期刊文献+
共找到47篇文章
< 1 2 3 >
每页显示 20 50 100
Differential game strategy in three-player evasion and pursuit scenarios 被引量:10
1
作者 SUN Qilong QI Naiming +1 位作者 XIAO Longxu LIN Haiqi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第2期352-366,共15页
A conflict of three players, including an attacker, a defender, and a target with bounded control is discussed based on the differential game theories in which the target and the defender use an optimal pursuit strate... A conflict of three players, including an attacker, a defender, and a target with bounded control is discussed based on the differential game theories in which the target and the defender use an optimal pursuit strategy. The current approach chooses the miss distance as the outcome of the conflict. Different optimal guidance laws are investigated, and feasible conditions are analyzed for the attacker to accomplish an attacking task. For some given conditions, the attacker cannot intercept the target by only using a one-to-one optimal pursuit guidance law; thus, a guidance law for the attacker to reach a critical safe value is investigated.Specifically, the guidance law is divided into two parts. Before the engagement time between the defender and the attacker, the attacker uses this derived guidance law to guarantee that the evasion distance from the defender is safe, and that the zero-effort-miss(ZEM) distance between the attacker and the target is the smallest.After that engagement time, the attacker uses the optimal one-toone guidance law to accomplish the pursuit task. The advantages and limited conditions of these derived guidance laws are also investigated by using nonlinear simulations. 展开更多
关键词 three players differential game theory zero-effort-miss(ZEM) distance guidance law
下载PDF
Physiochemical and Biological Properties of Modified Collagen Sponge from Porcine Skin 被引量:7
2
作者 许媛媛 武继民 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2009年第4期619-626,共8页
The aim of the present study was to compare one-step method to EDC/NHS crosslinking (EDC/NHS group) and one-step simultaneous method to EDC/NHS crosslinking and heparin immobilization (EDC/NHS- Heparin group) in i... The aim of the present study was to compare one-step method to EDC/NHS crosslinking (EDC/NHS group) and one-step simultaneous method to EDC/NHS crosslinking and heparin immobilization (EDC/NHS- Heparin group) in improving physiochemical and biological properties of native collagen sponge (Control group). Modified collagen sponge overcome the disadvantages of native collagen sponge. IR spectra suggest the change of the functional groups. DSC data indicate that the stability of caloric transformation in EDC/NHS group is slightly higher than that of EDC/NHS-Heparin group. The crosslinking degree, stability against enzymes, stability in morphologically and biomechanical properties of EDC/NHS-Heparin group are higher than those of EDC/NHS group, whereas, the water-binding capacity in EDC/NHS-Heparin group is lower than that of EDC/NHS group. HUVECs in EDC/NHS-Heparin group scaffold proliferate fast, migrate well and distribute uniformly. One-step simultaneous method gains the better effects in above aspects, heparinized collagen matrices increase in angiogenic potential and suit for defect repairing and tissue engineering. 展开更多
关键词 collagen sponge HEPARIN one-step method to EDC/NHS crosslinking one-step simultaneous method to EDC/NHS crosslinking and heparin immobilization
原文传递
SVD-TLS extending Prony algorithm for extracting UWB radar target feature 被引量:4
3
作者 Liu Donghong Hu Wenlong Chen Zhijie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第2期286-291,共6页
A new method, SVD-TLS extending Prony algorithm, is introduced for extracting UWB radar target features. The method is a modified classical Prony method based on singular value decomposition and total least squares th... A new method, SVD-TLS extending Prony algorithm, is introduced for extracting UWB radar target features. The method is a modified classical Prony method based on singular value decomposition and total least squares that can improve robust for spectrum estimation. Simulation results show that poles and residuum of target echo can be extracted effectively using this method, and at the same time, random noises can be restrained to some degree. It is applicable for target feature extraction such as UWB radar or other high resolution range radars. 展开更多
关键词 UWB radar Prony algorithm radar target feature singular value decomposition.
