Split representation of adaptively compressed polarizability operator

The polarizability operator plays a central role in density functional perturbation theory and other perturbative treatment of first principle electronic structure theories. The cost of computing the polarizability operator generally scales as $\mathcal{O}(N_{e}^4)$ where $N_e$ is the number of electrons in the system. The recently developed adaptively compressed polarizability operator (ACP) formulation [L. Lin, Z. Xu and L. Ying, Multiscale Model. Simul. 2017] reduces such complexity to $\mathcal{O}(N_{e}^3)$ in the context of phonon calculations with a large basis set for the first time, and demonstrates its effectiveness for model problems. In this paper, we improve the performance of the ACP formulation by splitting the polarizability into a near singular component that is statically compressed, and a smooth component that is adaptively compressed. The new split representation maintains the $\mathcal{O}(N_e^3)$ complexity, and accelerates nearly all components of the ACP formulation, including Chebyshev interpolation of energy levels, iterative solution of Sternheimer equations, and convergence of the Dyson equations. For simulation of real materials, we discuss how to incorporate nonlocal pseudopotentials and finite temperature effects. We demonstrate the effectiveness of our method using one-dimensional model problem in insulating and metallic regimes, as well as its accuracy for real molecules and solids.Comment: 32 pages, 8 figures. arXiv admin note: text overlap with arXiv:1605.0802

A study on Harada Shigeyoshi's Jujireki Chukai (Study of the History of Mathematics 2022)

After being introduced to Japan, the important ancient Chinese calendar, the Shoushi Calendar, was reprinted and disseminated. The Shoushili Yi in Yuan Shi·Li zhi is an important document about the ancient Chinese calendar theory. No one studied it in the Ming and Qing dynasties, but Japanese scholars in the Edo period commented on it, such as Takebe Katahiro (1664-1739), Nishimura Tōsato (1718-1787), and Harada Shigeyoshi (1740-1807), they annotated the Shoushili Yi. The article firstly verifies that the author of the Jujireki Chukai in the library affiliated to Tohoku University is Harada Shigeyoshi, not Takahashi Yoshitoki (1764-1804). Secondly, an investigation was carried out on Harada Shigeyoshi and his writings. The investigation found that there were three manuscripts of Harada Shigeyoshi's Jujireki Chukai, and the contents of the annotations and knowledge sources were verified and sorted out. It is believed that the Jujireki Chukai cited the contents of Tianwen Tujie Fahui (Nakane Genkei), Lisuan Quanshu (Mei Wending) and Juji Kai (Nishimura Tōsato) mostly. Finally, the article analyzes the annotations on “Yanqi (Collect or modify data for the solar terms)” and “Buyong Jinian Rifa (Abolition of the calendar epoch)” in Harada Shigeyoshi's Jujireki Chukai, and thinks that Harada's annotations in “Yanqi” through diagrams are commendable. The “Buyong Jinian Rifa” section is rich in annotations, which supplement the three possible situations that Li Qian and Qi Lvqian proposed to calculate Yanji Shangyuan. The two new situations which do not provide calculation procedures are similar to the methods of Li Qian and Qi Lvqian, and the other two situations are caculated by Seki Takakazu's Jianguan-Method. This method is essentially the same as that of Dayan-Zongshu-Method (Da-yan Rule) [大衍總數術]

Water-Soluble Flexible Organic Frameworks That Include and Deliver Proteins.

Four water-soluble hydrazone-based three-dimensional (3D) flexible organic frameworks FOF-1-4 have been synthesized from a semirigid tetracationic tetraaldehyde and four flexible dihydrazides. 1H NMR spectroscopy indicated the quantitative formation of FOF-1-4 in D2O, while dynamic light scattering experiments revealed that, depending on the concentration, these porous frameworks display hydrodynamic diameters ranging from 50 to 120 nm. The porosity of the frameworks is confirmed by ethanol vapor adsorption experiments of the solid samples as well as the high loading capacity for a 2.3 nm porphyrin guest in water. The new water-soluble frameworks exhibit low cytotoxicity and form inherent pores with diameters of 5.3 or 6.7 nm, allowing rapid inclusion of proteins such as bovine serum albumin and green and orange fluorescent proteins, and efficient delivery of the proteins into normal and cancer cells. Flow cytometric analysis reveals percentages of the delivered cells up to 99.8%

Thermal Conductivity Performance of Polypropylene Composites Filled with Polydopamine-Functionalized Hexagonal Boron Nitride

Mussel-inspired approach was attempted to non-covalently functionalize the surfaces of boron nitride (BN) with self-polymerized dopamine coatings in order to reduce the interfacial thermal barrier and enhance the thermal conductivity of BN-containing composites. Compared to the polypropylene (PP) composites filled with pristine BN at the same filler content, thermal conductivity was much higher for those filled with both functionalized BN (f-BN) and maleic anhydride grafted PP (PP-g-ma) due to the improved filler dispersion and better interfacial filler-matrix compatibility, which facilitated the development of more thermal paths. Theoretical models were also applied to predict the composite thermal conductivity in which the Nielsen model was found to fit well with the experimental results, and the estimated effective aspect ratio of fillers well corresponded to the degree of filler aggregation as observed in the morphological study

Ophiopogon japonicas (Linn. f.) Ker-Gawl. extract ameliorates chronic heart failure in rats

Purpose: To investigate the effect of Ophiopogon japonicas (Linn. f.) Ker-Gawl. extract (OJKE) on oxidative stress and hemodynamics in chronic congestive heart failure (CHF) rats. Methods: The rats were modelled to congestive heart failure (except normal group) , and then randomly divided into normal control group, model (untreated) group, captopril group, high-dose, middle-dose and low-dose of OJKE groups. They were treated for 4 weeks as appropriate for each group. At the end of treatment, the hemodynamic function, whole heart weight index, and blood creatinine kinase (CK), as well as superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), nitricoxide synthase (NOS) were determined. Results: Compared with the normal control group, arterial systolic pressure (SBP), diastolic pressure (DBP), mean arterial pressure (MAP), heart rate (HR), left ventricular systolic peak (LVSP), and left ventricular pressure change rate (dp/dt max) significantly decreased (p < 0.05), while left ventricular end diastolic pressure (LVEDP), whole heart weight index, blood CK, MDA, NO, NOS significantly increased in the untreated group (p < 0.05). A high dose of OJKE significantly improved hemodynamic function, lowered MDA (8.33 ± 2.12 nmol/mL) and NO (20.58 ± 3.53 umol/L) levels (p < 0.05), and also decreased CK (0.53±0.37 U/mL) and NOS (22.46±3.29 U/mL) in CHF rats (p < 0.05). Conclusion: OJKE improved adriamycin-induced chronic congestive heart failure in rats significantly

Semiconductor saturable absorber mirror mode-locked Yb:YAP laser

We report on sub-30 fs pulse generation from a semiconductor saturable absorber mirror mode-locked Yb:YAP laser. Pumping by a spatially single-mode Yb fiber laser at 979 nm, soliton pulses as short as 29 fs were generated at 1091 nm with an average output power of 156 mW and a pulse repetition rate of 85.1 MHz. The maximum output power of the mode-locked Yb:YAP laser amounted to 320 mW for slightly longer pulses (32 fs) at an incident pump power of 1.52 W, corresponding to a peak power of 103 kW and an optical efficiency of 20.5%. To the best of our knowledge, this result represents the shortest pulses ever achieved from any solid-state Yb laser mode-locked by a slow, i.e., physical saturable absorber