Super-hydrophobic Hybrid Coatings Preparation used by Methyltrithoxysilane (MTES) and Tetraethylorthosilicate(TEOS)

超疏水材料由于其优异的疏水自洁性能，在航空航天、海洋工程、除冰防腐等领域具有广阔的应用前景。本文采用简单的溶胶-凝胶制备超疏水涂层。 . 以甲基三乙氧基硅烷（MTES）和原硅酸四乙酯（TEOS）为前驱体，水解缩合后形成粗糙结构，1H,1H,2H,2H-全氟癸基三乙氧基硅烷（FAS）为低表面能的表面活性剂，系统研究了各自的最佳配比零件。涂层的疏水性和形貌分别通过水接触角测量、扫描电子显微镜（SEM）表征。同时，其官能团通过红外光谱表征。基于大量的实验和优化测试

Aqua­(2,6-dihy­droxy­benzoato-κO 1)bis­(1,10-phenanthroline-κ2 N,N′)manganese(II) 2,6-dihy­droxy­benzoate hemihydrate

In the complex cation of the title compound, [Mn(C7H5O4)(C12H8N2)2(H2O)](C7H5O4)·0.5H2O, the MnII atom has a six-coordinate octa­hedral environment defined by one carboxyl­ate O atom belonging to a 2,6-dihy­droxy­benzoate (DHB) ligand, four N atoms from two chelating 1,10-phenanthroline mol­ecules and one water mol­ecule. The lattice water mol­ecule lies on a twofold rotation axis. Intra­molecular O—H⋯O hydrogen bonds are present in the DHB anions and complex cations. Inter­molecular O—H⋯O hydrogen bonds link two cations, two anions and one water mol­ecule into a dimer. π–π inter­actions between the pyridine and benzene rings and between the benzene rings are also observed [centroid–centroid distances = 3.7774 (16), 3.7912 (16) and 3.7310 (17) Å]

Dynamic performance analysis for wind turbine in complex conditions

The effect of dynamic performance shall be considered when calculating the wind speed relative to the wind turbine structure, since it is essential to prolong its service life. This article presents a method to get dynamic responses of a wind turbine under different conditions. The time-varying load acting on the blade is calculated by using the blade element momentum theory, and the dynamic performance of the wind turbine are calculated by applying the modal superposition method with blade loads as excitations. A platform is constructed to experimentally test the dynamic responses of the wind turbine system. The dynamic response process is adopted to carry out a dynamic analysis, and theoretical results are compared with experimental results, indicated that the analysis presented in this paper is correct. In addition, the 2 MW wind turbine operating in different wind fields is analyzed by applying the computing method. The results indicate that the wind turbine experiences a huge transverse vibration under turbulent wind, the hub vibration is intensified up to 179.52 %, and the vibration of the blade tip intensifies up to 190.41 % under the action of gusts in extreme conditions relative to the steady state, which shall be considered during design

Long-term mechanical performance of geothermal diaphragm walls in stiff clay

Diaphragm wall equipped with ground heat exchangers is one type of thermo-active foundations, which harness the energy stored by the ground for heating and/or cooling buildings. Past investigations on geothermal diaphragm walls mainly focused on the thermal performance, but paid little attention on their mechanical response to geothermal energy operation. This paper conducts thermo-hydro-mechanical (THM) finite element analyses to investigate the long-term performance of geothermal diaphragm walls in stiff clay. The numerical analyses take account of both the station excavation process in short-term and long-term behaviour of the diaphragm wall. The long-term soil-structure interaction simulation includes three scenarios, examining the effects of ground consolidation, external thermal solicitations and seasonal geothermal operation, respectively. A comparison between the mechanical behaviour of the geothermal diaphragm wall and that of the same wall without geothermal activation indicates that geothermal operation may have an impact on structural serviceability issues (e.g. thermal-induced concrete cracks) although unlikely cause critical safety problems. In particularly, the ground settlement near the station is very sensitive to the stiffness degradation of the stiff clay during geothermal operation, while specific attention should be given to the structural performance at the connections between the wall and slabs due to thermo-induced additional stress concentration

Experimental research on mechanical properties of desert sand steel-PVA fiber engineered cementitious composites

An orthogonal experimental design method involving five-factor and four-level is adopted for the mix design of Desert Sand Steel-PVA fiber ECC. The effect of each level on Mechanical properties of ECC and the difference of Mechanical properties between each level is analyzed. The influence of different experimental factors is discussed, which includes water-binder ratio, fly ash substitution rate, desert sand substitution rate, proportion of PVA fiber and proportion of steel fiber. The experimental results indicate that water-binder ratio and fly ash substitution rate are the most principal and significant influencing factors on the compressive strength of ECC, regardless of age. Steel fiber is conducive to development of splitting tensile strength; PVA fiber is conducive to the development of flexural strength. High strength ECC can be prepared when the desert sand substitution rate is high. As the raw material of ECC, river sand can be 90% replaced by desert sand

