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In the field of CNC machining, high-speed and high-precision machining has been regarded as the key research by many scholars. In conventional methods, high-speed machining and high-precision machining are contradictory. It is inevitable to reduce the feedrate to improve the processing accuracy. In the paper, a pre-compensation based on discrete inverse transfer function (PDIT) theory is proposed. PDIT is able to improve machining accuracy by reducing contour errors without decreasing feedrate. The proposed PDIT theory is divided into three parts, NURBS interpolator, feedrate scheduling, and interpolator with pre-compensation. The NURBS interpolator has greatly advantage to interpolate the parameter curve directly. Therefore, the paper adopts the NURBS interpolator to accomplish interpolation. In the feedrate scheduling, S-type flexible acceleration and deceleration are used for path planning, and the maximum starting feedrate is obtained with the feedrate constraint. In the interpolator with pre-compensation, the NURBS interpolator is pre-compensated by PDIT. For inputs, the response of transfer function reach steady-state response with a little time. Before reaching steady-state response, the unsteady response exists in the transfer function. The unsteady response usually sustains tens of interpolation periods and must be lead contour error in machining. Hence, the PDIT theory is employed to compensate the contour error causing by the unsteady response of transfer function to NURBS interpolator. The drive system is a transfer function, so the unsteady response of drive system cause machining errors before reaching the steady-state response. In the paper, the NURBS interpolator is pre-compensated by PDIT theory before the drive system to reduce contour errors and improve machining accuracy. Finally, the performance of the proposed PDIT is evaluated by simulation experiments. The experimental results illustrate that PDIT theory obviously improve the machining accuracy and reduces the contour error.

Seawater leakage commonly leads to corrosion in the inner lining of submarine bimetallic pipes, with significant financial implications for the offshore oil and gas production industry. This study aims to improve understanding of the performance of bimetallic pipes by investigating the corrosion behaviors of mechanically bonded 316L stainless steel. Immersion experiments were conducted in a seawater environment, under both atmospheric conditions and high temperature and high pressure conditions, and corroded surfaces were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to reveal micromorphology and elementary compositions. The results demonstrated that the corrosion rates of the bonded 316L specimen were between 5% and 20% higher than those of specimens without bonding under atmospheric conditions. This is attributed to the stress cracking that occurs during corrosion. Under high temperature and high pressure conditions, the corrosion rates were remarkably increased (91% to 135%) and the corrosion process took longer to reach equilibrium. This may be attributed, firstly, to the products becoming increasingly porous and weak, and also to the fluid stress caused by stirring in these experiments to simulate seawater movement.

Background. Multiple interleukin (IL) family members were reported to be closely related to hypertension. We aimed to investigate whether IL-9 affects angiotensin II- (Ang II-) induced hypertension in mice. Methods. Mice were treated with Ang II, and IL-9 expression was determined. In addition, effects of IL-9 knockout (KO) on blood pressure were observed in Ang II-infused mice. To determine whether the effects of IL-9 on blood pressure was mediated by the signal transducer and activator of the transcription 3 (STAT3) pathway, Ang II-treated mice were given S31-201. Furthermore, circulating IL-9 levels in patients with hypertension were measured. Results. Ang II treatment increased serum and aortic IL-9 expression in a dose-dependent manner; IL-9 levels were the highest in the second week and continued to remain high into the fourth week after the treatment. IL-9 KO downregulated proinflammatory cytokine expression, whereas it upregulated anti-inflammatory cytokine levels, relieved vascular dysfunction, and decreased blood pressure in Ang II-infused mice. IL-9 also reduced smooth muscle 22α (SM22α) expression and increased osteopontin (OPN) levels both in mice and in vitro. The effects of IL-9 KO on blood pressure and inflammatory response were significantly reduced by S31-201 treatment. Circulating IL-9 levels were significantly increased in patients with the hypertension group than in the control group, and elevated IL-9 levels positively correlated with both systolic blood pressure and diastolic blood pressure in patients with hypertension. Conclusions. IL-9 KO alleviates inflammatory response, prevents phenotypic transformation of smooth muscle, reduces vascular dysfunction, and lowers blood pressure via the STAT3 pathway in Ang II-infused mice. IL-9 might be a novel target for the treatment and prevention of clinical hypertension.