下载PDF
Solving algorithm for TA optimization model based on ACO-SA 被引量:4
4
作者 Jun Wang Xiaoguang Gao Yongwen Zhu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第4期628-639,共12页
An ant colony optimization (ACO)-simulated annealing (SA)-based algorithm is developed for the target assignment problem (TAP) in the air defense (AD) command and control (C2) system of surface to air missi... An ant colony optimization (ACO)-simulated annealing (SA)-based algorithm is developed for the target assignment problem (TAP) in the air defense (AD) command and control (C2) system of surface to air missile (SAM) tactical unit. The accomplishment process of target assignment (TA) task is analyzed. A firing advantage degree (FAD) concept of fire unit (FU) intercepting targets is put forward and its evaluation model is established by using a linear weighted synthetic method. A TA optimization model is presented and its solving algorithms are designed respectively based on ACO and SA. A hybrid optimization strategy is presented and developed synthesizing the merits of ACO and SA. The simulation examples show that the model and algorithms can meet the solving requirement of TAP in AD combat. 展开更多
关键词 target assignment (TA) OPTIMIZATION ant colony optimization (ACO) algorithm simulated annealing (SA) algorithm hybrid optimization strategy.
下载PDF
Application of ATOVS Radiance-Bias Correction to Typhoon Track Prediction with Ensemble Kalman Filter Data Assimilation 被引量:3
5
作者 崔丽梅 孙建华 +1 位作者 乔琳琳 雷霆 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第1期178-186,共9页
In this paper, firstly, the bias between observed radiances from the Advanced TIROS-N Operational Vertical Sounder (ATOVS) and those simulated from a model first-guess are corrected. After bias correction, the obser... In this paper, firstly, the bias between observed radiances from the Advanced TIROS-N Operational Vertical Sounder (ATOVS) and those simulated from a model first-guess are corrected. After bias correction, the observed minus calculated (O-B) radiances of most channels were reduced closer to zero, with peak values in each channel shifted towards zero, and the distribution of O-B closer to a Gaussian distribution than without bias correction. Secondly, ATOVS radiance data with and without bias correction are assimilated directly with an Ensemble Kalman Filter (EnKF) data assimilation system, which are then adopted as the initial fields in the forecast model T106L19 to simulate Typhoon Prapiroon (2006) during the period 2-4 August 2006. The prediction results show that the assimilation of ATOVS radiance data with bias correction has a significant and positive impact upon the prediction of the typhoon's track and intensity, although the results are not perfect. 展开更多
关键词 ATOVS radiance scan bias correction air mass bias correction Ensemble Kalman Filter(EnKF) Typhoon Prapiroon
下载PDF
Information gain based sensor search scheduling for low-earth orbit constellation estimation 被引量:3
6
作者 Bo Wang Jun Li +1 位作者 Wei An Yiyu Zhou 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第6期926-932,共7页
This paper addresses the problem of sensor search scheduling in the complicated space environment faced by the low-earth orbit constellation.Several search scheduling methods based on the commonly used information gai... This paper addresses the problem of sensor search scheduling in the complicated space environment faced by the low-earth orbit constellation.Several search scheduling methods based on the commonly used information gain are compared via simulations first.Then a novel search scheduling method in the scenarios of uncertainty observation is proposed based on the global Shannon information gain and beta density based uncertainty model.Simulation results indicate that the beta density model serves a good option for solving the problem of target acquisition in the complicated space environments. 展开更多
关键词 low-earth orbit constellation sensor network scheduling algorithm information gain acquisition.
下载PDF
Study of vortex in flow fields induced by surface dielectric barrier discharge actuator at low pressure based on Q criterion 被引量:2
7
作者 张政 车学科 +5 位作者 聂万胜 李金龙 郑体凯 李亮 陈庆亚 郑直 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第1期41-46,共6页
Flow fields induced by a surface dielectric barrier discharge actuator at low pressure of 7 kPa are measured by particle image velocimetry. The distribution of local vortices in the flow field is revealed by the Q cri... Flow fields induced by a surface dielectric barrier discharge actuator at low pressure of 7 kPa are measured by particle image velocimetry. The distribution of local vortices in the flow field is revealed by the Q criterion. The reason for the generation of vortices is analyzed and the influence of pulse frequency and duty cycle on vortices is studied. The results show that the Q criterion can reveal the small-scale vortices, which cannot be indicated by the streamline. The direction transition zone where the induced jet moves from the vertical to the tangential and the shear layer between the jet and stationary air are prone to the generation of strong vortices. The influence of pulse frequency on vortices is not obvious, but the variation of duty cycle can significantly affect the strength and distribution of vortices. 展开更多
关键词 low pressure SDBD induced field Q criterion VORTEX
下载PDF
Extraction and Isolation of Type Ⅰ,Ⅲ and Ⅴ Collagens and Their SDS-PAGE Analyses 被引量:3
8
作者 武继民 李志宏 +3 位作者 袁晓燕 汪鹏飞 刘永清 王赫 《Transactions of Tianjin University》 EI CAS 2011年第2期111-117,共7页
