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Number of results: 42
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Abstract

In the current study, twenty lambs, aged 4 months, half male and half female, were classified into four groups, with five in each group. The experimental three groups of lambs were given intravenous (IV), intramuscular (IM) and subcutaneous (SC) administrations of recombinant ovine interferon-τ (roIFN-τ). The fourth group (normal control) of lambs was given normal saline injections in the same way. After administrations, blood samples were collected from the tested animals at different time points post injection, and the serum titers of roIFN-τ were measured using cytopathic effect (CPE) inhibition bioassay. The results of calculating pharmacokinetic (PK) parameters using DAS software showed that the PK characteristics of roIFN-τ through IV injection conformed to the two-compartment open model, whose half-life of distribution phases (T1/2α) was 0.33±0.034 h and the elimination half-life(T1/2β) was 5.01±0.24 h. However, the PK features of IM injection and SC injection of roIFN-τ conformed to the one compartment open model, whose Tmax were 3.11±0.26 h and 4.83±0.43 h, respectively, together with an elimination half life(T1/2β) of 9.11±0.76 h and 7. 43±0.58 h, and an absorption half-life (T1/2k(a)) of 1.13±0.31 h and 1.85±0.40 h, respectively. The bioavailability of roIFN-τ after IM administration reaches 73.57%, which is greater than that of SC administration (53.43%). These results indicate that the drug administration effect can be preferably obtained following a single dose IM administration of the roIFN-τ aqueous preparation. This study will facilitate the clinical application of roIFN-τ as a potential antiviral agent in future work.

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Authors and Affiliations

J. Zhao
H.Y. Yu
Y. Zhao
S.Q. Li
X.L. Fu
W. Zhou
B.B. Xia
M.L. Wang
J. Chen
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Abstract

Three-dimensional (3D) finite element analyses (FEA) are performed to simulate the local compression (LC) technique on the clamped single-edge notched tension (SE(T)) specimens. The analysis includes three types of indenters, which are single pair of cylinder indenters (SPCI), double pairs of cylinder indenters (DPCI) and single pair of ring indenters (SPRI). The distribution of the residual stress in the crack opening direction in the uncracked ligament of the specimen is evaluated. The outcome of this study can facilitate the use of LC technique on SE(T) specimens.

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Authors and Affiliations

Yifan Huang
Wenxing Zhou
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Abstract

Applying pesticides to crops is one of the causes of water pollution by surface runoff, and chlorpyrifos, trifluralin and chlorothalonil are used respectively as insecticide, herbicide and fungicide for crop plants widely. To explore effects of three pesticides on aquatic organisms, superoxide dismutase (SOD) and glutathione S-transferase (GST) activities were determined after 24 h and 48 h exposure of D. magna with ages of 6–24 h to several low concentrations of chlorpyrifos (0.36, 0.72, 1.43, 2.86, 5.72 μg∙L−1), trifluralin (0.17, 0.33, 0.66, 1.33, 2.65 mg∙L−1) and chlorothalonil (0.09, 0.18, 0.36, 0.72, 1.43 mg∙L−1) respectively. Main reproductive parameters including first pregnancy time, first brood time, the number of first brood and total fecundity after 21 d exposures at the same concentrations of pesticides as described above were also measured. The results showed that the activities of GST increased in lower concentrations and decreased in higher concentrations after 24 h exposure to three pesticides, respectively. The activities of SOD showed the same changes after 48 h exposure. With the time prolonged, the activities of GST decreased while the activities of SOD increased. After 21 d exposure, the first pregnancy time and first brood time were delayed, while the number of the first brood and total fecundity per female decreased with increasing concentrations. These results corroborated that GST activity was more sensitive to those pesticides than SOD activity, and there was a significant relationship between total fecundity and pesticides-dose(r>0.94, n=6), GST activity after 48 h exposure and total fecundity after 21 d exposure (r>0.92, n=6).