Multiple interleukin (IL) family members were reported to be closely related to hypertension. We aimed to investigate whether IL-9 affects angiotensin II- (Ang II-) induced hypertension in mice.Mice were treated with Ang II, and IL-9 expression was determined. In addition, effects of IL-9 knockout (KO) on blood pressure were observed in Ang II-infused mice. To determine whether the effects of IL-9 on blood pressure was mediated by the signal transducer and activator of the transcription 3 (STAT3) pathway, Ang II-treated mice were given S31-201. Furthermore, circulating IL-9 levels in patients with hypertension were measured.Ang II treatment increased serum and aortic IL-9 expression in a dose-dependent manner; IL-9 levels were the highest in the second week and continued to remain high into the fourth week after the treatment. IL-9 KO downregulated proinflammatory cytokine expression, whereas it upregulated anti-inflammatory cytokine levels, relieved vascular dysfunction, and decreased blood pressure in Ang II-infused mice. IL-9 also reduced smooth muscle 22IL-9 KO alleviates inflammatory response, prevents phenotypic transformation of smooth muscle, reduces vascular dysfunction, and lowers blood pressure via the STAT3 pathway in Ang II-infused mice. IL-9 might be a novel target for the treatment and prevention of clinical hypertension.

Carbon steel is one of the most important and widely used structural materials, but preventing its corrosion remains a great challenge. Herein, a metal–organic framework film consisting of Zif-8 nanosheets array was prepared using a one-step in situ growth method. This coating film can effectively inhibit the corrosion behavior of low carbon steel in seawater, resulting in improved corrosion resistance (4010 Ω·cm−2) and low corrosion current density (23 μA·cm−2). After long-term immersion in seawater, no notable pitting corrosion was observed and the film integrity was well preserved, demonstrating the feasibility of Zif-8 film for anti-corrosion coating.

The demand for lightweight vehicles that achieve energy conservation and emission reduction continues to grow. Aluminum alloys were commonly applied to the automotive industry to reduce the structural quality of the entire vehicle. However, the cost of aluminum alloy was higher than that of steel, so the industry considered the use of aluminum in combination with low-cost materials such as steel. Traditional welding technology was limited by the great physical difference between aluminum alloy and steel. Friction Stir Welding, a solid phase welding technology, can overcome the connection problem of aluminum and its alloys with steel, but the process parameters of FSW directly affect the welding quality. This paper established the FSW process of two different metals of DC05 and AL6061. Aimed to get a good welding joint, the error of tool speed is reduced by fuzzy PID system established in this paper, and the tool speed is controlled stably. Simulink simulation was established, and compared with the simulation results, fuzzy PID control can control the precision and stability of the tool speed of FSW, improve the welding quality, and provide a certain theoretical basis for the tool speed control.

Genistein (GEN), a typical isoflavone compound, exhibits desirable pharmacological activities, such as antioxidation, anti-inflammatory, , and anti-cancer properties. However, the pharmaceutical application of GEN is limited because of its poor water solubility in aqueous systems. In this study, cellulose nanocrystals (CNCs) and cetyltrimethylammonium bromide (CTAB)-coated CNCs were used as carriers for GEN to improve its dissolution rate and antioxidant activity in aqueous systems. The CNC/GEN and CNC/CTAB/GEN nanocomposites were successfully prepared and characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray diffraction analysis. The results showed that the nanonized GEN performed better and its crystalline structure decreased because of the formation of the CNC/GEN and CNC/CTAB/GEN nanocomposites. The GEN dissolution rates in the CNC/GEN and CNC/CTAB/GEN nanocomposites increased to 72.1% and 92.5% at 120 min, respectively, compared with that of the original GEN (0.85%). Furthermore, the in vitro antioxidant activity of the GEN, which was evaluated by the hydroxyl radical scavenging efficiency, was remarkably enhanced. Based on the above results, CNCs as nanocarriers are a useful method for improving the dissolution and antioxidant activities of GEN in aqueous system.

To better understand the properties of Mn-23Cu-6Ni alloy, its tribological behavior and wear mechanism were investigated under various conditions, including dry sliding, polyalphaolefin (PAO) lubrication, and PAO lubrication with molybdenum disulfide (MoS2) additive. The experimental results showed high friction and severe wear when exposed to dry sliding while the running-in process denoted contact under PAO lubrication. MoS2 nanosheets improved the friction reduction and anti-wear performance of PAO and suppressed the running-in process, rendering the sliding system stable from the beginning. The wear mechanism of the Mn-23Cu-6Ni alloy changed from adhesive wear in dry conditions to abrasive wear when exposed to PAO lubrication with MoS2 nanosheets.

