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The weak intermolecular forces of hydrogen‐bonded organic frameworks (HOFs) make it relatively difficult to synthesize and design HOFs with superprotonic conductivity and robustness. The self‐assembly of ionic hydrogen bonding organic frameworks (iHOFs) through acid–base pairing strategies are possible on account of the rich hydrogen bonding, strong ionic bonding, and π–π stacking interactions and so on. Herein, a case of iHOF (iHOF‐16) with a three‐dimensional (3D) hydrogen bonding network is reported, the doughty ionic bond interactions in the structure and π–π stacking interactions between layers make it exhibits excellent thermal and chemical stability, it can maintain high crystallinity and robust structure even under extreme conditions. Importantly, iHOF‐16 exhibits highly anisotropic proton conductivity of 0.388, 5.56 × 10−3, and 3.25 × 10−4 S cm−1 in the direction of a‐axis, b‐axis, and c‐axis, respectively. The proton transfer paths of single crystal on each axis are calculated using density functional theory (DFT) and, supported by joint experimental–theoretical calculations, protons are most easily transported in the a‐axis direction resulting in superprotonic conductivity. The present study provides a promising approach for the design of stable superprotonic conductivity materials through a simple yet effective charge‐assisted synthesis strategy. [ABSTRACT FROM AUTHOR]

The dual emission (DE) characteristics of atomically precise copper nanoclusters (Cu NCs) are of significant theoretical and practical interest. Despite this, the underlying mechanism driving DE in Cu NCs remains elusive, primarily due to the complexities of excited state processes. Herein, a novel [Cu4(PPh3)4(C≡C−p−NH2C6H4)3]PF6 (Cu4) NC, shielded by alkynyl and exhibiting DE, was synthesized. Hydrostatic pressure was applied to Cu4, for the first time, to investigate the mechanism of DE. With increasing pressure, the higher‐energy emission peak of Cu4 gradually disappeared, leaving the lower‐energy emission peak as the dominant emission. Additionally, the Cu4 crystal exhibited notable piezochromism transitioning from cyan to orange. Angle‐dispersive synchrotron X‐ray diffraction results revealed that the reduced inter‐cluster distances under pressure brought the peripheral ligands closer, leading to the formation of new C−H⋅⋅⋅N and N−H⋅⋅⋅N hydrogen bonds in Cu4. It is proposed that these strengthened hydrogen bond interactions limit the ligands′ vibration, resulting in the vanishing of the higher‐energy peak. In situ high‐pressure Raman and vibrationally resolved emission spectra demonstrated that the benzene ring C=C stretching vibration is the structural source of the DE in Cu4. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive circularly polarized luminescence (CPL) materials are ideal for information anti‐countering applications, but the best‐performing materials have not yet been identified. This work presents enantiomorphic hybrid antimony halides R‐(C5H12NO)2SbCl5 (1) and S‐(C5H12NO)2SbCl5 (2) showing mirror‐imaged CPL activity with a dissymmetry factor of 1.2×10−3. Interestingly, the DMF‐induced structural transformation is realized to obtain non‐emissive R‐(C5H12NO)2SbCl5 ⋅ DMF (3) and S‐(C5H12NO)2SbCl5 ⋅ DMF (4) upon exposure to DMF vapor. The transformation process is reversed upon heating. DFT calculations showed that the DMF‐induced‐quenched‐luminescence is attributed to the intersection of the ground and excited state curves on the configuration coordinates. Unexpectedly, the nanocrystals of the chiral antimony halides 1 and 2 were prepared and indicate the excellent solution process performance. The reversible PL and CPL switching gives the system applications in information technology, anti‐counterfeiting, encryption‐decryption, and logic gates. [ABSTRACT FROM AUTHOR]

