Mixed FE-SP method for nonlinear structure-water interactions with freak waves

This paper develops a mixed finite element – smoothing particle method for violent water-structure interactions involving freak waves and separation between structure and water. The structure undergoes a large rigid motion of 6 DOF with a small elastic deformation, so that its elastic displacement relative to the rigid motion can be represented in a mode summation based on FE analysis. The water is assumed inviscid - incompressible and its motion governed by nonlinear N-S equation. On the coupling interface where no FS separation happens, the equilibrium and consistence conditions are required. The numerical iteration process is suggested to solve the nonlinear FSI equations, and validation examples are shown a good agreement with available experiment results

Cross-thought for sentence encoder pre-training

In this paper, we propose Cross-Thought, a novel approach to pre-training sequence encoder, which is instrumental in building reusable sequence embeddings for large-scale NLP tasks such as question answering. Instead of using the original signals of full sentences, we train a Transformer-based sequence encoder over a large set of short sequences, which allows the model to automatically select the most useful information for predicting masked words. Experiments on question answering and textual entailment tasks demonstrate that our pre-trained encoder can outperform state-of-the-art encoders trained with continuous sentence signals as well as traditional masked language modeling baselines. Our proposed approach also achieves new state of the art on HotpotQA (full-wiki setting) by improving intermediate information retrieval performance.Comment: Accepted by EMNLP 202

Microwave-based preparation and characterization of Fe-cored carbon nanocapsules with novel stability and super electromagnetic wave absorption performance

Microwave-metal discharge was proposed as a facile methodology to prepare unique Fe-cored carbon nanocapsules (Fe@CNCs) with high purity, novel stability and extraordinary electromagnetic wave (EMW) absorption performance. The effect of microwave power, irradiation time and cyclohexane/ferrocene ratio on the production of Fe@CNCs was examined and the properties of the nanocapsules, such as their Fe content, phase, yield, degree of graphitization and associated microstructures were investigated in detail. It was found that the prepared Fe@CNCs, which can easily be separated from the reaction system, displayed exceedingly high electromagnetic wave (EMW) absorption performance over the 2–18 GHz range. At the minimal reflection loss (RL) values over −10 dB, the EMW absorption bandwidth can reach up to 13.8 GHz with an absorber thickness of 1.5–5 mm. In addition, novel thermo-oxidative stability and super anti-corrosion property were also obtained for the Fe@CNCs as no signs of any corrosion or oxidative degradation loss were observed from the accelerated degradation tests in air and acid at temperatures up to 420 °C. The exceedingly high EMW absorption performance coupled with the superior anti-degradation and anti-corrosion properties of the prepared nanocomposite microcapsules highlights the novel capability of microwave-metal discharge in synthesizing advanced metal-cored nanocarbon microcapsules with promising application potentials in diverse fields, such as but not limited to microwave absorption, EM shielding and advanced separations etc

4-(2,4-Dichloro­phen­yl)-5,5-dimethyl-2-(3-silatranyl­propyl­mino)-1,3,2-dioxa­phospho­rinane 2-oxide

In the title compound, C20H31Cl2N2O6PSi, the dioxaphospho­rinane ring adopts a cis conformation. The silatrane fragment forms a cage-like structure in which there exists an intra­molecular Si—N donor–acceptor bond. In the crystal, centrosymmetrically related mol­ecules are linked by pairs of N—H⋯O hydrogen bonds into inversion dimers, generating rings with graph-set motif R 2 2(8). The dimers are further connected into ribbons parallel to the a axis by inter­molecular C—H⋯O hydrogen bonds

The vital role of hole-carriers for superconductivity in pressurized black phosphorus

The influence of carrier type on superconductivity has been an important issue for understanding both conventional and unconventional superconductors [1-7]. For elements that superconduct, it is known that hole-carriers govern the superconductivity for transition and main group metals [8-10]. The role of hole-carriers in elements that are not normally conducting but can be converted to superconductors, however, remains unclear due to the lack of experimental data. Here we report the first in-situ high pressure Hall effect measurements on single crystal black phosphorus, measured up to ~ 50 GPa, and find a correlation between the Hall coefficient and the superconducting transition temperature (TC). Our results reveal that hole-carriers play a vital role in developing superconductivity and enhancing TC. Importantly, we also find a Lifshitz transition in the high-pressure cubic phase at ~17.2GPa, which uncovers the origin of a puzzling valley in the superconducting TC-pressure phase diagram. These results offer insight into the role of hole-carriers in developing superconductivity in simple semiconducting solids under pressure.Comment: 9 pages anf 3 figure