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. Th... 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 α1 ( 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 ℃, which differs from type Ⅲ collagen in relation to the locations of disulfide bonds. Compared with pepsin-treated collagen at 4 ℃, 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. 展开更多
关键词 COLLAGEN interchain SDS-PAGE PREPARATION structure
下载PDF
Study on biomechanical mechanism of bone remodeling 被引量:1
9
作者 Xizheng Zhang 《医用生物力学》 EI CAS CSCD 北大核心 2013年第S1期93-94,共2页
Background Bone is a dynamic tissue that constantly undergoes remodeling in which a coupled process of bone formation and resorption continues throughout life.This remodeling is necessary to maintain the structural in... Background Bone is a dynamic tissue that constantly undergoes remodeling in which a coupled process of bone formation and resorption continues throughout life.This remodeling is necessary to maintain the structural integrity of the skeleton under conditions of changing mechanical forces.It is important to develop bone remodeling theory in order to explain bone development and to instruct bone disease therapy and rehabilitation.However,the process and mechanism are not fully understood.Our study was carried out to investigate biomechanical mechanism of bone remodeling with the respect to bone tissue/cell mechanobiology,computational biomechanics and animal model. 展开更多
关键词 REMODELING rehabilitation constantly MAINTAIN understood SCAFFOLD SKELETON EXPLAIN integrity INTERMITTENT
原文传递
Interactive multigraph visualization and exploration with a two-phase strategy 被引量:1
10
作者 Huaquan Hu Lingda Wu +1 位作者 Chao Yang Hanchen Song 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第5期886-894,共9页
While it is very reasonable to use a multigraph consisting of multiple edges between vertices to represent various relationships, the multigraph has not drawn much attention in research. To visualize such a multigraph... While it is very reasonable to use a multigraph consisting of multiple edges between vertices to represent various relationships, the multigraph has not drawn much attention in research. To visualize such a multigraph, a clear layout representing a global structure is of great importance, and interactive visual analysis which allows the multiple edges to be adjusted in appropriate ways for detailed presentation is also essential. A novel interactive two-phase approach to visualizing and exploring multigraph is proposed. The approach consists of two phases: the first phase improves the previous popular works on force-directed methods to produce a brief drawing for the aggregation graph of the input multigraph, while the second phase proposes two interactive strategies, the magnifier model and the thematic-oriented subgraph model. The former highlights the internal details of an aggregation edge which is selected interactively by user, and draws the details in a magnifying view by cubic Bezier curves; the latter highlights only the thematic subgraph consisting of the selected multiple edges that the user concerns. The efficiency of the proposed approach is demonstrated with a real-world multigraph dataset and how it is used effectively is discussed for various potential applications. 展开更多
关键词 visual analytics information visualization multigraph visualization multiple edges aggregation graph magnifier model.
下载PDF
Wavelength modulation spectroscopy for measurements of gas parameters in combustion field 被引量:1
11
作者 屈东胜 洪延姬 +1 位作者 王广宇 潘虎 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第6期178-186,共9页
A novel wavelength modulation spectroscopy sensor for studying gas properties near 1.4 μm is developed, validated and used in a direct-connect supersonic combustion test facility. In this sensor there are two H2O tra... A novel wavelength modulation spectroscopy sensor for studying gas properties near 1.4 μm is developed, validated and used in a direct-connect supersonic combustion test facility. In this sensor there are two H2O transitions near 7185.60 cm^-1 and 7454.45 cm^-1 that are used to enable the measurements along the line-of-sight. According to an iterative algorithm, the gas pressure, temperature and species mole fraction can be measured simultaneously. The new sensor is used in the isolator and extender of the supersonic combustion test facility. In the isolator, the sensor resolves the transient and measured pressure, temperature and H2O mole fraction with accuracies of 2.5%, 8.2%, and 7.2%, respectively. Due to the non-uniform characteristic in the extender, the measured results cannot precisely characterize gas properties, but they can qualitatively describe the distinctions of different zones or the changes or fluctuations of the gas parameters. 展开更多
关键词 wavelength modulation spectroscopy SENSOR gas properties iterative algorithm
原文传递
Orthogonal discrete frequency coding waveform design based on chaos 被引量:1
12
作者 Yuxing Peng Jin Yang +1 位作者 Zhaokun Qiu Xiang Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第4期617-624,共8页
Orthogonal waveform design is quite an important issue for waveform diversity systems. A chaos based method for the orthogonal discrete frequency coding waveform (DFCW) design is proposed to increase the insufficien... Orthogonal waveform design is quite an important issue for waveform diversity systems. A chaos based method for the orthogonal discrete frequency coding waveform (DFCW) design is proposed to increase the insufficient orthogonal waveform number and their finite coding length. Premises for chaos choosing and the frequency quantification method are discussed to obtain the best correlation properties. Simulation results show the validity of the theoretic analysis. 展开更多
关键词 orthogonal waveform design waveform diversity CHAOS chaotic radar.
