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| 1 | Rapid growth and sterility of growth hormone gene transgenic triploid carp显示文摘Triploid carp(100%)with 150(3n=150)chromosomes were obtained by crossing the females of improved tetraploid hybrids(♀, 4n=200)of red crucian carp(♀)×common carp(♂)with the males of diploid yellow river carp(♂,2n=100).The crosses yielded transgenic triploid carp(positive triploid fish,44.2%of the progeny)and non-transgenic triploid carp(negative triploid fish). Histological examination of the gonads of 24-month-old positive triploid fish suggested they were sterile and the fish were not able to produce mature gametes during the breeding season.Morphologically,both the positive and negative triploid fish were similar.They had a spindle-shaped,laterally compressed,steel grey body with two pairs of barbells.Most of the quantifiable traits of the triploid carp were intermediate between those of the two parents.The positive and negative triploid fish were raised in the same pond for 2 years.The mean body weight of the positive triploid fish was 2.3 times higher than the negative triploid fish.The weight of the largest positive triploid fish was 2.91 times higher than that of the largest negative triploid fish.Thus,we produced fast-growing transgenic triploid carp that have a reduced ecological risk because of their inability to mate and produce progeny. | YU Fan XIAO Jun LIANG XiangYang LIU ShaoJun ZHOU GongJian LUO KaiKun LIU Yun HU Wei WANG YaPing ZHU ZuoYan | 2011 | Chinese Science Bulletin2011，56，16： | 11 |
| 2 | Adakitic rocks at convergent plate boundaries:Compositions and petrogenesis显示文摘Adakitic rocks are intermediate-acid magmatic rocks characterized by enrichment in light rare-earth elements,depletion in heavy rare-earth elements,positive to negligible Eu and Sr anomalies,and high La/Yb and Sr/Y ratios.Cenozoic adakitic rocks generated by partial melting of subducted oceanic crust(slab)under eclogite-facies conditions(i.e.,the original definition of“adakite”)occur mainly in Pacific Rim volcanic arcs(intra-oceanic,continental,and continental-margin island arcs),whereas those generated by partial melting of thickened lower crust occur mainly in Tethyan Tibetan collisional orogens.In volcanic arcs,adakitic melts derived from the melting of subducted oceanic crust metasomatize the mantle wedge to form a unique rock suite comprising adakite-adakite-type high-Mg andesite-Piip-type high-Mg andesite-Nb-rich basalt-boninite.This suite differs from the basalt-andesite-dacite-rhyolite suite formed from mantle wedge metasomatized by fluids derived from subducted oceanic crust.Previously published data indicate that partial melting of mafic rocks can generate adakitic magmas under pressure,temperature,and hydrous conditions of 1.2-3.0 GPa,800-1000℃,and 1.5-6.0 wt.%H_(2)O,respectively,leaving residual minerals of garnet and rutile with little or no plagioclase.Cenozoic Au and Cu deposits occur proximally to adakitic rocks,with host rocks of some deposits actually being adakitic rocks.Adakitic rocks thus have important implications for both deep-Earth dynamics and Cu-Au mineralization/exploration.Although studies of Cenozoic adakitic rocks have made many important advances,there remain weaknesses in some important areas such as their tectonic settings,petrogenesis,magma sources,melt-mantle interactions of pre-Cenozoic adakitic rocks,and their relationship with the onset of plate tectonics and crustal growth.Future research directions are likely to involve(1)the generation of adakitic magmas by experimental simulations of partial melting of different types of rock(including intermediate-acid rocks)and magma fractional crystallization at different temperatures and pressures,(2)the relationship between magma reservoir evolution and the formation of adakitic rocks,(3)the tectonic setting and petrogenesis of pre-Cenozoic adakitic rocks and related geodynamic processes,(4)interactions between slab melts and the mantle wedge,(5)the formation of Archean adakitic tonalite-trondhjemite-granodiorite and its link to the onset of plate tectonics and crustal growth,and(6)the relationship between the formation of adakitic rocks and metal mineralization in different tectonic settings. | Qiang Wang Lulu Hao Xiuzheng Zhang Jinsheng Zhou Jun Wang Qiwei Li Lin Ma Long Zhang Yue Qi Gongjian Tang Wei Dan Jingjing Fan | 2020 | Science China Earth Sciences2020，63，12： | 3 |
