A critical review on direct catalytic hydrogasification of coal into CH_(4):catalysis process configurations,evaluations,and prospects

Coal catalytic hydrogasification(CCHG)is a straightforward approach for producing CH_(4),which shows advantages over the mature coal-to-CH_(4) technologies from the perspectives of CH_(4) yield,thermal efficiency,and CO_(2) emission.The core of CCHG is to make carbon in coal convert into CH_(4) efficiently with a catalyst.In the past decades,intensive research has been devoted to catalytic hydrogasification of model carbon(pitch coke,activated carbon,coal char).However,the chemical process of CCHG is still not well understood because the coal structure is more complicated,and CCHG is a combination of coal catalytic hydropyrolysis and coal char catalytic hydrogasification.This review seeks to shed light on the catalytic process of raw coal during CCHG.The configuration of suitable catalysts,operating conditions,and feedstocks for tailoring CH_(4) formation were identified,and the underlying mechanisms were elucidated.Based on these results,the CCHG process was evaluated,emphasizing pollutant emissions,energy efficiency,and reactor design.Furthermore,the opportunities and strategic approaches for CCHG under the restraint of carbon neutrality were highlighted by considering the penetration of“green”H2,biomass,and CO_(2) into CCHG.Preliminary investigations from our laboratories demonstrated that the integrated CCHG and biomass/CO_(2) hydrogenation process could perform as an emerging pathway for boosting CH_(4) production by consuming fewer fossil fuels,fulfilling the context of green manufacturing.This work not only provides systematic knowledge of CCHG but also helps to guide the efficient hydrogenation of other carbonaceous resources such as biomass,CO_(2),and coal-derived wastes.

Numerical Study of the Biomechanical Behavior of a 3D Printed Polymer Esophageal Stent in the Esophagus by BP Neural Network Algorithm

Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinical practice.However, esophageal stents of different types and parameters have varying adaptability and effectiveness forpatients, and they need to be individually selected according to the patient’s specific situation. The purposeof this study was to provide a reference for clinical doctors to choose suitable esophageal stents. We used 3Dprinting technology to fabricate esophageal stents with different ratios of thermoplastic polyurethane (TPU)/(Poly-ε-caprolactone) PCL polymer, and established an artificial neural network model that could predict the radial forceof esophageal stents based on the content of TPU, PCL and print parameter. We selected three optimal ratios formechanical performance tests and evaluated the biomechanical effects of different ratios of stents on esophagealimplantation, swallowing, and stent migration processes through finite element numerical simulation and in vitrosimulation tests. The results showed that different ratios of polymer stents had different mechanical properties,affecting the effectiveness of stent expansion treatment and the possibility of postoperative complications of stentimplantation.

Overcoming chemoresistance in non-angiogenic colorectal cancer by metformin via inhibiting endothelial apoptosis and vascular immaturity

The development of chemoresistance which results in a poor prognosis often renders current treatments for colorectal cancer(CRC).In this study,we identified reduced microvessel density(MVD)and vascular immaturity resulting from endothelial apoptosis as therapeutic targets for overcoming chemoresistance.We focused on the effect of metformin on MVD,vascular maturity,and endothelial apoptosis of CRCs with a non-angiogenic phenotype,and further investigated its effect in overcoming chemoresistance.In situ transplanted cancer models were established to compare MVD,endothelial apoptosis and vascular maturity,and function in tumors from metformin-and vehicle-treated mice.An in vitro co-culture system was used to observe the effects of metformin on tumor cell-induced endothelial apoptosis.Transcriptome sequencing was performed for genetic screening.Non-angiogenic CRC developed independently of angiogenesis and was characterized by vascular leakage,immaturity,reduced MVD,and non-hypoxia.This phenomenon had also been observed in human CRC.Furthermore,non-angiogenic CRCs showed a worse response to chemotherapeutic drugs in vivo than in vitro.By suppressing endothelial apoptosis,metformin sensitized non-angiogenic CRCs to chemo-drugs via elevation of MVD and improvement of vascular maturity.Further results showed that endothelial apoptosis was induced by tumor cells via activation of caspase signaling,which was abrogated by metformin administration.These findings provide pre-clinical evidence for the involvement of endothelial apoptosis and subsequent vascular immaturity in the chemoresistance of non-angiogenic CRC.By suppressing endothelial apoptosis,metformin restores vascular maturity and function and sensitizes CRC to chemotherapeutic drugs via a vascular mechanism.

