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: In view of the unclear understanding of the basic scientific problems such as the rheological mechanism of seed cotton, especially the lack of research on the creep characteristics of seed cotton, the machine-harvested seed cotton in the Xinjiang region was taken as the research object to find out the compression creep characteristics. The universal material testing machine was used to carry out a one-factor creep test, taking moisture content, feed quality, compression times, and trash content as test factors and instantaneous elastic modulus, hysteretic elastic modulus, viscosity coefficient, and delay time as test indicators. The ANOVA and correlation were analyzed by SPSS, and the creep process of the seed cotton was simulated by ADAMS. Results show that moisture content significantly affects the instantaneous elastic modulus, hysteretic elastic modulus, and viscosity coefficient (p<0.01). In addition, each value of which decreases with the increase in moisture content. Feed quality significantly affects the hysteretic elastic modulus and viscosity coefficient (p<0.05). Moreover, the hysteretic elastic modulus and viscosity coefficient increase with the increase in feed quality. The compression times significantly influence the instantaneous elastic modulus, hysteretic elastic modulus, and viscosity coefficient (p<0.01), each value of which increases with the increase of compression times. Furthermore, the trash content significantly influenced the hysteretic elastic modulus and viscosity coefficient (p<0.05). The absolute error between the simulated and experimental values ek is within -0.011-0.030 mm, and the relative error φk is less than 7%. The experimental results can provide theoretical and data support for the study of rheological characteristics of machine-harvested seed cotton, the design of seed cotton packing devices, and the molding quality of cotton bale (mold). [ABSTRACT FROM AUTHOR]

Sn-based high-temperature Pb-free (HTLF) solder pastes have been developed as a drop-in solution to replace high- Pb solder pastes in power discrete applications. The pastes were designed with Indium Corporation's DurafuseVR technology, to combine the merits of two constituent powders. A SnSb-based Ag/ Cu-containing high-temperature powder, with a melting temperature above 320°C, was designed to maintain high-temperature performance. A Sn-rich SnAgCu-Sb powder, with a melting temperature around 228°C, was added to the paste to enhance wetting and improve joint ductility. In the design, the final joint will have the low-melting phase (the melting temperature >228°C) in a controllable quantity embedded into the high-melting SnSb matrix. HTLF-1, one of the designs, maintained the bond shear strength up to 15 MPa, even around 290°C. Another design, HTLF-2, has a similar bond shear strength as Pb92.5/Sn5/Ag2.5 around 290°C, but exceeds substantially below 250°C. The power discrete components had been built with both HTLF solder pastes for both die-attach and clip-bond through the traditional high-Pb process, which demonstrated the drop-in processing compatibility. The components survived three additional surface mounting (SMT) reflows (peak temperature upto 260°C) and passed moisture sensitivity level 1 (MSL1). This confirmed that the maintained joint strength (comparable to or stronger than high-Pb), helped to keep the joint integrity within the encapsulated components in the following SMT process, even with the controlled quantity of the melting phases above 228°C. Both HTLF solder pastes outperformed Pb92.5/Sn5/Ag2.5 in the resistance from drain to source when power is on (RDS(on)), even after 1,000 cycles of temperature cycling test (TCT) under 255/175°C, which is attributed to the intrinsic lower electrical resistivity of Sn in both HTLF pastes. Microstructural observation had shown no corner cracks for both die-attach and clip-bond joints after TCT. [ABSTRACT FROM AUTHOR]

Aim: The TTC21B gene is now known as causative of nephronophthisisrelated ciliopathies (NPHP-RC).We reported two Chinese paediatric cases with end-stage renal disease and other phenotypes caused by the TTC21B gene mutations. Methods: The clinical features of Chinese paediatric cases with NPHP-RC were summarized. Mutation analysis of the TTC21B gene was performed using nextgeneration sequencing. Results: The twocases both had nephrotic proteinuria, renal failure, hypertension and abnormal liver function (or hepatic fibrosis). One case also presented situs inversus and short phalanges. They developed end-stage renal disease (ESRD) at 1 year old and 8 years old, respectively, when renal pathology both showed focal segmental glomerular sclerosis (FSGS) with tubulointerstitial lesions including interstitial fibrosis and atrophic tubules. Three novel diseasecausing TTC21B mutations were identified. One case carried homozygous mutation c.2211 +3A>G,while the other case carried compoundheterozygous mutations c.1552 T > C (p.C518R) and c.1456dupA (p.R486KfsX22). Conclusion: Mutations in TTC21B cause a range of ciliopathy phenotypes in humans. We identified 3 novel TTC21B mutations in two Chinese paediatric cases that both presented end-stage renal disease and other different features. This is the first TTC21B mutations ever reported in China. [ABSTRACT FROM AUTHOR]

