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Polyphosphoric acid (PPA) and styrene–butadiene–styrene (SBS) were adopted to produce PPA-SBS-modified bio-blend bitumen, which achieved excellent mechanical performance. However, its long-range performance, such as the fatigue and thermal cracking behavior under long-term thermal oxidation, is not well understood. Therefore, a pressure aging vessel (PAV) system was applied to simulate the aging behavior of the bitumen under the action of thermal oxidation. Then, a linear amplitude sweep (LAS) test combined with a viscoelastic continuum damage (VECD) model was applied to investigate the fatigue properties of the bitumen. Moreover, a bending beam rheometer (BBR) test was conducted to evaluate the thermal cracking resistance of the bitumen before and after PAV aging. Meanwhile, an atomic force microscope (AFM) was applied to observe the microscopic topography. The results show that the original compound-modified bitumen can bear more fatigue damage than that of the control bitumen at the failure point, and it also has excellent fatigue resistance at 2.5%, 5%, 7.5%, and 10% applied strain. Moreover, the VECD model can accurately predict the fatigue life of the bitumen under different applied strains. The variation ratio of stiffness modulus for the compound-modified bitumen is below that of the control bitumen after PAV aging, so it shows a better anti-aging performance. Finally, the AFM test shows that PPA and bio-bitumen decrease the heterogeneity of the bitumen, reducing the difference between phases.

Digital rock physics (DRP) is an emerging technique that has rapidly become an indispensable tool to estimate elastic properties. The success of DRP mainly depends on three factors: acquiring a 3D rock structure image, accurately identifying 3D minerals, and using a proper numerical simulation method. Shales present a substantial challenge for DRP owing to their heterogeneous structure, composition, and properties from micron to centimeter scale. To obtain a sufficiently large field-of-view (FOV) image of a sample that reflects the detailed and representative internal structure and composition, we have developed a new DRP workflow to obtain large-FOV high-resolution digital rocks with 3D mineralogical information. Using the “divide-and-stitch” technique, a long shale sample is divided into several subunits, imaged separately by high-resolution X-ray microscopy (XRM), and then stitched to obtain a large-FOV 3D digital rock. An FOV of a rock cylinder (736 μm in diameter, 2358 μm in height, and 1 μm resolution) is used as an example. By correlating XRM and automated mineralogy, a large-FOV 3D mineral digital rock is obtained from a shale sample. Six mineral phases are identified and verified by automated mineralogy, and four laminae are detected according to the grain size, which offer a new perspective to study sedimentary processes and heterogeneities at the millimeter scale. The finite-difference method is used to compute the elastic properties of the large-FOV 3D mineral digital rock, and the results of Young’s modulus are within the limit of the Voigt/Reuss bounds. It also reveals that there is a difference in simulated elastic properties in the four laminae. The large-FOV 3D mineral digital rock offers the potential to explore the relationship between elastic properties and mineral phases, as well as the heterogeneities of elastic properties at the millimeter scale.

In this study, we fabricated an Al-doped ZnO/intrinsic ZnO (AZO/i-ZnO) bilayer film using a radio frequency generator coupled with a direct current voltage bias. An 800-nm AZO/50 nm i-ZnO transparent conductive oxide layer with a resistivity of 2.58 × 10-4 Ω cm and a sheet resistance of 3.22 Ω/□ was fabricated using this method. The resistivity of the AZO/i-ZnO layer remained unchanged even after 1 h of Cl treatment at 400 °C. The layer showed an average light transmission rate of 85% over the wavelength range of 400–800 nm. The material, optical, and electric properties of the AZO/i-ZnO layer were investigated. The mechanism underlying the Cl treatment resistance of the AZO/i-ZnO layer was also investigated.

