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Background: It is unknown whether gabapentin is effective in reducing acute pain following laparoscopic cholecystectomy. The purpose of the current meta-analysis was to evaluate the efficacy of gabapentin in reducing pain intensity and postoperative nausea and vomiting (PONV) after laparoscopic cholecystectomy. Methods: All randomized controlled trials (RCTs) evaluating the efficacy of gabapentin in reducing pain intensity and PONV after laparoscopic cholecystectomy were searched on the following databases: PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the Google database, the Chinese Wanfang database, and the China National Knowledge Infrastructure (CNKI). The most recent literature search was conducted on March 21, 2017. Outcomes including visual analog scale (VAS) at 12 and 24 hours, total morphine consumption, and the occurrence of PONV. Continuous outcomes were expressed as the weighted mean difference (WMD) and 95% confidence interval (CI), and the one discontinuous outcome was expressed as risk ratio (RR) and 95% CI. Stata 12.0 software was used for meta-analysis. Results: A total of 9 studies involving 966 patients were identified. In total, there were 484 gabapentin subjects and 482 controls. Compared with the control group, gabapentin was associated with lower VAS at 12 hours (WMD = −10.18, 95% CI: −17.36 to −2.80, P = .007) and 24 hours (WMD = −6.33, 95% CI: −8.41 to −4.25, P = .000), which was equivalent on a 110-point VAS scale to 10.18 points at 12 hours and 6.33 points at 24 hours. Compared with the control group, gabapentin was associated with less total morphine consumption by approximately 110.83 mg (WMD = −110.83, 95% CI: −183.25 to −38.42, P = .003). In addition, the occurrence of nausea and vomiting in gabapentin was decreased (25.2% vs 47.6, RR = 0.53, 95% CI: 0.44–0.63, P = .000). Conclusion: Gabapentin was efficacious in reducing postoperative pain, total morphine consumption, and morphine-related complications following laparoscopic cholecystectomy. In addition, there was a negative correlation between the gabapentin dosage and the occurrence of nausea and vomiting. The number of included studies is limited, and more studies are needed to verify the effects of gabapentin in laparoscopic cholecystectomy patients.

An experimental device for the liquid explosive disseminations with constraints formed by up and down plains was set up. Applying the shadow photograph technology, the time series about the breakup shape of liquid-air interfaces were recorded. And using the PLIF (planar laser induced fluorescence) technology, the fluorescence photos about liquid shell expanding in radial direction were obtained. By means of digital image processing, fractal geometry and numerical simulation methods, systematic analyses to the experimental results were made. Finally some problems about how to establish the mathematical models for describing the unsteady motion of liquid shell and liquid-gas interfaces were discussed.

Evaluation of equipmentsupport distributionplan in wartime scientifically and accurately is crucial to improve the efficiency of distribution and meet the demand of war timely. In this paper Topsis is adopted to conduct comprehensive evaluation of the equipment support distribution plan at war time. Topsis is an effective resolution of multiple objectives, nearly an ideal resolution plan, which effectively avoids the difficulty in combining the multiple evaluation parameters into a single efficacy value and provides a new way to evaluate the equipment support distribution plan in wartime.

This research adopts the Projection Pursuit Model to analyze the level standards for the evaluating indexes about the testability of a particular type of armored equipment. The Model is built with the samples randomly generated at all the levels; the weight coefficients of indexes are determined for the evaluation on testability of the armored equipment; and the correspondence is found between the variation ranges of characteristic values of projection and the levels of classification. Furthermore, an analysis is conducted on the original testability data of the equipment, which came from the final approval test of its type, to decide its testable level in evaluation. And the results are acceptable. This research provides the theoretic basis and methods of another approach to evaluate the testability and its design for a particular type of armored equipment in a scientific, accurate and objective way.

