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.

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.

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.

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.

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.

1988年日地联测期间北京地区TEC行为(英文)

本文研究1988年3月15日—21日、4月16日—21日、6月24日—7月8日及12月15日—25日四个联测时段内太阳事件对电离层产生扰动时,总电子含量(TEC)的几种特性。 一、磁暴对电离层TEC的影响。在后三次联测期出现三个急始型(SC)磁暴和一个缓始(GS)型暴,分别发生在春季夏季及冬季。把暴时TEC的实测值与相应月磁静日或控制日TEC的均值进行比较,高于磁静日者称为正效应,低于磁静日者称为负效应。结果有三。1、冬季磁暴对电离层电子含量的影响是正效应,即磁暴使TEC增加。2、夏季磁暴对TEC的影响是负效应。3、分季磁暴也是正效应。 二、耀斑对电离层的影响。耀斑爆发后,电离层受到扰动,如SID、电离层暴等。过去的研究发现亮耀斑(1B、2B和3B级)引起TEC增加。88年联测期间TEC行为亦表现出增加特性。伴有紫外爆发的89年4月9日0840UT的耀斑事件,使TEC突增2π(=1.04×10^(17)电子/米~2)。伴有X射线爆的耀斑事件,引起VLF相位超前,即D层电离增加,地电波导的有效高度降低。 三、其他现象。冬季TEC行为明显地呈现周期为2日的行星波波动,春季亦然,但夏季(第三次联测)2日波特性极不明显。TEC的季节变化,夏季最低,变化量亦小,分季(4月,10月)最大,变化量亦大,冬季次之。这与最近分析出的北京地区f_0F_2的行为一致。它反映了电离?

Gender Differences on the Use of Amplifiers in Academic Writings

This study aims to investigate the use of amplifiers in term of gender and disciplinary groups in academic research arti cles,which is based on the British Academic Written English Corpus(BAWE).18 amplifiers were examined across two dimen sions:gender and disciplinary groups.The results show amplifiers are more common in males' academic writings than in those of females in general,amplifiers are used more often in AH discipline.However,not all amplifiers show significant gender differ ences between men and women.Six words show a significant difference between male and female writers:pretty,by far,perfect ly,quite,a great deal,totally,which are used more often by males.However,the interesting is in LS discipline,most amplifiers are used more often by female than male writers and males tend to use by far more frequently than females.

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.

Performance Evaluation of the Thick Pinhole Gamma Rays Diagnostic System

The diagnostic methods for the profile of the radiation source were estab-lished at first based on the pinhole imaging principle. In this paper, the relationships among various parameters of the gamma-rays crammer such as the modulation transfer function (MTF), the noise power spectrum (NPS), the signal-noise ratio (SNR) and the detective quantum efficiency (DQE) are developed and studied experimentally on the cobalt radiation source. The image diagnostic system is consisting with rays-fluorescence convertor (YAG crystal), optical imaging system, MCP image intensifier, CCD camera and other devices. The spatial resolution of the modulation transfer function (MTF) at 10% intensity was measured as 1 lp/mm by knife-edge method. The quantum of the measurement system is about 150 under weak radiation condition due to the single particle detection efficiency of the system. The dynamic range was inferred preliminarily as about 437. The required radiation intensity was calculated using the experiment result for the (SNR) = 1, 5, 10, respectively. The theoretical investigation results show that the radiation image with (SNR) = 1 can be only obtained when the pinhole diameter is 0.7 mm, object distance and image distance are both 200 cm, and the radiation intensity is about 1.0 × 1012 Sr-1·cm-2.