Previous neuroimaging has paid little attention to the differences in brain network integration between patients with treatment-resistant depression(TRD) and non-TRD (nTRD), and the relationship between their impaired brain network integration and clinical symptoms has not been elucidated.Eighty one major depressive disorder (MDD) patients (40 in TRD, 41 in nTRD) and 40 healthy controls (HCs) were enrolled for the functional magnetic resonance imaging (fMRI) scans. A seed-based functional connectivity (FC) method was used to investigate the brain network abnormalities of default mode network (DMN), affective network (AN), salience network (SN) and cognitive control network (CCN) for the MDD. Finally, the correlation was analyzed between the abnormal FCs and 17-item Hamilton Rating Scale for Depression scale (HAMD-17) scores.Compared with the HC group, the FCs in DMN, AN, SN, CCN were altered in both the TRD and nTRD groups. Compared with the nTRD group, FC alterations in the AN and CCN were more abnormal in the TRD group, and the FC alterations were generally decreased at the SN in the TRD group. In addition, the FC values of right dorsolateral prefrontal cortices and left caudate nucleus in the TRD group and the FC values of right subgenual anterior cingulate cortex and left middle temporal gyrus in the nTRD group were positively correlated with HAMD-17 scale scores.Abnormal FCs are present in four brain networks (DMN, AN, SN, CCN) in both the TRD and nTRD groups. Except of DMN, FCs in AN, SN and CCN maybe underlay the neurobiological mechanism in differentiating TRD from nTRD.

Major depressive disorder is associated with a reward deficit manifested by abnormal striatal function. However, differences between treatment-resistant depression (TRD) and non TRD (nTRD) in striatal whole-brain functional connectivity (FC) have not been elucidated. Thirty-eight patients with TRD, 42 patients with nTRD, and 39 healthy controls (HCs) were recruited for this study. A seed-based FC approach was used to analyze abnormalities in six predefined striatal subregion circuits in the three groups of subjects, and further explore the correlation between abnormal FC and clinical symptoms. Results revealed that compared with the nTRD group, the TRD group showed increased FC of the inferior ventral striatum with the bilateral orbital area of the middle frontal gyrus, right cerebellum posterior lobe, left parahippocampal gyrus, left middle occipital gyrus and left lingual gyrus. Compared with the HC group, the TRD group showed a wider range of altered striatal function than the nTRD group. In the TRD group, the HAMD-17 scores were positively correlated with the FC between the right VRP and the left caudate. This study provides new insights into understanding the specificity of TRD striatal circuits.

Background Acupuncture plays a positive role in promoting the rehabilitation of post-stroke hemiplegia, but its specific central effect mechanism remains unclear. The changes of cerebral integrity, bilateral regulation and coordination are closer to the actual running state of brain after injury, while the research on bilateral cerebral reconstruction after unilateral motor pathway injury is not sufficient. The study of cerebral functional remodeling after stroke and mechanisms of acupuncture for post-stroke hemiplegia still faces many challenges. This study will explore the the underlying mechanisms of bilateral cerebral remodeling and acupuncture for post-stroke hemiplegia rehabilitation. Methods This is a single-center, cross-sectional, multimodal functional magnetic resonance imaging(fMRI) study, with participants and data analyst blinded. 24 post-stroke patients with motor dysfunction and 24 healthy subjects that meet the inclusion criteria will be recruited in this study. All the patients enrolled in this study will receive the conventional standard medical care according to their chief doctors. Clinical data including motor function scales, high-sensitivity C-reactive protein(hs-CRP), other related scales as well as fMRI imaging data will be collected at baseline and 2 weeks later. Functional connectivity(FC) is the primary and core outcome indicator of this study. Voxel-mirrored homotopic connectivity (VMHC), fractional anisotropy (FA),voxel-based morphometry (VBM), Fugl-Meyer Assessment(FMA) and hs-CRP are secondary outcome indicators. During the MRI scan, true or sham Yanglingquan(GB34) acupuncture stimulation on the left side and passive finger movement will be performed on the participants. The connection between cerebral imaging indicators and clinical indicators will be obtained by calculating the Pearson’s correlation coefficient. Discussion The results of our study will help to understand the cerebral remodeling mechanism of motor function improvement after stroke better and provide data support for the better application of acupuncture in clinical practice. Trial registration: Chinese Clinical Trial Registry (ChiCTR1900022220). Regisered on 30 March 2019. http://www.chictr.org.cn/showprojen.aspx?proj=37359

