A high speed column-parallel CDS/ADC circuit with nonlinearity compensation is proposed in this paper. The correlated double sampling (CDS) and analog-to-digital converter (ADC) functions are integrated in a three-phase column-parallel circuit based on two floating gate inverters and switched-capacitor network. The conversion rate of traditional single-slope ADC is speeded up by dividing quantization to coarse step and fine step. A storage capacitor is used to store the result of coarse step and locate the section of ramp signal of fine step, which can reduce the clock step from 2 ⁿ to 2^(n/2+1). The floating gate inverters are implemented to reduce the power consumption. Its induced nonlinear offset is cancelled by introducing a compensation module to the input of inverter, which can equalize the coupling path in three phases of the proposed circuit. This circuit is designed and simulated for CMOS image sensor with 640×480 pixel array using Chartered 0.18 μm process. Simulation results indicate that the resolution can reach 10-bit and the maximum frame rate can reach 200 frames/s with a main clock of 10 MHz. The power consumption of this circuit is less than 36.5 μW with a 3.3 V power supply. The proposed CDS/ADC circuit is suitable for high resolution and high speed image sensors.

In this paper, the explicit estimates of central moments for one kind of exponential-type operators are derived. The estimates play an essential role in studying the explicit approximation properties of this family of operators. Using the proposed method, the results of Ditzian and Totik in 1987, Guo and Qi in 2007, and Mahmudov in 2010 can be improved respectively.

As a basic mathematical structure, the system of inequalities over symmetric cones and its solution can provide an effective method for solving the startup problem of interior point method which is used to solve many optimization problems. In this paper, a non-interior continuation algorithm is proposed for solving the system of inequalities under the order induced by a symmetric cone. It is shown that the proposed algorithm is globally convergent and well-defined. Moreover, it can start from any point and only needs to solve one system of linear equations at most at each iteration. Under suitable assumptions, global linear and local quadratic convergence is established with Euclidean Jordan algebras. Numerical results indicate that the algorithm is efficient. The systems of random linear inequalities were tested over the second-order cones with sizes of 10,100, ...,1 000 respectively and the problems of each size were generated randomly for 10 times. The average iterative numbers show that the proposed algorithm can generate a solution at one step for solving the given linear class of problems with random initializations. It seems possible that the continuation algorithm can solve larger scale systems of linear inequalities over the second-order cones quickly. Moreover, a system of nonlinear inequalities was also tested over Cartesian product of two simple second-order cones, and numerical results indicate that the proposed algorithm can deal with the nonlinear cases.

The trajectory model of dispersed phase drops and distribution model of drop diameters were derived. By numerical simulation, the analytical results indicate that a large number of dispersed phase drops accumulate on the upper plate in different directions and form a hydrodynamic area with the stream-wise location in the range of 0–0.4 m, where the flow of trickling film obtains kinetic drive from flowing field. The flowing field of trickling film exhibits an unstable state if the stream-wise location is less than 0.02 m, and a stable state otherwise. Moreover, different velocity vectors of drops in the x-y plane result in different interactions between the trickling film and drops. For the non-uniform distribution of drop diameters, there is a stronger interaction between the trickling film and drop if the stream-wise location is less than 0.02 m, because the amplitudes of velocity vectors are higher than those in the range of 0.02–1.0 m. The result reveals a complexity and diversity of stratified two-phase flowing field. On the other hand, both the basic flowing field and distributions of drop diameters have a great influence on the distributions of comparable kinetic energy of drops. The complicated motions of larger drops are helpful to coalescence because they will consume much more kinetic energy on the trickling film than those of smaller drops. The change of comparable kinetic energy of smaller drops is continuous and steady. The smaller drops are easily entrained by the liquid-liquid flowing field.

To investigate the feasibility and effectiveness of the designed control system used for driving and steering of an electric scooter, a model of differential steering was developed. The function of electronic differential steering was realized by controlling the speed of right or left wheel and the corresponding speed difference. The control system was simulated with MATLAB/SIMULINK and ADAMS. It is found that the motor load torque is proportional to the tire vertical force, so the adhesive capacity is met. The electric scooter can operate stably on the slope road at a speed of more than 1.5 m/s and turn stably at yawing velocities of 10° and 90° per second.

N-valeronitrile-N′-methylimidazolium hexafluorophosphate ([C₄CNmim]⁺PF₆ ⁻), as a novel ionic liquid with polar nitrile functional group, was prepared. The structure of the ionic liquid was characterized by using IR and ¹H NMR. As a medium, the ionic liquid plays an important role in copolymerization of carbon monoxide (CO) with styrene (St). Some synthetic conditions were determined, including the usage of ionic liquid, palladium composite catalyst and methanol, CO pressure, reaction time and reaction temperature. The influence of these factors on catalytic activity was analyzed. The results show that the catalytic activity has reached 1 724.1 gStCO/(gPd·h) and the catalyst could be reused 5 times under the optimal condition: composite catalyst 0.015 mmol, ionic liquid 3 mL, methanol 0.75 mL, CO pressure 2 MPa, reaction time 2 h and reaction temperature 70 °C. This CO/St copolymerization within [C₄CNmim]⁺PF₆ ⁻ system could facilitate ionic liquids with efficient and economical applications to polymeric materials.