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Authors and Affiliations

Yuzhi Song
Mindong Chen
Junying Zhou
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Abstract

Eutectoid growth, as the important reaction mechanism of the carbon steel heat treatment, is the basis to control the microstructure and

performance. At present, most studies have focused on lamellar growth, and did not consider the nucleation process. Mainly due to the

nucleation theory is inconclusive, a lot of research can support their own theory in a certain range. Based on the existing nucleation theory,

this paper proposes a cooperative nucleation model to simulate the nucleation process of eutectoid growth. In order to ensure that the

nucleation process is more suitable to the theoretical results, different correction methods were used to amend the model respectively. The

results of numerical simulation show that when the model is unmodified, the lateral growth of single phase is faster than that of

longitudinal growth, so the morphology is oval. Then, the effects of diffusion correction, mobility correction and ledges nucleation

mechanism correction on the morphology of nucleation and the nucleation rate were studied respectively. It was found that the

introduction of boundary diffusion and the nucleation mechanism of the ledges could lead to a more realistic pearlite.

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Authors and Affiliations

Dongqiao Zhang
Yajun Yin
Jianxin Zhou
Zhixin Tu
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Abstract

The accuracy and reliability of Kalman filter are easily affected by the gross errors in observations. Although robust Kalman filter based on equivalent weight function models can reduce the impact of gross errors on filtering results, the conventional equivalent weight function models are more suitable for the observations with the same noise level. For Precise Point Positioning (PPP) with multiple types of observations that have different measuring accuracy and noise levels, the filtering results obtained with conventional robust equivalent weight function models are not the best ones. For this problem, a classification robust equivalent weight function model based on the t-inspection statistics is proposed, which has better performance than the conventional equivalent weight function models in the case of no more than one gross error in a certain type of observations. However, in the case of multiple gross errors in a certain type of observations, the performance of the conventional robust Kalman filter based on the two kinds of equivalent weight function models are barely satisfactory due to the interaction between gross errors. To address this problem, an improved classification robust Kalman filtering method is further proposed in this paper. To verify and evaluate the performance of the proposed method, simulation tests were carried out based on the GPS/BDS data and their results were compared with those obtained with the conventional robust Kalman filtering method. The results show that the improved classification robust Kalman filtering method can effectively reduce the impact of multiple gross errors on the positioning results and significantly improve the positioning accuracy and reliability of PPP.

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Authors and Affiliations

Qieqie Zhang
Long Zhao
Jianhua Zhou
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Abstract

The authors studied the fracture mechanical properties under half-symmetric loading in this paper. The stress distribution around the crack tip and the stress intensity factor of three kinds of notched specimens under half symmetric loading were compared. The maximum tensile stress σmax of double notch specimens was much greater than that of single notch specimens and the maximum shear stress τmax was almost equal, which means that the single notch specimens were more prone to Mode II fractures. The intensity factors KII of central notch specimens were very small compared with other specimens and they induced Mode I fractures. For both double notch and single notch specimens, KII was kept at a constant level and did not change with the change of a/h, and KII was much larger than KI. KII has the potential to reach its fracture toughness KIIC before KI and Mode II fractures occurred. Rock-like materials were introduced to produce single notch specimens. Test results show that the crack had been initiated at the crack tip and propagated along the original notch face, and a Mode II fracture occurred. There was no relationship between the peak load and the original notch length. The average value of KIIC was about 0.602 MPa×m1/2, and KIIC was about 3.8 times KIC. The half symmetric loading test of single notch specimens was one of the most effective methods to obtain a true Mode II fracture and determine Mode fracture toughness.

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Authors and Affiliations

Zhi Wang
Jiajia Zhou
Long Li
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Abstract

Real-time monitoring of deformation of large structure parts is of great significance and the deformation

of such structure parts is often accompanied with the change of curvature. The curvature can be obtained

by measuring changes of strain, surface curve and modal displacement of the structure. However, many

factors are faced with difficulty in measurement and low sensitivity at a small deformation level. In order

to measure curvature in an effective way, a novel fibre Bragg grating (FBG) curvature sensor is proposed,

which aims at removing the deficiencies of traditional methods in low precision and narrow adjusting. The

sensor combines two FBGs with a specific structure of stainless steel elastomer. The elastomer can transfer

the strain of the structure part to the FBG and then the FBG measures the strain to obtain the curvature.

