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Nanomaterials based colorimetric detection is an area of vital importance in the field of sensing applications. The nanoparticles are the main component of colorimetric sensor in replacing the natural enzyme based sensor. In this context, zero valent nanoparticles have revolutionized the field of optical sensing especially due to easily shift of electron, facile and low cost of preparation, and ease of surface modification. In this work, zero valent manganese nanoparticles (ZV-Mn NPs) are prepared through a simple and very quick method and modulated with new type of ionic liquid (IL). As-prepared materials were characterized through FE-SEM, HR-TEM, BET, FTIR, and XRD. Subsequently, the peroxidase like catalytic activity of pure and modified ZV-Mn NPs to catalyze oxidation of N,N′,N,N′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2) investigated. Moreover, the absorbance peak is observed at wavelength 652 nm. The enhanced catalytic activity of ZV-Mn NPs was attributed to the fast transfer of electron mechanism in between substrate and H2O2. The coating of IL on ZV-Mn NPs permitted a low limit of detection 0.2 M with a linear range of 10-280 M. This work can find wide spread interest in the colorimetric sensing applications. In order to verify the successful demonstration of H2O2 sensor, we have applied it in the dairy milk products with satisfactory results.

The permanent magnetic properties of Nd-Fe-B magnets strongly depend on the alloy composition. Machine learning is based on mathematical and information science methods and uses existing Nd-Fe-B data to predict the magnetic properties of Nd-Fe-B materials. We use the ensemble learning boosting method to establish the gradient boosting regression tree (GBRT) model for Nd 2 Fe 14 B melt-spun bonded magnets, in comparison with three other methods of machine learning: support vector machine (SVR), multiple linear regression (MLR), and random forest (RFR). The results show that the machine learning GBRT model developed using the ensemble learning algorithm has higher prediction accuracy and better stability than those three traditional machine learning (SVR, MLR, RFR) models used in the past to predict the magnetic properties of melt-spun Nd-Fe-B bonded magnets. We also used the GBRT model to predict hard magnetic properties of melt-spun Nd 2 Fe 14 B/Fe 3 B composite materials. Several new alloy compositions of melt-spun Nd-Fe-B bonded magnets and Nd 2 Fe 14 B/Fe 3 B composite materials with high-performances were also predicted. Machine learning based on the GBRT model can play an important role in the design, preparation, and development of melt-spun Nd 2 Fe 14 B bonded magnets and Nd 2 Fe 14 B/Fe 3 B composite materials.

Many large paleo-lakes in North China were formed after the Triassic Era. Seawater incursion events (SWIEs) in these lakes have been extensively discussed in the literature, yet lack reliable methodology and solid evidence, which are essential for reconstructing and confirming SWIEs. The present study employs specific marine biological markers (24- n -propyl and 24-isopropyl cholestanes) to trace SWIEs in a dated core taken from the Songliao Basin (SLB). Two SWIEs were identified. The first SWIE from 91.37 to 89.00 Ma, was continuous and variable but not strong, while the second SWIE from 84.72 to 83.72 Ma was episodic and strong. SWIEs caused high total organic carbon (TOC) and negative δ 13 C org values in the sediments, which were interpreted as an indication of high productivity in the lake, due to the enhancement of nutrient supplies as well as high levels of aqueous CO 2 , due to the mixing of alkaline seawater and acidic lake water. The SWIEs in SLB were controlled by regional tectonic activity and eustatic variation. Movement direction changes of the Izanagi/Kula Plate in 90 Ma and 84 Ma created faults and triggered SWIEs. A high sea level, from 90 to 84 Ma, also facilitated the occurrence of SWIEs in SLB.

TMR (tunneling magnetoresistance) has the characteristics of high sensitivity, large linear range, low power consumption, and easy miniaturization, and has received great attention in the field of miniaturized and high-performance magnetic sensors. Widely used in marine magnetic field detection, earthquake monitoring, industrial control, and other fields. In this paper, A TMR marine magnetometer with AC modulation and magnetic field feedback compensation is proposed, designed, and manufactured, which can be used for the measurement of weak marine magnetic fields. After testing, its measurement range is ±100,000nT, the noise fluctuation level is 0.27nT, and nonlinearity level reaches 0.07%. It works by means of ac modulation and real-time compensation of feedback magnetic field, which greatly reduces magnetic hysteresis and increases the linearity. Compared with the nonlinearity of TMR material (more than 20% within ±1Oe, more than 7% within ±0.3Oe), it has been significantly improved.

In this work, we have prepared a novel laminated bimodal structure with layer-by-layer distribution of α p and α s phase in high temperature titanium alloy by α+β phase rolling and aging treatment. The lamellar bimodal microstructure is comprised of long-primary α p and secondary α s phase in the Ti-6.0Al-3Sn-5Zr-0.5Mo-1.0Nb-1.0Ta-0.4Si-0.2Er alloy. During α+β phase rolling at 990 °C, the primary α p grain deformed to elongated layer structure, while the lamella secondary α s deformed to kinked and broken chaos morphology. After 800 °C for 1h stabilization and 700 °C for 5h aging treatment, the thickness of the elongated α p layer slightly grew, while the kinked and broken α s were recovered and partially recrystallized to form a layered fine grain structure. The lamellar bimodal microstructure, i.e., elongated primary α p with layered bimodal α s phase has enhanced strength and ductility of the high temperature titanium alloy. This enhanced strength and toughness is mainly attributed to the lamellae α p structure and layered fine α s grain formed by hot rolling and aging treatment.

