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Chiral optical metamaterials have attracted a great deal of attention due to their intriguing properties with respect to fundamental research and practical applications. For metamaterials with achiral structures, the system composed of metamaterials and obliquely incident light has extrinsic chirality and can produce circular dichroism (CD) effect. However, there have been few studies on the azimuth-dependent CD spectra of achiral metamaterials that have greatly improved our understanding of optical phenomena caused by external chirality. In this work, we experimentally studied the azimuth-dependent CD that originated from the extrinsic chirality of the metamaterials in an asymmetric-U shape and a U-bar-shape gold unit structure, separately. We explain the origin of the CD in the coupling of the macro-electric dipole and magnetic dipole, and the simulation results are in good agreement with the experiment. Our results provide a possible way to build an on-chip azimuth sensor based on azimuth-dependent CD spectra of metamaterials.

In quasi-two-dimensional (quasi-2D) perovskite films, carriers transport in the cascade structural systems involving various quantum wells (QWs) n, but their efficiency is limited by the severe nonradiative recombination within plentiful n = 1, 2, 3 domains induced by traditional ammonium bromide passivation. Here, we fabricate the quasi-2D films with the elimination of n = 1, 2, 3 domains by introducing the ionic liquid n-butylamine acetate (BAAc) instead of n-butylamine hydrobromide (BABr), which increases the photoluminescence quantum yield (PLQY) and lowers the surface roughness of films. Due to the anion exchange between BAAc and methylamine hydrobromide (MABr), BAAc exhibits a sole passivation effect on methylamine-based perovskites. As a result, the ionic liquid-derived perovskite light-emitting diodes (PeLEDs) display blue emission at 479 nm and show significantly improved performance on external quantum efficiency (EQE) and luminance. Our finding provides insights into the passivating effect of ionic liquid on quasi-2D perovskites and will benefit fabricating PeLEDs with enhanced performance.

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In quasi-two-dimensional (quasi-2D) perovskite films, carriers transport in the cascade structural systems involving various quantum wells (QWs)

The project of “multi-stage model rocket launch and payload recovery” is one of the important projects of China Aeromodelling Design Challenge (CADC). Participants are required to complete the model rocket launch and payload recovery task through scheme designs, simulation analysis, model assemblies and flight experiments, which has high requirements for innovation and practicality in scientific research. Aiming at the design requirements of the project, this paper takes the model rocket as the object, and provides a design scheme of multi-stage model rocket with good performance. In the scheme, light materials such as hard paper, carbon rods and light wood are used as the main materials of the rocket. It combines mature model rocket engines, flight control devices, shelves products and 3D printing components. Based on the self-developed multidisciplinary design optimization and performance evaluation software platform of the aircraft, the integrated design optimization and flight performance analysis of the engine, aerodynamics and trajectory are completed, and the detailed rocket design scheme is obtained. Through the production of rocket, ground tests and flight tests, the performance excellence and stability of the scheme to complete the tasks of safe launch, rocket aviation, reliable stage separation, first recovery and second payload recovery are verified. The design scheme proposed in this paper combines the simulation calculation with the physical flight experiment through the design optimization and performance evaluation platform, and puts forward the spin disturbance rejection scheme of the oblique engines and the first-stage tails. It proposes the method of “correction of wind” that determines the launch angle according to the speed and direction of wind to increase the flight height. It has the advantages of lightweight, modularization, high efficiency, low cost and high reliability.

Chlorpyrifos (CPF), an organophosphate pesticide widely used on food crops and in households, has been a critical public health concern due to its neurotoxic effects. Investigations of CPF-induced neurotoxicity have focused on dysregulation of acetylcholinergic signaling but recent work suggests that alterations in glutamatergic neurotransmission and astrocytic glutamate metabolism may occur. L-glutamate is a major excitatory neurotransmitter that is mostly removed from the synaptic cleft by astrocytic glutamate transporters. Here we assessed the effects of CPF on net glutamate uptake by human-induced pluripotent stem cell derived astrocytes using electrochemical analysis. Our microclinical analyzer (µCA) paired with screen-printed electrodes (SPE) offers an automated sensing system that can be used to monitor cellular metabolism and signaling. In this work, a platinum based SPE combined with the µCA was used to electrochemically quantify glutamate uptake in human astrocytes. Immobilized glutamate oxidase on electrode surfaces provided stable and sensitive glutamate detection. The temperature modification of these electrodes (37°C) led to a nearly four-fold improvement in sensitivity (0.84±0.04 nA/µM), with low limits of detection (2.8±0.1 µM), and quantitation (9.3±0.5 µM). The linear range of the sensor (1-667 µM) is on the same order as typical extracellular glutamate concentrations. These sensors were used to assess the net glutamate uptake efficiency by using escalating concentrations of glutamate (10-200 µM). Glutamate uptake was most efficient when astrocytes were exposed to 50 µM glutamate for 30min (50% net uptake). We are investigating acute and chronic effects of net glutamate uptake using sublethal doses of CPF (0-100 µM). Identifying these cellular mechanisms affected by CPF is critical for the understanding of the impact of organophosphate toxicity.

