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The X-ray irradiation of gold salt aqueous solutions in the synthesis of gold nanoparticles (AuNPs) in the absence of any reducing agent or stabilizer is presented. The size, dispersion, number of particles, yield and morphology evolution during the radiolytic formation of AuNPs were followed simultaneously using in situ small-angle X-ray scattering. This study provides an insight into the overall kinetics and formation mechanisms at the initial stage of AuNP synthesis without reductants and stabilizers. The pH-dependent speciation of aqueous HAuCl4 and its influence on the synthesis, structure and properties of AuNPs were observed. The result sheds light on the key parameters required to obtain stable monomodal particles and the influence of the surface charge and reactivity of the chemical solution on the final particle size and shape.

A glancing incident X-ray fluorescence (GIXRF) spectrometry using a single-bounce parabolic capillary (SBPC) was proposed for the analysis of layered samples. The divergence of the X‐ray beam was 0.33 mrad. In this paper, we used this instrumental setup to analyze Si single crystal and a 50 nm HfO2 single layer film deposited on a Si substrate.

Two paint fragments from an oil pipeline were analyzed with a confocal three-dimensional micro-X-ray fluorescence (3D-XRF) spectrometer. The depth distributions of iron (Fe), titanium (Ti) and zinc (Zn) metal elements were obtained based on confocal 3D-XRF analysis. The quantitative element results were obtained by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). The corrosion process of the oil pipeline was investigated based on the experimental results, which provided information for designing an oil pipeline protection scheme.

Liver fibrosis is the intermediate process and inevitable stage of the development of chronic liver disease into cirrhosis. Reducing the degree of liver fibrosis plays an extremely important role in treating chronic liver disease and preventing liver cirrhosis and liver cancer. The formation of liver fibrosis is affected by iron deposition to a certain extent, and excessive iron deposition further induces liver cirrhosis and liver cancer. Herein, confocal microbeam X-ray fluorescence (μ-XRF) was used to determine the intensity and biodistribution of iron deposition at different time points in the process of liver fibrosis induced by thioacetamide (TAA) in rats. To our best knowledge, this is the first study using confocal μ-XRF to analyze hepatic iron deposition in hepatic fibrosis. The results showed that there are minor and trace elements such as iron, potassium, and zinc in the liver of rats. Continuous injection of TAA solution resulted in increasing liver iron deposition over time. The intensity of iron deposition in liver tissue was also significantly reduced after bone mesenchymal stem cells (BMSCs) were injected. These findings indicated that confocal μ-XRF can be used as a nondestructive and quantitative method of evaluating hepatic iron deposition in hepatic fibrosis, and iron deposition may play an important role in the progression of hepatic fibrosis induced by TAA.

Confocal X-ray fluorescence (XRF) based on the peak to background ratio was applied to quantitatively analyse the elemental composition of an ion liquid. The confocal micro-volume of the confocal XRF for non-destructive quantitative analysis is often submerged at varying depths in the sample. The modification of the absorption of the detected X-rays coming from the confocal micro-volume submerged at varying depths is complicated. For avoiding complicated modification of the sample absorption outside the confocal micro-volume, the peak to background ratio which was related to elemental concentration was used to quantitatively analyse the elemental composition of the ion liquid. A standard curve using the peak to background ratio was obtained with the confocal micro-volume at a fixed distance from the wall of the container which contained the ion liquid. The standard curve enabled the analysis of the data obtained with the confocal micro-volume at varying distances from the container wall.

An equation for the relation between the X-ray source size and focal spot size of a single-bounce ellipsoidal glass monocapillary X-ray condenser (SBEGMXC) was constructed. According to this equation, a method by measuring the focal spot size of an SBEGMXC was used to determine the average slope error of the SBEGMXC, and this method based on an X-ray source with an adjustable source size. Compared with the existing methods for measuring the slope error of an SBEGMXC, this method could be used to obtain the average of slope errors originating from every point on the inner surface of the SBEGMXC.