Axillary osmidrosis (AO) and primary hyperhidrosis (PH) are common diseases, but there are still difficulties in treatment. Microwave therapy may become a new method. In order to evaluate long‐time efficacy of patients with AO or PH treated by microwave and to discuss possible mechanism of microwave therapy by combining results of clinical and pathological, the study was carried out. Ten AO or PH patients with moderate or severe level were selected as subjects, and each subject received microwave treatment of bilateral armpits. The follow‐up period lasted 2 years, and the changes of perspiration and odor were evaluated in subjective and objective ways. Each subject took skin biopsy in the treatment area before and after treatment or each follow‐up. Hematoxylin‐eosin and immunohistochemical staining were performed. Both subjective and objective index reflected the significant improvement of AO and PH after treatment (p < 0.05). Dermatology life quality index score decreased by 10.4 ± 4.6 (p < 0.05). The number of apocrine glands decreased significantly after treatment, and most of them changed from secretory phase to quiescent phase. In conclusion, microwave therapy can destroy apocrine sweat glands, reduce number of functional glands, so as to improve symptoms of AO and PH and elevate quality of life, which is safe, effective, and stable. [ABSTRACT FROM AUTHOR]

Considering the propellant of solid rocket motor with tube grain is in the state of superimposed pressure after ignition, the effect of pressures, temperatures, and tensile rates on the mechanical properties of solid propellant were investigated together. A test system with wide temperature‐ambient pressure range was developed to investigate the effects of superimposed pressure on the performance of propellant. The uniaxial constant tensile rate tests for a certain HTPB propellants under different superimposed pressures and temperatures were performed at different tensile rates. Research shows that there are no apparent dewetting points in the propellant stress‐strain curves under superimposed pressures. Moreover, the performance of propellant under superimposed pressure related to propellant itself such as composition of the propellant was evaluated by comparing to another propellant. Relevant methods and conclusions can provide a reference for structural analysis and storage life prediction of solid rocket motors. [ABSTRACT FROM AUTHOR]

The weakly coordinated anionic nitrate ligands in a centrosymmetric Ag20 cluster are replaced in a stepwise manner by chiral amino acids and two achiral luminescent sulfonic‐group‐containing ligands while nearly maintaining the original silver(I) cage structure. This surface engineering enables the atomically precise Ag20 clusters to exhibit the high‐efficiency synergetic effects of chirality and fluorescence, producing rare circularly polarized luminescence among the metal clusters with a large dissymmetry factor of (|glum|) ≈ 5 × 10−3. This rational approach using joint functional ligands further opens a new avenue to diverse multifunctional metal clusters for promising applications. [ABSTRACT FROM AUTHOR]

The migratory plant‐parasitic nematode Bursaphelenchus xylophilus is the causal agent of pine wilt disease, which causes serious damage to pine forests in China. Plant immunity plays an important role in plant resistance to multiple pathogens. Activation of the plant immune system is generally determined by immune receptors, including plant pattern recognition receptors, which mediate pattern recognition. However, little is known about molecular pattern recognition in the interaction between pines and B. xylophilus. Based on the B. xylophilus transcriptome at the early stages of infection and Agrobacterium tumefaciens‐mediated transient expression and infiltration of recombinant proteins produced by Pichia pastoris in many plant species, a novel molecular pattern (BxCDP1) was characterized in B. xylophilus. We found that BxCDP1 was highly up‐regulated at the early infection stages of B. xylophilus, and was similar to a protein in Pararhizobium haloflavum. BxCDP1 triggered cell death in Nicotiana benthamiana when secreted into the apoplast, and this effect was dependent on brassinosteroid‐insensitive 1‐associated kinase 1, but independent of suppressor of BIR1‐1. BxCDP1 also exhibited cell death‐inducing activity in pine, Arabidopsis, tomato, pepper, and lettuce. BxCDP1 triggered reactive oxygen species production and the expression of PAMP‐triggered immunity marker genes (NbAcre31, NbPTI5, and NbCyp71D20) in N. benthamiana. It also induced the expression of pathogenesis‐related genes (PtPR‐3, PtPR‐4, and PtPR‐5) in Pinus thunbergii. These results suggest that as a new B. xylophilus molecular pattern, BxCDP1 can not only be recognized by many plant species, but also triggers innate immunity in N. benthamiana and defence responses of P. thunbergii. [ABSTRACT FROM AUTHOR]

