Search

Editor's Note: As a new, emerging branch of learning, the science of policy making is arousing the close attention of policymakers at various levels as well as theoretical workers. All kinds of complicated and arduous new problems posed by socialist modernization and the increasing complexity of the structure and laws of social activities make a scientific approach to policy making and its modernization an extremely urgent task. Herein lies the necessity and urgency of a philosophical analysis of the question of policy making. A series of problems have arisen, such as scientific policy making and objective laws (including the laws of nature, society, and thought), scientific policy making and practice and recognition, scientific policy making and scientific prediction, scientific method and standard of value in scientific policy making, all of which must be answered from the high plane of philosophy. Meanwhile, the modern science of policy making is showing the trend of comprehensive use of all kinds of new achievements and new methods in science and technology. Such comprehensive application has opened up broad fields for applying Marxist world outlook and methodology in philosophy to solve all kinds of complicated problems. To seek effective ways of applying philosophy to the modernization drive, paying close attention to the development of new disciplines such as the science of policy making may be helpful in finding out the "joining points" between philosophy and various branches of concrete science, between philosophy and reality, between applied research and basic theory research in philosophy and opening up a new situation in the study of philosophy. [ABSTRACT FROM AUTHOR]

Germanium-tin films with rather high Sn content (28.04% and 29.61%) are deposited directly on Si (100) and Si (111) substrates by magnetron sputtering. The mechanism of the effect of rapid thermal annealing on the Sn surface segregation of Ge1 −xSnx films is investigated by x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The x-ray diffraction (XRD) is also performed to determine the crystallinities of the Ge1−xSnx films. The experimental results indicate that root mean square (RMS) values of the annealed samples are comparatively small and have no noticeable changes for the as-grown sample when annealing temperature is below 400 °C. The diameter of the Sn three-dimensional (3D) island becomes larger than that of an as-grown sample when the annealing temperature is 700 °C. In addition, the Sn surface composition decreases when annealing temperature ranges from 400 °C to 700 °C. However, Sn bulk compositions in samples A and B are kept almost unchanged when the annealing temperature is below 600 °C. The present investigation demonstrates that the crystallinity of Ge1−xSnx/Si (111) has no obvious advantage over that of Ge1−xSnx/Si (100) and the selection of Si (111) substrate is an effective method to improve the surface morphologies of Ge1−xSnx films. We also find that more severe Sn surface segregation occurs in the Ge1−xSnx/Si (111) sample during annealing than in the Ge1−xSnx/Si (100) sample. [ABSTRACT FROM AUTHOR]

The analysis of threading dislocation density (TDD) in Ge-on-Si layer is critical for developing lasers, light emitting diodes (LEDs), photodetectors (PDs), modulators, waveguides, metal oxide semiconductor field effect transistors (MOSFETs), and also the integration of Si-based monolithic photonics. The TDD of Ge epitaxial layer is analyzed by etching or transmission electron microscope (TEM). However, high-resolution x-ray diffraction (HR-XRD) rocking curve provides an optional method to analyze the TDD in Ge layer. The theory model of TDD measurement from rocking curves was first used in zinc-blende semiconductors. In this paper, this method is extended to the case of strained Ge-on-Si layers. The HR-XRD scan is measured and Ge (004) single crystal rocking curve is utilized to calculate the TDD in strained Ge epitaxial layer. The rocking curve full width at half maximum (FWHM) broadening by incident beam divergence of the instrument, crystal size, and curvature of the crystal specimen is subtracted. The TDDs of samples A and B are calculated to be 1.41 × 108 cm−2 and 6.47 × 108 cm−2, respectively. In addition, we believe the TDDs calculated by this method to be the averaged dislocation density in the Ge epitaxial layer. [ABSTRACT FROM AUTHOR]

The physical properties of newly discovered orthocarbonate Ca 3 CO 5 are of significant importance in understanding the carbon cycle and storage in the Earth's interior. Here, the structural, elastic, seismic, and thermal properties of Ca 3 CO 5 polymorphs under the Earth's lower mantle pressure are investigated using first-principles calculations, and the results are compared with those of orthocarbonate Ca 2 CO 4 - Pnma. Our findings demonstrate that the pressure of the Cmcm phase of Ca 3 CO 5 to the I 4/ mcm phase is 53.8 GPa, and the transition pressure and equation of state align with prior research. Additionally, the elastic moduli, densities, and wave velocities of Ca 3 CO 5 polymorphs are similar to those of Ca 2 CO 4 - Pnma. However, the azimuthal anisotropies of Ca 3 CO 5 polymorphs are greater than those of Ca 2 CO 4 - Pnma. Furthermore, the minimum thermal conductivity and diffusion thermal conductivity of Ca 3 CO 5 polymorphs are smaller than those of Ca 2 CO 4 - Pnma. Ultimately, the thermodynamic properties of Ca 3 CO 5 polymorphs are obtained utilizing the quasi-harmonic approximation method. These results provide valuable insight into the physical properties of Ca 3 CO 5 , which can aid in further understanding the carbon cycle and storage within the Earth's underground. • According to the stress-strain method, the elastic properties of Ca 3 CO 5 polymorphs under high pressure are obtained. • Based on the obtained elastic constants, the seismic properties of Ca 3 CO 5 polymorphs under lower mantle pressure are studied. • The thermal properties of Ca 3 CO 5 polymorphs at high temperatures and high pressures are calculated. [ABSTRACT FROM AUTHOR]

Depression is a pervasive and often undetected mental health condition, which poses significant challenges for early diagnosis due to its silent and subtle nature. To evaluate exhaled volatile organic compounds (VOCs) as non-invasive biomarkers for the detection of depression using a virtual surface acoustic wave sensors array (VSAW-SA). A total of 245 participants were recruited from the Hangzhou Community Health Service Center, including 38 individuals diagnosed with depression and 207 control subjects. Breath samples were collected from all participants and subjected to analysis using VSAW-SA. Univariate and multivariate analyses were employed to assess the relationship between VOCs and depression. The findings revealed that the responses of virtual sensor ID 14, 44, 59, and 176, which corresponded respectively to ethanol, trichloroethylene or isoleucine, octanoic acid or lysine, and an unidentified compound, were sensitive to depression. Taking into account potential confounders, these sensor responses were utilized to calculate a depression detection indicator. It has a sensitivity of 81.6% and a specificity of 81.6%, with an area under the curve of 0.870 (95% CI = 0.816-0.923). Conclusions: exhaled VOCs as non-invasive biomarkers of depression could be detected by a VSAW-SA. Large-scale cohort studies should be conducted to confirm the potential ability of the VSAW-SA to diagnose depression., (Creative Commons Attribution license.)