Effects of Cutting Intensity on Soil Physical and Chemical Properties in a Mixed Natural Forest in Southeastern China

The mixed Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), Masson’s pine (Pinus massoniana Lamb.), and hardwood forest is a major forest type in China and of national and international importance in terms of its provision of both timber and ecosystem services. However, over-harvesting has threatened its long-term productivity and sustainability. We examined the impacts of timber harvesting intensity on soil physical and chemical properties 10 and 15 years after cutting using the research plots established with a randomized block design. We considered five treatments, including clear cutting and low (13.0% removal of growing stock volume), medium (29.1%), high (45.8%), and extra-high (67.1) intensities of selective cutting with non-cutting as the control. The impact on overall soil properties derived from principal component analysis showed increasing with a rise in cutting intensity, and the most critical impact was on soil nutrients, P and K in particular. Soil nutrient loss associated with timber harvesting even at a low cutting intensity could lead to nutrient deficits in this forest although most of the soil physical properties could be recovered under the low and medium intensities of cutting. These results indicate that clear cutting and the selective cutting of extra-high and high intensities should be avoided in this type of forest in the region

Vitamin K Supplementation in Postmenopausal Women with Osteopenia (ECKO Trial): A Randomized Controlled Trial

Angela Cheung and colleagues investigate whether vitamin K1 can prevent bone loss among postmenopausal women with osteopenia

An Effective, Economical and Ultra-Fast Method for Hydrophobic Modification of NCC Using Poly(Methylhydrogen)Siloxane

Poor compatibility between nanocellulose crystals (NCCs) and major polymers has limited the application of NCC as bio-reinforcements. In this work, an effective and ultra-fast method was investigated to significantly improve the hydrophobicity of NCC by using poly(methylhydrogen)siloxane (PMHS) as modifier. PMHS possessed amounts of reactive –Si–H groups and hydrophobic –CH3 groups. The former groups were reactive with the hydroxyl groups of NCC, while the latter groups afforded NCC very low surface energy. As the weight ratio of PMHS to NCC was only 0.0005%, the hydrophobicity of NCC was significantly improved by increasing the water contact angle of NCC from 0° to 134°. The effect of weight ratio of PMHS to NCC and the hydrogen content of –Si–H in PMHS on the hydrophobicity and thermal stability was investigated in detail by Fourier transform infrared spectroscopy (FTIR), (X-ray Diffraction) XRD and (thermogravimetric analysis) TGA. The results indicated that PMHS chains were covalently grafted onto NCC and PMHS modification improved the thermal stability of NCC

Study on Assembly Precision Reliability Assessment for Industrial Sensing Devices

This paper investigates the method of assembly precision reliability assessment for industrial sensing devices. The part variation is formulated by small displacement torsor. The assembly error model is developed through the approach of pose transformation matrix, then the error transfer between the parts is analyzed and the assembly error is calculated. The concept of assembly precision reliability is proposed. Monte Carlo simulation is adopted to calculate the reliability, after that the procedure of assembly precision reliability is determined. Case study of a laser sensor is provided therefore the effectiveness of the proposed models is verified

Study on Assembly Precision Reliability Assessment for Industrial Sensing Devices

This paper investigates the method of assembly precision reliability assessment for industrial sensing devices. The part variation is formulated by small displacement torsor. The assembly error model is developed through the approach of pose transformation matrix, then the error transfer between the parts is analyzed and the assembly error is calculated. The concept of assembly precision reliability is proposed. Monte Carlo simulation is adopted to calculate the reliability, after that the procedure of assembly precision reliability is determined. Case study of a laser sensor is provided therefore the effectiveness of the proposed models is verified

Discovery of a New Class of Lipophilic Pyrimidine-Biphenyl Herbicides Using an Integrated Experimental-Computational Approach

Herbicides are useful tools for managing weeds and promoting food production and sustainable agriculture. In this study, we report on the development of a novel class of lipophilic pyrimidine-biphenyl (PMB) herbicides. Firstly, three PMBs, Ia, IIa, and IIIa, were rationally designed via a scaffold hopping strategy and were determined to inhibit acetohydroxyacid synthase (AHAS). Computational simulation was carried out to investigate the molecular basis for the efficiency of PMBs against AHAS. With a rational binding mode, and the highest in vitro as well as in vivo potency, Ia was identified as a preferable hit. Furthermore, these integrated analyses guided the design of eighteen new PMBs, which were synthesized via a one-step Suzuki–Miyaura cross-coupling reaction. These new PMBs, Iba-ic, were more effective in post-emergence control of grass weeds compared with Ia. Interestingly, six of the PMBs displayed 98–100% inhibition in the control of grass weeds at 750 g ai/ha. Remarkably, Ica exhibited ≥ 80% control against grass weeds at 187.5 g ai/ha. Overall, our comprehensive and systematic investigation revealed that a structurally distinct class of lipophilic PMB herbicides, which pair excellent herbicidal activities with new interactions with AHAS, represent a noteworthy development in the pursuit of sustainable weed control solutions

Hydrophobic Modification of Nanocellulose via a Two-Step Silanation Method

Dodecyltrimethoxysilane (DTMOS), which is a silanation modifier, was grafted onto nanocellulose crystals (NCC) through a two-step method using KH560 (ɤ-(2,3-epoxyproxy)propytrimethoxysilane) as a linker to improve the hydrophobicity of NCC. The reaction mechanism of NCC with KH560 and DTMOS and its surface chemical characteristics were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and HCl–acetone titration. These analyses confirmed that KH560 was grafted onto the surface of NCC through the ring-opening reaction, before DTMOS was covalently grafted onto the surface of NCC using KH560 as a linker. The grafting of NCC with DTMOS resulted in an improvement in its hydrophobicity due to an increase in its water contact angle from 0° to about 140°. In addition, the modified NCC also possessed enhanced thermal stability

Enhanced superconductivity in a misfit compound (PbSe)

We report the discovery of superconductivity with a maximum Tc ≈ 1.85 K in a new misfit layered compound $(\text{PbSe})_{1.12}(\text{TaSe}_2)_2$ , which consists of alternating layers of a distorted rocksalt layer PbSe and a double-layer dichalcogenide $2H\text{-}\text{TaSe}_2$ . A large anisotropic parameter of resistivity ${\gamma}_\rho = {\rho_c}/{\rho_{ab}} \approx 650$ and that of the upper critical field $\gamma_{H_{c2}}$  = $H_{c2}^{ab} /H_{c2}^{c} \approx 6.6$ are obtained. The estimated c-axis coherence length ${\xi}_c \approx 2.1\ \text{nm}$ is comparable to the c-axis lattice constant. Moreover, the estimated upper critical field $H_{c2}^{ab}(0) = 7.82\ \text{T}$ , significantly exceeding the Pauli paramagnetic limit. All these data indicate a quasi-two-dimensional nature of the superconducting properties in $(\text{PbSe})_{1.12}(\text{TaSe}_2)_2$ . Compared with the physical properties of the misfit compound superconductor $(\text{PbSe})_{1.12}(\text{TaSe}_2)$ with only the half-layer of the $2H\text{-}\text{TaSe}_2$ unit, our study suggests that the enhancement of Tc in $(\text{PbSe})_{1.12}(\text{TaSe}_2)_2$ with double TaSe2 layers is presumably related to the increase in hole carrier density. The reduced charge transfer from the PbSe layer to the conducting TaSe2 layer could account for the variation in the charge carrier density