Publications by authors named "Zhixin Zeng"

(Orchidaceae, Epidendoideae) plants have flowers with a wide variety of colors that persist for a long period throughout the year. The yellow coloration of flowers is mainly determined by the flavonol pathway and the flavone pathway, but the relevant biosynthesis mechanisms during vernalization remain unclear. To explore the similarities and differences in flavonoid biosynthesis in different tissues during vernalization, we selected two species of for a flower color study: Rchb (which has yellow flowers) and Lindl (which has white flowers).

View Article and Find Full Text PDF

Understanding of the complex mechanical behavior of metal-organic frameworks (MOF) beyond their elastic limit will allow the design of real-world applications in chemical engineering, optoelectronics, energy conversion apparatus, and sensing devices. Through in situ compression of micropillars, the uniaxial stress-strain curves of a copper paddlewheel MOF (HKUST-1) were determined along two unique crystallographic directions, namely the (100) and (111) facets. We show strongly anisotropic elastic response where the ratio of the Young's moduli are E ≈ 3.

View Article and Find Full Text PDF

A novel macro-architectures material FeO-N-GO@sodium alginate (SA) gel film was successfully produced, which was used to remove series azo dye wastewater. The optimal adsorption rates were attained, which achieved the maximum removal efficiency of 74.22%, 45.

View Article and Find Full Text PDF

As a next-generation power system, the smart grid can implement fine-grained smart metering data collection to optimize energy utilization. Smart meters face serious security challenges, such as a trusted third party or a trusted authority being attacked, which leads to the disclosure of user privacy. Blockchain provides a viable solution that can use its key technologies to solve this problem.

View Article and Find Full Text PDF

Nanoscale mechanical property measurements of nanoporous nanosheets face many challenges. Herein we show atomic force microscope (AFM)-based nanoindentation to probe the nanoscale mechanical properties of a 2-D metal-organic framework (MOF) nanosheet material containing atomic-sized pores, termed CuBDC [copper 1,4-benzenedicarboxylate]. The sample thickness ranged from ∼10 nm (tens of monolayers) up to ∼400 nm (a stack of multilayers).

View Article and Find Full Text PDF

Nanocomposites comprising metal-organic frameworks (MOFs) embedded in a polymeric matrix are promising carriers for drug delivery applications. While understanding the chemical and physical transformations of MOFs during the release of confined drug molecules is challenging, this is central to devising better ways for controlled release of therapeutic agents. Herein, we demonstrate the efficacy of synchrotron microspectroscopy to track the in situ release of 5-fluorouracil (5-FU) anticancer drug molecules from a drug@MOF/polymer composite (5-FU@HKUST-1/polyurethane).

View Article and Find Full Text PDF

The metal-free hybrid organic-inorganic perovskite [MDABCO](NH)I (with MDABCO = N-methyl-1,4-diazabicyclo[2.2.2]octane) was recently discovered to exhibit an excellent ferroelectric performance, challenging established ceramic ferroelectrics.

View Article and Find Full Text PDF

Fluorous organic building blocks were utilized to develop two self-assembled, hydrophobic, fluorinated porous organic polymers (FPOPs), namely, FPOP-100 and FPOP-101. Comprehensive mechanical analyses of these functionalised triazine network polymers marked the introduction of mechanical stiffness among all porous organic network materials; the recorded stiffnesses are analogous to those of their organic-inorganic hybrid polymer congeners, that is, metal-organic frameworks. Furthermore, this study introduces a new paradigm for the simultaneous installation of mechanical stiffness and high surface hydrophobicity into polymeric organic networks, with the potential for transfer among all porous solids.

View Article and Find Full Text PDF

The field of metal-organic framework (MOF) materials is rapidly advancing toward practical applications; consequently, it is urgent to achieve a better understanding and precise control of their physical properties. Yet, research on the dielectric properties of MOFs is at its infancy, where studies are confined to the static dielectric behavior or lower-frequency response (kHz-MHz) only. Herein, we present the pioneering use of synchrotron-based infrared reflectivity experiments combined with density functional theory (DFT) calculations to accurately determine the dynamic dielectric properties of zeolitic imidazolate frameworks (ZIFs, a topical family of MOFs).

View Article and Find Full Text PDF

A critical bottleneck for the use of natural gas as a transportation fuel has been the development of materials capable of storing it in a sufficiently compact form at ambient temperature. Here we report the synthesis of a porous monolithic metal-organic framework (MOF), which after successful packing and densification reaches 259 cm (STP) cm capacity. This is the highest value reported to date for conformed shape porous solids, and represents a greater than 50% improvement over any previously reported experimental value.

View Article and Find Full Text PDF

The mechanical properties of individual nanocrystals and small micron-sized single crystals of metal-organic frameworks (MOFs), hitherto, cannot be measured directly by employing the conventional instrumented nanoindentation approach. Here we propose the application of atomic force microscopy (AFM)-based nanoindentation technique, equipped with a calibrated diamond cube-corner indenter tip to quantify the Young's modulus, hardness, adhesion energy, and interfacial and fracture strengths of a zeolitic imidazolate framework (ZIF-8) porous material. We use ZIF-8 as a model MOF system to develop AFM nanoindentation leveraging the concept of unloading strain rate, enabling us to critically assess the practicality and technical limitations of AFM to achieve quantitative measurements of fine-scale MOF crystals.

View Article and Find Full Text PDF

Emerging nanoporous materials, such as metal-organic frameworks (MOFs), are promising low-k dielectrics central to next-generation electronics and high-speed communication. Hitherto, the dielectric characterization of MOFs is scarce, with very limited experimental data for guiding new materials design and synthesis. Herein we demonstrate the efficacy of high-resolution synchrotron infrared (IR) specular reflectance experiments to study the dynamic dielectric properties of a flexible MOF structure: bistable MIL-53(Al) that exhibits switching between a large pore (LP) and a narrow pore (NP) architecture.

View Article and Find Full Text PDF

Two new triterpenoid saponins, namely caraganoside C (1) and caraganoside D (2), were isolated from the seeds of Caragana microphylla. Their structures were elucidated on the basis of spectroscopic analyses, including homo- and hetero-nuclear correlation NMR experiments (COSY, HSQC and HMBC). Both 1 and 2 exhibited moderate inhibitory activity against NO production in LPS-stimulated RAW264.

View Article and Find Full Text PDF