Optimization of Force Sensitivity in Q-Controlled Amplitude-Modulation Atomic Force Microscopy

We present control of force sensitivity in Q-controlled amplitude-modulation atomic force microscopy (AM-AFM) that is based on the high-Q quartz tuning-fork. It is found that the phase noise is identical to the amplitude noise divided by oscillation amplitude in AM-AFM. In particular, we observe that while Q-control does not compromise the signal-to-noise ratio, it enhances the detection sensitivity because the minimum detectable force gradient is inversely proportional to the effective quality factor for large bandwidths, which is due to reduction of frequency noise. This work demonstrates Q-control in AM-AFM is a useful technique for enhancement of the force sensitivity with increased Q or improvement of the scanning speed with decreased Q

Anomalous microwave conductivity coherence peak in c-axis MgB2 thin film

The temperature dependence of the real part of the microwave complex conductivity at 17.9 GHz obtained from surface impedance measurements of two c-axis oriented MgB2 thin films reveals a pronounced maximum at a temperature around 0.6 times the critical temperature. Calculations in the frame of a two-band model based on Bardeen-Cooper-Schrieffer (BCS) theory suggest that this maximum corresponds to an anomalous coherence peak resembling the two-gap nature of MgB2. Our model assumes there is no interband impurity scattering and a weak interband pairing interaction, as suggested by bandstructure calculations. In addition, the observation of a coherence peak indicates that the pi-band is in the dirty limit and dominates the total conductivity of our filmsComment: 10 pages, 4 figures, to be published in Phys. Rev. Let

What is the Difference Between ABNORMAL CLIMATE and EXTREME CLIMATE that Cause Yield Damage to Silage Maize (Zea mays L.)?

This study aimed to compare the characteristics by estimating the impacts of abnormal climate and extreme climate on silage maize. In the maize-climate database, the variables were dry matter yield (DMY, kg/ha), mean temperature (MT, °C), lowest temperature (LT, °C), highest temperature (HT, °C), maximum precipitation (MP, mm/hr), accumulated precipitation (AP, mm), maximum wind speed (MW, m/s), mean wind speed (WS, m/s), sunshine duration (SD, hr). To define the abnormal climate, favorable condition was confirmed using the principal component analysis against a normal climate. In order to define the extreme climate, firstly, the median-interquartile method was used instead of the mean-standard deviation method. As a result, in mid-June, the characteristics of early monsoons without typhoons were confirmed as poor. In particular, MP in abnormal climate (20.54 mm/hr) was three times greater than that in normal climate (6.61 mm/hr). The damage in DMY caused by the abnormal climate in mid-June was estimated to be 1,155.9 kg/ha. For the extreme climate in mid-June, the low-extreme LT, high-extreme AP, and high-extreme MW were detected in the trends. However, the year records were different for each point. Thus, the damage in DMY was estimated based on high-extreme AP, as a representative scenario. As a result, the damage in DMY caused by the extreme climate in mid-June was estimated to be 927.2 kg/ha. Hence, the magnitude of yield damage to silage maize caused by extreme climate and abnormal climate, as well as characteristics of high precipitation, were similar

Effects of Fall Dormancy, Cutting Frequency, and K Application Rate on Dry Matter Yield and Nutritive Value of Alfalfa

[Introduction] This study was conducted to determine the effect of the cutting frequency and K application rate on the dry matter yield (DMY) and nutritive value of new alfalfa varieties in Korea. [Material and Methods] The sowing date and rate were September 21, 2019, and 20 kg/ha, respectively. The treatment was by the split-split plot design, and the main plot was the Fall dormancy (FD) of 3 (Rugged Rancher), 4 (SW4113), and 9 (SW9720), the sub-plot was excess 40 day (LCF), from 31 to 40 days (MCF), and under 30 day (HCF) times of cutting frequency (CF), and the sub-sub plot was 150 (K 150), 300 (K 300), and 450 (K 450) kg/ha of K application rate. The first harvest reached 10% of the flowering, and after the first harvest, it was conducted according to the cutting frequency treatment. The survey contents were investigated as DMY, Crude protein (CP), Neutral detergent fiber (NDF), Acid detergent fiber (ADF), and K content. [Results and Discussion] K 450 of DMY was significantly higher than K 150 (p \u3c 0.05). The CF was not significant at each level (p \u3e 0.05). FD 3 and FD 4 of DMY were significantly higher than FD 9 (p \u3c 0.05). The CP, NDF, and ADF according to FD and CF were significantly different at each treatment (p \u3c 0.05). The CP and ADF according to the K treatment were significantly higher at K 150 than K 300 and K 450 (p \u3c 0.05). In addition, the NDF according to the K treatment was significantly higher in K 150 and K 450 than K 300 (p \u3c 0.05). The K content of alfalfa significantly differed according to the K treatment (p \u3c 0.05). Therefore, it is judged that a high DMY can be expected when the K application rate, cutting frequency, and FD is 450 kg/ha, HCF, and 4, respectively