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Designing highly active catalysts at an atomic scale is required to drive the hydrogen evolution reaction (HER). Copper–platinum (Cu-Pt) dual sites were alloyed with palladium nanorings (Pd NRs) containing 1.5 atom % Pt, using atomically dispersed Cu on ultrathin Pd NRs as seeds. The ultrafine structure of atomically dispersed Cu-Pt dual sites was confirmed with X-ray absorption fine structure (XAFS) measurements. The Pd/Cu-Pt NRs exhibit excellent HER properties in acidic solution with an overpotential of only 22.8 mV at a current density of 10 mA cm−2 and a high mass current density of 3002 A g−1(Pd+Pt) at a −0.05 V potential.

To design highly efficient and low-cost electrocatalysts for oxygen evolution reaction (OER) is a great challenge for electrochemical water splitting. Herein, we report the preparation of hierarchical Fe-doped NiO x nanotubes assembled from ultrathin nanosheets with a thickness of 2.4 nm. X-ray photoelectron spectroscopy (XPS) spectra, X-ray absorption near-edge structure (XANES) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy investigations have been suggested that the incorporation of Fe results in abundant trivalent nickel and nickel vacancies. Benefitting from their unique geometric and electronic structure, the as-prepared hierarchical Fe-doped NiO x nanotubes exhibit outstanding OER activity and stability, with overpotential of 310 mV and a small Tafel slope of ~ 49 mV dec −1 at 10 mA cm −2 .

We prepared single Ni atoms embedded in an N-doped carbon catalyst with the assistance of metal organic frameworks. The dispersion of Ni atoms was verified by taking X-ray absorption fine structure measurements. Under the typical conditions for hydrogenation of acetylene, this single-site heterogeneous catalyst showed great potential as an alternative to Pd-based materials.

Platinum (Pt)-based nanostructures are the most efficient catalysts for the oxygen reduction reaction (ORR) in acid media. Here, Pt9 Ni wavelike nanowires (W-NWs) have been synthesized by etching Pt3 Ni@PtNi2 core-shell nanowires with 2,5-dihydroxyterephthalic acid for 24 hours. Compared to the commercial Pt/C catalyst, the free-standing Pt9 Ni W-NWs show improvements of up to 9.3 times for mass activity and 12.6 times for specific activity, respectively.

We report an atomic-scale controllable synthesis of the face-centered cubic Ru overlayers on Pd nanosheets (Pd@Ru NSs) by a solution-based epitaxial growth method. The thickness of Ru overlayers can be accurately tuned at an atomic level, which has been confirmed by atomic force microscopy and high-angle annular dark-field scanning transmission electron microscopy. After annealing in air, the Pd@Ru NSs were transformed to PdO@RuO

Atom diffusion processes govern the structure and composition of core-shell nanomaterial, which play a crucial role in determining their properties. By using aberration-corrected high-resolution transmission electron microscopy and X-ray absorption near-edge structure spectroscopy in combination with in situ X-ray diffraction, we confirm that single-atom diffusion of Au to Ag2S occurs, and that the transition from the Au@Ag2S core-shell nanostructure to AuAgS-AuAgx or Ag3AuS2-AuAgx heterostructures was observed. Moreover, the phase of the ternary sulfide induced by Au single-atom diffusion in Ag2S is determined by the ratio of Au and Ag, thus exhibiting a significant difference in the photocatalytic activity performance.

Engineering noble metal nanostructures at the atomic level can significantly optimize their electrocatalytic performance and remarkably reduce their usage. We report the synthesis of atomically dispersed Pt on screw-like Pd/Au nanowires by using ultrafine Pd nanowires as seeds. Au can selectively grow on the surface of Pd nanowires by an island growth pattern to fabricate surface defect sites to load atomically dispersed Pt, which can be confirmed by X-ray absorption fine structure measurements and aberration corrected HRTEM images. The nanowires with 2.74 at % Pt exhibit superior HER properties in acidic solution with an overpotential of 20.6 mV at 10 mA cm-2 and enhanced alkaline ORR performance with a mass activity over 15 times greater than the commercial platinum/carbon (Pt/C) catalysts.