Intensity distribution of the X-ray beam redirected through a conventional monolithic poly-capillary quasi-parallel lens is similar to a Gaussian distribution, which will bring about unsatisfactory imaging quality for medical applications and affect the peak-to-background ratio in X-ray diffraction experiments. These disadvantages can be overcome by adopting poly-capillary X-ray lenses structured with three tiers that fabricated from different diameters of capillaries. This paper developed a mathematical model of monolithic poly-capillary quasi-parallel lens composed with different diameter tubes, and experimental data of intensity distribution, transmission efficiency and divergence have been compared with simulation results based on a ray-tracing technique.

The inner diameter is an important parameter in the design and fabrication of monocapillary X-ray optics which is widely used in X-ray technology. The confocal X-ray fluorescence (CXRF) based on X-ray capillary optics was proposed to nondestructively measure the inner diameter of the monocapillary. The zinc chlorine solutions were filled into monocapillary in order to measure its inner diameter with the CXRF. With a scan of the edge of zinc solutions in a monocapillary optic through the confocal volume of the CXRF, the inner diameter could be obtained directly and nondestructively. The mean of relative errors of this method for measuring the inner diameter were approximately 4.1%. This proposed method of determining the inner diameter of monocapillary optics plays a significant role in design, fabrication and application of the monocapillary X-ray optics.

Confocal 3D Micro-XRF is a well established and none-destructive analytical method which has a wide range of fields for applications such as environmental science, archaeology, material science and so on. This kind of technique showed dramatic results in 3D image reconstruction, surface morphology and elemental depth sensitive profiles. Therefore, 3D Micro-XRF analysis method based on a confocal X-ray set-up is very suitable for evaluation and illustration with depth sensitive investigation of oil paintings. It is meaningful to characterize the surface elemental distribution in different layer depth by surface scanning. In this work, a 3D Micro-XRF experimental set-up is established based on a Mo target X-ray source. The operated voltage is 20kV and the currents is 0.5mA. The core optical components, two polycapillary X-ray lenses were designed and manufactured by the Key Laboratory of Beam Technology of the Ministry of Education, Beijing Normal University. The FWHMs of the confocal volume is 33.0 μm , 32.4 Μm and 35 μm in three dimensions, respectively. With a proposed progressive approximation method, a modern oil painting segament was anlysed using 3D Micro-XRF spectroscopy. The surface elemental distributions were mapped through surface scanning in different motor steps. This investigation can be referred for furture works that attempt to answer for questions on painting techniques, pigmant palette, production process, counterfeit identification and so on.

Poly-capillary X-ray lens provided a special mechanism to control X-ray radiation. In recent reported works, polycapillary X-ray lens started to be applied in medical imaging fields. The use of poly-capillary X-ray lens in medical imaging systems brought proper benefits in Compton scattering rejection and resolution enhancement. However, the Xray intensity distribution of the output has unsatisfied uniformity when using conventional poly-capillary lens if the primary rays emitted by a common X-ray tube. Uneven intensity distribution will cause problems such as details loss and longer exposure time for better reconstruction results. In this work, a new type of poly-capillary X-ray collimating lens was introduced for medical imaging. Different from the conventional ones, this kind of lens was divided into three regions and subarray units of different diameter channels were placed in their corresponding regions. A program was written based on ray-tracing method for optical design and imaging simulation. The optical properties of this new type collimating lens were tested, using a 50.0μm Cu target X-ray tube with 20.0kV voltage and 0.2mA currents. A plateau region that had good uniformity which is 4.0mm in diameter was obtained. In addition, X-ray transmission imaging experiments for small samples showed improvements in imaging qualities using this new optical component. Although the existence of manufacturing difficulties effects the finished product quality, this new kind of X-ray poly-capillary lens shows its potential in medical imaging.