Highly efficient and selective conversion of CO2 into a reusable form is desirable to the sustainable production of valuable chemicals out of greenhouse gases. Metal-based electrocatalysts often suffer from poor product selectivity for CO2 reduction, and the activity is always limited to a narrow potential range. In this study, the worm-like Au nanoparticles anchored to three-dimensional (3D) graphene foam were synthesized via a potential-cycling method, termed as Au/GF. It can high-efficient catalyze CO2 reduction to CO in aqueous 0.1 M KHCO3 at the potential range of −0.2 V to −0.7 V versus reversible hydrogen electrode (vs RHE). At −0.5 V vs RHE, the reduction Faradaic efficiency (FE) reaches 92% and stays at this level for 48 h without any noticeable decay. The work promotes a facile strategy for nano-Au electrode production toward efficient and selective CO2 reduction to CO.

Because the traditional paper medical record has the disadvantages of illegible handwriting and being difficult to save, we design the electronic medical record system for the university hospital. Additionally, the neural network model is used to realize auxiliary diagnosis and help doctors make decisions, which can provide effective reference for preventive health care, health education, and medical services in school hospitals. The system is putting into use in our university and has effectively improved the work efficiency of our school hospital.

The Biginelli reactions of salicylaldehyde and 2-hydroxy-l-naphthaldehyde with ethyl or methyl acetoacetate, ethyl benzoylacetate, and urea have been reinvestigated both in the structures of the reaction products and in the reaction conditions. Salicylaldehyde with ethyl and methyl acetoacetate resulted in oxygen-bridged tricyclic tetrahydro pyrimidines, whereas with ethyl benzoylacetate afforded the only normal 3,4-dihydropyrimidin-2-one. 2-Hydroxy-l-naphthaldehyde with ethyl and methyl acetoacetate formed the tricyclic compounds. Steric effect is likely to be the principal determinant in governing the formation of product dichotomy. Previous controversial results as to the structure of the Biginelli products have been discussed and settled. The molecular structures of the dihydropyrimidinones and bridged tricyclic products have been fully characterized and confirmed unambiguously by single crystal X-ray diffraction.

Microwave-assisted synthesis of 3,4-dihydropyrimidin-2-thiones via Biginelli reaction from aldehydes, acetoacetates, and thiourea in the presence of iodine under solvent-free conditions has been accomplished in good yields and purity without chromatographic separation.

Electrocatalysis on the degradation of methyl orange is investigated using Sb2O3-loaded activated carbon (Sb2O3/AC), a new particle electrode. The electrode was prepared by an impregnation method. An orthogonal array with four factors and three levels was selected to carry out the experiment. Electrocatalysis on the degradation of methyl orange through Sb2O3/AC was characterized by a series of parameters, including the amount of the particle electrode, the concentration of Na2SO4, the cell voltage, and the electrolysis time, and the results were compared with those of a conventional AC particle electrode. The results indicate that calcination temperature has the greatest impact on the catalytic activity of the particle electrode. The optimal conditions for preparing the Sb2O3/AC electrode include an 8 mL SbCl3 solution, 90 min hydrolysis time, 400 °C calcination temperature, and 180 min calcination time. As well, the degradation efficiency of the Sb2O3/AC electrode is consistently higher than that of the AC electrode under the same electrolysis conditions. The electrochemical oxidation of methyl orange of both electrodes conformed to pseudo first-order kinetics, but the rate constant of the Sb2O3/AC electrode was 2.29 times that of the AC electrode; this is likely due to the high electrocatalytic activity of the experimental electrode. The electrocatalysis results exhibited the synergetic effects of AC and Sb2O3 in the new particle electrode.

Motivated by the excellent performance of three-axis NURBS interpolation, this paper presents a numerically efficient and accuracy controllable five-axis sculptured surface machining method with dual NURBS curve. Unlike the traditional three-axis NURBS interpolation, a dual NURBS format of the five-axis toolpath is developed to accurately and smoothly describe the tool movement in the part coordinate system. Different from the subdivision methods using the Taylor series expansion or inverse function, a piece-wise Bezier curve method is implemented to fast subdivide the NURBS curve within the user-defined tolerance. A generic rotation tool center point management module is also designed to realize the coordinate transformation and adaptive nonlinear error control for major five-axis machine tools. The overall effectiveness of the proposed five-axis NURBS machining scheme is demonstrated by the five-axis machining of an impeller’s flow channel.