To explore rapidly the potential chemical markers for differentiating Pseudostellariae Radix from different cultivated fields :and germplasms, a method is proposed based on ultra-performance liquid chromatographytriple time-of-flight mass/mass spectrometry (UPLC-Triple TOF-MS/MS) coupled with multivariate statistical analysis. Peak matching, peak alignment, and noise filtering were used in analyzing mass spectrometric data. Accurate m/z value analysis of MS data based on software of database search and MS/MS fragment analysis were applied to identify constituents. The obtained. data were statistically analyzed with hierarchical cluster analysis (HCA), principal component analysis (PCA), and partial least squared-discriminant analysis (PLS-DA) to compare the differences among these samples. The PLS-DA loading plot obtained from all mass data showed that 21 compounds were identified as the potential chemical markers to characterize the samples. The results provide experimental data to reveal the influence of ecological environments and germplasms on metabolite biosynthesis in Pseudostellariae Radix.

Heterogeneous noble-metal-based catalysis plays an essential role in the production of fine chemicals. Rh-based catalysts are one of the most active candidates for indole synthesis. However, it is still highly desired to develop heterogeneous Rh-based catalysts with high activity and selectivity. In this work, a general, facile wet-chemical method is reported to synthesize ultrathin amorphous/crystalline heterophase Rh and Rh-based bimetallic alloy nanosheets (NSs), including RhCu, RhZn, and RhRu. Impressively, the amorphous/crystalline heterophase Rh NSs exhibit enhanced catalytic activity toward the direct synthesis of indole compared to the crystalline counterpart. Importantly, the obtained amorphous/crystalline heterophase RhCu alloy NSs can further enhance the selectivity to indole of >99.9% and the conversion is 100%. This work demonstrates the importance of phase engineering and metal alloying in the rational design and synthesis of tandem heterogeneous catalysts toward fine chemical synthesis.

We report a one-pot synthesis of atomically dispersed Ru on ultrathin Pd nanoribbons. By using synchrotron radiation photoemission spectroscopy (SRPES) and extended X-ray absorption fine structure (EXAFS) measurements in combination with aberration corrected high-resolution transmission electron microscopy (HRTEM), we show that atomically dispersed Ru with content up to 5.9% was on the surface of the ultrathin nanoribbon. Furthermore, the ultrathin Pd/Ru nanoribbons could remarkably prohibit the hydrogenolysis in chemoselective hydrogenation of C═C bonds, leading to an excellent catalytic selectivity compared with commercial Pd/C and Ru/C.

A new strategy for achieving stable Co single atoms (SAs) on nitrogen-doped porous carbon with high metal loading over 4 wt % is reported. The strategy is based on a pyrolysis process of predesigned bimetallic Zn/Co metal–organic frameworks, during which Co can be reduced by carbonization of the organic linker and Zn is selectively evaporated away at high temperatures above 800 °C. The spherical aberration correction electron microscopy and extended X-ray absorption fine structure measurements both confirm the atomic dispersion of Co atoms stabilized by as-generated N-doped porous carbon. Surprisingly, the obtained Co-Nx single sites exhibit superior ORR performance with a half-wave potential (0.881 V) that is more positive than commercial Pt/C (0.811 V) and most reported non-precious metal catalysts. Durability tests revealed that the Co single atoms exhibit outstanding chemical stability during electrocatalysis and thermal stability that resists sintering at 900 °C. Our findings open up a new routine for general and practical synthesis of a variety of materials bearing single atoms, which could facilitate new discoveries at the atomic scale in condensed materials.

