Phenanthroline-based Fluorescent Chemosensor for Selective Detection of Zn^(2+) in DMF Buffer Solution

A simple ＂off-on＂ fluorescent chemosensor with high selectivity to zinc ions based on 1,10-phenanthro-line receptor dipyrido[3,2-d：2＇,3＇-f]quinoxaline（L） was investigated.The selectivity response of receptor L to zinc ion was demonstrated by UV-Vis absorption and fluorescence spectroscopies in DMF buffer solution.The experiment results show that the fluorescent chemosensor L exhibits the optimum response behavior to Zn2＋ in the range of pH 8.0―9.0 and shows excellent selectivity to Zn2＋ over other cations tested.

Selective detection of Zn^(2+) and Cd^(2+) ions in water using a host-guest complex between chromone and Q[7]

In this paper,the host-guest interaction of cucurbit[7]uril(Q[7]) and chromone(CMO) has been developed as a fluorescent probe for the highly selective detection of Zn2+ and Cd^(2+) in water based on a chelation-enhanced fluorescence(CHEF) mechanism.There was a good linear relationship between the fluorescence intensity of the CMO@Q[7] probe and the concentration of Zn^(2+ )or Cd^(2+) in the range of 0-3.0×10^(-5) mol/L and the detection limit for Zn^(2+) and Cd2+ was found to be 2.03×10^(-6) mol/L and 1.89×10^(-6)mol/L,respectively.The X-ray crystal structure indicated that different coordination fashions were triggered by Zn^(2+) and Cd^(2+ )in the CMO@Q[7] complexes,respectively.However,both metal ions coordinated with the carbonyl oxygen of CMO,which was encapsulated in the cavity of Q[7],thus leading to the enhancement of recognition fluorescence emission of CMO.

Adaptive Robust Waveform Selection for Unknown Target Detection in Clutter

A basic assumption of most recently proposed waveform design algorithms is that the target impulse response is a known deterministic function or a stochastic process with a known power spectral density （PSD）. However, it is well-known that a target impulse response is neither easily nor accurately obtained; besides it changes sharply with attitude angles. Both of the aforementioned cases complicate the waveform design process. In this paper, an adaptive robust waveform selection method for unknown target detection in clutter is proposed. The target impulse response is considered to be unknown but belongs to a known uncertainty set. An adaptive waveform library is devised by using a signal-to-clutter-plus-noise ratio （SCNR）- based optimal waveform design method. By applying the minimax robust waveform selection method, the optimal robust waveform is selected to ensure the lowest performance bound of the unknown target detection in clutter. Results show that the adaptive waveform library outperforms the predefined linear frequency modulation （LFM） waveform library on the SCNR bound.

Cobalt phthalocyanine-graphene complex for electro-catalytic oxidation of dopamine

Cobalt phthalocyanine-graphene （CoPc-Gr） complex are fabricated through 7r-Tr interaction of each components, with CoPc adsorbed/inserted on/in the graphene sheets. The obtained complex could be used in the electro-chemical detection of various medicines. CoPc-Gr modified glassy electrode shows excellent response to the electro-oxidation of dopamine （DA） and ascorbic acid （AA）, much better than those of CoPc, graphene oxide （GrO） or graphene （Gr） modified electrode. Significantly, the detection of dopamine is a diffusion-controlled process, highly selective, and has a low detection limit and broad linear range.

Europium Activated Aluminum Organic Frameworks for Highly Selective and Sensitive Detection of Fe and Cr(Ⅵ) in Aqueous Solution

The aluminum based MOFs compound, MIL-96(Al), has been studied as a luminescence sensor by incorporating of Eu3+ ions, which renders the compound strong red-light emission. The as-synthesized MIL-96(Al):Eu3+ nanocrystals exhibit water dispersibility and environmental stability, which are general requirement for an ideal sensing material. The MIL-96(Al):Eu3+ nanocrystals show excellent selective detection ability on Fe3+ ions in aqueous solution with value of low detection limit 20 μM. Meanwhile, it also exhibits excellent selective detection ability on CrO42- and Cr2O72- in aqueous solution with value of low detection limit 10 and 22 μM, respectively. The results of this study show that MIL-96(Al):Eu3+ nanocrystals could be used as a multi-responsive luminescent senor for Fe3+ and Cr(Ⅵ) species in aqueous solution. The possible luminescence quenching mechanism has also been discussed.