下载PDF
ANALYSIS OF TRANSMIT BEAMFORMING PERFORMANCE ON MULTIPLE-TRANSMIT BINARY ZCZ WAVEFORMS 被引量:1
13
作者 Li Weiping Liao Guisheng +1 位作者 Tao Haihong Zhang Jinze 《Journal of Electronics(China)》 2013年第2期118-129,共12页
The Transmit BeamForming (TBF) technology, applied in a multiple-transmit radar system, is studied in this paper, where multiple elements of antenna array transmit binary Zero Correlation Zones Orthogonal Signals (ZCZ... The Transmit BeamForming (TBF) technology, applied in a multiple-transmit radar system, is studied in this paper, where multiple elements of antenna array transmit binary Zero Correlation Zones Orthogonal Signals (ZCZ-OS) independently. For each Direction Of Arrival (DOA) with respect to the transmitting array, the analysis on the gain and sidelobe level of TBF output is presented. This paper focuses on the range sidelobes performance within the main beam (in angle domain). For the normal direction, due to the inherent phase property of ZCZ-OS, the TBF output has part zero sidelobes area, of which the distribution is discussed. For the other directions, a systematic search algorithm to optimize the transmission order of signals is proposed for an optimal relationship chart of DOA and transmission order. The range sidelobe performance within the main beam can be improved as the optimal transmission order is adopted. 展开更多
关键词 Multiple-Input Multiple-Output (MIMO) radar Stealth radar Sidelobe suppression Transmit BeamForming (TBF) Zero Correlation Zone (ZCZ) codes
下载PDF
Flow Visualization of Supersonic Flow over a Finite Cylinder 被引量:1
14
作者 WANG Deng-Pan ZHAO Yu-Xin +2 位作者 XIA Zhi-Xun WANG Qing-Hua LUO Zhen-Bing 《Chinese Physics Letters》 SCIE CAS CSCD 2012年第8期156-159,共4页
The flow structures of a supersonic flow over a cylinder with a finite height are investigated using the method of flow visualization with nanoparticle-based planar laser scattering(NPLS),in a supersonic quiet wind tu... The flow structures of a supersonic flow over a cylinder with a finite height are investigated using the method of flow visualization with nanoparticle-based planar laser scattering(NPLS),in a supersonic quiet wind tunnel at Ma=2.68.The complex structures of shock waves and three-dimensional vortices in a supersonic flow over a finite cylinder are visualized.Based on the time correlation of NPLS images,the time-space evolutionary characteristics of the coherent structures in a supersonic flow over a finite cylinder are studied,and the evolutionary characteristics of the coherent structure in the flow direction are obtained,which are used to identify the model and rotation direction of shedding vortices. 展开更多
关键词 CYLINDER FLOW COHERENT
原文传递
Mechanical Strain Regulates Osteoblast Proliferation Through Ca^(2+)-CaMK-CREB Signal Pathway 被引量:1
15
作者 Yong Guo Qi Lv +2 位作者 Xian-qiong Zou Zhi-xiong Yan Yu-xian Yan 《Chinese Medical Sciences Journal》 CAS CSCD 2016年第2期100-106,共7页
Objective To investigate the effects of mechanical strain on Ca^(2+)-calmodulin dependent kinase(CaMK)-cA MP response element binding protein(CREB) signal pathway and proliferation of osteoblasts. Methods Using a four... Objective To investigate the effects of mechanical strain on Ca^(2+)-calmodulin dependent kinase(CaMK)-cA MP response element binding protein(CREB) signal pathway and proliferation of osteoblasts. Methods Using a four-point bending device, MC3T3-E1 cells were exposed to mechanical tensile strains of 2500 μs and 5000 μs at 0.5 Hz respectively. The intracellular free Ca^(2+)([Ca^(2+)]i) concentration and calmodulin activity were assayed by fluorospectrophotometry, CaMK II β, CREB, and phosphorylated(activated) CREB(p-CREB) were assessed by Western blot, and cells proliferation was assayed with MTT. Pretreatment with verapamil was carried out to block Ca^(2+) channel, and inhibitor U73122 was used to inhibit phospholipase C(PLC). Results Mechanical strains of 2500 μs and 5000 μs for 1 to 10 minutes both increased [Ca^(2+)]i level of the cells. The 2500 μs strain, a periodicity of 1 h/d for 3 days, activated calmodulin, elevated protein levels of CaMK II β and p-CREB, and promoted cells proliferation, which were attenuated by pretreatment of verapamil or U73122. The effects of 5000 μs strain on calmodulin, CaMK II β, p-CREB and proliferation were contrary to 2500 μs strain. Conclusion The mechanical strain regulates osteoblasts proliferation through Ca^(2+)-Ca MK-CREB signal pathway via Ca^(2+) channel and PLC/IP_3 transduction cascades. 展开更多