The performed simulation and experiment show that the sensor can effectively amplify the strain to the

FBG through the unique structure of the elastomer, and the accuracy of the sensor used in the experiment is

increased by 14% compared with that of the FBG used for direct measurement.

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Authors and Affiliations

Ming-Yao Liu
Shi-Guang Zhou
Han Song
Wei-Jian Zhou
Xiong Zhang
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Abstract

In this paper, the deviation from eutectic composition in boundary layer for eutectic growth is studied by phase-field method. According to a series of artificial phase diagram, the lamellar eutectic growth of these alloy is simulated during directional solidification. At steady state, average growth velocity of eutectic lamella is equal to the pulling velocity. With the increasing of the liquidus slope of β phase, the average composition in boundary layer would deviate from eutectic composition and the deviation increases. The constitutional undercooling difference between both solid phases caused by the deviation increases with the increasing of the deviation. The β phase would develop a depression under the influence of the deviation.

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Authors and Affiliations

Zhixin Tu
Jianxin Zhou
Yajun Yin
Xiaoyuan Ji
Xu Shen
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Abstract

A new soft-fault diagnosis approach for analog circuits with parameter tolerance is proposed in this paper. The approach uses the fuzzy nonlinear programming (FNLP) concept to diagnose an analog circuit under test quantitatively. Node-voltage incremental equations, as constraints of FNLP equation, are built based on the sensitivity analysis. Through evaluating the parameters deviations from the solution of the FNLP equation, it enables us to state whether the actual parameters are within tolerance ranges or some components are faulty. Examples illustrate the proposed approach and show its effectiveness.

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Authors and Affiliations

Wei Zhang
Longfu Zhou
Yibing Shi
Chengti Huang
Yanjun Li
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Abstract

The main work of this paper focuses on the simulation of binary alloy solidification using the phase field model and adaptive octree grids.

Ni-Cu binary alloy is used as an example in this paper to do research on the numerical simulation of isothermal solidification of binary

alloy. Firstly, the WBM model, numerical issues and adaptive octree grids have been explained. Secondary, the numerical simulation

results of three dimensional morphology of the equiaxed grain and concentration variations are given, taking the efficiency advantage of

the adaptive octree grids. The microsegregation of binary alloy has been analysed emphatically. Then, numerical simulation results of the

influence of thermo-physical parameters on the growth of the equiaxed grain are also given. At last, a simulation experiment of large scale

and long-time has been carried out. It is found that increases of initial temperature and initial concentration will make grain grow along

certain directions and adaptive octree grids can effectively be used in simulations of microstructure.

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Authors and Affiliations

Y. Yin
Y. Li
K. Wu
J. Zhou
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Abstract

The field of mechanical manufacturing is becoming more and more demanding on machining accuracy. It is essential to monitor and compensate the deformation of structural parts of a heavy-duty machine tool. The deformation of the base of a heavy-duty machine tool is an important factor that affects machining accuracy. The base is statically indeterminate and complex in load. It is difficult to reconstruct deformation by traditional methods. A reconstruction algorithm for determining bending deformation of the base of a heavy-duty machine tool using inverse Finite Element Method (iFEM) is presented. The base is equivalent to a multi-span beam which is divided into beam elements with support points as nodes. The deflection polynomial order of each element is analysed. According to the boundary conditions, the deformation compatibility conditions and the strain data measured by Fiber Bragg Grating (FBG), the deflection polynomial coefficients of a beam element are determined. Using the coordinate transformation, the deflection equation of the base is obtained. Both numerical verification and experiment were carried out. The deflection obtained by the reconstruction algorithm using iFEM and the actual deflection measured by laser displacement sensors were compared. The accuracy of the reconstruction algorithm is verified.

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Authors and Affiliations

Mingyao Liu
Xiong Zhang
Han Song
Jingliang Wang
Shiguang Zhou
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Abstract

In the external target experiment for heavy ion collisions in the HIRFL-CSR, Multi-Wire Drift Chambers are used to measure the drift time of charged particles to obtain the track information. This 128-channel high precision time measurement module is designed to perform the time digitization. The data transfer is based on a PXI interface to guarantee a high data rate. Test results show that a 100 ps resolution with a data transfer rate up to 40 MBps has been achieved; this module has also been proven to function well with the detector through a commissioning test.

