变径玻璃毛细管的制备及应用

提出两种用普通毛细管拉制机制备变径玻璃毛细管的新方法。通过改变炉温或拉伸比，拉制出不同形状的优质变径毛细管，并将其用于毛细管色谱柱的制备和毛细管的连接。

Automatic Guidance of an Agricultural Tractor along with the Side Shift Control of the Attached Row Crop Cultivator

This paper presents the automatic guidance system of an agricultural tractor and the side shift control of the attached row crop cultivator using electro-hydraulic actuators. In order to simulate the dynamic behaviour of the tractor along with the attached cultivator, the modified bicycle model was adopted. Steering angle sensor, fibre optic gyroscope （FOG） and RTK-DGPS technologies are assumed for measurements of the steering angle, yaw rate and the lateral position of the tractor, respectively. The kinematics model was used for the implement. In this study four cascade controllers were designed and simulated for tractor guidance which consists ofPD, PD, P and PID controllers. Other PI and PID controllers also had been designed for implement side shifting purpose. Then, these two systems were combined and the performance of the whole system was evaluated through the simulation results. According to the results tractor reaches the desired path after less than 10 seconds. Simulations showed that the maximum deviation of the tractor from the desired path was about 5 cm within this period. And the cultivator blades would follow the predetermined path with steady state error of about 5 cm too.

Effect of partial recrystallization on microstructure and tensile properties of NiFeCoCrMn high-entropy alloy

To obtain a balance between strength and ductility in NiFeCoCrMn high-entropy alloy, the degree of dislocation strengthening was tuned via partial recrystallization during traditional thermomechanical processing(cold rolling and recrystallization). The tensile properties in each state were then examined. Significant improvements in uniform elongation and work hardening rate, with decrease in yield strength and ultimate tensile strength, are associated with increase in the recrystallized fraction, i.e., reductions in the degree of strain hardening. In particular, recrystallized fractions of 37% and 74% are obtained by annealing at 650 ℃ for 10 min and 15 min, respectively, which results in yield strengths of 1003 MPa and 742 MPa and uniform elongations of 4% and 24%, respectively. The strengthening is due to the unrecrystallized grains with a high density of dislocations, whereas the ductility benefits from the presence of recrystallized strain-free grains.

Evenness Control of Rapier Loom Tension by Using Neural Network

The neural network model (NNM) is used to control the evenness of rapier loom tension and to model the uncertain parameters of drafting process. This model can estimate recursively the tension and incorporate predictive control strategies. After controlling the effect testing,it can be seen that the behavior is excellent following different set point and variations, such as the diameter of the beam of weaver, air stream, density of warp and weft, type of textile, etc. An optimum steady state scheme has been fixed in keeping evenness of tension of loom. This method improves obviously the efficiency and quality of production.

Reflections on the Mechanism of Cooperation between China and Arab States

During the Cold War,China’s diplomacy failed to treat the Arab states as a whole.It was not until the end of the Cold War that China established diplomatic relations with all 22 Arab states.Since then,a multilateral cooperation mechanism between China and Arab states has come into existence and become steadily developed.In 2004,the China-Arab States Cooperation Forum was established.In 2010,China and the Arab states announced the establishment of a strategic cooperative relationship.After the Gulf War,the Arab world entered a period of fragmentation and division.The situation deteriorated after the drastic changes in the Middle East in 2011,to the point of entering an era of granulation.The ability of The League of Arab States to operate as a single international actor has been greatly impaired.In the era of the fragmentation of the Arab world,the mechanism of multilateral cooperation between China and the Arab States has developed in spite of these great difficulties.In future,the role and function of the multilateral mechanism of cooperation between China and the Arab states needs to be clarified,and efficiency needs to be improved based on the existing mechanisms.

Molecular mechanism and functional consequences of lansoprazole-mediated heme oxygenase-1 induction