Accelerating future water shortages in the world require a development of operational water governance models as illustrated by the case studies. Conversion process and its coupling simulation of surface water and groundwater are the foundation of water resources development, utilization, and scientific evaluation. In order to simulate the impact of climate change on the water cycle in basins, the quasi-distributed watershed Surface Water (SW) model was coupled with the fully-distributed Ground Water (GW) model in the simulation. The Hydrologic Response Units (HRU) in the SW model were exchanged with cells in the GW model. By using the HRU–CELL conversion interface, the distributed groundwater recharge rate (RCH) and the groundwater evapotranspiration (EVT) calculated by the SW model were imported into the RCH and EVT modules of the GW model. The application of groundwater simulation in the Heihe River basin demonstrated that the correlation coefficient between the simulation results and the measured values was 0.89, the deterministic coefficient of the simulation results was 0.86. Under future predictions the discharge from the Heihe River will decrease in the first 20 years (2020–2039). In the later 20 years (2040–2059) the discharge will increase. The simulation groundwater along with the recharge value showed the same change trend of the measured groundwater level. The coupled SW–GW model was capable of predicting the future water cycle.

Herein, a series of porous nano-structured carbocatalysts have been fused and decorated by Mo-based composites, such as Mo2 C, MoN, and MoP, to form a hybrid structures. Using the open porosity derived from the pyrolysis of metal-organic frameworks (MOFs), the highly dispersive MoO2 small nanoparticles can be deposited in porous carbon by chemical vapor deposition (CVD). Undergoing different treatments of carbonization, nitridation, and phosphorization, the Mo2 C-, MoN-, and MoP-decorated carbocatalysts can be selectively prepared with un-changed morphology. Among these Mo-based composites, the MoP@Porous carbon (MoP@PC) composites exhibited remarkable catalytic activity for the hydrogen evolution reaction (HER) in 0.5 m H2 SO4 aqueous solution versus MoO2 @PC, Mo2 C@PC, and MoN@PC. This study gives a promising family of multifunctional lab-on-a-particle architectures which shed light on energy conversion and fuel-cell catalysis.

Herein, we report an epitaxial-growth-mediated method to grow face-centered cubic (fcc) Ru, which is thermodynamically unfavorable in the bulk form, on the surface of Pd-Cu alloy. Induced by the galvanic replacement between Ru and Pd-Cu alloy, a shape transformation from a Pd-Cu@Ru core-shell to a yolk-shell structure was observed during the epitaxial growth. The successful coating of the unconventional crystallographic structure is critically dependent on the moderate lattice mismatch between the fcc Ru overlayer and PdCu3 alloy substrate. Further, both fcc and hexagonal close packed (hcp) Ru can be selectively grown through varying the lattice spacing of the Pd-Cu substrate. The presented findings provide a new synthetic pathway to control the crystallographic structure of metal nanomaterials.

Cost-efficient utilization of Pt in the oxygen reduction reaction (ORR) is of great importance for the potential industrial scale demand of proton-exchange membrane fuel cells. Designing a hollow structure of a Pt catalyst offers a great opportunity to enhance the electrocatalytic performance and maximize the use of precious Pt. Herein we report a routine to synthesize ultrathin icosahedral Pt-enriched nanocages. In detail, the Pt atoms were conformally deposited on the surface of Pd icosahedral seeds, followed by selective removal of the Pd core by a concentrated HNO3 solution. The icosahedral Pt-enriched nanocage that is a few atomic layers thick includes the merits of abundant twin defects, an ultrahigh surface/volume ratio, and an ORR-favored Pt{111} facet, all of which have been demonstrated to be promoting factors for ORR. With a 10 times higher specific activity and 7 times higher mass activity, this catalyst shows more extraordinary ORR activity than the commercial Pt/C. The ORR activity of icosahedral Pt-enriched nanocages outperforms the cubic and octahedral nanocages reported in the literature, demonstrating the superiority of the icosahedral nanocage structure.

The structure competition and evolution in minimum-energy nanoparticle clusters are studied in detail, which will not only benefit our control of the structure and thus the properties of NP clusters, but also promote our understanding of normal crystal nucleation and growth.

