Metal-Ion Coupling in Metal-Organic Framework Materials Regulating the Output Performance of a Triboelectric Nanogenerator.

Metal-organic frameworks (MOFs) as friction nanopower generation materials have attracted more and more research and attention because of the inherent three-dimensional framework structure and large aperture. In this work, the ZUT-75(Mn) with a one-dimensional pore structure was synthesized by using electron-rich benzimidazole carboxylic acid ligands, and isomorphic offspring MOF materials were obtained by single crystal-single crystal solvent-assisted metal-ion exchange. The exchange process was monitored by liquid UV-vis spectroscopy, atomic absorption spectrometry, and energy-dispersive X-ray spectroscopy. The metal-oxygen coordination energy, X-ray photoelectron spectroscopy binding energy, and hard-soft acid-base principle verified the spontaneity of the central-metal-exchange reaction. The four materials were applied to a triboelectric nanogenerator (TENG), and the output performance law of ZUT-75 was Co-MT > Zn-MT > Cu-MT > Mn-MT. Among them, the charge and power densities of Co-MT were up to 127.05 µC m-2 and 3280.50 mW m-2. When the density functional theory calculation and variable-temperature magnetic susceptibility test results were combined, it was concluded that low metal-ion-coupling degree promoted the formation and transfer of contact electrifications, which greatly improved the output performance of the TENG. This work provided a new idea for improving the output performance of the TENG.

First-principles study on bilayer SnP3 as a promising thermoelectric material.

The bilayer SnP3 is recently predicted to exfoliate from its bulk phase, and motivated by the transition of the metal-to-semiconductor when the bulk SnP3 is converted to the bilayer, we study the thermoelectric performance of the bilayer SnP3 using first-principles combined with Boltzmann transport theory and deformation potential theory. The results indicate that the bilayer SnP3 is an indirect band gap semiconductor and possesses high carrier mobility. The high carrier mobility results in a large Seebeck coefficient observed in both n- and p-doped bilayer SnP3, which is helpful for acquiring a high figure of merit (ZT). Moreover, by analyzing the phonon spectrum, relaxation time, and joint density of states, we found that strong phonon scattering makes the phonon thermal conductivity extremely low (∼0.8 W m-1 K-1 at room temperature). Together with a high power factor and a low phonon thermal conductivity, the maximum ZT value can reach up to 3.8 for p-type doping at a reasonable carrier concentration, which is not only superior to that of the monolayer SnP3, but also that of the excellent thermoelectric material SnSe. Our results shed light on the fact that bilayer SnP3 is a promising thermoelectric material with a better performance than its monolayer phase.

Intrinsically low thermal conductivity of bismuth oxychalcogenides originating from interlayer coupling.

The anharmonicity of phonons in a solid is ultimately rooted in the chemical bonding. However, the direct connection between phonon anharmoncity and chemical bonding is difficult to make experimentally or theoretically, mainly due to their complicated lattice structures. Here, with the help of first-principles calculations, we show that the intrinsically low lattice thermal conductivity (κ) of Bi2O2X (X = S, Se, Te) shows a strong connection to the electrostatic inter-layer coupling. We explain our results by the strong anharmonic chemical bonding between Bi and chalcogen atoms. Additionally, due to the strong anharmonicity, a large portion of phonon modes has a mean free path shorter than the average atomic distance. We employ a recently proposed two-channel model to take into account their contribution to κ.

P-GaSe/N-MoS2 Vertical Heterostructures Synthesized by van der Waals Epitaxy for Photoresponse Modulation.