This literature review found that it is doubtful that there is water ice in the polar craters on the Moon. In the course of this review, the following findings were found: (1) The absorption strength of hydroxyl radicals and hydroxyl groups are all 2.9μm, so it is easy to confuse hydroxyl radicals and hydroxyl groups when interpreting M3 spectra data. I do not doubt the ability of LCROSS to detect OH from water, but only suspect that LCROSS is unable to distinguish between hydroxyl radicals from water ice and hydroxyl groups from Moon's methanol due to ignore their spectral identity; (2) The water brought by comets and asteroids and the one caused by solar wind has been exhausted by reacts with the widespread methanol on the Moon in the presence of Pt/α-MoC or Pt/C catalysts. These reacts form large amount of hydrogen, thus clarifying a question NASA raised that "Scientists have long speculated about the source of vast quantities of hydrogen that have been observed at the lunar poles"; (3) The vast quantities of hydrogen in lunar polar craters at extremely low temperatures might be in liquid or solid state now, easy to confuse with water ice. It seems that all our previous misconceptions about water ice in the lunar polar craters might be due to the neglect of the widespread chemical role of lunar methanol. It is necessary to conduct in-depth research in this field in the future.

We report constraints on the dark photon effective kinetic mixing parameter (${\kappa}$) with data taken from two ${p}$-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90\% confidence level upper limits on ${\kappa}$ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (${m_V}$) from 10 to 300 eV/${c^2}$ in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90\% confidence level with ${m_V}$ from 0.1 to 4.0 keV/${c^2}$ are set from 449.6 kg-day data, with a minimum of ${\rm{\kappa=1.3 \times 10^{-15}}}$ at ${\rm{m_V=200\ eV/c^2}}$., Comment: 5 pages, 6 figures

We present weakly interacting massive particles (WIMPs) search results performed using two approaches of effective field theory from the China Dark Matter Experiment (CDEX), based on the data from both CDEX-1B and CDEX-10 stages. In the nonrelativistic effective field theory approach, both time-integrated and annual modulation analyses were used to set new limits for the coupling of WIMP-nucleon effective operators at 90% confidence level (C.L.) and improve over the current bounds in the low $m_{\chi}$ region. In the chiral effective field theory approach, data from CDEX-10 were used to set an upper limit on WIMP-pion coupling at 90% C.L. We for the first time extended the limit to the $m_{\chi}, Comment: version accepted by Science China-PMA, 8 pages, 8 figures

Lithological recognition is of great significance in oil drilling fields. To investigate the relationship between rock properties and the vibro-acoustic signal characteristics generated by drilling, a rock drilling vibration measurement system has been developed, and a relative drilling test is conducted indoors. This paper illustrates the application of a vibration sensor and a special wideband acoustic sensor method to distinguish the specific time–frequency characteristics generated by drilling in different types of rock. Furthermore, an intuitive comparison of these two approaches is performed. In particular, an acoustic focusing device was designed to assist the wideband acoustic condenser microphone in detecting specific signals during the drilling process. In addition, time-domain and time–frequency analyses were proposed to reveal the differences in signal characteristics generated by different kinds of rock. The results indicate that both the vibration spectral characteristics and the acoustic spectral characteristics from 4 types of rock show significant differences, which may be promising for lithological recognition using the feature model. However, the acoustic sensor approach, benefiting from the specially designed acoustic focusing device, presents a better signal-to-noise ratio than the vibration sensor approach.

Conventional polycapillary X-ray lenses are fabricated using an arrangement of hollow cylindrical tubes (i.e., capillaries) in a hexagonal structure, which necessarily includes triangular-shaped non-functional spaces between the capillaries. These non-functional spaces reduce the transmission efficiency of the lens, and can also affect the utilization of the pixels of charge-coupled devices in imaging applications. These disadvantages can be overcome by adopting a polycapillary X-ray lens structure with a square cross-section fabricated from a square matrix array of capillaries, each with equivalent square cross-sections. We develop a mathematical model of a square poly-capillary X-ray lens, and also present a simulation-driven numerical method for calculating the X-ray transmission efficiency, intensity distribution of the exit plane and the focal spot based on a ray-tracing technique.

A new type of monocapillary X-ray optic , called ‘two bounces monocapillary X-ray optics’ (TBMXO), is proposed for generating a small focal spot with high power-density gain for micro X-ray analysis , using a common laboratory X-ray source . TBMXO is consists of two parts: an ellipsoidal part and a tapered part. Before experimental testing, the TBMXO was simulated by the ray tracing method in MATLAB. The simulated results predicted that the proposed TBMXO would produce a smaller focal spot with higher power-density gain than the ellipsoidal monocapillary X-ray optic (EMXO). In the experiment, the TBMXO performance was tested by both an optical device and a Cu target X-ray tube with focal spot of 100 μ m. The results indicated that the TBMXO had a slope error of 57.6 μ rad and a 13.1 μ m focal spot and a 1360 gain in power density were obtained.