Summary The size and shape control of amorphous nanomaterials has long been a bottleneck restricting their further development. Here, we present a general approach to synthesize more than twenty kinds of amorphous metal oxide nanosheets. The amorphous state of the nanosheets is determined using aberration-corrected high-resolution transmission electron microscopy and X-ray diffraction. By using extended X-ray absorption fine structure analysis, we demonstrate that amorphous nanosheets have a larger interatomic distance and a looser packing characteristic compared with crystalline counterparts. The as-prepared amorphous FeOx nanosheets are used as sodium-ion batteries anode materials, exhibiting notable performance with a specific capacity of 263.4 mAh g−1 at 100 mA g−1 and long-term cyclic stability. Significantly, a reversible amorphous-crystalline-amorphous structure transformation phenomenon during the cycling test is observed at the atomic scale.

Core-shell noble metal catalysts have gained significant attention in the past few decades, as they not only reduce the use of noble metals effectively but also exhibit unique properties derived from the synergistic effect between core and shell metals. In particular, regulating the surface structure of shells to maximize the atomic utilization efficiency of noble metals is critically important. Controlling the shell thickness of noble metal catalysts at the atomic level as an efficient approach to realize this goal has been attracting growing attention; this approach involves the formation of ultrathin shells (typically 2-6 atomic layers), monolayers, or even atomically dispersed noble metals embedded in the host metal. These strategies drive the core/support metals to improve the number of active sites and the intrinsic activity of the deposited noble metals remarkably, meanwhile minimizing the usage of noble metals. Herein, recent advances regarding atomic control of the core-shell noble metal catalysts is reviewed, with focus on the surface regulation. First, synthesis methods and surface structures are summarized, and then catalytic applications of these architectures are highlighted.

The activity and stability of bimetallic nanocatalysts strongly depend on their structures, compositions, and interfaces. Here, we report the synthesis of mesoporous Pd@Ru core-shell bimetallic nanorods composed of face-centered cubic Pd and hexagonal close-packed Ru. The nanorods have two types of cavities with diameters of 3.0 ± 0.9 and 20.3 ± 8.1 nm. The mutual diffusion process between Ru and Pd is characterized by the high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy mapping, and the synchrotron radiation photoemission spectroscopy measurements. The mesoporous Pd@Ru nanorods exhibit superior catalytic performance and stability for hydrogen evolution reactions (overpotentials of 30 mV at 10 mA·cm-2 in 1.0 M KOH solution and 37 mV at 10 mA·cm-2 in 0.5 M H2SO4 solution).

To analyze the correlation between index components and climatic factors of Pseudostellariae Radix.Correlation analysis ( CA), partial least square (PLS) and PCA ordination were applied to analyze the correlation of index components in Pseudostellariae Radix and climatic factors, and to explore the main climatic factors affecting the accumulation of index components in Pseudostellariae Radix.The origin and harvest time had influence on index components. The monthly minimum temperature, monthly average humidity, monthly precipitation and the annual precipitation were the dominant factors influencing the content of index components.Through the positive and negative correlation between climatic factors and index components, it could explain the rationality of traditional harvest time and the reason of high content of heterophyllin B in Pseudostellariae Radix from Jiangsu Jurong.

Platinum (Pt)-based nanostructures are the most efficient catalysts for the oxygen reduction reaction (ORR) in acid media. Here, Pt

