complications, combined treatment, death time and other information of the patients died from diabetes. The results showed that most of the diabetes deaths were of middle aged and elderly people, more often in males than females. The complications with higher incidence included hypertension, pulmonary infection, coronary heart disease, cerebral infarction and renal inadequacy. In combined treatment rules, western medicines insulin, cefuroxime, furosemide, dopamine, nikethamide and sodium bicarbonate were used in combination at highest frequencies, followed by the combinations of traditional Chinese medicines panax notoginseng, radix bupleuri and western medicines, and the combinations between Chinese medicines had the lowest use frequency. Most of the diabetes deaths were of middle aged and elderly people, more often in males than females. They mainly died from 3 pm to 5 pm and from 5 pm to 7 pm. Therefore, the diabetes deaths often had complications of cardiovascular and cerebrovascular diseases, and early prevention shall be noted in clinics; the clinical treatment plan was basically in accordance with the guidelines for clinical treatment of diabetes; the drugs with promoting blood circulation to remove blood stasis and soothing liver-qi stagnation effects were the common Chinese medicines in treatment of diabetes., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To re-evaluate the diagnoses of ankylosing spondylitis (AS) and nonradiographic axial spondyloarthritis (nr-axSpA) and analyze the incidence and reason of misdiagnosis., Methods: Patients who were previously diagnosed as AS and nr-axSpA before referrals to Peking Union Medical College Hospital (PUMCH) were re-evaluated by three rheumatologists of PUMCH according to the modified New York criteria for AS and Assessment of SpondyloArthritis international Society (ASAS) axial SpA classification criteria for nr-axSpA., Results: Totally 87 prior AS patients and 53 prior nr-axSpA patients were enrolled in this study. After re-evaluation, 57 patients were still diagnosed as AS and 16 patients were still diagnosed as nr-axSpA. The misdiagnosis incidences were 34.48% and 69.81%, respectively. The misdiagnosis incidence of nr-axSpA was higher than that of AS (P < 0.01)., Conclusions: The misdiagnosis of AS were mainly due to the misjudgment of sacroiliac joints by CT. The misdiagnosis of nr-axSpA were mainly due to the misjudgment of sacroiliac joints by magnetic resonance imaging. Moreover, the misuse of ASAS axial SpA classification criteria contributed to the misdiagnosis also.

Objective: To investigate the effect of laparoscopic and open proctectomy on plasma levels of vascular endothelial growth factor (VEGF)., Methods: From January 2011 to December 2012, 100 rectal cancer patients in Shantou Central Hospital were enrolled in the study. Patients were divided into laparoscopic (LR) group and open (OR) group based on the decision of the patients. There were 63 patients in the LR group (44 cases undergoing low anterior resection and 19 abdominoperineal resection) and 37 patients in the OR group(26 cases undergoing low anterior resection and 11 abdominoperineal resection). Double antibody sandwich enzyme-linked immunohistochemistry was used to detect the level of VEGF on 1-day before and 1-day, 3-day, 7-day after operation., Results: In the LR group, the postoperative levels of VEGF increased slowly, and the level of VEGF was significantly higher than that before operation until the 7-day after operation(P<0.05) regardless of the procedure. In the OR group, all the postoperative levels of VEGF were significantly increased(P<0.05). There was no significant difference of the VEGF level on 1-day before and 1-day after operation between the two groups(all P>0.05). The VEGF level in the OR group was significantly higher than that in the LR group on the day 3 and day 7 after operation(P<0.05)., Conclusion: Compared with open approach, laparoscopic proctectomy has smaller short-term impact on the plasma level of VEGF in rectal cancer patients.

Landsat Thematic Mapper (TM) image was used to estimate Moso bamboo forest biomass, and six atmospheric calibration methods (FLAASH model, 6S model, and DOS1-4 models) were adopted to analysis the effects of atmospheric calibration on the remote sensing estimation of Moso bamboo forest biomass. All the six calibration methods could effectively reduce the atmospheric impacts on TM spectral responses. The relationships between NDVI and Moso bamboo forest biomass under the calibration by the six calibration methods were improved. Great differences were observed in the relationships of Moso bamboo forest biomass with NDVI, II, and MI when using the same calibration methods, suggesting that atmospheric calibration should be made for studying the biophysical significance of vegetation indices. The Landsat TM data corrected with DOS3 model had the highest correlation coefficient with Moso bamboo forest biomass, but there were no significant differences in the correlation coefficients after corrected with the six calibration methods, which indicated that atmospheric calibration might be not required if a single TM image was used for biomass estimation with multiple linear regression model.

Objective: To investigate the expressions of stromal cell-derived factor-1 (SDF-1) and CX chemokine receptor-4 (CXCR-4) in patients with hepatocellular carcinoma (HC) and liver cirrhosis., Methods: Peripheral blood and/or ascites fluid were collected from 39 hepatocellular carcinoma patients, 16 patients with liver cirrhosis, 12 with hepatitis and 12 healthy donors. The SDF-1 expression was assayed by ELISA and CXCR-4 was measured by immunohistochemical methods., Results: The level of SDF-1 expression in the carcinoma patients was higher than that of the liver cirrhosis, hepatitis patients and healthy donors, but there was no significant difference between those of the healthy donors and hepatitis patients or liver cirrhosis patients. The levels of CXCR-4 expression were closely related to the tumor differentiation., Conclusion: The expression of SDF-1 in the peripheral blood and the CXCR4 expression in the HCC tissues of the HC patients may be regarded as markers of HC and they may have a positive relationship with the differentiation and metastasis of HC.