Dynamic tear meniscus parameters in complete blinking:insights into dry eye assessment

AIM:To investigate the relationship between dynamic tear meniscus parameters and dry eye using an automated tear meniscus segmentation method.METHODS:The analysis of tear meniscus videos captured within 5s after a complete blink includes data from 38 participates.By processing video data,several key parameters including the average height of the tear meniscus at different lengths,the curvature of the tear meniscus’s upper boundary,and the total area of the tear meniscus in each frame were calculated.The effective values of these dynamic parameters were then linearly fitted to explore the relationship between their changing trends and dry eye disease.RESULTS:In 94.74%of the samples,the average height of central tear meniscus increased over time.Moreover,97.37%of the samples exhibited an increase in the overall tear meniscus height(TMH)and area from the nasal to temporal side.Notably,the central TMH increased at a faster rate compared to the nasal side with the temporal side showing the slowest ascent.Statistical analysis indicates that the upper boundary curvature of the whole tear meniscus as well as the tear meniscus of the nasal side(2,3,and 4 mm)aid in identifying the presence of dry eye and assessing its severity.CONCLUSION:This study contributes to the understanding of tear meniscus dynamics as potential markers for dry eye,utilizing an automated and non-invasive approach that has implications for clinical assessment.

A Numerical Investigation on the Influence of the Circular Ring on the Aerodynamic Noise Generated by a Cooling Fan

The influence of the width of the circular ring of a car cooling fan on the aerodynamic noise is investigated numerically through the determination of the overall sound pressure level(OASPL).The results demonstrate that when the circular rings cover near 2/3 of the width of the blade tips of the rotor in the axis direction,the rotor has the lowest OASPL and the related total pressure efficiency and flow mass rate are better than the corresponding values obtained for a reference rotor without a circular ring.With increasing the width of the circular ring in the axis direction,the tip vortex around the trailing edge of the blade tip becomes smaller and finally disappears.Meanwhile,a separated flow field arises gradually and then grows in size around the middle of the junction of the blade tips with the ring.When the circular rings cover nearly 2/3 s of the width of the blade tips of the fan in the axis direction,the extension of the separated flow around the blade’s tip attains a minimum.

光质对蚕豆芽苗菜生长及营养品质的影响

以黑暗作为对照组,采用LED灯调节光质和光量,研究不同光质对蚕豆芽苗菜生长和营养品质的影响。结果表明,红光、蓝光和白光处理不仅显著抑制了蚕豆芽苗菜下胚轴的伸长,还显著减少了蚕豆芽苗菜地上部的鲜质量。蓝光条件下,蚕豆芽苗菜的可溶性蛋白质、维生素C和左旋多巴含量均显著高于对照组(P <0.05)。游离氨基酸含量在白光条件下达到最大为1.72 g/100g。研究表明,光质处理蚕豆芽苗菜,特别是蓝光处理,能提高芽苗菜的营养品质。

近期非洲猪瘟临床表现的新特点

非洲猪瘟在经过多次传染、传代后,必然会出现变化,表现为潜伏期长、猪只带毒时间长、传播速度变慢、死亡率降低的慢性非洲猪瘟、温和性非洲猪瘟。同时非法疫苗的出现,使得非洲猪瘟临床早期发现难度增加,精准剔除操作困难,一旦发现时,往往全群已经大面积感染,损失惨重。为了更好指导生产,有必要对非洲猪瘟的临床新特点进行总结。