To overcome the urgency of zirconium and hafnium separation, a novel mesoporous silica sorbent (PS-G1.0-MSNs) modified with phosphorous-functionalized G1.0 PAMAM dendrimers was prepared. The adsorption and separation behaviors of PS-G1.0-MSNs adsorbent on Zr(IV) and Hf(IV) were perfromed as a function of acidity, contact time, temperature, and ion concentrations by batch sorption methods. The maximum adsorption capacities for Zr(IV) and Hf(IV) were 25.7 mg g−1 and 5.36 mg g−1 under optimal experimental conditions, respectively, and the separation factor βHf/Zr = 2.0 > 1 demonstrated that the prepared sorbent had preferential selectivity for Hf(IV) in rich Zr(IV) solution. Moreover, kinetic data indicated that the sorption process on Zr(IV) and Hf(IV) achieved equilibrium within 120 min, and followed the pseudo-first-order model with a rate-determining step. The adsorption amount increased as temperature raised from 283 K to 303 K and the isothermal data plotted with the Langmuir model was better than the Freundlich model with monolayer behavior. Thermodynamic data analysis indicated that the sorption process was spontaneous and endothermic. Furthermore, XPS analysis revealed that the metal ion adsorption was mainly induced by the chemical coordination of Zr(IV) and Hf(IV) ions with N, O, P atoms of amide and phosphate groups. The present work provides good guidelines on the design of high efficient sorbent for the separation of Hf(IV) from Zr(IV) solutions.

Dysregulations in metabolic and physiological cellular processes are generally accompanied by changes in concentration profiles of multiple biomarkers. Measuring dynamic changes in concentrations of several affected biomarkers can enhance our comprehension of the underlying disease pathophysiology and/or mechanisms of cytotoxicity. Most analytical detection techniques require samples to be obtained at pre-defined times for offline analysis. However, the inadequate temporal resolution of these methods can lead to key biological events that occur at shorter timescales, being overlooked. Electrochemical biosensors are relatively simple, cost-effective detection techniques that have been used extensively for continuous analyte monitoring, and more recently, for sensing multiple analytes. We describe the design and functionality of a novel electrochemical detection platform, comprising a screen-printed Pt electrode array, a microfluidic chip, and an automated pump and valve system, capable of quantitatively detecting up to eight analytes. As a proof of concept, we show the simultaneous, sensitive, and selective amperometric detection of four essential biomarkers- glucose, lactate, glutamate, and acetylcholine, in real time. We also demonstrate the biological application of this platform by continuously monitoring exocytotic glutamate release from human induced pluripotent stem cell-derived neuronal cultures over time. Excessive accumulation of glutamate in the synaptic cleft leads to prolonged stimulation of glutamate receptors on neurons, triggering a cascade of neurotoxic events that ultimately results in loss of neuronal function and cell death. The results suggest that our multianalyte electrochemical sensor platform can be coupled with more complex biological systems such as in vitro organotypic models, for the accurate monitoring of biomarker changes during adverse events like acute neurotoxicity and microbial infection.

Since the 1990s, China has implemented the policy of “suppress the second industry and develop the third industry” in order to promote the adjustment of social and economic structure, and thus the industry has begun to face industrial transformation. As time goes by, the material language of the existing industrial buildings gradually conveys a broken, desolate expressiveness, which makes people have a certain “sense of fright caused by the fracture of time”, and it has also brought negative impacts to the shaping of the image of a beautiful city. Therefore, we need to re-understand the expression methods of materials in existing industrial buildings according to the needs of the new era. Louis Kahn once said, “It is easier for materials to reveal the existence of meaning than space, and materials are easier to decode and illustrate. The rich texture and color of materials make it easier to perceive and grasp by human senses and has a more direct meaning than space.” Therefore, this paper explains the material types (material vocabulary) in the renovation of existing industrial buildings in China, and then through the analysis of related cases, derives the strategy and methods for the renovation of existing industrial buildings in China (materials pragmatics).

