Performance optimization of the neutron-sensitive image intensifier used in neutron imaging

As a non-destructive testing technology,neutron imaging plays an important role in various fields,including material science,nuclear engineering,and fundamental science.An imaging detector with a neutron-sensitive image intensifier has been developed and demonstrated to achieve good spatial resolution and timing resolution.However,the influence of the working voltage on the performance of the neutron-sensitive imaging intensifier has not been studied.To optimize the performance of the neutron-sensitive image intensifier at different voltages,experiments have been performed at the China Spallation Neutron Source(CSNS)neutron beamline.The change in the light yield and imaging quality with different voltages has been acquired.It is shown that the image quality benefits from the high gain of the microchannel plate(MCP)and the high accelerating electric field between the MCP and the screen.Increasing the accelerating electric field is more effective than increasing the gain of MCPs for the improvement of the imaging quality.Increasing the total gain of the MCP stack can be realized more effectively by improving the gain of the standard MCP than that of the n MCP.These results offer a development direction for image intensifiers in the future.

Obstructive Effects of Ultrasonic Microbubble Intensifier on CHG-5 Cell with Survivin Antisense Oligonucleotides Transfection

Objective： To study the effects on human glioma cell line CHG-5 by ultrasonic microbubble intensifier with survivin antisense oligonucleotides （ASODN） transfection. Methods： Antisense oligonucleotides targeting survivin mRNA was designed and synthesized. Four regimen groups were designed, group A： survivin antisense oligonucleotides transfected with ultrasonic microbubble intensifier combined with ultrasound irradiation, group B： survivin antisense oligonucleotides transfected with lipofectamine combined with ultrasound irradiation, group C： survivin antisense oligonucelotides with lipofectamine transfection, group D： blank control. The expression changes of surviving protein were measured by immunohistochemical staining and Western blotting, and MTT assay was used to measure the changes of proliferation. Results： Survivin protein expression in group A was decreased significantly in human glioma cell line CHG-5 than other groups（P〈0.05）, and the proliferating rate of CHG-5 in group A was also significantly inhibited（P〈0.05）. Conclusion： Ultrasonic microbubble intensifier transfection combined with ultrasound irradiation is a promising method in gene transfection effectively and noninvasively.

PROCESS AND PROPERTIES OF THE MODERN MULTIALKALI PHOTOCATHODE USED IN A CASCADE IMAGE INTENSIFIER

A new processing technology and the properties of multialkali antimonide photocathodesare described.The technique requires an initial antimony layer to be deposited on a fiber-optic window at asuitable temperature.After that.the layer is activated by multialkali and antimonide.Thus.the multialkaliphotocathodes named“The Modern Multialkali Photocathode”are obtained.It has been found that aphotocathode thus processed gives a sensitivity of 200 to 300μA/Im for white light at a color temperature of2854K.This paper shows the variation of photosensitivity during processing of a Modern MultialkaliPhotocathode and the variatioon of spectral sensitivity at different wavelengths.The author discusses theresults.gives a supposition of“photoemission center”,and discusses the role of Cs in multialkaliphotocathodes.

The US-Philippines Special Relationship Revitalized:Motivations,Implications,and Constraints

US-Philippines relations have been rapidly strengthened since Marcos Jr.became Philippine President.The strong revitalization of the special relationship based on traditional ties has not only had an impact on regional security hotspots,but also profoundly stirred up the security situation in the Asia-Pacific,especially in the context of intensified China-US strategic rivalry.However,prospects of the revitalization remain uncertain given,among others,the variables in domestic politics and the emergence of a“special dilemma”within the alliance.

Only With Talent,Can There Be Productivity

The Chinese government attaches great importance to the legal protection of innovation and intellectual property rights.At the parallel forum named"Rule of Law and Innovation"with the theme of"Intellectual Property and the Development of New Productive Forces"held during the Global Business and Law Conference2024,experts had a heated discussion.Zhang Shaogang,Vice Chairman of the CCPIT,said at the forum,"At present,the momentum of world economic growth is insufficient,and the competition in the frontier areas of the new round of scientific and technological revolution and industrial transformation has intensified.