Type I, III and V collagens were extracted from bovine dermis and cornea by using pepsin treatment in acetic acid solution, followed by salt precipitation and dialysis, to purify and isolate each type of collagens. The preparation process was analyzed by using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). A reducing agent, 2-mercaptoethanol, was used to remove disulfide bonds and analyze the structure of the bonds involved between α chains in some types of collagens. The use of delayed reducing methods resulted in the difference between α1(III) and α 1(I) chains in a mixture containing type I and III collagens. The structure of disulfide bonds among α chains exists potentially in type V collagen prepared from the pepsin-treatment extraction at 4 °C, which differs from type III collagen in relation to the locations of disulfide bonds. Compared with pepsin-treated collagen at 4 °C, the relative molecular weights of α1(V) and α2(V) chains treated at room temperature decrease by 4.6% and 6.0%, respectively. It is concluded that type I, III and V collagens can be prepared from bovine dermis and cornea by the use of pepsin treatment, salt precipitation and dialysis. The interchain disulfide bonds lie potentially near the edges of termini of type V collagen molecules in extracellular matrix, and a small number of interchain crosslinks exist in type V collagen.

As a raw material, kaolin was modified to prepare a high-performance ammonium ion-exchange material. According to cation-exchange capacity (CEC) measurement, the prepared ammonium ion-exchange material has an ammonium ion-exchange capacity greater than 75 mg /g and can be used to remove ammonia nitrogen in water treatment. A pharmaceutical extruder-rounder was used to study the effects of granulation process. Polyethylene glycol-6000 (PEG-6000) was used as the pore-forming agent and calcining temperature of 650 °C was used as the optimal condition. NMR data indicate that ²⁷Al is mainly converted from hexa-coordinated Al to tetra-coordinated Al during the modification. Compared with ²⁹Si in the original kaolin, ²⁹Si in the modified kaolin does not have an obvious change. A comparison of the data with Langmuir and Freundlich isotherm models shows a good correlation. The Freundlich model describes the process more accurately, and the adsorption process of ammonia nitrogen in water with the ammonium ion-exchange material closely matches the pseudo-second-order reaction.

The behaviors of infill wall in earthquakes show that infill masonry walls, which are used as nonstructural elements of concrete frames, are vulnerable when they are subjected to earthquake. In order to achieve an optimal anti-seismic behavior, or even stability, two methods of connection are investigated. The shaking table tests, with 1:3 scale walls of two-storey model subjected to horizontal earthquake loads, were carried out to investigate the out-of-plane behaviors with different connections between walls and beams. The test results show that the connection methods employed between walls and beams have a significant effect on the out-of-plane stability of infill walls. The walls bound by bars with the beams perform better than those with inclined bricks without gaps.

Based on mechanical characteristics such as large vertical load, large horizontal load, large bending moment and complex geological conditions, a large scale composite bucket foundation (CBF) is put forward. Both the theoretical analysis and numerical simulation are employed to study the bearing capacity of CBF and the relationship between loads and ground deformation. Furthermore, monopile, high-rise pile cap, tripod and CBF designs are compared to analyze the bearing capacity and ground deformation, with a 3-MW wind generator as an example. The results indicate that CBF can effectively bear horizontal load and large bending moment resulting from upper structures and environmental load.

In this paper, a theoretical solution of vertical buckling is proposed with regard to the typical initial imperfection cases of submarine pipelines. Analytical tools are applied to predicting the occurrence and consequence of inservice buckling of a buried heated pipeline in Bohai Gulf. An evaluation is performed to ensure the pipeline structural integrity during operation under loading conditions. Different protection measures are proposed and their validities are analyzed. Analyses show that for the same magnitude of initial imperfection, the upheaval buckling of pipeline with isolated prop model is the most likely to occur. The empathetic model represents a special sub-case of continuous prop model, and the calculated buckle temperature is between the first stage and the second stage of post-upheaval buckling of continuous prop model. And the larger the initial imperfection, the less the axial force required for the upheaval buckling. Meanwhile, it can be seen that a peak point appears on the curves of temperature difference against buckling amplitude for small initial imperfection. Besides, trenching-burial is one kind of protection measures preventing the pipeline from thermal upheaval. The covered depth-to-diameter ratio depends on the design conditions and subsoil properties. For the given pipeline in this paper, the covered depth-to-diameter ratio is recommended to be 5.

This paper investigates the scaled prediction variances in the errors-in-variables model and compares the performance with those in classic model of response surface designs for three factors. The ordinary least squares estimators of regression coefficients are derived from a second-order response surface model with errors in variables. Three performance criteria are proposed. The first is the difference between the empirical mean of maximum value of scaled prediction variance with errors and the maximum value of scaled prediction variance without errors. The second is the mean squared deviation from the mean of simulated maximum scaled prediction variance with errors. The last performance measure is the mean squared scaled prediction variance change with and without errors. In the simulations, 1 000 random samples were performed following three factors with 20 experimental runs for central composite designs and 15 for Box-Behnken design. The independent variables are coded variables in these designs. Comparative results show that for the low level errors in variables, central composite face-centered design is optimal; otherwise, Box-Behnken design has a relatively better performance.

In this paper, the control of complex delayed networks with different nodes is proposed. Firstly, the stabilization of coupled networks with time delay is investigated. By constructing a Lyapunov function, a linear feedback controller design procedure for the networks is converted to the problem of solving a set of linear matrix inequalities. Then the results are extended to networks with both delayed dynamical nodes and delayed couplings. It is shown that the stabilization of complex networks is determined by the dynamics of each uncoupled node, coupling matrix and feedback gain matrix of networks. Two examples are simulated. In the first example, a network with 10 nodes consisting of Lorenz systems and systems proposed by Zhang in 2009 is given. It is found that the network states are divergent without control, and convergent under designed linear feedback controllers. In the second example, a larger network with 100 nodes consisting of delayed Chen systems and delayed Lorenz systems is given. The proposed method is also effective for large scale networks.