This work was designed to investigate proteins differentially expressed in cultivated Pseudostellaria heterophylla and its wild type using i TRAQ proteomics approach. The extracted proteins were digested using FASP method and identified by i TRAQ coupled with LC-MS/MS technology and then analyzed by Protein Pilot 5.0 search engine. Proteins differentially expressed were searched through comparison of relatively quantified proteins. The analysis was conducted using GO(gene ontology), KEGG and STRING. A total of 3 775 proteins were detected, among them, 3 676 proteins can be quantified, of which 127 proteins were up-regulated and 205 were down-regulated in cultivated Pseudostellaria heterophylla. We found 71 significantly differentially expressed proteins for further analysis. These proteins were classified into nine categories: heat shock proteins, transferases, oxidoreductases, lyases, isomerases, ligases, hydrolases, tubulin and translocases. The results indicated that the carbohydrate and cellular amino acids metabolism of cultivated Pseudostellaria heterophylla were weaker than its wild type and its ability of responding to stress was much stronger. GWD1, PHS1, GBE1, PGM, and BAM1 are the important proteins to regulate sucrose; met E and CYS are the key proteins that regulate amino acids in cultivated and wild Pseudostellaria heterophylla. This will provide the basic information for exploring the cause of secondary metabolites differences in different ecotype of Pseudostellaria heterophylla and the protein mechanism of its quality formation.

An analytical method based on UFLC-QTRAP-MS/MS was established for simultaneous determination of thirty-three components including steroidal saponins, homoisoflavonoids, amino acids and nucleosides in Ophiopogonis Radix. Thirty-three target components of commercial medicinal materials of Maidong were comparative analysis. Synergi™ Hydro-RP 100 column (2.0 mm × 100 mm, 2.5 μm) was used with 0.1% formic acid solution-0.1% formic acid acetonitrile for gradient elution at a flow rate of 0.4 mL·min⁻¹. In addition, multiple reaction monitoring (MRM) mode was employed. The data were comprehensively processed and analyzed with hierarchical clustering analysis(HCA), principal component analysis(PCA) and partial least squares discriminant analysis(PLS-DA) methods. All components showed good linearity(

A method, for determination of saponins, amino acids and nucleosides in Panacis Japonici Rhizoma of ultra fast liquid chromatography with triple quadrupole linear ion trap mass spectrometry (UFLC-QTRAP-MS/MS), was established to investigate the effect of different processing methods on the target components of Panacis Japonici Rhizoma. The chromatographic separation was performed on a XBridgeC₁₈(4.6 mm×100 mm, 3.5 μm) at 30 °C with a gradient elution of 0.1% formic acid solution-0.1% formic acid acetonitrile, and the flow rate was 0.8 mL·min⁻¹, using multiple-reaction monitoring (MRM) mode. The grey relational analysis was adopted for the analysis of different processing samples. The results showed that the thirty-three constituents were in a good linear range and the correlation coefficient was greater than 0.999 0; the precision, repeatability and stability were good; the average recovery rates were between 95.33% and 101.8%, and the relative standard deviations were less than 5%. The result of grey relational analysis showed that the complete rhizomes without peeling, which were adopted for the microwave dried method, had the best quality. The established method was accurate and reliable, which could be used to appraise the quality of Panacis Japonici Rhizoma. Our study may lay the way for the processing method of Panacis Japonici Rhizoma in optimization,normalization and standardization.

Dao-di herbs have been recognized as "quality models" with a firmly stable status. The formation of Dao-di herbs quality is involved from the genetic inheritance on the molecular level to the metabolic phenotype of final products, and the full material-based biosynthetic pathway remains unknown. In recent years, an increasing variety of omics technologies has provided new methods and ideas for the analysis of complex life systems and are suitable for explanation of quality formation in Dao-di herbs as well. In order to alleviate the scarcity of natural resources and offer scientific guidance of transplanting varieties, achievements of omics in the aspects of Dao-di herbs from genetics to phenotyping, the biosynthetic pathway of secondary metabolites, the interaction with human body and the new methods of quality evaluation have been summarized. It will be a fundamental work for protection and utilization of Chinese medicine resources.