Chronology of 50 Years of China-Malaysia Diplomatic Relations

This year marks the 50th anniversary of the establishment of diplomatic ties between China and Malaysia.Over the past half century,China and Malaysia have maintained close economic and trade ties and intensified people-to-people exchanges.China and Malaysia are important trade partners and enjoy complementary economic advantages.

In Brief

CNPC achieved a high-quality“Good Start”in Q12024 On April 29,PetroChina Company Limited announced its Q12024 achievements,highlighting coordinated efforts in production and operations,safety and environmental protection,quality improvement and efficiency enhancement,reform and innovation,and green transformation.The Company optimized operations and product mixes,intensified market outreach,and rigorously managed costs.Its oil and gas chains ran safely and efficiently,while new energy and materials sectors witnessed rapid growth.

Asia-Pacific Regional Economic Cooperation Under the Reshaping of Global Production and Supply Chains

As part of the important trends of the current development of the world economy,the reshaping of global industry and supply chains interacts with the intensified changes unprecedented in the past century in an increasingly close manner.“Benefit-sharing and risk-sharing”,the characteristics of global industry and supply chains,have a profound influence on the distribution of benefits among countries and the effectiveness of global economic governance.

SUMMARIES OF TOP EVENTS IN CHINA AND AFRICA

China Increases Payment Convenience for Foreigners China has recently intensified efforts to enhance the convenience of payment services for foreigners,who primarily rely on bank cards and cash,while mobile payment is emerging as the predominant method of payment in China.

THROUGH MY EYES

Rare Appearance.An aurora is seen above the Jinshanlin section of the Great Wall in Chengde,north China’s Hebei Province,on 11 October.Recently,intensified solar activity has made auroras occasionally visible in parts of China.SOURCE:VCG.

EXCERPTS FROM MAJOR CHINESE MAGAZINES

NEW QUALITY PRODUCTIVE FORCES Outlook Weekly 11 March Faced with increasingly fierce international competition,China’s intensified push to foster new quality productive forces is of great significance in propelling the intelligent,green and highend development of industries,improving the resilience and security of industrial and supply chains,and consolidating the economic recovery momentum.

New Drivers of Development China’s reform and opening up has benefitted Africa in multifarious ways

Joaquim Chissano,former President of Mozambique,has said that Africa has gained much from China’s economic development,particularly due to its reform and opening up policy.China inspires African nations in their quest for national renewal and creates new development prospects through mutually beneficial cooperation.Since the establishment of the Forum on China-Africa Cooperation in 2000 and the launch of the Belt and Road Initiative in 2013,exchanges between the two sides have intensified.Platforms such as the China-Africa Economic and Trade Expo and the China International Import Expo have further strengthened this momentum.

Middle and near ultraviolet spectrograph of the Scientific Experimental system in Near SpacE(SENSE)

The Scientific Experimental system in Near SpacE(SENSE)consists of different types of instruments that will be installed on a balloon-based platform to characterize near-space environmental parameters.As one of the main scientific payloads,the middle and near ultraviolet spectrograph(MN-UVS)will provide full spectra coverage from middle ultraviolet(MUV,200−300 nm)to near ultraviolet(NUV,300−400 nm)with a spectral resolution of 2 nm.Its primary mission is to acquire data regarding the UV radiation background of the upper atmosphere.The MN-UVS is made up of six primary components:a fore-optical module,an imaging grating module,a UV intensified focal plane module,a titanium alloy frame,a spectrometer control module,and a data processing module.This paper presents in detail the engineering design of each functional unit of the MN-UVS,as well as the instrument’s radiometric calibration,wavelength calibration,impact test,and low-pressure discharge test.Furthermore,we are able to report ground test and flight test results of high quality,showing that the MN-UVS has a promising future in upcoming near-space applications.

