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Pollen morphology of 26 taxa of Clerodendrum, as well as one species of Volkameria from China, was investigated through a scanning electron microscope (SEM). Pollen grains of Clerodendrum are monads, radiosymmetric and tricolpate, with medium or large size. The equatorial view of the pollen grains is spheroidal or subprolate and the polar view is (sub) circular or rounded triangular. The colpus membrane of the investigated taxa is sunken (rarely even). Five varying pollen types are delimited on the basis of exine sculpturing: (1) spine-tectum perforatum; (2) spine-tectum imperforatum; (3) microspine- tectum perforatum; (4) microspine-tectum imperforatum; and (5) obtuser spine. The results indicate that Clerodendrum is closely related to several genera in Lamiaceae, including Aegiphila, Amasonia, Kalaharia, Tetraclea, Volkameria, Oxera, Faradaya, and Hosea, as supported by previous phylogenic studies. Additionally, the conventional infrageneric classification of Clerodendrum based on inflorescence and leaf characters is not supported by the results. However, the palynological data can be used to identify some closely related species with similar external characteristics. In conclusion, the investigation of pollen morphology not only contributes novel data from palynology for Clerodendrum but also provides a basis for future comprehensive classification of this genus. [ABSTRACT FROM AUTHOR]

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With the increasing development of pest resistances, it is not easy to achieve satisfactory control effects by using only one agrochemical. Additionally, although the alkaloid matrine (MT) isolated from Sophora flavescens is now utilized as a botanical pesticide in China, in fact, its pesticidal activities are much lower in magnitude than those of commercially agrochemicals. To improve its pesticidal activities, here, the joint pesticidal effects of MT with another alkaloid oxymatrine (OMT) (isolated from S. flavescens) and the monoterpene essential oil 1,8-cineole (CN) (isolated from the eucalyptus leaves) were investigated in the laboratory and greenhouse conditions. Moreover, their toxicological properties were also studied. Against Plutella xylostella, when the mass ratio of MT and OMT was 8/2, good larvicidal activity was obtained; against Tetranychus urticae, when the mass ratio of MT and OMT was 3/7, good acaricidal activity was obtained. Especially when MT and OMT were combined with CN, the significant synergistic effects were observed: against P. xylostella, the co-toxicity coefficient (CTC) of MT/OMT (8/2)/CN was 213; against T. urticae, the CTC of MT/OMT (3/7)/CN was 252. Moreover, the activity changes over time of two detoxification enzymes, carboxylesterase (CarE) and glutathione S-transferase (GST) of P. xylostella treated with MT/OMT (8/2)/CN, were observed. In addition, by scanning electron microscope (SEM), the toxicological study suggested that the acaricidal activity of MT/OMT (3/7)/CN may be related to the damage of the cuticle layer crest of T. urticae. [ABSTRACT FROM AUTHOR]

This paper describes and illustrates the morphological traits of Impatiens zhaojueensis Q. Luo (Balsaminaceae), a new species from the Sichuan Province of southwestern China. Using a scanning electron microscope (SEM), the micromorphological characteristics of its pollen grains and seeds are also described. The new species is closely related to Impatiens baishaensis, but it has larger flowers, obround dorsal petals, somewhat clawed lateral united petals, obround or obround‐dolabriform distal lobes and the ornamentation on the pollen grains has wider meshes. [ABSTRACT FROM AUTHOR]

This paper further enriches the taxonomic study of Feltriidae Viets, 1926 in China since it was first reported by Yi & Jin in 2011. Seven species, Feltria hanmaensis sp. nov., Feltria pesici sp. nov., Feltria pseudoparva sp. nov., Feltria expendis sp. nov., Feltria yinjiangensis sp. nov., Feltria neoflatheadensis sp. nov. and Feltria glandulosa sp. nov., are described as new to science; Feltria minuta Koenike, 1892 is new to the Chinese water mite fauna. In addition, some slit organs of these species are photographed by SEM (scanning electron microscope) and illustrated in detail by optical microscope to provide material for exploiting valuable character in specific identification. [ABSTRACT FROM AUTHOR]