关键词 mechanical strain calcium PHOSPHOLIPASE C proliferation CAMP response element BINDING protein
下载PDF
Study on the Evolution of a Northeast China Cold Vortex during the Spring of 2010 被引量:2
16
作者 FU Shen-Ming SUN Jian-Hua QI Lin-Lin 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第2期149-156,共8页
Based on the final analysis data with horizontal resolution of 1°× 1°(four times a day) from the National Centers for Environmental Prediction(NCEP), a typical Northeast China cold vortex(NCCV) during t... Based on the final analysis data with horizontal resolution of 1°× 1°(four times a day) from the National Centers for Environmental Prediction(NCEP), a typical Northeast China cold vortex(NCCV) during the spring of 2010 was examined with the quasi-Lagrange- form eddy flux circulation(EFC) budget equation. Results indicated that the mechanisms that account for the development, maintenance, and attenuation of the cyclone varied with levels and stages. Displacement of the cyclone and transports by background environmental circulations dominated the variation of the cyclone in the middle and upper levels, whereas displacement and divergence associated with the cyclone dominated the evolution of the NCCV in the middle and lower levels. Moreover, interactions between the NCCV and other subsynoptic weather systems were important for the development of the cyclone, and the pattern of background environmental circulations was also important for the evolution of the NCCV, since the cyclone enhanced(weakened) as it moved from areas of low(high) vorticity to high(low) ones. 展开更多
关键词 Northeast China cold vortex quasi-Lagrange-form eddy flux circulation budget
下载PDF
Mechanical Stimulus Inhibits the Growth of a Bone Tissue Model Cultured In Vitro 被引量:1
17
作者 Zong-ming Wan Lu Liu +5 位作者 Jian-yu Li Rui-xin Li Yong Guo Hao Li Jian-ming Zhang Xi-zheng Zhang 《Chinese Medical Sciences Journal》 CAS CSCD 2013年第4期218-224,共7页
Objectives To construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vtro. Methods C... Objectives To construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vtro. Methods Cancellous bone were extracted from rabbit femoral head and cut into I-ram-thick and 8-ram-diameter slices under sterile conditions. HE staining and scanning electron microscopy were employed to identify the histomorphology of the model after being cultured with a new dynamic load and circulating perfusion bioreactor system for 0, 3, 5, and 7 days, respectively. We built a three-dimensional model using microCT and analyzed the loading effects using finite element analysis. The model was subjected to mechanical load of 1000, 2000, 3000, and 4000 με respectively for 30 minutes per day. After 5 days of continuous stimuli, the activities of alkaline phosphatase (AKP) and tartrate-resistant acid phosphatase (TRAP) were detected. Apoptosis was analyzed by DNA ladder detection and caspase-3/8/9 activity detection. Results After being cultured for 3, 5, and 7 days, the bone explant model grew well. HE staining showed the apparent nucleus in cells at the each indicated time, and electron microscope revealed the living cells in the bone tissue. The activities of AKP and TRAP in the bone explant model under mechanical load of 3000 and 4000 με were significantly lower than those in the unstressed bone tissues (all P〈0.05). DNA ladders were seen in the bone tissue under 3000 and 4000με mechanical load. Moreover, there was significant enhancement in the activities of caspase-3/8/9 in the mechanical stress group of 3000 and 4000 με (all P〈0.05). Conclusions The cancellous bone explant model extracted from the rabbit femoral head could be alive at least for 7 days in the dynamic load and circulating perfusion bioreactor system, however, pathological mechanical load could affect the bone tissue growth by apoptosis in vitro. The differentiation of osteobiasts and osteoclasts might be inhibited after the model is stimulated by mechanical load of 3000 and 4000 με. 展开更多