IntroductionAcupuncture is safe and effective for improving the motor function of poststroke hemiplegic patients, but there still exists a certain gap between clinical practice and understanding its neural mechanisms. The cerebral functional reconstruction after unilateral motor pathway injury exhibits a bilateral tendency, however current studies seldom pay attention to it. Hence, based on cerebral bilateral connections, the underlying mechanism of acupuncture in stroke rehabilitation remains an area for further research. The results of this study will increase our understanding of acupuncture-induced motor recovery in patients who had suffered a stroke and demonstrate the differences in brain response and clinical assessments.Methods and analysisThis is a single-centre, randomised controlled, paralleled neuroimaging trial, with patients and outcome assessors blinded. Thirty patients who had a stroke with motor dysfunction meeting the inclusion criteria will be randomly assigned (2:1) to receive either 10 sessions true or sham acupoints treatments (five sessions per week for 2 weeks). All the participants will receive conventional standard medical care and rehabilitation. Motor function assessments and neuroimaging scanning will be conducted before and after the entire acupuncture treatment. The clinical and neuroimaging data will be analysed, respectively. The voxel-mirrored homotopic connectivity will be the primary outcome and the primary effect indicator. The secondary outcomes comprise clinical evaluations and neuroimaging assessments, which include Fugl-Meyer Assessment, the National Institutes of Health Stroke Scale, fractional anisotropy and gray matter volume. The Needle Sensation Assessment Scale is an additional outcome. The correlation analysis will be explored between the neuroimaging indicators, clinical motor assessments and needle sensation.Ethics and disseminationThe protocol has been approved by the ethics committee of Dongzhimen Hospital affiliated to Beijing University of Chinese Medicine (DZMEC-KY-2018-04). The results of the neuroimaging trial will be disseminated through peer-reviewed publications and conferences.Trial registration numberChinese Clinical Trials Registry (ChiCTR 1800016263).

The deposition rate, transmittance and resistivity of aluminium-doped zinc oxide (AZO) films deposited via radio frequency (r.f.) sputtering change with target thickness. An effective method to control and maintain AZO film properties was developed. The strategy only involved the regulation of target bias voltage of r.f. magnetron sputtering system. The target bias voltage considerably influenced AZO film resistivity. The resistivity of the as-deposited AZO film was 9.82×10 −4 Ω cm with power density of 2.19 W/cm 2 at target self-bias of −72 V. However, it decreased to 5.98×10 −4 Ω cm when the target bias voltage was increased to −112 V by applying d.c. voltage. Both growth rate and optical band gap of AZO film increased with the absolute value of target bias voltage – growth rate increased from 10.54 nm/min to 25.14 nm/min, and band gap increased from 3.57eV to 3.71 eV when target bias voltage increased from −72 V to −112 V at r.f. power density of 2.19 W/cm 2 . The morphology of AZO films was slightly affected by the target bias voltage. Regulating target bias voltage is an effective method to obtain high-quality AZO thin films deposited via r.f. magnetron sputtering. It is also a good choice to maintain the quality of AZO film in uptime manufacturing deposition.

Radio frequency magnetron sputtered cadmium stannate (Cd2SnO4) or cadmium tin oxide (CTO) films were annealed in a nitrogen (N2) atmosphere. The resistivity of argon/oxygen (Ar/O2) gas sputtered CTO films decreased drastically after high temperature annealing, and the lowest resistivity of 1.73 × 10−4 Ω cm was achieved. The Cd2SnO4 crystal phase of CTO films deposited in Ar/O2 gas occurred after annealing at 600 °C to 635 °C, and the optical band gap increased obviously after annealing. When the deposition atmosphere was pure Ar, the as-deposited CTO resistivity was in the order of 10−4 Ω cm. The resistivity of thin films deposited in Ar gas could decline slightly after annealing. However, the resistivity of thick films deposited under Ar gas increased drastically after annealing. No Cd2SnO4 crystal phase of Ar gas sputtered CTO occurred after annealing. The visible region and near infrared spectrum transmittance of CTO films increased after annealing in a N2 atmosphere. The resistivity of CTO films deposited in Ar/O2 and after annealing in N2 gas at 620 °C increased slightly after chlorine treatment. Furthermore, the resistivity of films deposited in Ar/O2 and then annealed in N2 gas at 620 °C decreased slightly after vacuum annealing at 600 °C for 5 min.