In this study, enantioselective Biginelli reaction of aldehyde, β-ketoester, and urea catalyzed by natural (2R, 3R)-tartaric acid has been investigated using density functional theory calculations. The results indicate that the most favorable pathway involves a protonated imine from aldehyde and urea in the first step. Tartaric acid forms H-bonds network with substrates enhancing the electrophilicity of protonated imine and the nucleophilicity of β-ketoester. (R)-3,4-Dihydropyrimidin-2-(1H)-ones is preferable for the reaction. The solvent effect is discussed in the prediction of enantiomeric excess (ee) values in ethanol and water. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011

To reconfigure computer numerical control (CNC) system, the authors divide the reconfiguration technology of CNC system into three interactive levels: hardware system reconfiguration, software system reconfiguration, and module reconfiguration. On the software–hardware platform of CNC system designed in this study, hardware system reconfiguration is based on a rapid field programming of Field-Programmable Gate Array (FPGA) and performed with different FPGA configuration files. Meanwhile, software system reconfiguration is conducted through design, modification, selection, and configuration of different databases on a guiding software reconfiguration development platform. For modular reconfiguration, PROFIBUS-DP industry field-bus is involved as the communication media among function modules of CNC system, to facilitate the increase and decrease of modules. Finally, an application case of aforementioned reconfiguration methods is given. A CNC system with five synchronously moveable axes in total eight stepping axes is reconfigured successfully from the existing CNC system with three synchronously moveable axes in four ones.

An easy-to-prepare chemosensor, 2-(4-formylphenyl)phenanthroimidazole 1, synthesized by facile one-step condensation under microwave irradiation, has been indicated to be a colorimetric and fluorometric probe for fluoride anion with good sensitivity and high selectivity. This probe shows obvious red shift and absorbance intensity changes in UV absorption and fluorescence spectra in the presence of fluoride anions. Such color and absorbance intensity changes are attributed to the deprotonation of N-H on the imidazole moiety with fluoride anion.

The part’s precision-machined quality of NC machining is influenced by the chord error greatly during precision machining. The confined chord error Algorithm for Machining Complex Parametric Curve is proposed for the complexity of the chord error. The information of the arc length error is utilized to control the chord error of the interpolated point indirectly. The arc length error of interpolated point is computed by Simpson expressions, the information of coordinate and the first order derivative of interpolated point is computed by the interpolation algorithm, so the computed difficulty is not increased greatly. The computed error of the algorithm is discussed and the simulation example of NURBS curve proves that the destined precision of the chord error can be satisfied by this algorithm.

A facile synthesis of Hantzsch 1,4-dihydropyridines with unsymmetrical 2,6- and 3,5-substituents in a one-pot two-step tandem reaction under solvent-free conditions, promoted by microwave irradiati...

4-Methyl-2-phenylbenzo[de]cyclobut[i]isoquinoline-3,5(2H)-dione, C21H15NO2, resulted from the photochemical reaction of N-methyl-1,8-naphthalenedicarboximide with phenylacetylene, has been characterized by 1H NMR, IR, and MS spectra and established by single-crystal X-ray crystallography. The crystal structure belongs to the monoclinic space group P21/n with cell parameters a = 12.530(2) A, b = 9.324(2) A, c = 13.296(2) A, β = 96.85(1)○, V = 1542.3(4) A3, and Z = 4.

The presented variation of the classical Hantzsch synthesis constitutes a facile one-pot two step procedure.

41 Title compounds are prepared by a iodine-catalyzed Biginelli reaction under microwave irradiation.

The characteristics of real time operating system (RTOS) are analyzed and its advantages in design of embedded computer numerical control system (CNC system) are highlighted, according to comparisons with general operating systems. In this study, RTOS μC/OS - II is introduced in the embedded hardware platform of CNC system based on ARM and Motion Control Chip. Furthermore, the software architecture of the CNC system is constructed and tasks of CNC system are given the PRI and task schedule is analyzed. Lastly, an application example is given.