| 3 | HF radar sea clutter rejection by nonlinear projections显示文摘In the background of signal detection for high frequency (HF) radar, the sea clutter is quite significant and can mask some weak target signals. A new clutter rejection method named “nonlinear projection” is given to improve the SNR of the target. This approach is based on the recent observation that HF sea clutter may be modeled as a nonlinear deterministic dynamical system. After approximating the multidimensional reconstruction of the clutter by a lowdimensional attractor, projections onto this attractor can separate the clutter from other components. Real sea clutter, simulated target data and real target data are used to show that a nonlinear clutter rejection method is a promising technique to suppress sea clutter and enhances target detection. | Zhou Gongjian Jin Yonggao Dong Huachun Quan Taifan | 2005 | Journal of Systems Engineering and Electronics2005，16，4： | 3 |
| 4 | A Tracking Filter in Spherical Coordinates Enhanced by De-noising of Converted Doppler Measurements显示文摘Tracking problem in spherical coordinates with range rate (Doppler) measurements, which would have errors correlated to the range measurement errors, is investigated in this paper. The converted Doppler measurements, constructed by the product of the Doppler measurements and range measurements, are used to replace the original Doppler measurements. A de-noising method based on an unbiased Kalman filter (KF) is proposed to reduce the converted Doppler measurement errors before updating the target states for the constant velocity (CV) model. The states from the de-noising filter are then combined with the Cartesian states from the converted measurement Kalman filter (CMKF) to produce final state estimates. The nonlinearity of the de-noising filter states are handled by expanding them around the Cartesian states from the CMKF in a Taylor series up to the second order term. In the mean time, the correlation between the two filters caused by the common range measurements is handled by a minimum mean squared error (MMSE) estimation-based method. These result in a new tracking filter, CMDN-EKF2. Monte Carlo simulations demonstrate that the proposed tracking filter can provide efficient and robust performance with a modest computational cost. | ZHOU Gongjian YU Changjun CUI Naigang QUAN Taifan | 2012 | Chinese Journal of Aeronautics2012，25，5： | 2 |
| 5 | Complex Motion Modeling and State Estimation in Road Coordinates显示文摘Constrained modeling and state estimation have attracted much attention in recent years. This paper focuses on target motion modeling and tracking in road coordinates. An improved initialization method,which uses the optimal fusion of the position measurements in different directions,is presented for the constraint coordinate Kalman filter(CCKF). The CCKF is evaluated with a comprehensive comparison to the state-of-art linear equality constraint estimation methods. Numerical simulation results demonstrate the better performance of the CCKF. Then the interacting multiple model CCKF(IMM-CCKF) is proposed to manifest the advantages of the CCKF in complex motion modeling and state estimations. The effectiveness of the IMM-CCKF in maneuvering target tracking with spatial equality constraints is demonstrated by numerical experiments. | Keyi Li Xi Chen Gongjian Zhou | 2017 | Journal of Harbin Institute of Technology(New Series)2017，24，1： | 1 |
| 6 | Maneuvering target state estimation based on separate model-ing of target trajectory shape and dynamic characteristics显示文摘The state estimation of a maneuvering target,of which the trajectory shape is independent on dynamic characteristics,is studied.The conventional motion models in Cartesian coordinates imply that the trajectory of a target is completely determined by its dynamic characteristics.However,this is not true in the applications of road-target,sea-route-target or flight route-target tracking,where target trajectory shape is uncoupled with target velocity properties.In this paper,a new estimation algorithm based on separate modeling of target trajectory shape and dynamic characteristics is proposed.The trajectory of a target over a sliding window is described by a linear function of the arc length.To determine the unknown target trajectory,an augmented system is derived by denoting the unknown coefficients of the function as states in mileage coordinates.At every estimation cycle except the first one,the interaction(mixing)stage of the proposed algorithm starts from the latest estimated base state and a recalculated parameter vector,which is determined by the least squares(LS).Numerical experiments are conducted to assess the performance of the proposed algorithm.Simulation results show that the proposed algorithm can achieve better performance than the conventional coupled model-based algorithms in the presence of target maneuvers. | ZHANG Zhuanhua ZHOU Gongjian | 2022 | Journal of Systems Engineering and Electronics2022，33，5： | 1 |