Controllable and flexible fabrication of ultrathin and uniform oxide layer-wrapped noble metal nanoparticles (NPs) has been expected. Here a new strategy is presented for them based on colloidal electrostatic attraction and self-assembly on the metal NPs via one-step laser ablation of noble metal targets in the hydrolysis-induced hydroxide sol solutions at room temperature. The Au NPs, with several tens of nanometers in size, are taken as core part and TiO2 as shell-layer to demonstrate the validity of the presented strategy. It has been shown that the TiO2 shell-wrapped Au NPs are obtained after laser ablation of Au target in the hydrolysis-induced Ti(OH)4 sol solution. The Au NPs are about 35 nm in mean size, and the TiO2 shell layers are amorphous in structure and about 2.5 nm in thickness. The shell thickness is nearly independent of the Au NPs' size. Further experiments have shown that the thickness and crystallinity of the shell-layer can be tuned and controlled via changing the temperature or pH value of the Ti(OH)4 sol solution or prolonging the laser ablation duration. The formation of the TiO2 shell-wrapped Au NPs is attributed to attachment and self-assembly of Ti(OH)4 colloids on the laser-induced Au NPs due to the electrostatic attraction between them. Importantly, the presented strategy is universal and suitable for fabrication of many other ultrathin oxide-wrapped noble metal NPs. A series of oxide shell-wrapped noble metal NPs have been successfully fabricated, such as Au@oxides (Fe2O3, Al2O3, CuO, and ZnO) as well as Pt@TiO2 and Pd@TiO2, etc. Further, compared with the pure gold NPs-built film, the TiO2-wrapped Au NPs-built film has exhibited much stronger surface enhanced Raman scattering (SERS) performance to the anions NO3-, which weakly interact with noble metals, and the good reusability for the SERS-based detection of 4-nitrophenol, which could be photodegraded by xenon lamp irradiation. This work provides a flexible and universal route to the ultrathin and uniform oxide layer-wrapped noble metal NPs. [ABSTRACT FROM AUTHOR]

A very simple route is developed for fast fabrication of nanosized amorphous titanium dioxide (TiO2) hollow spheres (THPs) just via dropping the pure four titanium chloride (TiCl4) liquid droplets into deionized water at around room temperature. The THPs, at around 80 nm in mean diameter, can be formed within a few seconds after dropping TiCl4 droplets into water. The shell layers of the obtained THPs are amorphous and porous in structure with a porosity of 58-80% and show a linear increase in thickness with the size of THPs. Further experiments have revealed that the reaction temperature, initial pH value, and size of the TiCl4 droplet are crucial to the formation, size, productivity, and microstructure of the THPs. A model is proposed on the basis of the fragmentation of liquid droplets, hydrolysis-induced formation, and inward growth of TiO2 shell layers, which can well describe the formation of the THPs. Importantly, such amorphous nanoscaled THPs have exhibited some strong hollow structure-enhanced performances. Typically, the THP-built film shows the highest reflectivity in the visible region compared to the other structured TiO2 films. Especially, if it supports the film of the Au nanoparticle, the surface-enhanced Raman scattering effect is significantly enhanced by more than 1 order of magnitude. This work provides not only a simple and quick fabrication method for the THPs but also a new member for their family. [ABSTRACT FROM AUTHOR]