Architecture of distributed numerical control (NC) system based on field-bus is discussed in the paper for solving the problems in robustness and openness coming from the current integration-design method of NC system. The basic framework of system, nodding model, expanding structure are proposed in this paper, followed by a case study, so to explore solutions to improve functions and openness of complex NC systems.

A Fe-catalytic highly selective ring expansion reaction of alkynylcyclopropyl alkanols to alkynylcyclobutanols via a 1,2-carbon shift under mild conditions was developed. A new class of homogeneous FeCl2/O2 catalytic system was employed in these novel transformations.

The reconfigurable hardware has been widely applied in Computer Numerically Controlled (CNC) systems. The reconfigurable hardware provides high performance and flexibilities for the designer. This work presented a novel CNC controller architecture using reconfigurable hardware. Several logic modules, including a new resampling module for threading, are designed to support the reconfiguration process. By employing different type of logic modules, the hardware logic of the controller can be changed to control various targets. An experimental system was built, and applied to a milling machine and a lathe machine to valid the proposed architecture.

Dimethyl 1,4-dihydro-2,6-dimethyl-1-(4-methylphenyl)-4-(4-methoxylphenyl)–pyridine-3,5-dicarboxylate has been synthesized via Hantzsch condensation reaction of p-methoxybenzaldehyde, methyl acetoacetate and p-toluidine promoted by microwave irradiation (MWI) in the presence of iodine under solvent-free conditions.

Methyl 6-methyl-4-(4-iodophenyl)-1,2,3,4-tetrahydro-2-thioxo-5-pyrimidinecarboxylate has been synthesized via Biginelli reaction of 4-iodobenzaldehyde, methyl acetoacetate and thiourea, promoted by microwave irradiation in the presence of iodine under solvent-free conditions in high yield and good purity.

This paper presents the methods on the structure reliability design of embedded computer numerically controlled (CNC) system. An effective reliability model is developed and tested in a real-time CNC system. The evaluation method for the importance of the reliability of each function module of CNC systems is also investigated. Fuzzy mathematics is used to judge the importance of module reliability design. Cases studies have been performed to validate and illustrate all the analysis.

Irradiation of N-methyl-1,2-naphthalendicarboximide 1 together with phenylacetylene in benzene afforded unprecedented reductive insertion products dihydronaphthazepinediones 2a and 2b, which were characterised by NMR spectroscopy ( 1 H, 13 C), IR spectroscopy, MS, elemental analysis and assignments confirmed by X-ray crystallographic analysis.

The title compound, C18H19NO5, is a product of the Hantzsch reaction of p-phthalaldehyde, methyl acetoacetate, and ammonium acetate. The 1,4-dihydropyridine ring of the molecule adopts a flattened boat conformation. The benzene ring is almost perpendicular to the 1,4-dihydropyridine ring; the plane through the six C atoms of the benzene ring and the plane through the four C atoms that form the base of the boat-shaped 1,4-dihydropyridine ring (excluding the ring N atom and the opposite ring C atom) make a dihedral angle of 87.60 (3)°. Intermolecular N—H...O hydrogen bonds result in the formation of extended chains along the a axis.

In the title compound, C(16)H(12)N(2)S(4), which is the result of the S-alkylation reaction of 2-mercaptobenzothiazole with ethylene dibromide, the planes of the two benzothiazole moieties form a dihedral angle of 3.84 (14) degrees. The bridging chain moiety, -SCH(2)CH(2)S-, adopts an antiperiplanar conformation. There are intermolecular S.S non-bonded contacts of 3.6471 (9) A, which stabilize the crystal packing.

In the title compound, C(21)H(15)NO(3), which is one of the photoreaction products of N-methyl-1,8-naphthalenedicarboximide with phenylacetylene, the cyclobutene and epoxy rings are trans to each other across the cyclohexene ring of the tetralin moiety. The dihedral angle between the mean planes of the cyclobutene and cyclohexene rings is 112.80 (2) degrees, while the latter makes a dihedral angle of 103.70 (9) degrees with the epoxy ring. The crystal structure is stabilized by C-H...O intermolecular interactions.

Irradiation of N-methyl-1,2-naphthalendicarboximide 1 together with phenylacetylene in benzene afforded unprecedented reductive insertion products dihydronaphthazepinediones 2a and 2b, which were characterised by NMR spectroscopy (1H, 13C), IR spectroscopy, MS, elemental analysis and assignments confirmed by X-ray crystallographic analysis.