A Fluorescent In (Ⅲ) Metal-Organic Framework for Explosives Detection

Anovel metal-organic framework{[In_(3)(TATAT)_(2)]·3CH_(3)NH_(3)·7NMF·8H_(2)O}[JLU-MOF101,H_(6)TATAT=5,5′,5″-(1,3,5-triazine-2,4,6-triyl)tris-(azanediyl)triisophthalate,NMF=N-methyl-formamide]with cor topology has been synthesized under solvothermal conditions.The framework of JLU-MOF101 is constructed by{In(COO)_(4)}-nodes and a hexacarboxylic organic ligand.JLU-MOF101 exhibits excellent fluorescence properties in N,N-dimethylformamide(DMF)solution,and its emission spectrum can be greatly overlapped with the ultraviolet absorption spectra of trinitrophenol(TNP)and 2,4-dinitrophenol(2,4-DNP).As a result,JLU-MOF101 exhibits excellent performance of fluorescence quenching for TNP and 2,4-DNP.In addition,we demonstrate the selective detection capability of JLU-MOF101 through a large number of anti-interference tests.

A genome scan of recent positive selection signatures in three sheep populations

Domesticated sheep have been exposed to artificial selection for the production of fiber, meat, and milk as well as to natural selection. Such selections are likely to have imposed distinctive selection signatures on the sheep genome. Therefore, detecting selection signatures across the genome may help elucidate mechanisms of selection and pinpoint candidate genes of interest for further investigation. Here, detection of selection signatures was conducted in three sheep breeds, Sunite （n=66）, German Mutton （n=159）, and Dorper （n=93）, using the Illumina OvineSNP50 Genotyping BeadChip array. Each animal provided genotype information for 43 273 autosomal single nucleotide polymorphisms （SNPs）. We adopted two complementary haplotype-based statistics of relative extended haplotype homozygosity （REHH） and the cross-popu- lation extended haplotype homozygosity （XP-EHH） tests. In total, 707,755, and 438 genomic regions subjected to positive selection were identified in Sunite, German Mutton, and Dorper sheep, respectively, and 42 of these regions were detected using both REHH and XP-EHH analyses. These genomic regions harbored many important genes, which were enriched in gene ontology terms involved in muscle development, growth, and fat metabolism. Fourteen of these genomic regions overlapped with those identified in our previous genome-wide association studies, further indicating that these genes under positive selection may underlie growth developmental traits. These findings contribute to the identification of candidate genes of interest and aid in understanding the evolutionary and biological mechanisms for controlling complex traits in Chinese and western sheep.

Step-size selection for split-step based nonlinear compensation with coherent detection in 112-Gb/s 16-QAM transmission

Non-uniform step-size distribution is implemented for split-step based nonlinear compensation in singlechannel 112-Gb/s 16 quadrature amplitude modulation （QAM） transmission. Numerical simulations of the system including a 20 × 80 km uncompensated link are performed using logarithmic step size distribution to compensate signal distortions. 50% of reduction in number of steps with respect to using constant step sizes is observed. The performance is further improved by optimizing nonlinear calculating position （NLCP） in case of using constant step sizes while NLCP optimization becomes unnecessary when using logarithmic step sizes, which reduces the computational effort due to uniformly distributed nonlinear phase for all successive steps.

H2S gas sensor based on integrated resonant dual-microcantilevers with high sensitivity and identification capability

Detection of trace-level hydrogen sulfide(H2 S)gas is of great importance whether in industrial production or disease diagnosis.This research presents a novel H2 S gas sensor based on integrated resonant dual-microcantilevers which can identify and detect trace-level H2 S in real-time.The sensor consists of two integrated resonant microcantilever sensors with different functions.One cantilever sensor can identify H2 S by outputting positive frequency shift signals,while the other cantilever sensor will detect H2 S as a normally used cantilever sensor with negative frequency shifts.Combined the two cantilever sensors,the proposed gas sensor can distinguish H2 S from a variety of common gases,and the detection limit to H2 S of the sensor is as sensitive as below 1 ppb.

Negative Selection of Written Language Using Character Multiset Statistics

We study the combination of symbol frequence analysis and negative selection for anomaly detection of discrete sequences where conventional negative selection algorithms are not practical due to data sparsity.Theoretical analysis on ergodic Markov chains is used to outline the properties of the presented anomaly detection algorithm and to predict the probability of successful detection.Simulations are used to evaluate the detection sensitivity and the resolution of the analysis on both generated artificial data and real-world language data including the English Wikipedia.Simulation results on large reference corpora are used to study the effects of the assumptions made in the theoretical model in comparison to real-world data.