AIM： To investigate the molecular mechanism and functional consequences of heme oxygenase-1 （HO-1） activation by lansoprazole in endothelial cells and macrophages. METHODS： Expression of HO-1 mRNA was analyzed by Northern blotting. Western blotting was used to determine the HO-1 and ferritin protein levels. NADPH-dependent reactive oxygen species （ROS） formation was measured with lucigenin-enhanced chemiluminescence. HO-1 promoter activity in mouse fibroblasts, stably transfected with a 15-kb HO-1 gene that drives expression of the reporter gene luciferase, was assessed usingin vivo bioluminescence imaging. RESULTS： Lansoprazole levels in endothelial cells increased HO-1 mRNA and HO-1 protein levels in macrophages. In addition, lansoprazole-induced ferritin protein levels in both cell systems. Moreover, induction of the antioxidant proteins HO-1 and ferritin by lansoprazole was followed by a decrease in NADPH- mediated ROS formation. The radical scavenging properties of lansoprazole were diminished in the presence of the HO inhibitor, chromium mesoporphyrin IX. Induction of HO-1 gene expression by lansoprazole was not related to oxidative stress or to the activation of the mitogen-activated protein kinase pathway. However, the phosphatidylinositol 3-kinase inhibitor LY294002 showed a concentration-dependent inhibition of HO-1 mRNA and promoter activity.CONCLUSION： Activation of HO-1 and ferritin may account for the gastric protection of lansoprazole and is dependent on a pathway blocked by LY294002.

Surface Modification Mechanism of Fine Coal by Electrochemical Methods

In order to reveal the surface modification mechanism of fine coal by electrochemical methods, the structural changes of the coal surface before and after electrochemical modification were investigated by Fourier Transform In- frared Spectra (FTIR) and Raman Spectra. The results show that under certain electrochemical conditions, the oxy- gen-containing functional group in the coal structure and the oxygen content of absorption could be reduced and the floatability of coal improved. At the same time, the sulfur in the coal was reduced to the hydrophilic S2– which could be separated easily from coal. Thus electrochemical modification methods could be used to change the structure and func- tional group on the coal surface and to enhance the floatability of coal.

Statistical damage model for quasi-brittle materials under uniaxial tension

Based on the parallel bar system, combining with the synergetic method, the catastrophe theory and the acoustic emission test, a new motivated statistical damage model for quasi-brittle solid was developed. Taking concrete for instances, the rationality and the flexibility of this model and its parameters-determining method were identified by the comparative analyses between theoretical and experimental curves. The results show that the model can simulate the whole damage and fracture process in the fracture process zone of material when the materials arc exposed to quasi-static uniaxial tensile traction. The influence of the mesoscopic damage mechanism on the macroscopic mechanical properties of quasi-brittle materials is summarized into two aspects, rupture damage and yield damage. The whole damage course is divided into the statistical even damage phase and the local breach phase, corresponding to the two stages described by the catastrophe theory. The two characteristic states, the peak nominal stress state and the critical state are distinguished, and the critical state plays a key role during the whole damage evolution course.

Mechanism of anti-tumor effect of HIF-1α silencing on cervical cancer in nude mice

Objective： The aim of our study was to observe the anti-tumor effect of silencing the expression of HIF-1α on cervical cancer in nude mice and to explore its mechanism of action. Methods： Human cervical cancer cell line Siha cells were divided into 3 groups： mock control group, control group transfected with scrambled sequence plasmid, and experimental group transfected with pU-HIF-la-shRNA eukaryotic expression plasmid. Cultured cells of the three groups were inoculated in nude mice to establish cervical cancer-bearing nude mice. HIF-la RNAi assay was performed to evaluate the tumor-suppressive effect of HIF-1α silencing on cervical cancer-bearing nude mice. Immunohistochemistry and Western blot were used to observe the distribution and protein expression of HIF-1α and GLUT1, while RT-PCR was adopted to detect the gene expression of HIF-1α, GLUTI and HK I1. The product of glycolysis （tactic acid） and apoptosis in tumor cells were detected by colorimetry and semi-quantitative TUNEL staining, respectively. Results： The tumor growth in experimental group was significantly slower than that in the two control groups （P 〈 0.05）. In the 50th day after transplantation, the tumor weight in the experimental group was （1.90 ± 0.28） g, significantly lower than （2.95 ± 0.77） g in the control group and （2.54 ± 0.56） g in the mock group （P 〈 0.01）. In the experimental group, the gene and protein levels of HIF-1α were 0.45 ± 0.04 and 1.25 ± 0.92, and the levels of GLUT1 were 0.32 ± 0.02 and 1.25 ± 0.48, respectively. Both indicators in HIF-la and GLUT1 were lower than that in the two control groups （P 〈 0.05）. The expression levels of HK Ⅱ gene and lactic acid in the experimental group were lower than that in the two control groups （P 〈 0.05）, but the apoptotic cells were much more numerous in the experimental group than that in matched control groups （P 〈 0.01）. Conclusion： The 9ene therapy by siRNAtargeted silencing of HIF-1α may down-regulate its downstream genes GLUT1 and HK Ⅱ expression, therefore, to reduce the tumor glycolysis activity and promote tumor cell apoptosis, and exert a tumor-suppressing effect in vivo.