UPPRESSO: Untraceable and Unlinkable Privacy-PREserving Single Sign-On Services

Single sign-on (SSO) allows a user to maintain only the credential at the identity provider (IdP), to login to numerous RPs. However, SSO introduces extra privacy threats, compared with traditional authentication mechanisms, as (a) the IdP could track all RPs which a user is visiting, and (b) collusive RPs could learn a user's online profile by linking his identities across these RPs. This paper proposes a privacypreserving SSO system, called UPPRESSO, to protect a user's login activities against both the curious IdP and collusive RPs. We analyze the identity dilemma between the security requirements and these privacy concerns, and convert the SSO privacy problems into an identity transformation challenge. In each login instance, an ephemeral pseudo-identity (denoted as PID_RP ) of the RP, is firstly negotiated between the user and the RP. PID_RP is sent to the IdP and designated in the identity token, so the IdP is not aware of the visited RP. Meanwhile, PID_RP is used by the IdP to transform the permanent user identity ID_U into an ephemeral user pseudo-identity (denoted as PID_U ) in the identity token. On receiving the identity token, the RP transforms PID_U into a permanent account (denoted as Acct) of the user, by an ephemeral trapdoor in the negotiation. Given a user, the account at each RP is unique and different from ID_U, so collusive RPs cannot link his identities across these RPs. We build the UPPRESSO prototype on top of MITREid Connect, an open-source implementation of OIDC. The extensive evaluation shows that UPPRESSO fulfills the requirements of both security and privacy and introduces reasonable overheads

Halide perovskites enable polaritonic \u3ci\u3eXY\u3c/i\u3e spin Hamiltonian at room temperature

Exciton polaritons, the part-light and part-matter quasiparticles in semiconductor optical cavities, are promising for exploring Bose–Einstein condensation, non-equilibrium many-body physics and analogue simulation at elevated temperatures. However, a room-temperature polaritonic platform on par with the GaAs quantum wells grown by molecular beam epitaxy at low temperatures remains elusive. The operation of such a platform calls for long-lifetime, strongly interacting excitons in a stringent material system with large yet nanoscale-thin geometry and homogeneous properties. Here, we address this challenge by adopting a method based on the solution synthesis of excitonic halide perovskites grown under nanoconfinement. Such nanoconfinement growth facilitates the synthesis of smooth and homogeneous single-crystalline large crystals enabling the demonstration of XY Hamiltonian lattices with sizes up to 10 × 10. With this demonstration, we further establish perovskites as a promising platform for room temperature polaritonic physics and pave the way for the realization of robust mode-disorder-free polaritonic devices at room temperature

Effects of fermentation medium on cigar filler

The addition of medium during industrial fermentation can improve the quality of cigar tobacco leaves after agricultural fermentation. In this study, the cigar filler tobacco “Brazilian Frogstrips YA14” was used as the test material to determine the contents of main chemical components in cigar tobacco leaves after fermentations with the additions of water (control group) and a medium (test group), and the changes in the community structure and abundances of bacteria on tobacco leaves during the fermentation process were analyzed. The results of the study were as follows: 1) During the fermentation process, the protein content of tobacco leaves fluctuated slightly, basically stabilized at 19%–20%. 2) Under the impact of the medium, the total content of main amino acids in tobacco leaves showed a downward trend, and the difference of which between the control group and the test group was the most obvious on the fourth day of fermentation. 3) The change trend of the content of petroleum ether extract in cigar leaves for the control group was not obvious, and the content of petroleum ether extract in the tobacco leaves for the test group decreased by 12.4% under the impact of the medium. 4) After fermentation, the relative content of saturated fatty acids for the control group and the test group all increased, while the relative content of unsaturated fatty acids all decreased. 5) After the addition of the medium, the diversity of bacteria on tobacco leaves changed significantly, the number of OTUs in tobacco leaves increased, and the bacterial community structure changed. This research indicates that after adding the medium to ferment cigar filler, the changes of bacterial community and dominant bacterial group on cigar tobacco leaves have impacts on the contents of chemical components in tobacco leaves, and the fermentation with the addition of medium has a positive effect on improving the quality of tobacco leaves

Effects of a novel microbial fermentation medium produced by Tremella aurantialba SCT-F3 on cigar filler leaf

IntroductionAdding a fermentation medium is an effective way to improve the quality of cigar tobacco leaves.MethodsA novel microbial fermentation medium produced by an edible medicinal fungus, Tremella aurantialba SCT-F3 (CGMCC No.23831) was used to improve the quality of cigar filler leaves (CFLs). Changes in sensory quality, chemical components, volatile flavor compounds (VFCs), and the structure and function of microbes were investigated during the fermentation process.ResultsThe sensory quality of CFLs supplemented with the T. aurantialba SCT-F3 fermentation medium significantly improved. Adding the fermentation medium increased the total alkaloid, reducing sugar, total sugar, and 12 VFCs significantly. A total of 31 microbial genera were significantly enriched, which increased the microbial community’s richness and diversity. Microbial functions increased, including nucleotide biosynthesis, amino acid biosynthesis, fatty acid and lipid biosynthesis, nicotine degradation, and nicotinate degradation. During fermentation, the total alkaloid, reducing sugar, and total sugar content decreased. The richness and diversity of the microbial community decreased, whereas bacterial enzyme activity increased. At the end of fermentation, the sensory quality was excellent. The microbial structure gradually stabilized, and functional genes were low. The contents of the four Maillard reaction products and three nicotine degradation products increased significantly. 2-Ethyl-6-methylpyrazine, methylpyrazine, D,L-anatabine, β-nicotyrine, nicotinic degradation products, and total nitrogen were significantly and positively correlated with sensory quality. Methylpyrazine, D,L-anatabine, and β-nicotyrine were negatively correlated with Luteimonas, Mitochondria, Paracoccus, Stemphylium, and Stenotrophomonas.ConclusionThis research provides not only a new microbial fermentation medium that utilizes edible and medicinal fungi to improve the quality of fermented CFLs, but also new ideas for the development and application of other edible medicinal fungi to improve the quality of cigar tobacco leaves