Evaluation of Major Factors Affecting Spatial Resolution of Gamma-Rays Camera

The spatial resolution of the gamma-rays camera was measured on a60Co gamma-rays source with edge method. The gamma-rays camera is consisting with rays-fluorescence convertor, optical imaging system, MCP image intensifier, CCD camera, electronic control system and other devices, and is mainly used in the image diagnostics of the intense pulse radiation sources [1]. Due to the relatively big quantum detective efficiency (DQE) and quantum gain of the gamma-rays, etc., the experimental data were processed by averaging multiple images and fitting curves. According to the experimental results, the spatial resolution MTF (modulation transfer function) at the 10% intensity was about 2lp/mm. Meanwhile, because of the relatively big dispersion effects of the fluorescence transmissions in the scintillator and the optical imaging system, the maximal single-noise ratio (SNR) of the camera was found to be about 5:1. In addition, the spatial resolution of the camera was measured with pulse X-rays with 0.3MeV in average energy and exclusion of the effects of secondary electrons from consideration. Accordingly, the spatial resolution MTF at the 10% intensity was about 5lp/mm. This could be an additional evidence to verify the effects of secondary electrons induced by the 1.25MeV gamma-rays in the scintillator upon the spatial resolution. Based on our analysis, the dispersion sizes of the secondary electrons in the scintillator are about 0.4mm-0.6mm. Comparatively, as indicated by the detailed analysis of the spatial resolutions of the MCP image intensifier and CCD devices, both of them have little effect on the spatial resolution of the gamma-rays camera that could be well neglected.

The Influence of ENSO on the Summer Climate Change in China and Its Mechanism

The influence of ENSO on the summer climate change in China and its mechanism from the observed data is discussed. It is discovered that in the developing stage of ENSO, the SST in the western tropical Pacific is colder in summer, the convective activities may be weak around the South China Sea and the Philippines. As a consequence, the subtropical high shifted southward. Therefore, a drought may be caused in the Indo-China peninsula and in the South China. Moreover, in midsummer the subtropical high is weak over the Yangtze River valley and Huaihe River valley, and the flood may be caused in the area from the Yangtze River valley to Huaihe River valley. On the contrary, in the decaying stage of ENSO. the convective activities may be strong around the Philippines, and the subtropical high shifted northward, a drought may be caused in the Yangtze River valley and Huaihe River valley.

Numerical Simulation of the Relationship between the Anomaly of Subtropical High over East Asia and the Convective Activities in the Western Tropical Pacific

In this paper, a close relationship between the intraseasonal variation of subtropical high over East Asia and the convective activities around the South China Sea and the Philippines is analysed from OLR data.This relationship is studied by using the theory of wave propagating in a slowly varying medium and by using a quasi-geoslrophic, linear, spherical model and the IAP-GCM, respectively. The results show that when the SST is warming around the western tropical Pacific or the Philippines, the convective activities are intensified around the Philippines. As a consequence, the subtropical high will be intensified over East Asia. The computed results also show that when the anomaly of convective activities are caused around the Philippines, a teleconnection pattern of circulation anomalies will be caused over South Asia, East Asia and North America.

The Modified Envelope Orography and the Air Flow over and around Mountains

By use of the two-layer adiabatic globe spectral model and the zonally averaged climatic data of winter season as initial values, 10-day integrations are carried out based on three kinds of model topography (i.e., (1) the averaged topography; (2) the envelope topography; (3) the modified envelope topography). The results show that the orography of the Northern Hemisphere plays an important role in the simulation of large-scale weather patterns in winter season. The simulation based on the envelope topography developed by Wallace et al. has some improvements in the Rocky Mountains area. But this scheme causes very serious horizontal expansion around the Tibetan Plateau (hereafter referred to as the TV). A modified envelope topography scheme has been worked out that increases the slope of the TP by decreasing the horizontal expansion while keeping the maximum altitude. The results show some improvements of the scheme around the TP. By analysis of the mechanical effects of the large-scale orography on

Sensitivities of Numerical Model Forecasts of Extreme Cyclone Events

A global forecast model is used to examine various sensitivities of numerical predictions of three extreme winter storms that occurred near the eastern continental margin of North America: the Ohio Valley blizzard of January 1978, the New England blizzard of February 1978, and the Mid-Atlantic cyclone of February 1979. While medium-resolution simulations capture much of the intensification, the forecasts of the precise timing and intensity levels suffer from various degrees of error. The coastal cyclones show a 5-10 hPa dependence on the western North Atlantic sea surface temperature, which is varied within a range (± 2.5℃) compatible with interannual fluctuations. The associated vertical velocities and precipitation rates show proportionately stronger dependences on the ocean temperature perturbations. The Ohio Valley blizzard, which intensified along a track 700-800 km from the coast, shows little sensitivity to ocean temperature. The effect of a shift of - 10?latitude in the position of the snow

Neoadjuvant-intensified treatment for rectal cancer:Time to change?