Experimental Research of Automotive Needlepunched Carpets at Thermoforming Temperatures

Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Investigations on the tensile properties were performed as a function of thermoforming temperature,extensile speed and fiber orientation based on an orthogonal experiment design.The experimental results show that the automotive carpets are rate-dependent anisotropic one and very sensitive to the forming temperature.The tensile properties are strongly depended on the forming temperature when compared with the extensile speed and the fiber orientation.Experiments only varying with the temperature were performed because of the dominative effect of the temperature.Different deformation performances were observed with different temperatures.Deformation mechanisms at the thermoforming temperatures were presented to explain the nonlinear trend of the ultimate elongation with the temperatures based on the combination of the experimental observations and the corresponding polymer theories.

Crack branching mechanism of rock-like quasi-brittle materials under dynamic stress

The cracking patterns of a thin sheet with a pre-existing crack subjected to dynamic loading are numerically simulated to investigate the mechanism of crack branching by using the FEM method.Six numerical models were set up to study the effects of load,tensile strength and heterogeneity on crack branching.The crack propagation is affected by the applied loads,tensile strength and heterogeneity.Before crack branching,the crack propagates by some distance along the direction of the pre-existing crack.For the materials with low heterogeneity,the higher the applied stress level is and the lower the tensile strength of the material is,the shorter the propagation distance is.Moreover,the branching angle becomes larger and the number of branching cracks increases.In the case of the materials with high heterogeneity,a lot of disordered voids and microcracks randomly occur along the main crack,so the former law is not obvious.The numerical results not only are in good agreement with the experimental observations in laboratory,but also can be extended to heterogeneity media.The work can provide a good approach to model the cracking and fracturing of heterogeneous quasi-brittle materials,such as rock,under dynamic loading.

Path-tracking Control of a Tractor-aircraft System

An aircraft tractor plays a significant role as a kind of important marine transport and support equipment. It＇s necessary to study its controlling and manoeuvring stability to improve operation efficiency. A virtual prototyping model of the tractor-aircraft system based on Lagrange＇s equation of the first kind with Lagrange mutipliers was established in this paper, According to the towing characteristics, a path-tracking controller using fuzzy logic theory was designed. Direction control herein was carried out through a compensatory tracking approach. Interactive co-simulation was performed to validate the path-tracking behavior in closed-loop, Simulation results indicated that the tractor followed the reference courses precisely on a flat ground.

Klatskin tumor treated by inter-disciplinary therapies including stereotactic radiotherapy: A case report

In view of the poor prognosis of patients with cholangiocarcinoma （CCC）, there is a need for new therapeutic strategies. Inter-disciplinary therapy seems to be most promising. Radiotherapy is an effective alternative to surgery for hilar CCC （Klatskin tumors） if an adequate radiation dose can be delivered to the liver hilus. Here, we describe a patient for whom we used a stereotactic radiotherapy technique in the context of an inter-disdplinary treatment concept. We report a 45-year-old patient with a locally advanced Klatskin tumor. Explorative laparotomy showed that the tumor was not resectable. A metallic stent was implanted and the patient was treated by stereotactic radiotherapy using a body frame. A total dose of 48 Gy （3×4 Gy/wk） was administered. Therapy was well tolerated. After 32 too, local tumor recurrence and a chest wall metastasis developed and were controlled by radio-chemotherapy. After more than 56 mo with a good quality of life, the patient died of advanced neoplastic disease. Stereotactic radiotherapy led to a long-term survival of this patient with a locally advanced Klatskin tumor. In the context of inter-disciplinary treatment concepts, this radiotherapy technique is a promising choice of treatment for patients with hilar CCC.

Control of the Colorado Potato Beetle, Leptinotarsa decemlineata （Say）, Using Predator Insects Released by a Mechanical Prototype

The CPB （Colorado potato beetle） is unquestionably the major insect pest of potato crops in North America, Europe, and Asia. The use of chemical insecticides to control this insect pest started in the 1860s. To date, no registered chemical has been capable of effectively managing this agricultural pest. Moreover, the CPB has developed over the years a resistance to most of the registered chemical insecticides. The biological control through manual release of natural enemies of the CPB has been successful at small scale. However, hand release of these predators at large scale is not realistic. The objective of this study was to investigate the effectiveness of controlling the CPB through mechanical release of predator insects under real conditions in a potato field. Obtained results indicate that the mechanical release of predator insects resulted in a better control of the CPB populations and egg masses than the manual release. The success of this mechanical release of predator insects in potato fields will be highly valuable for the biological control of insect pests in many other row crops such as strawberry, lettuce, etc..