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Authors and Affiliations

Longfei Kang
Lei Zhao
Jiawen Zhou
Qi An
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Abstract

Accurate flatness measurement of silicon wafers is affected greatly by the gravity-induced deflection (GID) of the wafers, especially for large and thin wafers. The three-point-support method is a preferred method for the measurement, in which the GID uniquely determined by the positions of the supports could be calculated and subtracted. The accurate calculation of GID is affected by the initial stress of the wafer and the positioning errors of the supports. In this paper, a finite element model (FEM) including the effect of initial stress was developed to calculate GID. The influence of the initial stress of the wafer on GID calculation was investigated and verified by experiment. A systematic study of the effects of positioning errors of the support ball and the wafer on GID calculation was conducted. The results showed that the effect of the initial stress could not be neglected for ground wafers. The wafer positioning error and the circumferential error of the support were the most influential factors while the effect of the vertical positioning error was negligible in GID calculation.
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Authors and Affiliations

Haijun Liu
Zhigang Dong
Renke Kang
Ping Zhou
Shang Gao
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Abstract

Lichens, as typical obligate associations between lichenized fungi and their photosynthetic partners, are dominant in Antarctica. Three Antarctic lichens, Ochrolechia frigida , Umbilicaria antarctica , and Usnea aurantiaco−atra with different growth forms, were sampled nearby the Great Wall Station, King George Island. Molecular data revealed that the photosynthetic algae in these three lichens were Trebouxia jamesii . The net photo − synthesis (Pn) of three individuals from these species, together with environmental factors such as light and temperature, were recorded by CO 2 gas exchange measurements using a CI−340 portable photosynthetic system in situ . Differences between T(leaf) (the temperature of the thalli) and T(air) (the air temperature) for these lichens were not consistent, which reflected that environment and the growth form of thalli could affect T(leaf) significantly. Strong irradiation was expected to have adverse effects on Pn of Ochrolechia frigida and Umbilicaria antarctica whose thalli spread flat; but this photoinhibition had little effect on Usnea aurantiaco−atra with exuberant tufted thallus. These results indicated that photo − synthetic activity in lichens was affected by the growth forms of thalli besides microhabitat factors. One species of lichenized alga could exhibit diversified types of photosynthetic behavior when it was associated with various lichenized fungi in different microhabitats. It will be helpful for understanding how lichens are able to adapt to and colonize in extreme environments.
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Authors and Affiliations

Shunan Cao
Jie Zhang
Hongyuan Zheng
Chuanpeng Liu
Qiming Zhou
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Abstract

The technology for gob-side entry retaining in steep coal seams is still in the development stage. The

analysis results of the caving structure of main roof, low influence of gateway’s stability because of long

filling distance and weak dynamic effect of the gateway, and the low stress redistribution environment

indicate that using this technology in steep coal seams has significant advantages. Moreover, to reinforce

the waste rock and the soft floor and to better guard against the impact of the waste rock during natural

filling, a rock blocking device and grouting reinforcement method were invented, and theoretical calculations

result show that the blocking device has high safety factor. In addition, we also developed a set of

hydraulic support devices for use in the strengthening support zone. Furthermore, because the retaining

gateway was a systematic project, the selection of the size and shape of the gateway cross section and its

support method during the initial driving stage is a key step. Thus, first, a section the size of bottom width

and roof height of a new gateway was determined to meet any related requirements. Then, according

to the cross sections of 75 statistical gateways and the support technique, it chosen a trapezoidal cross

section when the dip of the coal seam is 35° < α ≤ 45°, a special and an inclined arch cross section when

45° < α ≤ 55°. Eventually, a support system of bolts and cables combined with steel mesh and steel belts

was provided. The support system used optimized material and improved parameters, can enhanced the

self-bearing ability of the surrounding coal and rock masses.

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Authors and Affiliations

Hongyun Yang
Shugang Cao
Guisong Zhou
Yuan Zhao
Guodong Li
Yong Li
Yingchong Fan

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