Genome sequencing revealed the red-flower trait candidate gene of a peach landrace

Peach(Prunus persica)is an economically important fruit crop globally and an excellent material for genomic studies.While considerable progress has been made in unveiling trait-associated genes within cultivars and wild relatives,certain novel genes controlling valuable traits in peach landraces,such as the red-flowering gene,remained unclear.In this study,we sequenced and assembled the diploid genome of the red-flower landrace‘Yingzui’(abbreviated as‘RedY’).Multi-omics profiling of red petals of‘RedY’revealed the intensified red coloration associated with anthocyanins accumulation and concurrent decline in f lavonols.This phenomenon is likely attributed to a natural variant of Flavonol Synthase(FLS)harboring a 9-bp exonic insertion.Intriguingly,the homozygous allelic configurations of this FLS variant were only observed in red-flowered peaches.Furthermore,the 9-bp sequence variation tightly associated with pink/red petal color in genome-wide association studies(GWAS)of collected peach germplasm resources.Functional analyses of the FLS variant,purified from procaryotic expression system,demonstrated its diminished enzymatic activity in f lavonols biosynthesis,impeccably aligning with the cardinal trait of red flowers.Therefore,the natural FLS variant was proposed as the best candidate gene for red-f lowering trait in peach.The pioneering unveiling of the red-flowered peach genome,coupled with the identification of the candidate gene,expanded the knowledge boundaries of the genetic basis of peach traits and provided valuable insights for future peach breeding efforts.

Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate

The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine(4-HP) with tributyl phosphate(TBP), di(2-ethylhexyl) phosphoric acid(D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio(D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50-4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate(i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP,(ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA(1:1) and 4-HP:2D2EHPA(1:2) type complexes, while(iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA(1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

New Landscape of Energy Politics and Global Energy Governance

Since the 1990s,intern ational energy cooperation has ad­vanced on all fronts,and energy governance has become a focal point of global governance.However,with the emerging anti-globalization tide and intensified competition among major countries in recent years,the trend of“politicizing”energy coop­eration has been stronger.

Holographic Goggles Optical System

Based on the holographic theory, a pair of reflective holographic lenses have been utilized with an aim to improve the optical properties of night vision goggles. The aberration distribution of the holographic lens has been confirmed by experiments and compensated by a conventional symmetrical spherical system. Resulting data of the whole optical system are given.

Water leaching kinetics and recovery of potassium salt from sintering dust

Surface morphology and inner structure of the dust were observed by ICP-AES, SEM-EDS and XRD to examine the strengthening measures of leaching potassium salt from the sintering dust by water. The results showed that the main component of the sintering dust was iron-oxygen compound, with KCl adsorbed on its surface. Leaching experiments showed that the KCl in the ESP dust could be separated and recovered by water leaching and fractional crystallization. The yield of K-Na vaporized crystalline salt was 18.56%, in which the mass fractions of KCl, NaCl, CaSO4 and K2SO4 were about 61.21%, 13.40%, 14.62%and 10.86%, respectively. The leaching kinetics of potassium salt from the sintering dust fits the external diffusion model well. The leaching speed and the leaching rate of the potassium salt can be increased by increasing the leaching temperature, strengthening the stirring speed and increasing the liquid-solid ratio.

针-板电极空气隙直流放电光信息采集

为研究气体击穿的放电机理,采集直流电压下针-板电极空气隙流注放电击穿瞬间的光信号,实验设计了气体放电光学采集装置.利用光纤,光谱仪和ICCD组成光信号检测系统,其中ICCD单独使用可以捕捉光现象,配合光谱仪可采集光谱.实验中采用具有高速触发脉冲的外部触发方式操作控制器,进行图像及光谱的采集,并对采集到的结果进行分析和讨论.

Fast fluorescence lifetime imaging techniques:A review on challenge and development

Fluorescence lifetime imaging microscopy(FLIM)is increasingly used in biomedicine,material science,chemistry,and other related research fields,because of its advantages of high specificity and sensitivity in monitoring cellular microenvironments,studying interaction between proteins,metabolic state,screening drugs and analyzing their efficacy,characterizing novel materials,and diagnosing early cancers.Understandably,there is a large interest in obtaining FLIM data within an acquisition time as short as possible.Consequently,there is currently a technology that advances towards faster and faster FLIM recording.However,the maximum speed of a recording technique is only part of the problerm.The acquisition time of a FLIM image is a complex function of many factors.These include the photon rate that can be obtained from the sample,the amount of information a technique extracts from the decay functions,the fficiency at which it determines fluorescence decay parameters from the recorded photons,the demands for the accuracy of these parameters,the number of pixels,and the lateral and axial resolutions that are obtained in biological materials.Starting from a discussion of the parameters which determine the acquisition time,this review will describe existing and emerging FLIM techniques and data analysis algo-rithms,and analyze their performance and recording speed in biological and biomedical applications.