Transmission Mechanisms of Monetary Policy in Saudi Arabia： Evidence From SVAR Analysis

In this research, the authors evaluate different channels of the monetary policy transmission mechanisms in Saudi Arabia over the last 15 years with a baseline of structural vector autoregressive （SVAR） models. Contemporaneous coefficient in the structural model indicates that while Saudi Arabia pegs its currency to US dollar, monetary policy instrument reacts positively to unexpected changes in the monetary aggregate. In addition to the traditional interest rate channel, the authors have also found the effects of credit channel. Moreover, variance decomposition results show that past shocks of credit, nominal effective exchange rate （NEER）, federal funds rate （FFR） and treasury bill （TB） are found to be important for credit growth in shorter and longer horizons. The exchange rate channel has been less significant in comparison to other channels.

Design, Fabrication and Experimentation of a Deep Drawing Machine

This paper presents the work implemented in designing, fabricating and operating a model of a cheap hydraulic DDM （deep drawing machine）, which is currently utilized in the manufacturing processes lab in the IED （Industrial Engineering Department） at An-Najah National University. The machine is used to conduct different experiments related to the deep drawing process. This work was implemented in three stages： the first was the design stage, in which all design calculations of the DDM elements were completed based on the specifications of the product （cup） to be drawn; the second was the construction stage, in which the DDM elements were fabricated and assembled at the engineering workshops of the university; the last was the operating and experimentation stage, in which the DDM was tested by conducting different experiments. The experience gained from designing and constructing such a mechanical lab equipment was found to be successful in terms of obtaining practical results that agree with those available in literature, cost-effective relative to the cost of a similar purchased equipment, as well as enhancing students＇ abilities in understanding the deep drawing process in particular and machine elements design concepts in general.

Recouping Braking Energy from Diesel-Hauled Commuter Trains

Research was undertaken to define the concept of a coach-based braking energy recoupment, storage and regeneration system to augment the acceleration of regional commuter trains hauled by diesel locomotives. Functional specifications were developed having the goal of increasing by 25% the acceleration rate of a train consisting of 10 bi-level coaches hauled by a 3,000 hp diesel locomotive, typical of the rolling stock now in commuter services in Canada and the USA. Examining three alternate hybrid system technologies for train retardation based, respectively, on hydrostatic, battery and ultracapacitor energy storage. The ultracapacitor hybrid system appeared the most promising due to the capability ofultracapacitors to repeatedly and rapidly accept large energy charges without degradation, temperature insensitive and flexible in the placement of modules in the limited space available. Analyses of train operation simulations showed that in addition to augmenting acceleration and reducing trip time, braking energy recoupment reduced fuel consumption and concomitant diesel emissions.

Outcome of penetrating cardiac injuries in southern Iran, Shiraz

Objective： Cardiac injuries are one of the most challenging injuries in the field of trauma surgery. Their management often requires immediate surgical intervention, excellent surgical technique and the ability to provide excellent postoperative critical care to patients. The aim of this study was to evaluate the outcome and survival rate of patients with penetrating cardiac injury in southern Iran, Shiraz. Methods： From January 2001 to June 2007, medical records of all patients suffering from penetrating cardiac injuries were reviewed and their outcomes were investigated. The inclusion criterion was the presence of a confirmed penetrating cardiac injury intraoperatively or by autopsy. Patients with blunt cardiac injuries were excluded from the study. Results： The study consisted of 37 patients, including 1 gunshot wound （2.7%）, 35 stab wounds （94.6%） and 1 （2.7%） shotgun wound. The overall survival rate was 76% （28 in 37） and that in stab wound patients was 80%. The collected data of 9 expired patients revealed 11% death on arrival, 67% hypotensive, and 22% normotensive considering physiologic presentation. Paired sample test showed sig- nificant correlation between mortality and electrocardio- graphic changes, amount of retained blood in pericardium, clinical stage and physiologic condition at presentation, as well as associated injury type （gunshot more than stab wound）. Conclusion： Our results show that injury mechanism and initial cardiac rhythm are significant predictors of out- comes in patients with penetrating cardiac injuries. Besides, gunshot injury and exsanguination are the most important predictive variables of mortality.