Crystal structure, thermal analyses, and acetate binding properties in Zinc(II) complex of a urea-functionalized pyridyl ligand

1302-1310A zinc(II) acetate complex with a urea-functionalized pyridyl ligand, [ZnL2(OAc)2]·2H2O (1) (L = N-(4-chlorophenyl)-N'-(4-pyridyl)urea), has been synthesized by the reaction of L with Zn(OAc)2·2H2O under water-containing condition. X-ray single-crystal diffraction analyses reveal that 2-D sheetlike network structure has been formed by the urea N−H×××Npyridyl interactions and C–H···O interactions in the free ligand L. Complex 1 features 3-D hydrogen bonded network formed by intermolecular N−H···O hydrogen bonds and O−H×××O hydrogen bonds involving urea groups, acetate anions and bridged water molecules. The hydrogen bonds play an important role in stabilizing the supramolecular structures. Thermal gravity analyses have been used to investigate the thermal stabilities of L and 1, and the apparent activation energy (Ea) of the decompositions have also been calculated, and the results indicate that the main decomposition of L needs higher apparent activation energy values Ea than that of 1. The acetate binding properties of L in solution have also been evaluated by Ultraviolet-Visible (UV-Vis) spectroscopy. CCDC: 1506202, L; 1506203, 1

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Sparsity-Inducing Super-Resolution Passive Radar Imaging with Illuminators of Opportunity

Multiple illuminators of opportunity (IOs) and a large rotation angle are often required for current passive radar imaging techniques. However, a large rotation angle demands a long observation time, which cannot be implemented for actual passive radar system. To overcome this disadvantage, this paper proposes a super-resolution passive radar imaging framework with a sparsity-inducing compressed sensing (CS) technique, which allows for fewer IOs and a smaller rotation angle. In the proposed imaging framework, the sparsity-based passive radar imaging is modeled mathematically, and the spatial frequencies and amplitudes of different scatterers on the target are recovered by the log-sum penalty function-based CS reconstruction algorithm. In doing so, a super-resolution passive radar imagery is obtained by the frequency searching approach. Simulation results not only validate that the proposed method outperforms existing super-resolution algorithms, such as ESPRIT and RELAX, especially in the cases with low signal-to-noise ratio (SNR) and limited number of measurements, but also have shown that our proposed method can perform robust reconstruction no matter if the target is on grid or not

A Novel Two Dimensional Imaging Algorithm Based on Compressed Sensing for Multi-Channel SAR

Abstract In this paper, a novel synthetic aperture radar (SAR) two-dimensional (2-D) imaging algorithm which named CSMC is proposed based on compressed sensing (CS) and multi-channel (MC) SAR system. In particular, the algorithm operates in range and azimuth dimensions via CS technique, respectively. This new algorithm simultaneously provides a high resolution and wide-swath 2-D map of the spatial distribution of targets with a significant reduction in the number of data samples beyond the Nyquist theorem and with an implication in simplification of radar architecture. The simulation results show that this new imaging scheme presents many important applications and advantages which include higher resolution, less sampled data and higher noise immunity

Passive Localization Countermeasure Based on Frequency Diverse Array

Passive localization technology is an integral part of electronic warfare. However, most methods for countering passive localization systems, such as radio frequency stealth and electronic interference, have limitations. This paper proposes a new passive localization countermeasure method based on Frequency Diverse Array (FDA). The unique beam scanning property reduces dwell time at a certain azimuth direction, making it difficult for a passive localization system to intercept FDA signals for a long time. In contrast, the time-varying characteristics of the FDA considerably reduce the signal-to-noise ratio of the received signal, increasing the difficulty in accurately detecting the localization information of the radiation source. Thus, using this new technology, the electronic system platform can perceive the external environment through the signals radiated by the FDA antenna while deceiving the enemy’s passive localization system. Both theoretical analysis and numerical results showed that FDA transmitted signal achieved significantly better localization countermeasure performance in direction finding by an interferometer, frequency difference of arrival, and time difference of arrival, which are particularly useful for a new generation of electronic systems with reconnaissance detection and passive localization countermeasures capability

A novel, sensitive and non‐destructive method for quantitative determination of lipid in live Eriocheir sinensis using low‐field 1H Nuclear magnetic resonance

In this study, lipid content of live Eriocheir sinensis has been quickly and accurately determined by low‐field 1H Nuclear magnetic resonance (LF ‐1H NMR ). The experimental parameters of LF ‐1H NMR have been optimized and the validity of the established standard method has been confirmed with traditional Soxhlet extraction method. Results show that the lipid signal intensity is strongly correlated with its content and exhibits a good linear correlation (Y = 0.0376 + 4.899X , R 2 = 0.9999), thus demonstrating favorable accuracy and sensitivity for the quantitative determination of lipid content. In conclusion, the lipid content of live E. Sinensis can be directly obtained based on an established method, indicating a great application potential in food and other fields

Advances on Frequency Diverse Array Radar and Its Applications

Unlike the conventional phased array that provides only angle-dependent transmit beampattern, Frequency Diverse Array (FDA) employs a small frequency increment across its array elements to produce automatic beam scanning without requiring phase shifters or mechanical steering. FDA can produce both rangedependent and time-variant transmit beampatterns, which overcomes the disadvantages of conventional phased arrays that produce only angle-dependent beampattern. Thus, FDA has many promising applications. Based on a previous study conducted by the author, “Frequency Diverse Array Radar: Concept, Principle and Application” (Journal of Electronics & Information Technology, 2016, 38(4): 1000–1011), the current study introduces basic FDA radar concepts, principles, and application characteristics and reviews recent advances on FDA radar and its applications. In addition, several new promising applications of FDA technology are discussed, such as radar electronic warfare and radar-communications, as well as open technical challenges such as beampattern variance, effective receiver design, adaptive signal detection and estimation, and the implementation of practical FDA radar demos

(Z)-4-[(3-Aminonaphthalen-2-ylamino)(phenyl)methylidene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

The molecule of the title compound, C27H22N4O, assumes a non-planar conformation in which the pyrazolone ring forms dihedral angles of 12.73 (11), 65.17 (6) and 49.82 (6)°, respectively, with the two benzene rings and the naphthalene ring system. In the crystal, pairs of molecules are linked by intermolecular N—H...N hydrogen bonds, forming dimers. The secondary amino group is involved in an intramolecular N—H...O hydrogen bond

High-Resolution Bistatic ISAR Imaging Based on Two-Dimensional Compressed Sensing

10.1109/TAP.2015.2408337IEEE Transactions on Antennas and Propagation6352098-211

Sparsity-Inducing Super-Resolution Passive Radar Imaging with Illuminators of Opportunity

Multiple illuminators of opportunity (IOs) and a large rotation angle are often required for current passive radar imaging techniques. However, a large rotation angle demands a long observation time, which cannot be implemented for actual passive radar system. To overcome this disadvantage, this paper proposes a super-resolution passive radar imaging framework with a sparsity-inducing compressed sensing (CS) technique, which allows for fewer IOs and a smaller rotation angle. In the proposed imaging framework, the sparsity-based passive radar imaging is modeled mathematically, and the spatial frequencies and amplitudes of different scatterers on the target are recovered by the log-sum penalty function-based CS reconstruction algorithm. In doing so, a super-resolution passive radar imagery is obtained by the frequency searching approach. Simulation results not only validate that the proposed method outperforms existing super-resolution algorithms, such as ESPRIT and RELAX, especially in the cases with low signal-to-noise ratio (SNR) and limited number of measurements, but also have shown that our proposed method can perform robust reconstruction no matter if the target is on grid or not