An analytical method based on UFLC-QTRAP-MS/MS was developed for simultaneous determination of fifteen components including eleven lignans (schizantherin B, schisandrol B, schizandrin C, γ-schisandrin, deoxyschizandrin, schisantherin, schisandrin, schisanhenol, gomisin D, gomisin J, and angeloylgomisin H) and organic acids (S)-malic acid, D(-)-tartaric acid, protocatechuic acid, and quinic acid) in Schisandrae Chinensis Fructus. Samples from different product specifications were evaluated and analyzed. The chromatographic separation was performed on a Synergi™ Hydro-RP 100Å column (2.0 mm×100 mm, 2.5 μm) at 40 °C with a gradient elution by employing 0.1% aqueous formic acid (A)-acetonitrile (B) as the mobile phase, and the flow rate was 0.4 mL·min⁻¹, using an electrospray ionization (ESI) source and multiple reaction monitoring (MRM) mode. Fifteen components were evaluated synthetically by TOPSIS and gray related degree. The results showed that fifteen components had good linearity (r0.999 90), and the limits of detection were all satisfactory. The average recoveries of standard addition for the compounds were between 95.42 % and 98.86 %, and the relative standard deviations were less than 5%. The greatest difference of ri in grey related degree was 58.1%, whilst the greatest difference of Ci value in TOPSIS method was 94.8%. The results of these two methods showed that the holistic quality of No. 14 sample was the best. The developed method was accurate and reliable, which was suitable for the simultaneous determination of multiple functional substances and able to provide a new basis for the comprehensive assessment and overall control of the quality of Schisandrae Chinensis Fructus.

The design of active, selective, and stable CO

Assembly of noble metal nanocrystals into free-standing two-dimensional (2D) nanostructures with a regular shape is still a challenge. Here we report the preparation of a novel 2D AuAg nanosheet with length of 1.50 ± 0.30 μm, width of 510 ± 160 nm, and thickness of ∼100 nm via the assembly of ultrathin AuAg nanowires in the presence of the triblock copolymer Pluronic P123. The self-assembly of P123 and the fusion behavior of the nanowires during the assembly process are the key reasons for the formation of AuAg nanosheets in P123. Furthermore, the obtained AuAg nanosheet@P123 is used as the active material in a memory device that exhibits the write-once-read-many-times memory behavior.

The genes encoding six novel esterolytic/lipolytic enzymes, termed LC-Est1∼6, were isolated from a fosmid library of a leaf-branch compost metagenome by functional screening using tributyrin agar plates. These enzymes greatly vary in size and amino acid sequence. The highest identity between the amino acid sequence of each enzyme and that available from the database varies from 44 to 73%. Of these metagenome-derived enzymes, LC-Est1 is characterized by the presence of a long N-terminal extension (LNTE, residues 26–283) between a putative signal peptide (residues 1–25) and a C-terminal esterase domain (residues 284–510). A putative esterase from Candidatus Solibacter usitatus (CSu-Est) is the only protein, which shows the significant amino acid sequence identity (46%) to the entire region of LC-Est1. To examine whether LC-Est1 exhibits activity and its LNTE is important for activity and stability of the esterase domain, LC-Est1 (residues 26–510), LC-Est1C (residues 284–510), and LC-Est1C* (residues 304–510) were overproduced in E. coli, purified, and characterized. LC-Est1C* was only used for structural analysis. The crystal structure of LC-Est1C* highly resembles that of the catalytic domain of Thermotoga maritima esterase, suggesting that LNTE is not required for folding of the esterase domain. The enzymatic activity of LC-Est1C was lower than that of LC-Est1 by 60%, although its substrate specificity was similar to that of LC-Est1. LC-Est1C was less stable than LC-Est1 by 3.3°C. These results suggest that LNTE of LC-Est1 rather exists as an independent domain but is required for maximal activity and stability of the esterase domain.