The important role of p-n junction in modulation of the optoelectronic properties of semiconductors is widely cognized. In this work, for the first time the synthesis of p-GaSe/n-MoS2 heterostructures via van der Waals expitaxial growth is reported, although a considerable lattice mismatching of ≈18% exists. According to the simulation, a significant type II p-n junction barrier located at the interface is expected to be formed, which can modulate optoelectronic properties of MoS2 effectively. It is intriguing to reveal that the presence of GaSe can result in obvious Raman and photoluminescence (PL) shift of MoS2 compared to that of pristine one, more interestingly, for PL peak shift, the effect of GaSe-induced tensile strain on MoS2 has overcome the p-doping effect of GaSe, evidencing the strong interlayer coupling between GaSe and MoS2 . As a result, the photoresponse rate of heterostructures is improved by almost three orders of magnitude compared with that of pristine MoS2 .

[Pharmacological research of wild and cultivated Atractylodes lancea].

OBJECTIVE: To explore the differences of the main pharmacological action in wild and cultivated Atractylodes lancea. METHOD: Study the effect of the 70% ethanol extracts from the wild and the culticated A. lancea on the mice with gastriculcer induced by absolute ethyl alcohol or HCl. Stdudy the effect on intestinal propulsive function in mice by measuring the length of intestine and distance of Indian ink. Observe anti-bacteria effect in vitro of the A. lancea by determining the minimum inhibitory concentrations. RESULT: The pharmacological action, which made a little difference in the sane productive places, and made significant differences in different productive places. Compared to Jurong, it has better actions in Luotian on small intestinal propulsive function and bacteriostatic action. There was not an obvious difference in protective effect on gastric ulcer induced by absolute ethyl alcohol and 0.6 mol x L(-1) HC1 between different locations. CONCLUSION: To the main effect, cultvated A. lancea had no significant difference on the whole but having better result in some respects, which can provide the pharmacodynamics evidence of cultivated A. lancea being used instead of the wild.

[Advances in chemistry, molecular biology and pharmacological of Cangzhu].

We described chemical composition in Cangzhu in recent years, volatile oil is the important chemical composition, The beta-eudesmol, hinesol are active ingredient in volatile oil and there are 38 kind of glycosides. At the same time, we overview the applying of RAPD technology in atractylodes lancea. The results is that there are correlation in chemical composition, genetic differentiation and geographical distribution, there is some truth in bounded by a territorial division of the north-south Cangzhu, and genetic differentiation has been happened in atractylodes lancea to adapting the environment. We described advances of pharmacological in dampness spleen, cardiovascular system, genitourinary system, nervous system, and the results show that there are pharmacological activity in digestive system, cardiovascular system, genitourinary system of atractylodes lancea.

Monolayer PdSe2: A promising two-dimensional thermoelectric material.

Motivated by the recent experimental synthesis of two-dimensional semiconducting film PdSe2, we investigate the electronic and thermal transport properties of PdSe2 monolayer by using the density functional theory and semiclassical Boltzmann transport equation. The calculated results reveal anisotropic transport properties. Low lattice thermal conductivity about 3 Wm-1 K -1 (300K) along the x direction is obtained, and the dimensionless thermoelectric figure of merit can reach 1.1 along the x direction for p-type doping at room temperature, indicating the promising thermoelectric performance of monolayer PdSe2.

Tunneling Diode Based on WSe2 /SnS2 Heterostructure Incorporating High Detectivity and Responsivity.

van der Waals (vdW) heterostructures based on atomically thin 2D materials have led to a new era in next-generation optoelectronics due to their tailored energy band alignments and ultrathin morphological features, especially in photodetectors. However, these photodetectors often show an inevitable compromise between photodetectivity and photoresponsivity with one high and the other low. Herein, a highly sensitive WSe2 /SnS2 photodiode is constructed on BN thin film by exfoliating each material and manually stacking them. The WSe2 /SnS2 vdW heterostructure shows ultralow dark currents resulting from the depletion region at the junction and high direct tunneling current when illuminated, which is confirmed by the energy band structures and electrical characteristics fitted with direct tunneling. Thus, the distinctive WSe2 /SnS2 vdW heterostructure exhibits both ultrahigh photodetectivity of 1.29 × 1013 Jones (Iph /Idark ratio of ≈106 ) and photoresponsivity of 244 A W-1 at a reverse bias under the illumination of 550 nm light (3.77 mW cm-2 ).