Background: Acupuncture is safe and effective for improving the motor function of poststroke hemiplegic patients, but there still exists a certain gap between clinical practice and its neural mechanisms. The cerebral functional reconstruction after unilateral motor pathway injury exhibits a bilateral tendency, however current studies seldom pay attention to it. Hence, based on bilateral cerebral connections, the underlying mechanism of acupuncture in stroke rehabilitation remains research space to date. Methods: This is a single-center, randomized controlled, paralleled neuroimaging trial, with patients, outcome assessors, and data statisticians blinded. Stroke patients with motor dysfunction meeting the inclusion criteria will be randomly assigned (2:1) to receive either true acupoints treatment or sham acupoints treatment (5 sessions per week for 2 weeks). All the patients will receive conventional treatment and rehabilitation. Participants will undergo the neuroimaging scanning before and after the entire acupuncture treatment. The voxel-mirrored homotopic connectivity (VHMC) will be the primary outcome and the primary effect indicator. The secondary outcomes comprise clinical part and neuroimaging part, which included Fugl-Meyer assessments (FMA), the National Institutes of Health stroke scales (NIHSS), fractional anisotropy (FA) and gray matter volume (GMV). The Needle Sensation Assessment Scale (NSAS) is an additional outcome. The correlation analysis will be explored between the neuroimage indicators and clinical motor assessments. Discussion: From the perspective of bilateral connections, this trial will investigate the cerebral influence of acupuncture treatment on poststroke patients with motor dysfunction, promoting application of acupuncture in stroke rehabilitation. Trial registration: Chinese Clinical Trials Registry, ChiCTR 1800016263. Registered on 22 May, 2018. Keywords: Acupuncture, Poststroke hemiplegia, Functional magnetic resonance imaging, Diffusion tensor imaging, Cerebral mechanism, Bilateral cerebral connections

Stress-induced fracture evolution in tight sandstone reservoir is of great significance in hydraulic fracturing treatment and borehole stability. The meso scale fracture mechanism needs to be well understood. In this work, the smaller-sized tight sandstone specimens (4 mm in diameter and 8 mm in height) from Bashijiqike formation were studied under uniaxial compression in high resolution three dimensional (3D) X-ray microscopy (XRM). Using high-resolution XRM, 2D slices and 3D digital cores with real pore structure characteristics were reconstructed at different stages of uniaxial compression. During the uniaxial loading process, porosity and diameter distribution of the voids were obtained to analyze the progressive deformation of rock, and then the complexity and heterogeneity of the cracks were quantified by applying fractal analysis. The results show that the fracture evolution of tight sandstone at meso scale could be divided into compaction stage, linear elastic behavior stage, non-linear deformation stage and residual deformation stage. The mineral composition and meso structure of tight sandstone have significant effects to its mechanical properties, fracture pattern and crack morphology under uniaxial compression. The propagation direction of secondary cracks tends to parallel to the direction of axial stress, revealed by higher resolution of region of interest (ROI) imaging.