A passive characterization method to evaluate the quality of the single-bounce ellipsoidal capillary (SBEC) for the full field transmission X-ray microscopy was designed. The simulation model was established by measuring the outer diameter of the SBEC. The simulated shape of the focusing ring consisted with that from the experiment. This passive characterization method could be used evaluate efficiently the quality of SBEC and provide a guidance for SBEC manufacturing.

Ellipsoidal monocapillary x-ray optics are used as condenser lenses in full-field transmission x-ray microscopy. The numerical aperture (NA) of the ellipsoidal monocapillary is designed to match that of the x-ray zone plate objective. In practice, monocapillaries have inner-surface errors that lead to mismatches between the monocapillary and the zone plate. In this study, mathematical models of monocapillaries with elliptic cross-section deformation and centreline straightness errors were developed, respectively. Furthermore, the optical properties of these monocapillaries were simulated based on a ray-tracing method. The simulation provides a qualitative picture of the NA and illumination angle distributions of the ellipsoidal monocapillary with inner-surface errors, and it is useful for predicting the inner-surface imperfections from the x-ray ring behind the monocapillary.

The confocal three-dimensional micro X-ray fluorescence using polycapillary optics and a synchrotron radiation was applied to nondestructively analyze elemental compositions of minerals, and thereb...

A single bounce ellipsoidal glass monocapillary was designed and fabricated and its performance was measured by both an optical measurement and an X-ray test. This monocapillary had a slope error of 17 μrad. The images of the focal spot and the far-field pattern recorded by a CCD detector showed that this fabricated monocapillary had high quality and satisfied the requirement of the designed data for X-ray nano-imaging.

A confocal fluorescence endstation for depth-resolved micro-X-ray absorption spectroscopy is described. A polycapillary half-lens defines the incident beam path and a second polycapillary half-lens at 90° defines the probe sample volume. An automatic alignment program based on an evolutionary algorithm is employed to make the alignment procedure efficient. This depth-resolved system was examined on a general X-ray absorption spectroscopy (XAS) beamline at the Beijing Synchrotron Radiation Facility. Sacrificial red glaze (AD 1368–1644) china was studied to show the capability of the instrument. As a mobile endstation to be applied on multiple beamlines, the confocal system can improve the function and flexibility of general XAS beamlines, and extend their capabilities to a wider user community.

We present the improved constraints on couplings of solar axions and more generic bosonic dark matter particles using 737.1 kg-days of data from the CDEX-1B experiment. The CDEX-1B experiment, located at the China Jinping Underground Laboratory, primarily aims at the direct detection of weakly interacting massive particles using a p-type point-contact germanium detector. We adopt the profile likelihood ratio method for analysis of data in the presence of backgrounds. An energy threshold of 160 eV was achieved, much better than the 475 eV of CDEX-1A with an exposure of 335.6 kg-days. This significantly improves the sensitivity for the bosonic dark matter below 0.8 keV among germanium detectors. Limits are also placed on the coupling $g_{Ae} < 2.48 \times 10^{-11}$ from Compton, bremsstrahlung, atomic-recombination and de-excitation channels and $g^{eff}_{AN} \times g_{Ae} < 4.14 \times 10^{-17}$ from a $^{57}$Fe M1 transition at 90\% confidence level., version accepted by PRD, 9 pages, 11 figures

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses ($m_{\chi}$) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg$\cdot$day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg$\cdot$day exposure and 250 eVee threshold for AM analysis. The sensitive windows in $m_{\chi}$ are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on $\sigma_{\chi N}^{\rm SI}$ at 90\% confidence level are derived as $2\times$10$^{-32}\sim7\times$10$^{-35}$ $\rm cm^2$ for TI analysis at $m_{\chi}\sim$ 50$-$180 MeV/$c^2$, and $3\times$10$^{-32}\sim9\times$10$^{-38}$ $\rm cm^2$ for AM analysis at $m_{\chi}\sim$75 MeV/$c^2-$3.0 GeV/$c^2$., Comment: 5 pages, 4 figures