| 7 | Track-before-detect for bistatic radar based on pseudo-spectrum显示文摘Track-Before-Detect(TBD) is an efficient method to detect dim targets for radars. Conventional TBD usually follows an approximate motion model of the target, which may cause an inaccurate integration of the target energy. A TBD technique on basis of pseudo-spectrum in mixed coordinates adopting an accurate motion model for bistatic radar system is developed in this paper.The predicted position in bistatic polar plane is derived according to a nonlinear function that exactly describes the constant Cartesian velocity motion. Then around the predicted position, a pseudo-spectrum is formulated and its samples are accumulated to the integration frame for energy integration. The evolution of the state and the procedure of accumulation of the target energy are derived elaborately. The superior performance of the proposed method is demonstrated by some simulations. | Tao HAN Gongjian ZHOU | 2024 | Chinese Journal of Aeronautics2024，37，1： | 0 |
| 8 | The origin of arc basalts:New advances and remaining questions显示文摘Whether arc magmatism occurs above oceanic subduction zones is the forefront of studies on convergent plate margins.The most important petrologic issue related to the evolution of arc systems is the origin of arc magmatism,among which arc basalts are the most important one because they provide insights into mantle enrichment mechanism and crust-mantle interaction at oceanic subduction zones.Fluids or melts released either by dehydration or by melting of subducting oceanic slab infiltrate and metasomatize the overlying mantle wedge at varying depth,leading to the formation of source regions of arc basalts.Such processes make most of arc basalts commonly enriched in large ion lithosphile elements and light rare earth elements,but depleted in high-field strength elements and heavy rare earth elements.Small amounts of arc basalts are characterized by relatively high Nb contents or by Nb enrichment.Rare basalts with compositions similar to ocean island basalts or mid-ocean ridge basalt also occur in arc systems.For these peculiar rocks,it remains debated whether their source is affected by subduction-related components.During their ascent and before their eruption,arc basaltic magmas are subjected to crystal fractionation,mixing and crustal contamination.In addition to the contribution of subducting slab components to the mantle source of arc basalts,the materials above the subducting slab at forearc depths would have been transported either by drag or by subduction erosion into the subarc mantle and into the source of arc magmas.Heats and materials brought by corner flows also play important roles in the generation of arc basalts.Despite the important progresses made in recent studies of arc basalts,further efforts are needed to investigate subarc mantle metasomatism,material recycling,the formation of arc magma sources,geodynamic mechanism in generating arc basalts,and their implicationd s for the initiation of plate tectonics on Earth. | Yigang Xu Qiang Wang Gongjian Tang Jun Wang Hongyan Li Jinsheng Zhou Qiwei Li Yue Qi Pingping Liu Lin Ma Jingjing Fan | 2020 | Science China Earth Sciences2020，63，12： | 0 |
| 9 | Multiframe weak target track-before-detect based on pseudo-spectrum in mixed coordinates显示文摘Traditional multiframe Track-Before-Detect(TBD)may incur adverse integration loss resulting from model mismatch in sensor coordinates.Its suboptimal integration strategy may cause target envelope degradation.To address these issues,a pseudo-spectrum-based multiframe TBD in mixed coordinates is proposed firstly.The data search for energy integration is conducted based on an accurate model in the x-y plane while target energy is integrated based on pseudo-spectrum in sensor coordinates.The algorithm performance is improved since the model mismatch is eliminated,and the pseudo-spectrum based integration facilitates well maintained target envelope.The detailed multiframe integration procedure and theoretical target integrated envelope are derived.Secondly,to cope with the unknown target velocity,a velocity filter bank based on pseudo-spectrum in mixed coordinates is proposed.The effect of velocity mismatch on algorithm performance is analyzed and an efficient method for filter bank design is presented.Thirdly,a parameter estimation method using characteristics of integrated envelope is presented for improved target polar position and Cartesian velocity estimation.Finally,numerical results are provided to demonstrate the effectiveness of the proposed method. | Liangliang WANG Gongjian ZHOU Thiagalingam KIRUBARAJAN | 2022 | Chinese Journal of Aeronautics2022，35，5： | 0 |