云南省昆明市城市居民肺癌筛查结果分析

背景与目的肺癌筛查是降低肺癌死亡率的有效措施。目前国际及全国范围内均推荐肺癌筛查,我国于2009年、2012年分别启动了大规模的农村、城市肺癌早诊早治项目,云南省先后于2009年、2014年参与相关项目,但目前云南省尚未报道大规模肺癌筛查的研究结果。本研究通过参加国家癌症中心牵头的城市癌症早诊早治项目,分析2014年-2018年云南省昆明市10,154例城市居民肺癌筛查结果,评价城市癌症早诊早治肺癌筛查效果。方法以云南省昆明市40岁-74岁居民为研究对象,通过防癌风险问卷调查评估出肺癌高风险31,824人,对高风险人群进行胸部低剂量螺旋计算机断层扫描(computed tomography, CT),分析肺癌的高风险率、筛查率和检出率。结果 5年完成问卷调查150,535人,评估出肺癌高危人群31,824人,高风险率21.14%,共完成胸部低剂量螺旋CT筛查10,154人,参与率31.91%。肺内结节检出率22.28%(2,262/10,154),其中<5 mm实性/部分实性结节检出率11.30%(1,332/10,154)、<8 mm非实性结节检出率2.20%(219/10,154)、阳性结节检出率7.00%(711/10,154)、疑似肺癌检出率0.60%(59/10,154),肺癌检出率0.27%(27/10,154)。男性阳性结节、<8 mm非实性结节及疑似肺癌检出率显著高于女性;阳性结节、<5 mm实性结节、疑似肺癌及确诊肺癌检出率随年龄增加而增高,60岁以上年龄组最高。结论低剂量螺旋CT适合肺癌高危人群筛查,有助于早期发现肺内的阳性结节和相关疾病,应重视60岁以上人群肺癌的筛查工作;了解了昆明市居民的肺部健康状况,提高了居民的肺癌防治意识,提高肺癌的早诊早治率。

多维策略促进幼儿在绘本阅读中的全面协调发展

幼儿园教育应始终坚持幼儿全面协调发展的目的和原则。当前很多幼儿园都引进了绘本教学,但存在偏向关注幼儿语言和认知发展的弊端,忽略了幼儿在学习品质、情绪与社会能力等非认知领域的发展。教师应采取多维环境策略,为幼儿创造丰富的物质环境和具有支持性的心理环境,以此激发和培养幼儿的阅读兴趣。教师应善于利用幼儿对绘本的共同喜爱,采用多维教学与交往策略,关注幼儿在绘本阅读中的情绪体验与人际交往,发展幼儿的情绪能力与社会能力。

Unraveling Shuttle Effect and Suppression Strategy in Lithium/Sulfur Cells by In Situ/Operando X-ray Absorption Spectroscopic Characterization

The polysulfides shuttle effect represents a great challenge in achieving high capacity and long lifespan of lithium/sulfur(Li/S)cells.A comprehensive understanding of the shuttle-related sulfur speciation and diffusion process is vital for addressing this issue.Herein,we employed in situ/operando X-ray absorption spectroscopy(XAS)to trace the migration of polysulfides across the Li/S cells by precisely monitoring the sulfur chemical speciation at the cathodic electrolyte-separator and electrolyte-anode interfaces,respectively,in a real-time condition.After we adopted a shuttle-suppressing strategy by introducing an electrocatalytic layer of twinborn bismuth sulfide/bismuth oxide nanoclusters in a carbon matrix(BSOC),we found the Li/S cell showed greatly improved sulfur utilization and longer life span.The operando S Kedge XAS results revealed that the BSOC modification was bi-functional:trapping polysulfides and catalyzing conversion of sulfur species simultaneously.We elucidated that the polysulfide trapping-and-catalyzing effect of the BSOC electrocatalytic layer resulted in an effective lithium anode protection.Our results could offer potential stratagem for designing more advanced Li/S cells.