关键词 bone tissue engineering mechanical load bone explant culture apoptosis OSTEOBLAST OSTEOCLAST
下载PDF
PAM-PAA microgel inverse opal photonic crystal and pH response 被引量:1
18
作者 Yong Qiang He Xiao Dong Wang +3 位作者 Jian Ying Wang Yan Feng Yong Qiang Zhao Xiu Dong You 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第11期1395-1398,共4页
The colloidal crystal template or opal with a closed-packed face-centered cubic (fcc) lattice was prepared from monodisperse polystyrene (PS) spheres by vertical sedimentation. The template provided void space for... The colloidal crystal template or opal with a closed-packed face-centered cubic (fcc) lattice was prepared from monodisperse polystyrene (PS) spheres by vertical sedimentation. The template provided void space for infiltration of monomer precursor composed of acrylate acid, acrylamide and ammonium-persulfate, as well as microgel from the subsequent copolymerization. The sample was immersed in dimethylbenzene for completely removing PS spheres to form PAM inverse opal hydrogels (IOHPAM) or PAM/PAA inverse opal hydrogels (IOHPAM/PAA) photonic crystals. The PS spheres were replaced by air spheres, which interconnected each other through the windows. The study of responses to pH show that there are two peaks for both IOHPAM and IOHPAM/PAA films, but the IOHPAM/PAA peaks shift to higher pH, and the peaks are independent with the AA content. 展开更多
关键词 Photonic crystal pH response PAM/PAA OPAL Inverse opal hydrogel
下载PDF
TWO BIAS CORRECTION SCHEMES FOR ATOVS RADIANCE DATA 被引量:1
19
作者 崔丽梅 孙建华 齐琳琳 《Journal of Tropical Meteorology》 SCIE 2010年第1期71-76,共6页
To better assimilate Advanced TIROS Operational Vertical Sounder(ATOVS) radiance data and provide more accurate initial fields for a numerical model,two bias correction schemes are employed to correct the ATOVS radian... To better assimilate Advanced TIROS Operational Vertical Sounder(ATOVS) radiance data and provide more accurate initial fields for a numerical model,two bias correction schemes are employed to correct the ATOVS radiance data.The difference in the two schemes lies in the predictors use in air-mass bias correction.The predictors used in SCHEME 1 are all obtained from model first-guess,while those in SCHEME 2 are from model first-guess and radiance observations.The results from the two schemes show that after bias correction,the observation residual became smaller and closer to a Gaussian distribution.For both land and ocean data sets,the results obtained from SCHEME 1 are similar to those from SCHEME 2,which indicates that the predictors could be used in bias correction of ATOVS data. 展开更多
关键词 ATOVS radiance data bias correction schemes model first-guess
下载PDF
Calculation model of military aircraft suryiyability to a missile 被引量:1
20
作者 杨哲 Li Shulin +2 位作者 Li Shouan Zhou Li Zhang Jun 《High Technology Letters》 EI CAS 2014年第2期117-123,共7页
Since missiles are main threat against aircrafts in air war,a model is proposed for calculating the aircraft survivability to a missile.The hit characteristic of aircraft to a missile is analyzed,and then Monte Carlo ... Since missiles are main threat against aircrafts in air war,a model is proposed for calculating the aircraft survivability to a missile.The hit characteristic of aircraft to a missile is analyzed,and then Monte Carlo method is applied to generate missile detonation location according to its distribution rule.In addition,based on the analysis of fragment trajectory and critical components,the intersection point of these two is determined.Then the kill probability of critical component to a fragment can be calculated,and the aircraft survivability to a missile is obtained accordingly.Finally,the feasibility of the proposed method is demonstrated.Simulation results show that this method captures the basic effects of missile detonation locations on aircraft survivability,which may provide an effective reference to aircraft survivability research. 展开更多
关键词 SURVIVABILITY MISSILE miss distance Monte Carlo kill probability
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部