The inner diameter is one of most important parameters in the design and fabrication of monocapillary x-ray optics, which are widely used in x-ray technology. The confocal x-ray scattering method based on x-ray capillary optics was proposed to nondestructively measure the inner and outer diameters of the monocapillary. The positions of the boundaries of monocapillary x-ray optics were determined by a knife-edge scanning method, and the x-ray optics were profiled in two planes or in three-dimensional space accordingly. This confocal method could conveniently give the inner surface topography of the monocapillary optics, which can be used to show the difference between the actual inner surface and the theoretical one, and has potential applications in nondestructive measurements of stratified substances, or the profile morphology of a specific interface.

A new type of x-ray lens composed of multi-square polycapillary slices (ASPXRL) used in focusing parallel x-ray beam was presented in this paper. Compared with conventional x-ray polycapillary lens, ASPXRL can provide smaller and brighter focus. The effects of the manufacturing imperfections on focusing quality of ASPXRL were evaluated with the values of transmission efficiency and discussed. It is suggested that ASPXRL has application prospects as a condenser lens for x-ray microscopy and flux collectors for x-ray analytical instruments.

Confocal three-dimensional micro X-ray fluorescence (3D MXRF) is an excellent surface analysis technology. For a confocal structure, only the X-rays from the confocal volume can be detected. Confocal 3D MXRF has been widely used for analysing elements, the distribution of elements and 3D image of some special samples. However, it has rarely been applied to analysing surface topography by surface scanning. In this paper, a confocal 3D MXRF technology based on polycapillary X-ray optics was proposed for determining surface topography. A corresponding surface adaptive algorithm based on a progressive approximation method was designed to obtain surface topography. The surface topography of the letter “R” on a coin of the People's Republic of China and a small pit on painted pottery were obtained. The surface topography of the “R” and the pit are clearly shown in the two figures. Compared with the method in our previous study, it exhibits a higher scanning efficiency. This approach could be used for two-dimensional (2D) elemental mapping or 3D elemental voxel mapping measurements as an auxiliary method. It also could be used for analysing elemental mapping while obtaining the surface topography of a sample in 2D elemental mapping measurement.

In the present work, we presented an alternative method for monitoring of the oxidation situation of silicon carbide (SiC) ceramics at various high temperatures in air by measuring the Compton-to-Rayleigh intensity ratios ( I Co / I Ra ) and effective atomic numbers ( Z eff ) of SiC ceramics with the confocal energy dispersive X-ray fluorescence (EDXRF) spectrometer. A calibration curve of the relationship between I Co / I Ra and Z eff was established by using a set of 8 SiC calibration samples. The sensitivity of this approach is so high that it can be easily distinguished samples of Z eff differing from each other by only 0.01. The linear relationship between the variation of Z eff and the variations of contents of C, Si and O of SiC ceramics were found, and the corresponding calculation model of the relationship between the ΔZ and the ΔC C , ΔC Si , and ΔC O were established. The variation of contents of components of the tested SiC ceramics after oxidation at high temperature was quantitatively calculated based on the model. It was shown that the results of contents of carbon, silicon and oxygen obtained by this method were in good agreement with the results obtained by XPS, giving values of relative deviation less than 1%. It was concluded that the practicality of this proposed method for monitoring of the oxidation situation of SiC ceramics at high temperatures was acceptable.

This short communication presents a study of the use of an annular X-ray beam produced by an ellipsoidal single-bounce monocapillary (ESBC) to perform focal construct geometry (FCG) high-intensity angular-dispersive X-ray diffraction (ADXRD) in transmission mode. The ESBC optic effectively focused a large focal spot X-ray source into a smaller focal spot and produced a narrowed X-ray ring in the far-field pattern when combined with a beam stop. A CCD imaging detector was linearly translated along the principal axis of the ESBC-FCG and obtained the corresponding sequential images of diffraction concentric circular caustics and convergence points, which were formed by the constructive interference of a continuous set of Debye cones arising from the annular interrogation volume. Pixels from the central region of an approximately 0.6 mm2 area were interrogated on each sequential image; as a result, a one-dimensional diffractogram of an aluminium oxide sample was revealed. The presented ESBC-FCG ADXRD technique shows potential for increasing the diffracted intensity and streamlining the operation of crystallographic analysis.