The insertion of organic spacers into halide perovskite slabs has offered a trade-off between the efficiency and stability of perovskite solar cells (PSCs). The layered structure of diammonium-intercalated cesium lead halide perovskites is virtually unexplored, in contrast to several works on the monoammonium system. In this report, we find that perovskite with 1,4-butanediammonium (BDA) and cesium cations can only form n = 1 and n = 2 layered isologues defined by the chemical formula of (BDA)Csn-1Pbn(I0.7Br0.3)3n+1, while the n = 3-4 ones will self-construct into unique heterostructures comprising separated quantum wells (QWs; n = 1-2) and 3D (n = ∞) perovskites. We highlight that the 2D/3D heterostructures show a structural resemblance to that of bulk heterojunction in organics, thus improving the charge separation and transport more than surface passivation. Solar cells based on the (BDA)Cs3Pb4I9.1Br3.9 (n = 4) absorbing layer delivered a power conversion efficiency (PCE) reaching 9.49% with ideal light and thermal stability.

A new financial agent-based time series model is developed and investigated by multiscale-continuum percolation system, which can be viewed as an extended version of continuum percolation system. In this financial model, for different parameters of proportion and density, two Poisson point processes (where the radii of points represent the ability of receiving or transmitting information among investors) are applied to model a random stock price process, in an attempt to investigate the fluctuation dynamics of the financial market. To validate its effectiveness and rationality, we compare the statistical behaviors and the multifractal behaviors of the simulated data derived from the proposed model with those of the real stock markets. Further, the multiscale sample entropy analysis is employed to study the complexity of the returns, and the cross-sample entropy analysis is applied to measure the degree of asynchrony of return autocorrelation time series. The empirical results indicate that the proposed financial model can simulate and reproduce some significant characteristics of the real stock markets to a certain extent.

In this paper, recently introduced permutation entropy and sample entropy are further developed to the fractional cases, weighted fractional permutation entropy (WFPE) and fractional sample entropy (FSE). The fractional order generalization of information entropy is utilized in the above two complexity approaches, to detect the statistical characteristics of fractional order information in complex systems. The effectiveness analysis of proposed methods on the synthetic data and the real-world data reveals that tuning the fractional order allows a high sensitivity and more accurate characterization to the signal evolution, which is useful in describing the dynamics of complex systems. Moreover, the numerical research on nonlinear complexity behaviors is compared between the returns series of Potts financial model and the actual stock markets. And the empirical results confirm the feasibility of the proposed model.

In the paper, based on the combination of sample entropy and complexity-invariant distance, a new synchrony-measured method, called the composite complexity synchronization (CCS), is proposed to measure the degree of synchrony of two time series with same data length. Implementing the multiscale cross-sample entropy and multiscale composite complexity synchronization (MCCS) analysis for seven representative stock market indexes, multiscale coupling behaviors of logarithmic returns are compared. Furthermore, the selective data of different sampling frequency within the same time period are applied to analyze the effect of sampling rate in the data on the MCCS behaviors. And we apply the ensemble empirical mode decomposition to decompose the stock logarithmic returns into the intrinsic mode functions and investigate the extent that they have inherited the coupling behaviors of original returns. Empirical results demonstrate the feasibility and effectiveness of the proposed method, and exhibit its superiority in distinguishing the very subtle synchrony behaviors among the time series.

In this work, CE-LIF was employed to investigate the amino acid metabolites produced by Escherichia coli (E. coli) in microbial fuel cell (MFC). Two peptides, l-carnosine and l-alanyl-glycine, together with six amino acids, cystine, alanine, lysine, methionine, tyrosine, arginine were separated and detected in advance by a CE-LIF system coupled with a homemade spontaneous injection device. The injection device was devised to alleviate the effect of electrical discrimination for analytes during sample injection. All analytes could be completely separated within 8 min with detection limits of 20-300 nmol/L. Then this method was applied to analyze the substrate solution containing amino acid metabolites produced by E. coli. l-carnosine, l-alanyl-glycine, and cystine were used as the carbon, nitrogen, and sulfur source for the E. coli culture in the MFC to investigate the amino acid metabolites during metabolism. Two MFCs were used to compare the activity of metabolism of the bacteria. In the sample collected at the running time 200 h of MFC, the amino acid methionine was discovered as the metabolite with the concentrations 23.3 μg/L.