Numerical study of size effect in concrete penetration with LDPM

Projectile size effect is of great importance since the scaling researches are extensively applied to concrete penetration investigations. This paper numerically deals with the projectile size effect on penetration resistance via the recently developed Lattice Discrete Particles Model(LDPM) which is featured with mesoscale constitutive laws governing the interaction between adjacent particles to account for cohesive fracture, strain hardening in compression and compaction due to pore collapse. Simulations of two different penetration tests are carried to shed some light on the size effect issue. The penetration numerical model is validated by matching the projectile deceleration curve of and predicting the depth of penetration(DOP). By constant velocity penetration simulations, the target resistance is found to be dependent on the projectile size. By best fitting numerical results of constant velocity penetration, a size effect law for target resistance is proposed and validated against literature data. Moreover, the size effect is numerically obtained in the projectile with longer extended nose part meanwhile the shorter extended nose is found to improve the DOP since the projectile nose is sharpened.

Determination of chlorogenic acid by flow injection irreversible biamperometry

A flow injection irreversible biamperometric method for the determination of chlorogenic acid is described. The proposed method is based on the electrochemical oxidation of chlorogenic acid at pretreated platinum electrode and the reduction of permanganate at another electrode to form an irreversible biamperometric detection system. Under the external potential difference （z^v） of 0 V, in the 0.05 mol/L sulfuric acid, chlorogenic acid can be determined over the range 0.8-120 mg/L with a sample measurement frequency of 80 samples/h. The detection limit is 0.18 mg/L. The proposed method exhibits the satisfactory reproducibility with a relative standard derivation （R.S.D.） of 2.21% for 19 successive determinations of 40 mg/L.

Revealing the working mechanism of a multi-functional block copolymer binder for lithium-sulfur batteries

The lithium-sulfur(Li-S)battery is one of the most promising substitutes for current energy storage systems because of its low cost,high theoretical capacity,and high energy density.However,the high solubility of intermediate products(i.e.,lithium polysulfides)and the resultant shuttle effect lead to rapidly fading capacity and a low coulombic efficiency,which hinder the practical application of Li-S batteries.In this study,block copolymers are constructed with both an ethylene oxide unit and a styrene unit and then used as binders for Li-S batteries.Electrochemical performance improvements are attributed to the synergistic effects contributed by the different units of the block copolymer.The ethylene oxide unit traps polysulfide,which bonds strongly with the intermediate lithium polysulfide,and enhances the transport of lithium ions to reach high capacity.Meanwhile,the styrene unit maintains cathode integrity by improving the mechanical properties and elasticity of the constructed block copolymer to accommodate the large volume changes.By enabling multiple functions via different units in the polymer chain,high sulfur utilization is achieved,polysulfide diffusion is confined,and the shuttle effect is suppressed during the cycle life of Li-S batteries,as revealed by operando ultraviolet-visible spectroscopy and S Kedge X-ray absorption spectroscopy.

Numerical Investigation on the Secondary Flow Control by Using Splitters at Different Positions with Respect to the Main Blade

In turbomachinery,strong secondary flow can produce significant losses of total pressure near the endwall and reduce the efficiency of the considered turbomachine.In this study,splitters located at different positions with respect to the main blade have been used to reduce such losses and improve the efficiency of the outlet guide vane(OGV).Three different relative positions have been considered assuming a NACA 65-010 profile for both the main blade and the splitter.The numerical results indicate that splitters can effectively reduce the total pressure loss by suppressing the secondary flow around the main blade,but the splitters themselves also produce flow losses,which are caused by flow separation effects.

Trusted Blockchain Oracle Scheme Based on Aggregate Signature

With the development of blockchain technology, more and more applications need out-of-chain data. Thus, blockchain oracles have become an important bridge for transferring data on and off the chain. This paper studies the mainstream blockchain oracles scheme, summarizes the shortcomings of the existing schemes and proposes a new blockchain oracle scheme based on BLS (Bohen-Lynn-Shacham) aggregation signature to ensure that off-chain data can be transferred into the blockchain in a trusted and reliable way. Specifically, the scheme uses multiple blockchain oracles to avoid the single point of failure or even a small number of malicious oracles, and improve the credibility of data. At the same time, it not only uses BLS aggregate signature to reduce the storage cost and communication overhead, but also uses commitment mechanisms to ensure the reliability and authenticity of the data. Besides, the simulation results show that the scheme can meet the practical application requirements.