Aluminum-doped zinc oxides (AZOs) and AZO/i-ZnO films were deposited on Corning 7059 glass through a radio-frequency magnetron sputtering method. Films were annealed in CdCl2 atmosphere and dry air at 400 °C for 60 minutes. The electric properties of the AZO/i-ZnO bilayers demonstrated robustness to the standard CdCl2 treatment process. The optical band gap and transmittance of the AZO/i-ZnO film showed minimal change after annealing. These properties suggest that the bilayer is more suitable than single AZO film for a transparent conductive oxide (TCO) in CdTe. Moreover, the CdTe-related solar cells that adopted AZO/i-ZnO as a TCO electrode displayed a good performance with higher VOC and FF than those that that used AZO. The optimal efficiency was 12.65% with AZO/i-ZnO as a front contact.

We studied the twins structure, optical properties, electrical properties and cell performance of chlorine doped CdTe (CdTe:Cl) polycrystalline film deposited by magnetron sputtering. Serried twins structure consisting of only several atomic layers can be found in both as-deposited CdTe:Cl and CdTe:Cl with annealing. Relatively heavy chlorine doping by magnetron sputtering may also cause rapid donor-acceptor pair (DAP) recombination. These cause the series resistance of CdTe:Cl film to be too high compared to undoped CdTe film with CdCl 2 treatment.

A home-made CSS system in which the CdTe source was above the substrate was used to deposit CdTe thin film. The pressure (3.7~260 Pa) was controlled by nitrogen. The experimental results showed that the deposited rate increased with the decreasing pressure. As the pressure decreased, the center of the film was thicker than that in the edge. Accordingly, the micromorphology obtained by SEM showed that the crystal grain size became larger while the orientation was more random with the decreasing deposition pressure analyzed by XRD. The N on-stoichimometric composition shift of CdTe thin films was characterized by EDX and the Cd/ Te atomic ratio was 0.87 ± 0.04, 0.88 ± 0.08 and 0.93 ± 0.13 as the increasing pressure in our experiments. The calculated results showed that Te-5p orbitals of CdTe with Cd vacancy increased comparing with the bulk CdTe at G-point.

Research on the novel technology of fluidized roasting reduction of low-grade pyrolusite coupling with pretreatment of stone coal has been conducted. According to the response surface design and the analysis of results, orthogonal experiments have been conducted on the major factors and effects of the factors on the manganese reduction efficiency have been studied. The quadratic model between the manganese reduction efficiency and the factors has been established. Meanwhile, the contour or 3D response surface of the manganese reduction efficiency among various factors has been presented. The maximum manganese reduction efficiency could be optimized to nearly 100%, when the mass ratio of stone coal to pyrolusite was 2.5:1, the roasting temperature of stone coal was 1080?C, the roasting temperature of pyrolusite was 775?C, and the roasting time was 2h. The results of the manganese reduction efficiency of the actual experiments were close to those of the fitting model by the verification experiments, indicating that the optimum solution has a relatively high reliability. Other low-grade pyrolusite such as Guangxi pyrolusite (China), Hunan pyrolusite (China), and Guizhou pyrolusite (China) were tested and all these materials responded well giving nearly 100% manganese reduction efficiency.

The effect of grain boundaries (GBs), in particular twin boundaries (TBs), on CdTe polycrystalline thin films is studied by conductive atomic force microscopy (C-AFM), electron-beam-induced current (EBIC), scanning Kelvin probe microscopy (SKPM), electron backscatter diffraction (EBSD), and scanning transmission electron microscopy (STEM). Four types of CdTe grains with various densities of {111} Σ3 twin boundaries (TBs) are found in Cl-treated CdTe polycrystalline thin films: (1) grains having multiple {111} Σ3 TBs with a low angle to the film surface; (2) grains having multiple {111} Σ3 TBs parallel to the film surfaces; (3) small grains on a scale of not more than 500 nm, composed of Cd, Cl, Te, and O; and (4) CdTe grains with not more than two {111} Σ3 TBs. Grain boundaries (including TBs) exhibit enhanced current transport phenomena. However, the {111} Σ3 TB is much more beneficial to micro-current transport. The enhanced current transport can be explained by the lower electron potential at GBs (including TBs) than the grain interiors (GIs). Our results open new opportunities for enhancing solar cell performances by controlling the grain boundaries, and in particular TBs.