Land use and land cover changes (LUCC) are thought to be amongst the most important impacts exerted by humans on climate. However, relatively little research has been carried out so far on the effects of LUCC on extreme climate change other than on regional temperatures and precipitation. In this paper, we apply a regional weather research and forecasting (WRF) climate model using LUCC data from Heilongjiang Province, that was collected between the 1900s and 2010s, to explore how changes in forest cover influence extreme temperature indexes. Our selection of extreme high, low, and daily temperature indexes for analysis in this study enables the calculation of a five-year numerical integration trail with changing forest space. Results indicate that the total forested area of Heilongjiang Province decreased by 28% between the 1900s and 2010s. This decrease is most marked in the western, southwestern, and northeastern parts of the province. Our results also reveal a remarkable correlation between change in forested area and extreme high and low temperature indexes. Further analysis enabled us to determine that the key factor explaining increases in extreme high temperature indexes (i.e., calculated using the number of warm days, warm nights, as well as tropical nights, and summer days) is decreasing forest area; data also showed that this factor caused a decrease in extreme low temperature indexes (i.e., calculated using the number of cold days and cold nights, as well as frost days, and ice days) and an increase in the maximum value of daily minimum temperature. Spatial data demonstrated that there is a significant correlation between forest-to-farmland conversion and extreme temperature indexes throughout most of our study period. Spatial data demonstrated that there is a significant correlation between forest-to-farmland conversion and extreme temperature indexes throughout most of our study period. Positive correlations are also present between decreasing forest area, the more frequent occurrence of extreme high temperature events, and a rise in the maximum value of daily minimum temperature. At the same time, we found clear negative correlations between decreasing forest area and less frequent occurrence of extreme low temperature events. [ABSTRACT FROM AUTHOR]

Amodified seed growth routewas developed to fabricate theAu nanocrystalswith high-density tips based on kinetically-controlled growth via adjusting the adding rate of Au seeds into growth solution. The obtained Au nanostructures were chestnut-like in morphology and about 100 nm in size. They were built of the radial [111]-oriented nanoneedles andwere 30-50 nmin length. Therewere about 120-150 tips in each nanocrystal. The formation of chestnut-like Au nanocrystals is ascribed to surfactant-induced preferential growth of seeds along direction [111]. Importantly, the chestnut-like Au configuration displayed powerful surface enhanced Raman scattering (SERS) performance (enhance factor > 107), owing to the high density of tips. Further, such film was used as a SERS substrate for the detection of lindane (γ -666) molecules (the typical organochlorine pesticide). The detection limit was about 10 ppb, and the relationship between SERS intensity I and concentration C of 666 accords with the double logarithm linear. This work presents a simple approach to Au nanocrystal with high-density tips, and provides a highly efficacious SERS-substrate for quantitative and trace recognition of toxic chlorinated pesticides. [ABSTRACT FROM AUTHOR]

Rapid, ultrasensitive and reliable detection of mercury ions (Hg2+) by surface enhanced Raman spectroscopy (SERS) is of importance, but is restricted by the extremely low Raman cross section of the Hg2+. Here, we report a facile methodology that can realize such detection based on the organometallic Cu(CH4N2S)Cl · 0.5H2O nanobelts and SERS. In the assay, Hg2+ react with the nanobelts coated on a SERS active gold nanoparticle (NP) film to form ultrafine HgS NPs in situ. Subsequently, solid HgS is SERS determined to mirror the presence of Hg2+. Importantly, such detection is rapid and ultrasensitive. Within 10 min, limit of detection (LoD) of ppt level can be realized. The high detection efficiency is attributed to the superhydrophilicity, rich micropores and ultrathin nature of the organometallic nanobelts besides the strong SERS effect of Au NP film. In addition, this detection is highly resistant to various metal ions (Cu2+, Fe3+, Bi3+, Cr3+, Na+, Ni2+, Cd2+, etc) and is highly reliable in actual water (lake and tap water). Finally, influences of some substrate parameters and detection conditions on the test results are revealed. The optimal thickness of the gold NP film is about 80 nm, and the optimal wavelength of excitation light is about 633 nm. A small amount of Cu(CH4N2S)Cl · 0.5H2O nanobelts or a large volume of Hg2+ contaminated solution contributes to low LoDs. We believe that this work provides a rapid and sensitive detection for Hg2+. [ABSTRACT FROM AUTHOR]