AIM:To investigate whether neoadjuvant-intensified radiochemotherapy improved overall and disease-free survival in patients with locally advanced rectal cancer.METHODS:Between January 2007 and December 2011,80 patients with histologically confirmed rectal adenocarcinoma were enrolled.Tumors were clinically classified as either T3 or T4 and by the N stage based on the presence or absence of positive regional lymph nodes.Patients received intensified combined modality treatment,consisting of neoadjuvant radiation therapy(50.4-54.0 Gy) and infusional chemotherapy(oxaliplatin 50 mg/m 2) on the first day of each week,plus five daily continuous infusions of fluorouracil(200 mg/m 2 per die) from the first day of radiation therapy until radiotherapy completion.Patients received five or six cycles of oxaliplatin based on performance status,clinical lymph node involvement,and potential risk of a non-sphincter-conserving surgical procedure.Surgery was planned 7 to 9 wk after the end of radiochemotherapy treatment;adjuvant chemotherapy treatment was left to the oncologist's discretion and was recommended in patients with positive lymph nodes.After treatment,all patients were monitored every three months for the first year and every six months for the subsequent years.RESULTS:Of the 80 patients enrolled,75 patients completed the programmed neoadjuvant radiochemotherapy treatment.All patients received the radiotherapy prescribed total dose;five patients suspended chemotherapy indefinitely because of chemotherapyrelated toxicity.At least five cycles of oxaliplatin were administered to 73 patients.Treatment was well tolerated with high compliance and a good level of toxicity.Most of the acute toxic effects observed were classified as grades 1-2.Proctitis grade 2 was the most common symptom(63.75%) and the earliest manifestation of acute toxicity.Acute toxicity grades 3-4 was reported in 30% of patients and grade 3 or 4 diarrhoea reported in just three patients(3.75%).Seventy-seven patients underwent surgery;low anterior resection was performed in 52 patients,Miles' surgery in 11 patients and total mesorectal excision in nine patients.Fifty patients showed tumor downsizing ≥ 50% pathological downstaging in 88.00% of tumors.Out of 75 patients surviving surgery,67 patients(89.33%) had some form of downstaging after preoperative treatment.A pathological complete response was achieved in 23.75% of patients and a nearly pathologic complete response(stage ypT1ypN0) in six patients.An involvement of the radial margin was never present.During surgery,intra-abdominal metastases were found in only one patient(1.25%).Initially,45 patients required an abdominoperineal resection due to a tumor distal margin ≤ 5 cm from the anal verge.Of these patients,only seven of them underwent Miles' surgery and sphincter preservation was guaranteed in 84.50% of patients in this subgroup.Fourteen patients received postoperative chemotherapy.In the full analysis of enrolled cohort,eight of the 80 patients died,with seven deaths related to rectal cancer and one to unrelated causes.Local recurrences were observed in seven patients(8.75%) and distant metastases in 17 cases(21.25%).The fiveyear rate of overall survival rate was 90.91%.Using a median follow-up time of 28.5 mo,the cumulative incidence of local recurrences was 8.75%,and the overall survival and disease-free survival rates were 90.00% and 70.00%,respectively.CONCLUSION:The results of this study suggest oxaliplatin chemotherapy has a beneficial effect on overall survival,likely due to an increase in local tumor control.

Effect of Counter-Gradient in the Computation of Turbulent Fluxes of Heat and Moisture in a Regional Model

The counter-gradient terms in the computations of turbulent fluxes of heat and moisture have been included in the PBL parameterization of a regional model for monsoon prediction. Results show that inclusion of counter-gradient terms has a marginal impact in the prediction of large scale monsoon circulation and rainfall rates.

Building a global community of shared future free from poverty

Poverty alleviation has been highlighted as one of the essential aspects of global development.It has consistently ranked as the top priority among a list of sustainable development goals proposed by the United Nations.1 The coronavirus disease 2019(COVID-19)pandemic has created an unprecedentedly challenging climate for the global economy,society,and populations worldwide,which has consequently intensified socioeconomic inequities among different population groups,especially for the poor and vulnerable.In 2020,global extreme poverty rose for the first time over the past 20 years under the impact of COVID-19,which resulted in an additional 120 million people living in poverty(1.90 USD/day),with the total number of impoverished residents expected to reach approximately 150 million by the end of 2021.2 Such a changing climate has posed a huge obstacle to efforts to alleviate global poverty in terms of improving the affordability,accessibility,adaptability,and equity of medical services for impoverished populations.Under such circumstances,a sustainable strategy for health poverty alleviation needs to be urgently identified and adopted via global efforts to build a global community with shared future free from poverty.