There have been controversies over differing opinions in the source of the American Indians. In this paper, the writer criticized the so-called classical theory that the remote ancestors of the American Indians entered America from Asia through the Bering Straits 14,000 ~ 20,000 years ago, worn their “clothes” and carried kindling during the late Paleolithic, no matter how by “boat” across the Bering Sea or by foot through a “Bering Land Bridge” which might once link up Asia and North America during glacial period; and independently proposed a new hypothesis that American Indians might be originated from the Western Rift Valley of North America. On the basis of locus distribution of American ancient human’s remnants, the writer pointed out that American ancient humans might be first originated at Yukon Territory of Canada within the Western Rift Valley of North America (the Basin & Range Province), and then migrated south ward (Yukon Territory → Mojave Desert → Mexico → Peru → Chile). Moreover, American Indians would have long been a presence for 40,000 years, or even 100,000 ~ 200,000 years in the American continents. So far, the logical basis which American Indians came from Asia 14,000 ~ 20,000 years ago was crushed, and derived two inferences: 1) American Indians might be originated from the Western Rift Valley of North America; 2) Only the Eskimo might be the mover eastward from Asia, because of their gene B.

Despite better reconstruction quality for incomplete or noisy projection data compared to analytic reconstruction, computed tomography iterative techniques are time-consuming, mainly due to high system matrix computation. A polar-coordinate pixel model with concentric annuluses of different radial widths was established and a fast method for computing the system matrix was presented based on characteristics of this model. Compared with the Siddon algorithm and an efficient Cartesian algorithm introduced by Zhang, the proposed algorithm based on the simultaneous algebraic reconstruction technique shows speed advantages for both numerical simulation and experiment, without noticeable loss of image quality.

Many X-ray scattering experiments require an accurate determination of the net intensity or of the shape of the peak for the Compton and Rayleigh scattering processes. In this work, a new X-ray scattering instrument based on a polycapillary parallel X-ray optic (PPXRO) and a polycapillary collimating X-ray optic (PCXRO) was designed to increase the signal-to-noise ratio in order to improve the accuracy of the determination of the intensities of the Compton (inelastic) and Rayleigh (elastic) peaks, enabling accurate, rapid and non-destructive measurements. This low divergence configuration is beneficial for reducing Compton peak broadening and avoiding the Compton shift with a relatively high transmission efficiency and signal-to-noise ratio.

The atomic layer deposition method was used for coating the high-density material on the inner surface of a tapered glass monocapillary X-ray condenser (TGMXC). In this paper, HfO2 was selected as the high-density material. A HfO2 film with about 50 nm thickness was coated on the inner surface of the TGMXC. The energy upper limit of focused X-ray increased by about two times. The HfO2 coated the TGMXC maintained a high reflectivity (better than 84%) for X-rays with an energy below 25 keV. The acceptance angle of 16.8 keV X-ray increased by about 1.8 mrad, theoretically.

Herein we report a prototypical electronic substrate specifically designed to serve the weakly interacting massive particles (WIMPs) detectors at the China Dark Matter Experiment (CDEX). Because the bulky high-purity germanium (HPGe) detectors operate under liquid-nitrogen temperatures and ultralow radiation backgrounds, the desired electronic substrates must maintain high adhesivity across different layers in such cold environment and be free from any radioactive nuclides. To conquer these challenges, for the first time, we employed polytetrafluoroethylene ((C2F4) n ) foil as the base substrate, in conjunction with ion implantation and deposition techniques using an independently developed device at Beijing Normal University for surface modification prior to electroplating. The remarkable peeling strengths of 0.88±0.06 N/mm for as-prepared sample and 0.75±0.05 N/mm for that after 2.5-days of soaking inside the liquid nitrogen were observed, while the regular standards commonly require 0.4 N/mm ∼ 0.6 N/mm for electronic substrates.