| 10 | State estimation in range coordinate using range-only measurements显示文摘In some tracking applications,due to the sensor characteristic,only range measurements are available.If this is the case,due to the lack of full position measurements,the observability of Cartesian states(e.g.,position and velocity)are limited to particular cases.For general cases,the range measurements can be utilized by developing a state estimation algorithm in range-Doppler(R-D)plane to obtain accurate range and Doppler estimates.In this paper,a state estimation method based on the proper dynamic model in the R-D plane is proposed.The unscented Kalman filter is employed to handle the strong nonlinearity in the dynamic model.Two filtering initialization methods are derived to extract the initial state estimate and the initial covariance in the R-D plane from the first several range measurements.One is derived based on the well-known two-point differencing method.The other incorporates the correct dynamic model information and uses the unscented transformation method to obtain the initial state estimates and covariance,resulting in a model-based method,which capitalizes the model information to yield better performance.Monte Carlo simulation results are provided to illustrate the effectiveness and superior performance of the proposed state estimation and filter initialization methods. | LI Keyi GUO Zhengkun ZHOU Gongjian | 2022 | Journal of Systems Engineering and Electronics2022，33，3： | 0 |
| 11 | Sequential nonlinear tracking filter without requirement of measurement decorrelation显示文摘Sequential measurement processing is of benefit to both estimation accuracy and computational efficiency. When the noises are correlated across the measurement components,decorrelation based on covariance matrix factorization is required in the previous methods in order to perform sequential updates properly. A new sequential processing method, which carries out the sequential updates directly using the correlated measurement components, is proposed. And a typical sequential processing example is investigated, where the converted position measurements are used to estimate target states by standard Kalman filtering equations and the converted Doppler measurements are then incorporated into a minimum mean squared error(MMSE)estimator with the updated cross-covariance involved to account for the correlated errors. Numerical simulations demonstrate the superiority of the proposed new sequential processing in terms of better accuracy and consistency than the conventional sequential filter based on measurement decorrelation. | Gongjian Zhou Junhao Xie Rongqing Xu Taifan Quan | 2015 | Journal of Systems Engineering and Electronics2015，26，6： | 0 |
| 12 | Multiframe track-before-detect method based on velocity filtering in mixed coordinates显示文摘In this paper,a velocity filtering based track-before-detect algorithm in mixed coordinates is presented to address the problem of integration loss caused by inaccurate motion model in polar coordinate sensors.Since the motion of a con-stant velocity(CV)target is better modeled in Cartesian coordi-nates,the search of measurements for integration in polar sensor coordinates is carried out according to the CV model in Cartesian coordinates instead of an approximate model in polar sensor coordinates.The position of each cell is converted into Cartesian coordinates and predicted according to an assumed velocity.Then,the predicted Cartesian position is converted back to polar sensor coordinates for multiframe accumulation.The use of the correct model improves integration effectiveness and consequently improves algorithm performance.To handle the weak target with unknown velocity,a velocity filter bank in mixed coordinates is presented.The influence of velocity mis-match on the performance of filter bank is analyzed,and an effi-cient strategy for filter bank design is proposed.Numerical re-sults are presented to demonstrate the effectiveness of the pro-posed algorithm. | WANG Liangliang ZHOU Gongjian | 2022 | Journal of Systems Engineering and Electronics2022，33，2： | 0 |
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