Hefei Material Science and Technology Center

The Shanghai Coherent Light Facility (SCLF) is a newly proposed high repetition-rate X-ray FEL facility, based on an 8-GeV CW superconducting RF linac. It will be located at Zhangjiang High-tech Park, close to the SSRF campus in Shanghai, at the depth of ~38m underground and with a total length of 3.1 km. Using 3 phase-I undulators, the SCLF aims at generating X-rays between 0.4 and 25 keV at rates up to 1MHz. This paper describes the design concepts of this hard X-ray user facility.

Abstract Transition‐metal‐catalyzed cross‐coupling reactions are powerful tools for constructing carbon–carbon and carbon–heteroatom bonds. In this microreview we summarize the nickel‐catalyzed cross‐coupling reactions with pincer ligands. The reactions presented here include Kumada, Negishi, Suzuki, and Sonogashira reactions for the formation of different types of C–C bonds, as well as the thiolation of aryl iodides.

Abstract With the intensification of global environmental issues, corporate environmental information disclosure has received increasing attention. Different cultural and policy backgrounds have led to very different styles of corporate environmental information disclosure behavior. Whether Confucianism, the dominant culture that has influenced China for thousands of years, contributes to corporate environmental information disclosure deserves to be studied. Based on data from 3180 Chinese listed firms, this study confirms the positive effect of Confucian culture on environmental information disclosure. Meanwhile, Taoist culture and environmental regulation can positively moderate this effect. In addition, heterogeneity analysis unveils that Confucian culture plays a greater role in corporate environmental information disclosure for state‐owned firms and firms in highly polluting industries, while this role is weakened for firms with a high proportion of female executives and executives with foreign experience. This study links culture and environmental information disclosure, which helps to arouse the attention of whole society to utilize excellent traditional culture and helps the government to formulate effective environmental regulation policies.

Abstract The first example of a nickel‐catalyzed C–H trifluoromethylation of electron‐rich heteroarenes, including imidazopyridines, indoles and thiophenes, has been developed with the commercially available and relatively inexpensive industrial raw material iodotrifluoromethane (CF 3 I) as the trifluoromethylating reagent. The synthetic potential of this method is demonstrated by its successful application to the direct trifluoromethylation of the biologically active molecules melatonin and zolmitriptan. magnified image

By generating a temperature step in grid turbulence using two new methods (a mandoline and a toaster) the evolution of some first-, second-, third-, and fourth-order moment quantities of the temperature field in a thermal mixing layer are studied. The results confirm the earlier experimental findings of LaRue and Libby [Phys. Fluids 24, 597 (1981)] and LaRue et al. [Phys. Fluids 24, 1927 (1981)] who used a half-heated grid to generate the thermal field. It is also shown that although second-order quantities such as the heat flux coefficient and the centerline temperature variance appear to have reached their equilibrium values and that all quantities collapse well using the half-width of the mean temperature profile, the data is not consistent with self-similarity.

The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection applications. These materials are promising candidates for next-generation photodetectors (PDs) due to their unique optoelectronic properties and flexible synthesis routes. This review explores the approaches used in the development and use of optoelectronic devices made of different nanoscale perovskite architectures, including quantum dots, nanosheets, nanorods, nanowires, and nanocrystals. Through a thorough analysis of recent literature, the review also addresses common issues like the mechanisms underlying the degradation of perovskite PDs and offers perspectives on potential solutions to improve stability and scalability that impede widespread implementation. In addition, it highlights that photodetection encompasses the detection of light fields in dimensions other than light intensity and suggests potential avenues for future research to overcome these obstacles and fully realize the potential of nanoscale perovskite materials in state-of-the-art photodetection systems. This review provides a comprehensive overview of nanoscale perovskite PDs and guides future research efforts towards improved performance and wider applicability, making it a valuable resource for researchers.

Type 2 diabetes (T2D) with high morbidity and mortality is characterized by abnormal glucose and lipid metabolism due in part to insulin resistance in liver, which lead to elevated hyperglycemia and hyperlipidemia. This study sough to explore the effects of corosolic acid (CA) in different T2D models and explored the underlying mechanism. Separated from Eriobotrya japonica leaves, CA purity was above 95% measured by a HPLC method. Compared with cAMP and DEX induced T2D HepG2 model, CA significantly stimulated glucose consumption and improved glycogen accumulation by inhibiting PEPCK mRNA expression. And in cAMP and DEX induced T2D zebrafish model, CA reduced glycogen degradation and increased glucose consumption by regulating some key enzymes in carbon metabolism including GLUT1, GLUT2, GLUT3, LDHA, LDHB, GP, G6Pase, GYS1, and PFKFB3. In addition, insulin receptor signals were also involved in CA-regulated hypoglycemic action. Furthermore, in STZ-induced T2D rat model, compared with diabetic control groups, CA remarkably downregulated the levels of serum lipid, blood glucose, ICAM-1, malonaldehyde and insulin resistance index, while upregulated SOD activity and impaired glucose tolerance. In a conclusion, CA can regulate glucose and lipid metabolic adaptation in T2D like HepG2, zebrafish and rat models partly through reducing inflammation and oxidative stress and suppressing PEPCK.