Atomically precise enantiomeric metal clusters are scarce, and copper(I) alkynyl clusters with intense circularly polarized luminescence (CPL) responses have not been reported. A pair of chiral alkynyl ligands, (R/S)‐2‐diphenyl‐2‐hydroxylmethylpyrrolidine‐1‐propyne (abbreviated as R/S‐DPM) we successfully prepared and single crystals were characterized of optically pure enantiomeric pair of atomically‐precise copper(I) clusters, [Cu14(R/S‐DPM)8](PF6)6 (denoted as R/S‐Cu14), which feature bright red luminescence and CPL with a high luminescence anisotropy factor (glum). A dilute solution containing R/S‐Cu14 was nonluminescent and CPL inactive at room temperature. Crystallization‐ and aggregation‐induced emission (CIE and AIE, respectively) contribute to the triggering of the CPL of R/S‐Cu14 in the crystalline and aggregated states. Their AIE behavior and good biocompatibility indicated applications of these copper(I) clusters in cell imaging in HeLa and NG108‐15 cells. [ABSTRACT FROM AUTHOR]

Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH3OH)2(18‐crown‐6)]+[Cu5(StBu)6]− (1⋅CH3OH) in the chiral space group was prepared, in which the chiral red‐emissive anionic [Cu5(StBu)6]− cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH3OH of the cationic units turned the chiral 1⋅CH3OH crystal into a mesomeric crystal [K(18‐crown‐6)]+[Cu5(StBu)6]− (1), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu5(StBu)6]− units. The switchable chiral/achiral rearrangement of [Cu5(StBu)6]− clusters along with the capture/release of CH3OH were concomitant with an intense increase/decrease in luminescence. We also used cationic chiral amino alcohols to induce the chiral assembly of a pair of enantiomers, [d/l‐valinol(18‐crown‐6)]+[Cu5(StBu)6]− (d/l‐Cu5V), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL‐silent racemic mixture of 1⋅CH3OH and mesomeric 1. [ABSTRACT FROM AUTHOR]

In this work, a new type of high temperature fiber grating diaphragm pressure sensor is described, including the physical design structure, in-depth analysis of optical response to changes in pressure, and a discussion of the temperature compensation method. Mathematical model of high-temperature compressive shape change and normal-temperature compressive shape change is built, and effective temperature compensation method is proposed, which can both contribute to solve temperature interference of pressure sensor at high temperature. In addition, the simulation computation is conducted for the external encapsulation of the sensor under the high-temperature and pressure according to the design model. Through analysis and comparison of data affecting the changing position of grating signal, the correctness of the simulation result is verified by the development of the prototype. The temperature compensation method is proposed to realize pressure measurement of sensor with a relative error below 4.6%F.S. and range to 50 MPa in the environment of 300, which meets with the safety research requirement of the cartridge system. [ABSTRACT FROM AUTHOR]

A solid rocket motor is one of the critical components of solid missiles, and its life and reliability mostly depend on the mechanical behavior of a composite solid propellant (CSP). Effective mechanical properties are critical material constants to analyze the structural integrity of propellant grain. They are estimated by a numerical method that combines the Voronoi cell finite element method (VCFEM) and the homogenization method in the present paper. The correctness of this combined method has been validated by comparing with a standard finite element method and conventional theoretical models. The effective modulus and the effective Poisson’s ratio of a CSP varying with volume fraction and component material properties are estimated. The result indicates that the variations of the volume fraction of inclusions and the properties of the matrix have obvious influences on the effective mechanical properties of a CSP. The microscopic numerical analysis method proposed in this paper can also be used to provide references for the design and the analysis of other large volume fraction composite materials. [ABSTRACT FROM AUTHOR]