The paper proposes a new model to predict the backward extrusion force of Cu-0.75Cr copper alloy based on Projection Pursuit Regression (PPR). Three major technological parameters of the fault plane contraction rate, convex model awl angle and extrusion temperature are regarded as the influencing factors and the extrusion force in the backward extrusion process is regarded as the influencing object. A complex non-linear relationship is established through the PPR model between the influencing factors and the influencing object. The orthogonal test data are used to train the model. The trained model is used to predict the extrusion force of Cu-0.75Cr copper alloy in a certain backward extrusion condition. The result demonstrates that the prediction accuracy and processing speed of the model have greatly been improved and the mean error of the prediction is 0.5%.

According to the evaluation method of TOPSIS, the torpedo tactical performance indices are comprehensively evaluated taking the following seven performances as the indices: explosive weight, maximum speed, maximum depth, maximum range, anti—interference capacity, homing range, searching sector angle. Through calculating the relative degree to which the indicator value vector of the performance indices is close to the ideal value sector, it gives the order of comprehensive evaluation results for torpedo performance. The simulation result proves that the method eliminates the influence of human factors, so it is more scientific and reasonable about the comprehensive evaluation of torpedo tactical performance indices.

The fan pump is one component of the amphibious assault vehicle hydraulic system with high failure rate, whose performance has an important influence for the whole system. As the time increase, the oil leaked will increase. The projection pursuit regression method solves the abnormal, nonlinear and multifactor relative problems of higher dimensional data. It avoids the deviation made by artificial interaction through analyzing the sample original data directly. In this paper, projection pursuit regression method is applied in analysing the leakage of amphibious assault vehicle fan pump and the predicted effect is superior to partial least square regression model obviously. This model has better stability and precision. It has great significance for the fault diagnosis of fan pump of amphibious assault vehicle.

The impulsive synchronization of spatiotemprol chaos is investigated. A proof of the existence of a certain kind of impulses for synchronization such that the error dynamics is equi-attractive in the large is established. The method of choosing impulse duration and the magnitude of the impulses is discussed in detail. Moreover, as an application, a secure communication scheme based on the results of this paper is developed. It's concluded that the simulation results verify the proposed scheme's success in the communication application.

This paper realizes the fusion of multi-dimension oil monitoring data by the way of principal components analysis, gets the trend curve representing the degree of wear about the equipments, keep the wear information contained in the monitoring sample to a maximum limit, which is very important to the forecast and support of equipment technology condition.

The evaluation of the tank firepower performance is very important for the demonstration, research, and use of armored vehicles. The Topsis method is applied in this article to comprehensively evaluate the firepower performance of tank, and this method is the effective evaluation method by using the multi-objective decision method to approach the ideal solution, which could effectively solve the difficulty that traditional evaluation methods are hard to integrate multiple evaluation parameters as single-efficiency measurement value, and provide a new approach to comprehensively evaluate the firepower evaluation of tank.

Projection pursuit regression is used to make model about the combustion chamber and total sound level of the combustion chamber in order to fit total sound level of An Aircraft Engine. At last the average relative error is small to indicate the model is better, so it is important for aero-engine design and reliability analysis.

In this paper, we study the reliability problem of electrical system and power device of certain-type armored vehicle by Copula function. Considering the correlation relationship among variables, confirm the marginal distribution through Weibull distribution, get the Archimedes Copula function and verify it. Establish reliability binary model and get reliability function and failure rate which solves the determination of correlation degree and calculation model. It provides important reference for the computation of the reliability of the complex system.

We can judge the diesel active state by measuring the turbo supercharger speed, but in practical measurement, there are always many problems. In this paper, we build the regression model of relationship between turbo supercharger speed and pressure ratio, intake flow, turbine final pressure, turbine front pressure, turbine final temperature, gas compressor final pressure, gas compressor front pressure and gas compressor front temperature by the partial least square and cross validity test. Through the test, the explanation ability for the independent variables and the dependent variables of the model exceed 99%. Comparing with the practical values, this model has higher fitting precision and better prediction ability. This method solves the problem of install difficulty during actual vehicle measuring and the low precision which has great significance to the actual vehicle test of diesel turbo supercharger in low temperature conditions.

