重粒子刀（带电粒子定向放射外科）

重粒子刀（带电粒子定向放射外科）陈信康马安保综述编辑部审校１９５４年加里福尼亚大学Ｌａｗｒｅｎｃｅ放射实验室创始用加速带电粒子作为能源用于定向放射外科门。这项技术当初主要用来抑制垂体激素分泌治疗转移性乳腺癌问。后来治疗的病种逐渐增多，如前列腺癌、增殖...

Facile Preparation of Danazol Nanoparticles by High-Gravity Anti-solvent Precipitation （HGAP） Method

The nanoparticles of the hydrophobic drug of danazol with narrow size distribution are facilely prepared by controlled high-gravity anti-solvent precipitation （HGAP） process. Intensified micromixing and uniform nucleation environment are created by the high-gravity equipment （rotating packed bed） in carrying out the anti-solvent precipitation process to produce nanoparticles. The average particle size decreases from 55 μm of the raw danazol to 190 nm of the nanoparticles. The Brunauer-Emmett-Teller （BET） surface area sharply increases from 0.66 m^2·g^-1 to 15.08 m^2·g^-l. Accordingly, the dissolution rate is greatly improved. The molecular state, chemical composition, and crystal form of the danazol nanoparticles remains unchanged after processing according to Fourier transform infrared （FTIR） and X-ray diffraction （XRD）, The high recovery ratio and continuous production capacity are highly appreciated in industry. Therefore, the HGAP method might offer a general and facile platform for mass production of hydrophobic pharmaceutical danazol particles in nanometer range.

Continuous Quantum Nondemolition Measurements of a Particle in Electromagnetic and Gravitational Fields

The detection of a particle in electromagnetic plus gravitational fields is investigated. We obtain a set of quantum nondemolition variables. The continuous measurements of these nondemolition parameters are analyzed in the framework of restricted path integral formalism. We manipulate the corresponding propagators, and deduce the probabilities associated with the possible measurement outputs.

How the Orbital System of Particles Consolidates Gravity and Electromagnetism

There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute three-stage hierarchy of particles, atoms, and gravitational systems. Below 1/c waves are dissociated into strands and neutrinos are separated as points of charge. The electron and positron are single strands with opposed helical turns. Protons and neutrons have a nucleus of positrinos and negatrinos surrounded by concentric shells of strands in 2＂~ resonance. The orbital strands reverberate into space creating a field with gravitational and electromagnetic aspects. The orbital system defines matter, energy, motion, and time based on composition. The three stages have a constant field content but differ by field density and components.

Simultaneous estimation of soil moisture and hydraulic parameters using residual resampling particle filter

Land data assimilation(DA) has gradually developed into an important earth science research method because of its ability to combine model simulations and observations.Integrating new observations into a land surface model by the DA method can correct the predicted trajectory of the model and thus,improve the accuracy of state variables.It can also reduce uncertainties in the model by estimating some model parameters simultaneously.Among the various DA methods,the particle filter is free from the constraints of linear models and Gaussian error distributions,and can be applicable to any nonlinear and non-Gaussian state-space model;therefore,its importance in land data assimilation research has increased.In this study,a DA scheme was developed based on the residual resampling particle filter.Microwave brightness temperatures were assimilated into the macro-scale semi-distributed variance infiltration capacity model to estimate the surface soil moisture and three hydraulic parameters simultaneously.Finally,to verify the scheme,a series of comparative experiments was performed with experimental data obtained during the Soil Moisture Experiment of 2004 in Arizona.The results show that the scheme can improve the accuracy of soil moisture estimations significantly.In addition,the three hydraulic parameters were also well estimated,demonstrating the effectiveness of the DA scheme.

Self-Similar Solution of Spherical Shock Wave Propagation in a Mixture of a Gas and Small Solid Particles with Increasing Energy under the Influence of Gravitational Field and Monochromatic Radiation

Similarity solution for a spherical shock wave with or without gravitational field in a dusty gas is studied under the action of monochromatic radiation. It is supposed that dusty gas be a mixture of perfect gas and micro solid particles. Equilibrium flow condition is supposed to be maintained and energy is varying which is continuously supplied by inner expanding surface. It is found that similarity solution exists under the constant initial density. The comparison between the solutions obtained in gravitating and non-gravitating medium is done. It is found that the shock strength increases with an increase in gravitational parameter or ratio of the density of solid particles to the initial density of the gas, whereas an increase in the radiation parameter has decaying effect on the shock waves.

Bearing capacity of thin-walled shallow foundations： an experimental and artificial intelligence-based study

Thin-walled spread foundations are used in coastal projects where the soil strength is relatively low. Developing a predictive model of bearing capacity for this kind of foundation is of interest due to the fact that the famous bearing capacity equations are proposed for conventional footings. Many studies underlined the applicability of artificial neural networks （ANNs） in predicting the bearing capacity of foundations. However, the majority of these models are built using conventional ANNs, which suffer from slow rate of learning as well as getting trapped in local minima. Moreover, they are mainly developed for conventional footings. The prime objective of this study is to propose an improved ANN-based predictive model of bearing capacity for thin-walled shallow foundations. In this regard, a relatively large dataset comprising 145 recorded cases of related footing load tests was compiled from the literature. The dataset includes bearing capacity （Qu）, friction angle, unit weight of sand, footing width, and thin-wall length to footing width ratio （Lw/B）. Apart from Qu, other parameters were set as model inputs. To enhance the diversity of the data, four more related laboratory footing load tests were conducted on the Johor Bahru sand, and results were added to the dataset. Experimental findings suggest an almost 0.5 times increase in the bearing capacity in loose and dense sands when LJB is increased from 0.5 to 1.12. Overall, findings show the feasibility of the ANN-based predictive model improved with particle swarm optimization （PSO）. The correlation coefficient was 0.98 for testing data, suggesting that the model serves as a reliable tool in predicting the bearing capacity.

A Derivation of the Entropy-Based Relativistic Smoothed Particle Hydrodynamics by Variational Principle

In this work, a second order smoothed particle hydrodynamics is derived for the study of relativistic heavy ion collisions. The hydrodynamical equation of motion is formulated in terms of the variational principle. In order to describe the fluid of high energy density but of low baryon density, the entropy is taken as the base quantity for the interpolation. The smoothed particle hydrodynamics algorithm employed in this study is of the second order, which guarantees better particle consistency. Furthermore, it is shown that the variational principle preserves the translational invariance of the system, and therefore improves the accuracy of the method. A brief discussion on the potential implications of the model in heavy ion physics as well as in general relativity are also presented.