In this paper, we define Orlov-Schulman's operators ML, MR, and then use them to construct the additional symmetries of the bigraded Toda hierarchy. We further show that these additional symmetries form an interesting infinite-dimensional Lie algebra known as a Block type Lie algebra, whose structure theory and representation theory have recently received much attention in the literature. By acting on two different spaces under the weak W-constraints, we find in particular two representations of this Block type Lie algebra.

This paper deals with the problem of a robust filter design for discrete-time descriptor systems with uncertain noise. The problem addressed is the construction of a perturbating upper bound on uncertain noise covariances so as to guarantee that the deviation of the estimate error performance index remains within the precision prescribed in actual problems. Furthermore, the worst performance in the uncertain case can be minimized by a minimax robust filter.

Abstract A by‐product‐catalyzed redox‐neutral process has been established through tandem sulfenylation/deiodination/aromatization of cyclic alkenyl iodides with sulfonyl hydrazides. In the absence of external catalysts and additives a range of 4‐iodo‐1,2‐dihydronaphthalenes reacted with sulfonyl hydrazides to give structurally diverse 2‐naphthyl thioethers in good yields. Mechanistic studies showed that at an early stage sulfonyl hydrazides decomposed completely to thiosulfonates and disulfides and at a late stage the resulting thiosulfonates underwent tandem sulfenylation/deiodination/aromatization with 4‐iodo‐1,2‐dihydronaphthalenes involving a [1,5]‐sigmatropic hydrogen shift. Importantly, iodine was generated as a by‐product from 4‐iodo‐1,2‐dihydronaphthalenes upon heating and served as a catalyst for the decomposition of sulfonyl hydrazides and subsequent formation of 2‐naphthyl thioethers. magnified image

Abstract The synthesis of polyurea via the addition of carbon dioxide (CO 2 ) to a diamine of 4,7,10‐trioxa‐1,13‐tridecanediamine (TOTDDA) was investigated by using organic and inorganic base catalysts. It was found that 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) was the most active among the catalysts examined. The influence of CO 2 pressure, temperature, and reaction time was examined for the DBU‐catalyzed polyurea synthesis. The reaction mixture was analyzed by in situ high‐pressure attenuated total reflectance Fourier‐transform infrared spectroscopy (ATR‐FTIR) under reaction conditions, and possible reaction mechanisms, in which DBU can activate both CO 2 and TOTDDA, were proposed. Physicochemical properties of polyurea materials synthesized were examined by several techniques. In addition, the catalytic performance of DBU was further examined for the addition of CO 2 to other different diamine compounds. magnified image

Topical application of siRNAs through the skin is a potentially effective strategy for the treatment of melanoma tumors. In this study, we designed a new and safe fusion peptide carrier SPACE-EGF to improve the skin and cell penetration function of the siRNAs and their targeting ability to B16 cells, such that the apoptosis of B16 cells can be induced. The results show that the carrier is stable and less toxic. The EGF motif does not affect the skin and cell penetration function of the SPACE. Because EGF can strongly bind EGFR, which is overexpressed in cancer cells, the targeting ability of the SPACE-EGF-siRNA complex is increased. In vitro experiments indicate that GAPDH siRNAs conjugated with SPACE-EGF can significantly reduce the GAPDH concentration in B16 cells, and c-Myc siRNAs can cause the gene silencing of c-Myc and thus the apoptosis of cells. In vivo experiments show that the topical application of c-Myc siRNAs delivered by SPACE-EGF through the skin can significantly inhibit the growth of melanoma tumors. This work may provide insight into the development of new transdermal drug carriers to treat a variety of skin disorders.

The cortical contribution to the orientation and direction sensitivity of LGNd relay cells was investigated by recording the responses of relay cells to drifting sinusoidal gratings of varying spatial frequencies, moving bars, and moving spots in cats in which the visual cortex (areas 17, 18, 19, and LS) was ablated. For comparison, the spatial-frequency dependence of orientation and direction tuning of striate cortical cells was investigated employing the same quantitative techniques used to test LGNd cells. There are no significant differences in the orientation and direction tuning to relay cells in the LGNd of normal and decorticate cats. The orientation and direction sensitivities of cortical cells are dependent on stimulus parameters in a fashion qualitatively similar to that of LGNd cells. The differences in the spatial-frequency bandwidths of LGNd cells and cortical cells may explain many of their differences in orientation and direction tuning. Although factors beyond narrowness of spatial-frequency tuning must exist to account for the much stronger orientation and direction preferences of cells in area 17 when compared to LGNd cells, the evidence suggests that the orientation and direction biases present in the afferents to the visual cortex may contribute to the orientation and direction selectivities found in cortical cells.