Exploration of low-cost and earth-abundant photocatalysts for highly efficient solar photocatalytic water splitting is of great importance. Although transition-metal dichalcogenides (TMDs) showed outstanding performance as co-catalysts for the hydrogen evolution reaction (HER), designing TMD-hybridized photocatalysts with abundant active sites for the HER still remains challenge. Here, a facile one-pot wet-chemical method is developed to prepare MS2–CdS (M=W or Mo) nanohybrids. Surprisedly, in the obtained nanohybrids, single-layer MS2 nanosheets with lateral size of 4–10 nm selectively grow on the Cd-rich (0001) surface of wurtzite CdS nanocrystals. These MS2–CdS nanohybrids possess a large number of edge sites in the MS2 layers, which are active sites for the HER. The photocatalytic performances of WS2–CdS and MoS2–CdS nanohybrids towards the HER under visible light irradiation (>420 nm) are about 16 and 12 times that of pure CdS, respectively. Importantly, the MS2–CdS nanohybrids showed enhanced stability after a long-time test (16 h), and 70 % of catalytic activity still remained.

The controlled synthesis of gold nanocrystals has been the subject of intensive studies for decades because the properties and functions of gold nanomaterials are highly dependent on their particle size, shape, and dimensionality. Especially, anisotropic gold nanocrystals, such as nanowires, nanobelts, nanoplates and nanosheets, have attracted much attention due to their striking properties and promising applications in electronics, catalysis, photonics, sensing and biomedicine. In this review, we will summarize the recent developments of onedimensional (1D) and two-dimensional (2D) gold nanostructures. Various kinds of synthetic methods for preparation of these 1D and 2D gold nanocrystals will be described. Moreover, we will also briefly introduce the properties and potential applications of these 1D and 2D gold nanocrystals.

In order to study the influence of ecological environment regarding the synthesis and accumulation of metabolites in Eucommiae Cortex, LC-QTOF MS/MS method combined with multivariate statistical analysis was used to analyze the differences of chemical constituents in Eucommiae Cortex from different habitats. Through the analysis of the multistage tandem mass spectrometry, the characteristic peaks were extracted with mass spectrometry data peak matching, peak alignment, and noise filtering. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were used for data processing. The chemical constituents were identified or tentative presumed according to MS accurate mass and MS/MS spectrometry fragmentation information, combined with the software of database search, comparison with reference standards and literature. The results show the differences among samples of Eucommiae Cortex from different habitats are distinguishable. A total of 23 chemical constituents in Eucommiae Cortex were identified or tentative presumed. Among of them, 14 kinds of common differential chemical constituents (aucubin, geniposidic acid, neochlorogenic acid, syringin, olivil-4',4'-di-O-β-D-glucopyranoside, chlorogenic acid, cryptochlorogenic acid, 1-hydroxypinoresinol- 4',4'-di-O-β-D-glucopyranoside, caffeic acid, pinoresinol-di-O-β-D-glucopyranoside, syringaresionl-di-O-β-D-glucopyranoside, pinoresinol-4'-O-β-D-glucopyranoside, eucommiol, isochlorogenic acid C and asiatic acid) presented different changing laws. This study provides basic information for revealing the influence law of ecological environment on the biosynthesis of metabolites in Eucommiae Cortex.

Unmanned aerial vehicle (UAV) flight control system often needs the acquisition of sensor signal in analog form. In that case, the accuracy of the analog signal acquisition has a very important influence on the UAV flight control system. During the collection of analog signal, noise can have a negative effect on the accuracy of this collection, so we need to filter out the noise. However, some kinds of noise cannot be filtered out with hardware filters, which makes it necessary to combine oversampling technology and digital filters. In this paper, we make use of own-designed circuit to discuss some relative problems about the improvement of the analog data acquisition accuracy with oversampling technology which Verify the effectiveness of the oversampling method by comparing the traditional sampling method and the oversampling technology.

MoS2, TaS2, TiS2, WSe2 and TaSe2 nanobelts decorated with a PtAg alloy or Pt NPs have been successfully synthesized by etching the 2D nanosheets under a mild reaction condition followed by the subsequent nanosheet-to-nanobelt transformation mediated by the PVP template. The PtAg-MoS2 hybrid nanobelt coated with PVP is used as the active material in a memory device, which exhibits the hysteresis behavior with the function of dynamic random access memory.