A High Performance Terahertz Waveguide Detector Based on a Low-Barrier Diode

A Schottky barrier diode with low-barrier is presented, based on which a terahertz waveguide detector working at 500-600 GHz is designed and fabricated. By using the InGaAs/InP material system, the feature of the low barrier is obtained which greatly improves the performance of the detector. The measured typical voltage responsivity is about 900 V/W at 50-560 OHz and is about 400 V/W at 560 600 GHz. The proposed broadband waveguide detector has the characteristics of simple structure, compact size, low cost and high performance, and can be used in a variety of applications such as imaging, moleeuIar spectroscopy and atmospheric remote sensing.

Variance-of-instantaneous-frequency detector and its performance evaluation

The optimum detector for a determined signal in the stationary white noise background In ideal channels is a matched filter．But its performance degenerates seriously in a practical underwater acoustic system for the complexityof underwater acoustic channels．Based on the estimation of instantaneous frequency sequence and its statistical characteristics，a new type ofrobust detector，Varlance－of-Instantaneous-Frequency Detector（VIFD for short），is presented for the detection of CW pulse according to the features of underwater acousticchannels and operating environment of active sonars． It is proved through theoretical analysis，simulation and experiments that VIFD is promising for its robustness in nonstatlonary interference background and channels and that it is alsorobust for the fluctuations and decny of signal or mlsmatch caused by Doppler－frequency shift．

Study on chromatographic fingerprint of sarcandra glabra (Thunb.) by microwave-assisted extraction coupled to HPLC/DAD

Microwave-assisted extraction(MAE)was used for extraction of effective components of sarcandra glabra(Thunb.),and then chromatographic fingerprint of sarcandra glabra(Thunb.)was studied by high performance liquid chromatography/diode array detector(HPLC/DAD).The conditions of MAE were optimized by an orthogonal experiment,and then the authentication and validation of the chromatographic fingerprint were conducted.Nine peaks were identified as common peaks in the fingerprint chromatograms,and isofraxidin was considered as a reference compound and quantified.Relative standard deviations of retention time and peak area of each component were less than 3% and 8%,respectively.Similarity and difference analysis were conducted by use of PCA and relation coefficient.Twenty batches of sarcandra glabra(Thunb.)samples from two different producing areas could be classified into two different groups in the PCA model.The results showed that MAE-HPLC/DAD method was simple,efficient and stable for the study of complex chromatographic fingerprint of sarcandra glabra(Thunb.),which could provide more reliable and precise information for quality evaluation.

Quest towards ultimate performance in superconducting nanowire single photon detectors

In 2007,superconducting nanowire single photon detectors(SSPD or SNSPD)[1]made an outstanding impact in the field of quantum information technology by demonstrating quantum key distribution(QKD)over a 200-km optical fiber with a 42-dB optical loss using a practical SNSPD system[2].This successful demonstration was realized thanks to its

Phytochemical Analysis of Ziziphus jujuba Leaves in Six Cultivars at the Whole Life Stage by High Performance Liquid Chromatography

Leaves of Ziziphus jujuba Mill.（Z. jujuba） were used as a folk medicine to treat children suffering from typhoid fever, furuncle and ecthyma in China. The present study was to establish a high performance liquid chroma- tography-diode array detector（HPLC-DAD） method for quality control of Z. jujuba leaves. The validated method was applied to the simultaneous characterization and quantification of sixteen main constituents in thirty samples, which comprised the whole life stage of Z. ]ujuba leaves from six cultivars in Yulin, Shannxi Province, China. HPLC fin- gerprint file of Z. jujuba leaves was set up and the results indicate that the major constituents of Z. jujuba leaves are （-）-catechin（1）, quercetin-3-O-robinobioside（3）, rutin（4） and quercetin-3-O-a-L-arabinosyl-（1---~2）-a-L-rhamnoside（6） with the total contents of the nine flavonoids in respective batch ranging from 18.52 mg/g to 39.51 mg/g. In addition, the contents of compounds depend on both the season and the cultivar. During ripening of Z. jujuba leaves, flavo- noids of all the cultivars present a similar trend： initially decrease from 25th, Jun. to 5th, Aug., 2015, and then in- crease for a period of time, finally slightly fluctuate on 5th Oct. The highest contents of total flavonoids were regis- tered on 25th Jun., 2015. Different cultivars have 50%--90% variation on the content for the three classes of com- pounds. Taken together, the results demonstrate that Z. jujuba leaves have great potential to be a new health-promoting resource based on flavonoids and the best sampling time of them is in June.

Simultaneous Analysis of Indapamide and Related Impurities in Sustained-Release Tablets by a Single-Run HPLC-PDA Method

The contents of indapamide and related impurities in generic indapamide sustained-release tablets were simultaneously detected by a single-run high performance liquid chromatography equipped with photodiode array detector(HPLC-PDA)method for the quality control in this paper.The results showed the method had a good selectivity and was validated through linearity,limits of detection and quantification,recovery,and precision.The linear ranges of indapamide,2-methyl-1-nitroso-2,3-dihydro-1H-indole(impurity A,ImA),4-chloro-N-(2-methyl-1H-indol-1-yl)-3-sulphamoyl-benzamide(impurity B,ImB)and 4-chloro-3-sulfamoylbenzoic acid(impurity 1,Im1)were 0.028-1.80μg/mL(R=0.99995),0.060-1.20μg/mL(R=0.9996),0.0324-1.20μg/mL(R=0.99985)and 0.060-1.20μg/mL(R=0.9997)with detection limits of 0.0093,0.012,0.012 and 0.006μg/mL,respectively.ImA and Im1 were not detectable in the generic drug.The content of indapamide was 96.7%of the labeled amount with a relative standard deviation(RSD)of 1.30%,and the percentage of ImB relative to the labeled amounts of indapamide was 0.106%with an RSD of 1.82%.The content of other unspecified impurities all met the reference quality standards.The results provided references for the quality control and the quality standard study of generic indapamide sustained-release tablets.

Preparations for the study on the cluster structure of ^(16)C

In order to look for a proposed cluster structure of 16C, simulation work was made. The simulation of the reaction dynamics give the resolution of the excitation energy on 16C which was reconstructed prior to breakup. The excitation energy resolution is typically ～200 keV at 2 MeV above the two body decay threshold for 16C→12Be+4He. Moreover,some performances of detectors tested using 241Am α source are also reported.