The development of thermoelectric measurement technology at nanoscale is a challenging task. Here, a novel MEMS-based dual temperature control (DTC) measurement method for thermoelectric properties of individual nanowires was proposed. Different from conventional thermal bridge testing devices, this DTC thermoelectric testing device can obtain the thermoelectric properties by independently control ambient temperature and temperature difference between two ends of the nanowires through two separate resistance thermometers without auxiliary heating devices. The reliability of the model and the testing accuracy were verified by accurately measuring the thermal conductivity, electrical conductivity, and the absolute value of the Seebeck coefficient of VO2 nanowires.

Early maturity allows weedy rice (Oryza sativa L. f. spontanea) to persist by escaping harvest in paddy fields. A shorter grain-filling period contributes to the early maturity of weedy rice. However, the differences in morphology and endosperm development in the caryopsis between weedy and cultivated rice are largely unexplored. Here, we selected four biotypes of weedy rice and associated cultivated rice (ACR; Oryza sativa) from different latitudes to conduct a common garden experiment. The endosperm development process of the caryopsis was observed by optical microscopy and electron microscopy. Endosperm cell division and starch accumulation rate during grain filling were also measured. The grain development progress in weedy rice was more rapid and earlier than that in ACR. The endosperm development progress of weedy rice was 6 to 8 d earlier than that of ACR. The endosperm cells of weedy rice cellularized earlier and more rapidly than those of ACR, and the starch grains of weedy rice were more sharply polygonal and compactly arranged than those of ACR. The active endosperm cell division period in weedy rice was 4 to 7 d shorter than that in ACR, while the active starch accumulation period of weedy rice was 2 to 8 d shorter than that of ACR. The rapid development of endosperm cells and starch grains leads to the shorter grain-filling period of weedy rice. weedy rice.

Significant developments in micro-electrical-mechanical systems (MEMS)-based devices have led to the commercialization of windowed gas cells that now enable atomic-resolution scanning transmission electron microscopy (STEM) observation of phenomena occurring during gas-solid interactions at atmospheric pressure. An in situ atmospheric STEM study provides information that is beneficial to correlating the structure-properties relationship of catalytic nanomaterials, particularly under realistic gaseous reaction conditions. In this article, we illustrate the advantages of this tool as applied to our study of two important systems: (1) the CO-induced Pt nanoparticle surface reconstruction at saturation coverage and (2) the ordering and Pt surface enrichment in supported Pt3Co nanoparticles.

Significant developments in micro-electrical-mechanical systems (MEMS)-based devices for use in transmission electron microscopy (TEM) sample holders have recently led to the commercialization of windowed gas cells that now enable the atomic-resolution visualization of phenomena occurring during gas-solid interactions at atmospheric pressure. In situ atmospheric TEM study provides unique information that is beneficial to correlating the structure-properties relationship of catalytic nanomaterials, particularly under realistic gaseous reaction conditions. In this paper, we illustrate the capability of this novel in situ device as applied to our study of two catalyst systems: (1) In situ kinetic growth of free standing Pt nanowires as active catalysts toward oxygen reduction reaction (ORR); (2) In situ observation of facet-dependent oxidation of another promising ORR catalyst, Pt3Co nanoparticles.

Significant developments in micro-electrical-mechanical systems-based devices for use in transmission electron microscopy (TEM) sample holders have recently led to the commercialization of windowed gas cells that now enable the atomic-resolution visualization of phenomena occurring during gas–solid interactions at atmospheric pressure. In situ TEM study under atmospheric pressures provides unique information that is beneficial to correlating the structure–properties relationship of nanomaterials, particularly under real gaseous environments. We here provide a brief introduction of the advanced instrumentation of windowed gas cells and review recent progress of in situ atomic-resolution TEM study under atmospheric pressures, including some application examples of oxidation and reduction processes, dynamic growth of nanomaterials, catalytic reactions, and “operando” TEM.

A circular patch antenna with wide impedance bandwidth and monopolar radiation pattern for indoor wireless communication is proposed and analyzed in this paper. The antenna is a combination of circular patch and four capacitive feeds. By incorporating a cross-connected shorted conducting strip over the circular patch, the proposed antenna provides an enhanced impedance width of 65.4%, ranging from 1.46 to 2.88 GHz. Four capacitive feeds improve the design flexibility and make the ripple of horizontal radiation pattern less than 3 dB. A prototype of the proposed structure has been fabricated and measured. Both the simulated and measured results show that the proposed design has a stable monopolar radiation pattern over a wideband frequency range and a peak gain of 5.0 dBi, which can be widely applied for indoor wireless communication such as GSM1800, CDMA2000, WCDMA, and TD-LTE systems.

As the currently only available molluscicide, niclosamide has been widely used for snail control for over 2 decades in China. There is therefore a concern about the emergence of niclosamide-resistant snail populations following repeated, extensive use of the chemical. The purpose of this study was to investigate the likelihood of niclosamide resistance in Oncomelania hupensis in China. Active adult O. hupensis snails derived from 20 counties of 10 schistosomiasis-endemic provinces of China, of 10 snails in each drug concentration, were immersed in solutions of 1, 0·5, 0·25, 0·125, 0·063, 0·032, 0·016 and 0·008 mg L−1 of a 50% wettable powder of niclosamide ethanolamine salt (WPN) for 24 and 48 h at 25 °C, and the median lethal concentration (LC50) was estimated. Then, the 24- and 48-h WPN LC50 values were compared with those determined in the same sampling sites in 2002. The results indicated that the 24- and 48-h WPN LC50 values for O. hupensis were not significantly different from those determined in 2002 (P = 0·202 and 0·796, respectively). It is concluded that the current sensitivity of O. hupensis to niclosamide has not changed after more than 2 decades of repeated, extensive application in the main endemic foci of China, and there is no evidence of resistance to niclosamide detected in O. hupensis.