Eolian loess in China contains abundant information about paleoclimate evolution, but there have been few studies of the relationship between the changing permeability of loess and the paleoenvironment. To investigate how loess–paleosol permeability responds to climate change, 342 undisturbed soil samples were collected from the Jingyang Loess Plateau in the Guanzhong Basin. Permeability was measured by a TST-55 permeameter and soil microstructures were observed with a scanning electron microscope (SEM). The results showed that: (1) the permeability of the loess layers was higher than that of the paleosol layers; (2) loess–paleosol sequence permeability had a four-stage accumulation history; (3) the degree of permeability anisotropy (DPA) of most of the loess was greater than 1, whereas that of the paleosol layers were less than 1; (4) loess and paleosol microstructures were consistent with the results obtained by permeability, whose changes had been mainly caused by the pedogenesis controlled by the Quaternary climate. The higher permeability of the loess layers was largely the result of lower pedogenesis intensity due to the cold/dry climatic conditions at the time when the sediments were deposited. Conversely, the lower permeability of the paleosol layers was the result of higher pedogenesis intensity under warm/wet climatic conditions. Based on the permeability, DPA, and soil microstructures, we concluded that the gradual uplift of the Qinling Mountains and the changes in the intensity of the East Asian monsoon had played important roles in controlling the evolution of the climate in the Guanzhong Basin. Therefore, loess permeability can reflect Quaternary climate change and provide a new research method for interpreting the characteristics of the Jingyang Loess Plateau. [ABSTRACT FROM AUTHOR]

This paper has investigated the TSC characteristics of the HTV silicone rubber under a natural aging at high altitude areas in China, the SEM of the corresponding test samples have also been measured. The results show that there were obvious differences in the TSC characteristics of different kinds of HTV silicone rubber, and it has relationship with the change of its SEM. And the radiation of ultraviolet ray is the main influencing factors which caused the aging of the HTV silicon rubber at high altitudes areas. [ABSTRACT FROM AUTHOR]

Modern dust plays essential roles in marine and climate processes, which bring continental material to the ocean and sensitivity in marine ecosystems. However, the atmospheric dust deposition process has rarely been studied in the South China Sea (SCS). Here, we present 51 atmospheric dust samples, collected along the SCS, to investigate the grain size distribution, depositional flux, and features revealed by scanning electron microscopy, combined with 5-day back trajectories to indicate the present-day dust deposition process for the first time. The grain size distribution and depositional flux of aerosol samples illustrate the seasonal trend: coarser particle and higher flux mass in winter than summer. The average grain size is 5.75 μm during winter and 3.62 μm from summer, and the depositional flux in the winter is 1.4 times than that in summer, both are related to the transport pathway and power of the East Asian monsoon. Modeled 5-day back trajectories of dust samples suggest a southwesterly transport pathway in summer and the Southeast Asian monsoon as a possible source of the dust loading, while the northeast winds drove the aeolian dust transport during the winter monsoon from the Asian continent. Meanwhile, westerly circulation conveys the fine particles (~0.63 μm) as the stable terrigenous component into the SCS, deposited through the entire dust deposition process from the atmosphere and water to the surface sediment. Furthermore, the surface of quartz particles from atmospheric dust shows the unique structure in the aeolian environment as a reference to distinguish the different continental components in the sediments. This study provides new insights into the present-day dust deposition process in the SCS, significantly extending the current understanding of the relationship between atmospheric dust and the marginal sea. • Present-day dust grain size, seasonal trend change due to wind strength and dust availability in the South China Sea. • Modeled 5-day back trajectories show transport pathway and source in different prevailing monsoon for dust deposition. • Scanning electron microscope as a reference to distinguish continent components from terrigenous sediments. [ABSTRACT FROM AUTHOR]