Probing the Twist-Controlled Interlayer Coupling in Artificially Stacked Transition Metal Dichalcogenide Bilayers by Second-Harmonic Generation.

Interlayer coupling plays a critical role in the electronic band structures and optoelectronic properties of van der Waals (vdW) materials and heterostructures. Here, we utilize optical second-harmonic generation (SHG) measurements to probe the twist-controlled interlayer coupling in artificially stacked WSe2/WSe2 homobilayers and WSe2/WS2 and WSe2/MoS2 heterobilayers with a postannealing procedure. In the large angle twisted WSe2/WSe2 and WSe2/WS2, the angular dependence of the SHG intensity follows the interference relations up to angles above 10°. For lower angles, the SHG is significantly suppressed. Furthermore, for the twisted WSe2/MoS2 the SHG intensity largely deviates from the coherent superposition model and shows consistent quenching for all the stacking angles. The suppressed SHG in twisted transition metal dichalcogenide (TMDC) bilayers is predominantly attributed to the interlayer coupling between the two adjacent monolayers. The evolution of the interlayer Raman mode in WSe2 demonstrates that the interlayer coupling in the twisted WSe2/WSe2 and WSe2/WS2 is highly angle-dependent. Alternatively, the interlayer coupling generally exists in the twisted WSe2/MoS2, regardless of the different angles. The interlayer coupling is further confirmed by the quenching and red-shift of the photoluminescence of WSe2 in the twisted TMDC bilayers. Combined with density functional theory calculations, we reveal that the stacking-angle-modulated interlayer coupling originates from the variation of the interlayer spacing and the binding energy in the twisted TMDC bilayers.

[Scientific research on selection of medicinal herbs of Chloranthaceae based on materia medica theory].

The plants of Chloranthaceae are widely distributed and rich in resources in our country, records of ancient herbs indicaded that various species of plants of Chloranthaceae can be used for medicinal purposes, especially the Sarcandra glabra which with the least toxicity and possessed the function of clearing heat and cooling blood, activating blood to eliminate spots and removing wind and dredging collaterals. Based on the theory of herbage and by the method of consulting the past herbal literature, we summarized and analyzed the medicinal history, distribution characteristics of herbage geography, characteristics of herbage ecology, standard collection situation and the modern toxicology research of Chloranthaceae plants. Therefore we explained the scientificity for selection of medicinal herbs of Chloranthaceae plants, and provided a theoretical and scientific basis for further research of Chloranthaceae plants.

[Study on commercial specification of Gardenia jasminoides].

Collecting different commodity grade Gardenia jasminoides of wild and cultivated varieties all over the country, obtaining color information from each batch of G. jasminoides by the standard D65 light source and image acquisition system, quantifing the gardenia plumpness information by the digital display vernier caliper, determinating 6 kinds of effective components of G. jasminoides by HPLC, classifing from ten indicators by two step clustering analysis and correspondence analysis method of statistics, clearing the importance of the traditional identification indexes, establishing multiple corresponding relation between the skin color and commercial specification of G. jasminoides,exploring the correlation of the skin color and chemical composition, to provide the reference for the reasonable division of commercial specifications and grades of G. jasminoides. Medicine is divided into two classes and has obvious distinguish meaning, The importance of the skin color is greater than the plumpness in traditional identification characteristics, it can accurately distinguish the specifications of G. jasminoides. We improve and rebuild the standard of commodity specifications and grades of Gardenia jasminoides Ellis and establish the rapid evaluation method by the study, it provide a new way and idea for the comprehensive evaluation of G. jasminoides quality.

[Study on ecological suitability of Gardenia jasminoides based on ArcGIS and Maxent model].

The application of ArcGIS and Maxent modelto analyze the ecological suitability of Gardenia jasminoides.Taking 85 batches of Gardenia as the basis of analysis, the selection of ecological factors for the growth of Gardenia. The results showed that the average precipitation in April, the average precipitation in November and the average precipitation in August were the most important factors affecting the growth of Gardenia. The relative concentration of Gardenia suitable growth region,north to the south of Shaanxi province, south of Henan, central Anhui, south to the north of Hainan province, west to central Sichuan province, east of Zhejiang coastal area, northeast of Taiwan.

[Comparative Study on Protection Effects of CCl4-Induced Acute Liver Injury of Different Prepared Products from Gardenia jasminoides Fruits in Rats].

Objective: To provide the experimental evidence for the appropriate selection of the different prepared products from Gardenia jasminoides fruits by comparing their protection effects on carbon tetrachloride（ CCl4）-induced acute liver injury. Methods: The activities of ALT,AST,ADA,LDH,ALP and contents of PA,TP,TBIL,DBIL,TBA in serum,the activities of SOD and the content of MDA in liver tissue were measured in acute liver injury rats by carbon tetrachloride. Also the pathological changes of liver tissues were examined under microscope. Results: The biochemical indexes of AST,ALT,TBA,ADA,LDH and MDA were significantly improved in all groups of prepared products from Gardenia jasminoides fruits,but not SOD and ALP. The lesions of liver tissue had different degrees of reduction. Conclusion: The different prepared products from Gardenia jasminoides fruits had the effects of liver protection. The nut of Gardeniae Fructus was superior to the peel in enzyme decreasing and liver protection. The crude was superior to the stir-cooked in enzyme decreasing and liver protection.