Advantage of quantum coherence in postselected metrology

In conventional measurement, to reach the greatest accuracy of parameter estimation, all samples must be measured since each independent sample contains the same quantum Fisher information. In postselected metrology, postselection can concentrate the quantum Fisher information of the initial samples into a tiny post-selected sub-ensemble. It has been proven that this quantum advantage can not be realized in any classically commuting theory. In this work, we present that the advantage of postselection in weak value amplification (WVA) can not be achieved without quantum coherence. The quantum coherence of the initial system is closely related to the preparation costs and measurement costs in parameter estimation. With the increase of initial quantum coherence, the joint values of preparation costs and measurement costs can be optimized to smaller. Moreover, we derive an analytical tradeoff relation between the preparation, measurement and the quantum coherence. We further experimentally test the tradeoff relation in a linear optical setup. The experimental and theoretical results are in good agreement and show that the quantum coherence plays a key role in bounding the resource costs in the postselected metrology process

ApoG2, a novel inhibitor of antiapoptotic Bcl-2 family proteins, induces apoptosis and suppresses tumor growth in nasopharyngeal carcinoma xenografts

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in South China. It has been reported that overexpression of antiapoptotic Bcl-2 family proteins in NPC has caused the lack of long-term efficacy of conventional therapies. Apogossypolone (ApoG2), a novel small-molecule inhibitor of antiapoptotic Bcl-2 family proteins, has been discovered as the optimized derivative of gossypol. In this study, we found that in NPC cells, ApoG2 totally blocked the antiapoptotic function of Bcl-2 family proteins without affecting the expression levels of these proteins. ApoG2 selectively inhibited proliferation of 3 NPC cell lines (C666-1, CNE-1 and CNE-2) that highly expressed the antiapoptotic Bcl-2 proteins. This inhibitory activity was associated with release of cytochrome c, activation of caspase-9 and caspase-3 and apoptosis of sensitive NPC cells. However, ApoG2 had no obvious inhibitory effect on NPC cell line HONE-1, which expressed antiapoptotic Bcl-2 and Bcl-xL at a low level. We further found that ApoG2 effectively suppressed tumor growth of NPC xenografts in nude mice and enhanced the antitumor effect of CDDP (cisplatin) on NPC cells in vitro and in vivo . Immunohistochemical results showed that the expression of CD31 decreased after ApoG2 treatment, which suggested inhibition of angiogenesis in NPC xenografts. Our findings strongly suggest that ApoG2 may serve as a novel inhibitor of Bcl-2 family proteins and, by targeting these proteins, may become a promising drug for the treatment of NPC. © 2008 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60986/1/23752_ftp.pd

In vitro evaluation of anticancer nanomedicines based on doxorubicin and amphiphilic Y-shaped copolymers

Four monomethoxy poly(ethylene glycol)-poly(L-lactide-co-glycolide)2 (mPEG-P( LA-co-GA)2) copolymers were synthesized by ring-opening polymerization of L-lactide and glycolide with double hydroxyl functionalized mPEG (mPEG-(OH)2) as macroinitiator and stannous octoate as catalyst. The copolymers self-assembled into nanoscale micellar/vesicular aggregations in phosphate buffer at pH 7.4. Doxorubicin (DOX), an anthracycline anticancer drug, was loaded into the micellar/vesicular nanoparticles, yielding micellar/vesicular nanomedicines. The in vitro release behaviors could be adjusted by content of hydrophobic polyester and pH of the release medium. In vitro cell experiments showed that the intracellular DOX release could be adjusted by content of P(LA-co-GA), and the nanomedicines displayed effective proliferation inhibition against Henrietta Lacks’s cells with different culture times. Hemolysis tests indicated that the copolymers were hemocompatible, and the presence of copolymers could reduce the hemolysis ratio of DOX significantly. These results suggested that the novel anticancer nanomedicines based on DOX and amphiphilic Y-shaped copolymers were attractive candidates as tumor tissular and intracellular targeting drug delivery systems in vivo, with enhanced stability during circulation and accelerated drug release at the target sites