[Comparative study on antibacterial effects of huangqin-tang and its metabolites produced by intestinal flora].

OBJECTIVE: To compare the antibacterial effects of Huangqin-Tang with its metabolites produced by intestinal flora. METHOD: The antibacterial tests in vitro and in vivo were performed by agar dilution method and lethal protection of animal respectively. RESULT: Huangqin-Tang and its metabolites had antibacterial action on bacteria in vitro, however the antibacterial activity of metabolites of Huangqin-Tang on Salmomella, Dysentery bacillus and Proteus in vitro was stronger than Huangqin-Tang. The metabolites of Huangqin-Tang had protective effect on the animals infected by Staphylococcus aureus and Escherichia coli respectively from death, but Huangqin-Tang had no lethal protection action. CONCLUSION: The antibacterial effects of metabolites of Huangqin-Tang in vitro and in vivo are stronger than that of Huangqin-Tang, which shows that intestinal flora play a very important role in antibacterial effects of Huangqin-Tang.

[A comparison of the protective activity of liver injury induced by D-galact-osamine between huangqin-tang and their metabolites by human intestinal bacteria].

OBJECTIVE: To compare the protective activity of liver injury induced by D-galactosamine (GalN) between Huangqin-Tang and their metabolites by human intestinal bacteria(HIB). METHOD: The liver injuries in conventional and pseudo-germfree mice were induced by GalN. After oral administration of Huangqin-Tang and their metabolites mixtures by HIB, the serum transaminase (ALT and AST) activities were detected. RESULT: In conventional mice, large and medium doses (20 and 10 g.kg-1) of Huangqin-Tang decoction significantly reduced the increase of serum ALT activity after 18 h GalN treatment. In pseudo-germfree mice, metabolites significantly reduced the ALT levels. However, Huangqing-Tang didn't affect the ALT levels in this kind of mice. To all of the animals, AST levels remained the same after oral Huangqin-tang or their metabolites. CONCLUSION: The metabolism by intestinal bacteria plays a role in pharmacological effects of constituents of Chinese herbal medicine. The metabolites of the constituents by intestinal bacteria were the real active components in vivo.

Metabolism of constituents in Huangqin-Tang, a prescription in traditional Chinese medicine, by human intestinal flora.

In the course of studies on the metabolism of active components of Huangqin-Tang by human intestinal flora (HIF), Huangqin-Tang and all individual herbs in the decoctions were incubated with a human fecal suspension separately. By using a high-performance liquid chromatographic (HPLC) method which was previously established in our laboratory, the metabolites in both the compound prescription and all the single herb decoctions were identified and determined both qualitatively and quantitatively. We found that the constituents of Huangqin-Tang, incluing baicalin (baicalein 7-glucuronide; BG), wogonoside (wogoninoglucuronide; WG), oroxylin-A-glucuronide (OG) from Scutellariae Radix, paeoniflorin (PF) from Paeoniae Radix, liquiritin (liquiritigenin 4'-O-glucoside; LG), isoliquirtin (isoliquiritigenin 4-glucoside; ILG) and glycyrrhizic acid (GL) from Glycyhhizea Radix, were converted to their metabolites baicalein (B), wogonin (W), oroxylin-A (O), paeonimetabolin-I (PM-I), liquiritigenin (L), isoliquiritigenin (IL) and glycyrrhetinic acid (GA) by HIF. The contents of the metabolites in Huangqin-Tang and in each single herb decoction increased significantly after incubation with intestinal flora. Comparing with single herb decoctions, the transformation of BG, WG, OG, LG and ILG in the compound prescription was promoted, however, that of PF and GL was inhibited. All the results suggested that the glycosides of many medicinal herbs could be converted to aglycones by HIF, and the metabolism of most glycosides was improved in the compound prescription.