Vibrational Spectra and Adsorption of Trisiloxane Superspreading Surfactant at Air/Water Interface Studied with Sum Frequency Generation Vibrational Spectroscopy

The C-H stretch vibrational spectra of the trisiloxane superspreading surfactant Silwet L-77 （（CH3）3Si- O-Si（CH3）（C3H6）（OCH2CH2）7-8OCH3）-O-Si（CH3）3） at the air/water interface are measured with the surface Sum Frequency Generation Vibrational Spectroscopy （SFG-VS）. The spectra are dominated with the features from the -Si-CH3 groups around 2905 cm^-1 （symmetric stretch or SS mode） and 2957 ^-1 （mostly the asymmetric stretch or AS mode）, and with the weak but apparent contribution from the -O-CH2- groups around 2880 ^-1 （symmetric stretch or SS mode）. Comparison of the polarization dependent SFG spectra below and above the critical aggregate or micelle concentration （CAC） indicates that the molecular orientation of the C-H related molecular groups remained unchanged at different surface densities of the Silwet L-77 surfactant. The SFG-VS adsorption isotherm suggested that there was no sign of Silwet L-77 bilayer structure formation at the air/water interface. The Gibbs adsorption free energy of the Silwet surfactant to the air/water interface is -42.2±0.8kcal/mol, indicating the unusually strong adsorption ability of the Silwet L-77 superspreading surfactant.

The Study of Anti-tumor Activity of Trichosanthin by Cyclic Voltammogram

The anti-tumor activity of Trichosanthin (TCS) has been frequently reported in recent years. In our experiments, electrochemical methods were applied to detect the effects of TCS on human leukemia cells U937. 50 mu g/ml TCS treatment for 40 hours can cause irreversible negative effects on the viability of U937 cells. This effect largely depends on the concentration of TCS and the time period of treatment.

Fine-grained uncertainty relation for open quantum system

The fine-grained uncertainty relation (FUR) is investigated for accelerating open quantum system, which manifests the celebrated Unruh effect, a crucial piece of the jigsaw for combining relativity and quantum physics. For a single detector, we show that the inevitable Unruh decoherence can induce a smaller FUR uncertainty bound, which indicates an additional measurement uncertainty may exist. For an open system combined with two detectors, via a nonlocal retrieval game, the related FUR uncertainty bound is determined by the non-classical correlation of the system. By estimating the maximal violation of Bell inequality for an accelerating system, we show that the FUR uncertainty bound can be protected from Unruh decoherence, due to quantum correlation generated through Markovian dynamics.

Effect of Caffeic acid on the Tumor Cells U937 Evaluated by an Electrochemical Voltammetric Method

Electrochemical voltammetric method can;be used to monitor cell health state during its growth. Here we studied the effect of caffeic acid on leukemia cells U937 by the voltammetric behavior of the cells. The result showed that this drug had a negative influence on cell health. which suggests that caffeic acid may be used in inhibition of tumor cells.

Geometric phase under the Unruh effect with intermediate statistics

Utilizing the geometric phase(GP)acquired in a quantum evolution,we manifest the thermality and quantum nature of the Unruh effect of an accelerating detector.We consider an UDW detector coupling to a conformal field in Minkowski spacetime,whose response spectrum exhibits an intermediate statistics of(1+1)anyon field.We find that comparing to an inertial moving detector,the GP in accelerating frame is modified after the nonunitary evolution of the detector due to the Unruh effect.We show that such modification can distinguish the different thermalizing ways of the detector,which depends on the scaling dimension of the conformal primary field.Finally,we estimate the difference between the GP under the Unruh radiation and that in a thermal bath for a static observer,which reveals the quantum origin of the Unruh effect rather than a conventional thermal noise.