In this paper, Ni-Co compositional coatings were electrodeposited by brush-plating and the surface topography images were obtained with the help of scanning electron microscope. The surface topography of Ni-Co coating and the Co element in Ni-Co alloy coating were changed by changing the proportion of Co in plating solution. The fractal dimensions of the surface topography of Ni-Co coating with different Cos were counted based on gray image fractal theory. The impact on the surface topography of Ni-Co coating by the proportion of Co element in plating solution was studied by fractal dimension.

An integrated evaluation of the modern main battle tank based on Tops is method is discussed in this article. The method is a technique for order preference by similarity to ideal solution which can avoid the difficulty in traditional evaluations that regard the multi-evaluation parameters as a single efficiency evaluating value. The article provides a new system to the comprehensive evaluation of the modern main battle tank.

In this paper, the projection pursuit method is adopted to transform the main performance indexes which impact on the artillery quality into one-dimensional projection value and give the order of quality evaluation of every artillery sample, at the same time, get the weight of every main performance index. This method has stronger objectivity. It has great significance for assessment and management of artillery quality and improves the artillery equipments management and security ability.

The wide application of the information technology and the computer network in the military domain has hastened the born of the informationalized operation, and completely changed many characteristics of the limited communication of the mechanized operation, the big-scale operation, and the centralized command control and decision. Facing increasing complexity and network structure characteristics of the command information system, the research idea based on the complex network is proposed in this article, and the topology model of the command information system is established by mapping the three-dimensional structure to the two-dimensional link. By the method of the entity numerical analysis, the existence of the small world and the scale-free characteristics is tested and verified, which could provide positive theoretical reference for the construction of the future system of the armored and mechanized force.

In this paper, the principle of denoising with wavelet transform are discussed. The application of wavelet threshold denoising method in MCG-signal processing problem is introduced. Program is written by MATLAB to realize wavelet threshold denoising method. The results show that the wavelet threshold denoising method in the MCG-signal denoising can not only restrain the noise effectively, but also reserve the fault character information in the original signal. The signals by this method are better improvements than traditional method.

The problem of robust H ∞ control for fuzzy time-delay systems is addressed. On the basis of the fuzzy modeling, the fuzzy controller is designed which depends not only on the state, but also on the derivative of the state. The sufficient condition is derived such that the system is asymptotically stable and the H ∞ performance is satisfied for fuzzy time-delay systems. This condition is formuulated in the form of linear matrix inequalities. Simulation results show the effectiveness of the proposed method.

Using Markov chain model and by the changes of state transition about system, this paper describes the dynamic characteristics of teaching method of the basis course in the engineering institutions, which reflects the management of institutions and e ect of teaching and learning.

The method of box dimension is used in this paper for calculating the fractal dimension of the fuel air explosive(FAE) explosive images. The relationship between fractal dimension and the expansion law of fireballis discussed. The change of explosion image fractal dimension all the time is studied, and its change law isinferred, with the reason analyzed, which lays the foundation for the further study of explosive process.

A series of TiO2 hierarchical nanostructures were synthesized by a facile template-free hydrothermal method in the presence of sodium fluoride (NaF) using titanium tetrachloride (TiCl4) as precursor. The pompon-like and football-like TiO2 hierarchical microspheres are composed of aligned rutile and anatase nanoparticles. The TiO2 nanostructures are comprised of oriented anatase nanoparticles. It is found that the doping concentration of NaF plays an important role in controlling the morphology and structure of the hierarchical nanoarchitectures. A sequential phase transition is observed with increasing dopant concentration: rutile → rutile + anatase → anatase. X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) results indicated that F ions physically absorbed on the surface of TiO2 and incorporated into TiO2 crystal lattice. For the first time, a sequential red shift of absorption band edge of F-doped TiO2 is observed with increasing the concentration of NaF as compared to pure TiO2. The band gap could be tuned from 3.0 eV to 2.2 eV, which depends on the fluorine doping concentration. It is found that F-doped TiO2 nanostructures exhibit higher photocatalytic activity than that of pure TiO2 under visible light irradiation.