Flavonoids are important active ingredients in many traditional Chinese medicines. In this paper, capillary electrophoresis with amperometric detection was employed to separate and detect eight flavonoids, rutin, quercetrin, quercetin, kaempferol, kaempferide, catechin, apigenin, and luteolin, in a home-made capillary electrophoresis device. Under the separation voltage of 2000 V, the eight flavonoids could be completely separated within 33 min in 18 mM borax running buffer at pH 10.2. Good linear relationships were obtained for all analytes and the detection limits for flavonoids ranged from 0.46 to 0.85 μM. Then, the method was applied to separate and determine the flavonoids in three traditional Chinese medicines, hippophae rhamnoides, hypericum perforatum, and cacumen platycladi. Finally, rutin, kaempferol, quercetin, and quercetrin were discovered in these medicines and the concentrations ranged from 0.28 to 9.94 mg/g. The recoveries of flavonoids ranged from 84.7 to 113%, which showed the high reliability of this method.

In this work, CE-LIF was employed to investigate the amino acid metabolites produced by Escherichia coli (E. coli) in microbial fuel cell (MFC). Two peptides, l-carnosine and l-alanyl-glycine, together with six amino acids, cystine, alanine, lysine, methionine, tyrosine, arginine were separated and detected in advance by a CE-LIF system coupled with a homemade spontaneous injection device. The injection device was devised to alleviate the effect of electrical discrimination for analytes during sample injection. All analytes could be completely separated within 8 min with detection limits of 20-300 nmol/L. Then this method was applied to analyze the substrate solution containing amino acid metabolites produced by E. coli. l-carnosine, l-alanyl-glycine, and cystine were used as the carbon, nitrogen, and sulfur source for the E. coli culture in the MFC to investigate the amino acid metabolites during metabolism. Two MFCs were used to compare the activity of metabolism of the bacteria. In the sample collected at the running time 200 h of MFC, the amino acid methionine was discovered as the metabolite with the concentrations 23.3 μg/L.

Flavonoids are important active ingredients in many traditional Chinese medicines. In this paper, capillary electrophoresis with amperometric detection was employed to separate and detect eight flavonoids, rutin, quercetrin, quercetin, kaempferol, kaempferide, catechin, apigenin, and luteolin, in a home-made capillary electrophoresis device. Under the separation voltage of 2000 V, the eight flavonoids could be completely separated within 33 min in 18 mM borax running buffer at pH 10.2. Good linear relationships were obtained for all analytes and the detection limits for flavonoids ranged from 0.46 to 0.85 μM. Then, the method was applied to separate and determine the flavonoids in three traditional Chinese medicines, hippophae rhamnoides, hypericum perforatum, and cacumen platycladi. Finally, rutin, kaempferol, quercetin, and quercetrin were discovered in these medicines and the concentrations ranged from 0.28 to 9.94 mg/g. The recoveries of flavonoids ranged from 84.7 to 113%, which showed the high reliability of this method.

Leptin deficiency is principally linked to metabolic disorders. Leptin knockout (LepΔI14/ΔI14) Sprague Dawley rats created by CRISPR/Cas9 is a new model to study metabolic disorders. We used a whole rat genome oligonucleotide microarray to obtain tissue-specific gene expression profiles of the white adipose tissue, liver and hypothalamus in LepΔI14/ΔI14 and wild-type (WT) rats. We found 1,651 differentially expressed (enriched) genes in white adipose tissue, 916 in the liver, and 306 in the hypothalamus in the LepΔI14/ΔI14 rats compared to WT. Gene ontology category and KEGG pathway analysis of the relationships among differentially expressed genes showed that these genes were represented in a variety of functional categories, including fatty acid metabolism, molecular transducers and cellular processes. The reliability of the data obtained from microarray was verified by quantitative real-time PCR on 14 representative genes. These data will contribute to a greater understanding of different metabolic disorders, such as obesity and diabetes.

A high-speed separation method of capillary MEKC with LIF detection had been developed for separation and determination of amino acids in laver. The CE system comprised a manual slotted-vial array (SVA) for sample introduction that could improve the separation efficiency by reducing injection volume. Using a capillary with 80 mm effective separation length, the separation conditions for amino acids were optimized. Applied with the separation electric field strength of 300 V/cm, the ten amino acids could be completely separated within 2.5 min with 10 mol/L Na2HPO4-NaOH buffer (pH = 11.5) including 30 mmol/L SDS. Theoretical plates for amino acids ranged from 72,000 to 40,000 (corresponding to 1.1-2.0 μm plate heights) and the detection limits were between 25 and 80 nmol/L. Finally, this method was applied to analyze the composition of amino acids in laver and eight known amino acids could be found in the sample. The contents of five amino acids, tyrosine, glutamic acid, glycine, lysine, and aspartic acid that could be completely separated in real sample were determined. The recoveries ranged from 82.3% to 123% that indicated the good reliability for this method in laver sample analysis.