Abstract A Pd‐ t BuONO co‐catalyzed scalable and practical synthesis of indoles with molecular oxygen as terminal oxidant is developed. Either terminal or internal 2‐vinylanilines could be smoothly converted to desired indoles under one general condition. This method has been evaluated in the large scale synthesis of indomethacin and a potential anti ‐breast cancer drug candidate 1 . magnified image

Based on the equilibrium efficient frontier data envelopment analysis (EEFDEA) approach, Fang (J Oper Res Soc 67:412–420, ) developed an equivalent linear programming model to improve and strengthen the EEFDEA approach. Furthermore, Fang () indicated that his secondary goal approach can achieve a unique equilibrium efficient frontier. However, through a simple counterexample we demonstrate that Fang’s secondary goal approach cannot always achieve uniqueness of the equilibrium efficient frontier. In this paper, we propose an algorithm based on the secondary goal approach to address the problem. The proposed algorithm is proven mathematically to be an effective approach to guaranteeing the uniqueness of the equilibrium efficient frontier.

Abstract Bipolar membrane electrodialysis (BMED) is a promising technique for upgrading traditional manufacturing procedures and achieving a circular economy. However, the industrial applications of BMED technology have been restricted by the large consumption of expensive bipolar membranes and the unmatching behavior between water splitting and ion migration. Herein, we proposed a novel asymmetric bipolar membrane electrodialysis (ABMED) to regulate the water splitting in the bipolar membrane and orientational ion migration in the electrodialysis (ED). It was found that the ABMED exhibited comparable performances to BMED for acid/base production when the area of the bipolar membrane was reduced to 50% of the monopolar membrane. The total process cost of ABMED was 0.78 $/kg NaOH, which is 21% lower than the BMED process. The asymmetric membrane design was capable to boost the water splitting in the bipolar membrane and to eliminate the concentration polarization in the ED process.

The responses of X and Y type retinal ganglion cells were extracellularly recorded from the cat optic chiasm or tract before and during brief intraocular pressure (IOP) elevation. The responses of both X and Y cells to stimulus flashes decreased monotonically with increase of IOP. Y cells had significantly higher tolerance to IOP than did X cells. This systematic difference was independent of the cell's retinal position. The findings support the conclusion that during brief IOP elevation pressure-induced ischemia is the main factor causing a decrease in ganglion cell responsiveness. Our findings also suggest a means of selectively eliminating the contribution of X cells to visual function. At moderate levels of IOP elevation X cells, but not Y cells, virtually cease to function.

Rapid developments of wind industry arise the issue of heavy monitoring tasks. The residual monitoring based on normal behaviour modelling is a highly recommended method when fault record information is missing. However, it is difficult to achieve efficient normal behaviour modelling and dynamic residual monitoring simultaneously. To this end, a novel adaptive fault detection scheme, which merges random forest (RF) with adaptive cumulative sum (CUSUM), is proposed. The authors exploit RF to explore the non‐linear mechanism between features and the target variable robustly, and obtain the residuals quickly. Then, they design the adaptive CUSUM control chart of time‐varying shift to sensitively detect the changes of residuals. For illustration, they apply the proposed scheme to the supervisory control and data acquisition data acquired from a wind farm in China. The empirical results demonstrate that the proposed scheme is superior to several competing methods in capturing faults and reducing false alarms. Meanwhile, the authors find it can detect anomaly quickly, automatically and robustly under different signal‐to‐noise ratios. These provide operators sufficient time to adopt an effective maintenance strategy.

In this article, using Tchebycheff's integral inequality, the authors establish some estimates and inequalities for three kinds of the complete elliptic integrals.

Abstract China is currently under tremendous pressures to improve energy efficiency and reduce emissions. As an energy‐saving transportation innovation, electric vehicles (EVs) can alleviate this dilemma. This study adopts the Stimuli‐Organism‐Response (SOR) framework to explore the effect of information overload on consumers' psychological state and subsequent adoption intentions of EVs. Based on the 367 valid samples from Auto 4S shops in EV pilot cities in Mainland China, this study reveals that information overload negatively impacts perceived value and perceived effectiveness but positively impacts perceived risk. Furthermore, information quality offsets the negative impact of information overload on perceived value and enhances the positive impact of information overload on perceived risk. Interestingly, information quality not significantly affect the relationship between information overload and perceived effectiveness. In addition, perceived value and perceived effectiveness are positively related to purchase intentions, while perceived risk is negatively correlated with consumers' purchase intentions. On the basis of these findings, we discuss the policy implications of EVs and provide suggestions for future development.