In order to assess environmental exposure-associated human health risk of dioxin compounds for the population in the vicinity of a municipal solid waste incinerator (MSWI) in Shanghai, the atmospheric samples (n = 24) and soils samples (n = 96) were collected and analyzed to obtain the concentration level, pollution characteristics and seasonal changes of dioxin compounds in environmental medias. The toxicity equivalent concentration range of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was 30.9–409 fg WHO-TEQ·m−3 in atmosphere and 0.362–8.55 ng WHO-TEQ·kg−1 in soil. The non-carcinogenic health risk and carcinogenic health risk from PCDD/Fs environmental exposure of people living in the vicinity of the MSWI in Shanghai were all within the allowable range of the US Environmental Protection Agency, which implied that the MSWI in Shanghai did not produce additional risk for the population living in its vicinity.

Cucumber powdery mildew is a destructive foliar disease caused by Podosphaera xanthii (formerly known as Sphaerotheca fuliginea) that substantially damages the yield and quality of crops. The control of this disease primarily involves the use of chemical pesticides that cause serious environmental problems. Currently, numerous studies have indicated that some plant extracts or products potentially have the ability to act as natural pesticides to control plant diseases. It has been reported that turmeric (Curcuma longa L.) and its extract can be used in agriculture due to their insecticidal and fungicidal properties. However, the most effective fungicidal component of this plant is still unknown. In the current study, the crude extract of C. longa L. was found to have a fungicidal effect against P. xanthii. Afterwards, eight fractions (Fr.1–Fr.8) were gradually separated from the crude extract by column chromatography. Fraction 1 had the highest fungicidal effect against this pathogen among the eight fractions. The active compound, (+)-(S)-ar-turmerone, was separated from Fr 1 by semi-preparative high-performance liquid chromatography and identified based on its 1H nuclear magnetic resonance (NMR) and 13C NMR spectrum data. The EC50 value of (+)-(S)-ar-turmerone was found to be 28.7 µg/ml. The compound also proved to have a curative effect. This is the first study to report that the compound (+)-(S)-ar-turmerone has an effect on controlling this disease. These results provide a basis for developing a new phytochemical fungicide from C. longa L. extract.

The streamline curvature (SLC) method is still of great importance for modern compressor performance prediction. The models applied in it, such as minimum incidence, deviation and loss, affect prediction’s accuracy directly. An improved SLC approach is introduced in this paper, which is developed based on the analysis and summary of predecessor’s works. The improvement is embodied mainly in the incidence and loss, which is the result of a combination of the previous models and models’ revisions in order to consider the main effects for modern compressor cascade. A certain isolated stage axial transonic compressor is calculated by SLC method. The speed lines and span-wise aerodynamic parameters are compared with the experiment data to demonstrate the SLC approach presented in this paper.

The in-situ leaching of ionic rare earth minerals often causes serious nitride pollution in the mining area and surrounding areas. In this paper, the rare earth soil in the Zu Dong mining area of Long Nan, Gan Zhou city, was used as the research object. Through batch equilibrium adsorption tests, the adsorption properties of ammonium nitrogen in different sizes of rare earth soils, the adsorption dynamics and thermodynamics of ammonium nitrogen under different concentrations of ammonium sulfate solution, and the effect of the solution flow rate and concentration in the soil column under dynamic conditions on the adsorption of ammonium on the soil was systematically studied. The results showed that in different diameters of rare earth soils, the adsorption capacity was: clay (within 0.074 mm) > fine sand (range 0.074 to 0.25 mm) > sand (beyond 0.25 mm) > original soil (12.37% clay, 43.9% sandy soil, and 31.56% fine sand), indicating that the clay in the original soil played a major role; the adsorption of ammonium nitrogen in ionic rare earth soils satisfied the Langmuir model (the fitted R2 values all greater than 0.9), and the dynamics satisfied the quasi-second-order dynamics equation (the fitted R2 values all greater than 0.95), which showed that the adsorption of ammonium nitrogen in soil was monolayer adsorption and dominated by chemical adsorption process; the concentration of ammonia nitrogen, the speed of leaching, and the content of cations such as rare earths all play an important role in the adsorption of ammonia nitrogen in rare earths.

Though immensely successful, the standard model of particle physics does not offer any explanation as to why our Universe contains so much more matter than antimatter. A key to a dynamically generated matter–antimatter asymmetry is the existence of processes that violate the combined charge conjugation and parity (CP) symmetry 1 . As such, precision tests of CP symmetry may be used to search for physics beyond the standard model. However, hadrons decay through an interplay of strong and weak processes, quantified in terms of relative phases between the amplitudes. Although previous experiments constructed CP observables that depend on both strong and weak phases, we present an approach where sequential two-body decays of entangled multi-strange baryon–antibaryon pairs provide a separation between these phases. Our method, exploiting spin entanglement between the double-strange Ξ − baryon and its antiparticle 2 Ξ ¯ + , has enabled a direct determination of the weak-phase difference, ( ξ P  −  ξ S ) = (1.2 ± 3.4 ± 0.8) × 10 −2  rad. Furthermore, three independent CP observables can be constructed from our measured parameters. The precision in the estimated parameters for a given data sample size is several orders of magnitude greater than achieved with previous methods 3 . Finally, we provide an independent measurement of the recently debated Λ decay parameter α Λ (refs.  4 , 5 ). The Λ Λ ¯ asymmetry is in agreement with and compatible in precision to the most precise previous measurement 4 . Using spin-entangled baryon–antibaryon pairs, the BESIII Collaboration reports on high-precision measurements of potential charge conjugation and parity (CP)-symmetry-violating effects in hadrons.