This paper presents a new method for solving feedback gains in guidance based on optimal control theory. The determination of feedback gains is a critical problem for nominal guidance, because landing precision benefits from appropriate feedback gains. The magnitude of the bank angle is determined by minimizing the total error of final altitude as well as downrange requirement to the landing site. The problem is formulated as an optimal control problem by means of the Pontryagin's maximum principle, and backward integration is used to solve the problem based on homogeneous property. The proposed approach not only can avoid linearizing the nonlinear dynamic equations, but also are applicable to different guidance equations. Validation shows that the proposed approach can provide consistent results with that of Apollo. Despite employment of nominal guidance in the entire reentry of lunar mission, the proposed approach demonstrates good performance in all simulation cases while subject to significant disturbances. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A study of optimal impulsive Moon-to-Earth trajectories is presented in a planar circular restricted three-body framework. Two-dimensional return trajectories from circular lunar orbits are considered, and the optimization criterion is the total velocity change. The optimal conditions are provided by the optimal control theory. The boundary value problem that arises from the application of the theory of optimal control is solved using a procedure based on Newton's method. Motivated by the difficulty of obtaining convergence, the search for the initial adjoints is carried out by means of two different techniques: homotopic approach and adjoint control transformation. Numerical results demonstrate that both initial adjoints estimation methods are effective and efficient to find the optimal solution and allow exploring the fundamental tradeoff between the time of flight and required Δ V. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The weak intermolecular forces of hydrogen‐bonded organic frameworks (HOFs) make it relatively difficult to synthesize and design HOFs with superprotonic conductivity and robustness. The self‐assembly of ionic hydrogen bonding organic frameworks (iHOFs) through acid–base pairing strategies are possible on account of the rich hydrogen bonding, strong ionic bonding, and π–π stacking interactions and so on. Herein, a case of iHOF (iHOF‐16) with a three‐dimensional (3D) hydrogen bonding network is reported, the doughty ionic bond interactions in the structure and π–π stacking interactions between layers make it exhibits excellent thermal and chemical stability, it can maintain high crystallinity and robust structure even under extreme conditions. Importantly, iHOF‐16 exhibits highly anisotropic proton conductivity of 0.388, 5.56 × 10−3, and 3.25 × 10−4 S cm−1 in the direction of a‐axis, b‐axis, and c‐axis, respectively. The proton transfer paths of single crystal on each axis are calculated using density functional theory (DFT) and, supported by joint experimental–theoretical calculations, protons are most easily transported in the a‐axis direction resulting in superprotonic conductivity. The present study provides a promising approach for the design of stable superprotonic conductivity materials through a simple yet effective charge‐assisted synthesis strategy. [ABSTRACT FROM AUTHOR]

In the title compound, {[Zn(C(8)H(3)ClO(4))(C(12)H(12)N(2))(H(2)O)]·[Zn(C(8)H(3)ClO(4))(C(12)H(12)N(2))]}(n), one Zn(2+) ion is five-coordin-ated by two O atoms from two different 3-chloro-benzene-1,2-dicarboxyl-ate ligands, one O atom from a water mol-ecule and two N atoms from a 4,4'-dimethyl-2,2'-bipyridine ligand, while the second Zn(2+) ion is four-coordinated by two O atoms from two different 3-chloro-benzene-1,2-dicarboxyl-ate ligands, and two N atoms from a 4,4'-bimethyl-2,2'-bipyridine ligand. The crystal structure exhibits a three-dimensional supra-molecular structure composed of alternate Zn(C(8)H(3)O(4)Cl)(C(12)H(12)N(2)) and Zn(C(8)H(3)O(4)Cl)(C(12)H(12)N(2))(H(2)O) chains, which are linked together by face-to-face π-π inter-actions [shortest centroid-centroid distances of 3.661 (4) and 3.6901 (3) Å], O-H⋯O and C-H⋯O hydrogen bonds.