Development and application of high-precision multifunction astronomical plate digitizers in China

Before charge-coupled device detectors became widely employed in observational astronomy,for more than a hundred years,the main detection method was photography on astronomical glass plates.Recently,in order to preserve these historical data and maintain their usability,the International Astronomical Union has appealed to all countries for global digitization of astronomical plates by developing or adopting advanced digitization technology.Specialized digitizers with high precision and high measuring speed represent key equipment for this task.The Shanghai Astronomical Observatory and the Nishimura Co.,Ltd in Japan cooperated between 2013 and 2016 to develop the first Chinese high-precision astronomical plate digitizer,which was then used for complete digitization of all nighttime-observation astronomical plates in China.Then,in 2019–2021,the Shanghai Astronomical Observatory independently developed new models of plate digitizers that enabled countries such as Uzbekistan and Italy to digitize their astronomical plates.Additionally,a new high-precision and multifunction digitizer was also used to digitize valuable microscope slides from the Shanghai Natural History Museum,providing a successful example of cross-domain application of high-precision digitization technology.

Design of Thermo-Optic Variable Optical Attenuator Based on Quartz Substrate

In this paper, we designed a thermo-optic variable optical attenuator (VOA) based on quartz substrate, which consists of a Mach-Zehnder interferometer (MZI) and a thin film heater above the phase-modulation arm. The transmission properties of the waveguide and attenuation characteristics of the device have been simulated by beam propagation method (BPM), and the simulated results illustrated that the designed VOA had good performance.

Immune checkpoint therapy for solid tumours: clinical dilemmas and future trends

Immune-checkpoint inhibitors(ICBs),in addition to targeting CTLA-4,PD-1,and PD-L1,novel targeting LAG-3 drugs have also been approved in clinical application.With the widespread use of the drug,we must deeply analyze the dilemma of the agents and seek a breakthrough in the treatment prospect.Over the past decades,these agents have demonstrated dramatic efficacy,especially in patients with melanoma and non-small cell lung cancer(NSCLC).Nonetheless,in the field of a broad concept of solid tumours,non-specific indications,inseparable immune response and side effects,unconfirmed progressive disease,and complex regulatory networks of immune resistance are four barriers that limit its widespread application.Fortunately,the successful clinical trials of novel ICB agents and combination therapies,the advent of the era of oncolytic virus gene editing,and the breakthrough of the technical barriers of mRNA vaccines and nano-delivery systems have made remarkable breakthroughs currently.In this review,we enumerate the mechanisms of each immune checkpoint targets,associations between ICB with tumour mutation burden,key immune regulatory or resistance signalling pathways,the specific clinical evidence of the efficacy of classical targets and new targets among different tumour types and put forward dialectical thoughts on drug safety.Finally,we discuss the importance of accurate triage of ICB based on recent advances in predictive biomarkers and diagnostic testing techniques.

RCEP框架下的国际税收合作与协调

作为全面、现代、高质量、互惠的大型区域自贸协定,RCEP代表了亚太地区高质量、以发展包容为导向的经贸新规则,具有显著的示范效应和规则溢出性,并由此开创了区域和全球开放合作的新局面。税收规则是国际经贸规则的重要内容,税收条款同样是RCEP协定的重要组成部分。RCEP税收条款明确了清晰的政策边界、与投资章节紧密相关、明确了政策优先次序、遵守以WTO为核心的国际规则,并充分考虑了发展中国家的诉求,体现了适度性、兼容性的特点。RCEP协定代表了国际税收合作与协调发展的新趋势,即硬性规则的“约束”与软性规则的“协调”相结合,力求在高水平开放、监管一致性和包容性之间更好地取得平衡。未来RCEP数字经济、投资议题等升级谈判,将对各成员国之间税收合作提出更高的、新的要求。中国应以RCEP为基础、结合双边税收协定,积极构建新型区域税收合作机制,推进国际税收合作与协调向更加开放、包容、普惠、共赢的方向发展。

塔里木河干流胡杨径向生长对地表径流变化的响应

以塔里木河干流荒漠河岸胡杨(Populus euphratica)为研究对象,在塔里木河干流河道上游和中游选择帕满水库和坎白尔吾斯坦2个断面,分析胡杨径向生长的特点。根据不同断面的河道径流数据,采用小波分析和相关性分析方法研究塔里木河胡杨径向生长随径流动态变化的响应。结果表明,帕满水库一新其满断面,胡杨基部断面生长增量(BAI)与径流在15—24年时间尺度上都发生震荡,且径流震荡年份要早于基部断面生长增量震荡年份。坎白尔吾斯坦一英巴扎断面,胡杨BAI与径流在10-20年时间尺度上都发生震荡,BAI震荡周期出现时间较晚。在塔里木河干流沿岸,径流是胡杨径向生长的主要限制因素之一。上游帕满水库断面,胡杨BAI与前一年11月至当年3月的径流量呈显著相关:中游坎白尔吾斯坦断面,胡杨BAI与前一年12月至当年3月的径流量呈显著相关。塔里木河不同河段胡杨BAI对径流变化响应的敏感度存在差异。研究表明,塔里木河上游采样区胡杨生长良好,所对应的最佳径流达1.3340×10^8m^3;塔里木河中游采样区胡杨径向生长的最合理径流量的范围为0.3803×10^8-1.2056×10^8m^3。

Disclosure of government financial information and the cost of local government's debt financing——Empirical evidence from provincial investment bonds for urban construction

China's slowing economic growth and rapid urbanization have made local government debt financing a significant issue.This study uses a sample of China's provincial government data for the 2006–2012 period to examine the effect of the disclosure of financial information by local governments on their debt financing costs.The results show that financial information disclosure is conducive to public supervision and enhances government credibility,leading to a decrease in the cost of debt financing.Furthermore,increased government economic intervention increases the strength of the association between financial information disclosure and the cost of debt financing.Increased government audit prevention function weakens the strength of the association between financial information disclosure and the cost of debt financing.

4 × 20 GHz silica-based AWG hybrid integrated receiver optical sub-assemblies

Both the 4 × 20 GHz coarse wavelength division multiplexing and LAN-WDM receiver optical sub-assemblies（ROSAs） were developed. The ROSA package was hybrid integrated with a planar lightwave circuit arrayed waveguide grating（AWG） with 2% refractive index difference and a four-channel top-illuminated positive-intrinsicnegative photodetector（PD） array. The output waveguides of the AWG were designed in a multimode structure to provide flat-top optical spectra, and their end facet was angle-polished to form a total internal reflection interface to realize vertical coupling with a PD array. The maximum responsivity of ROSA was about 0.4 A/W, and its 3 dB bandwidth of frequency response was up to 20 GHz for each transmission lane. The hybrid integrated ROSA would be a cost-effective and easy-assembling solution for 100 Gb E data center interconnections.

25 × 50 Gbps wavelength division multiplexing silicon photonics receiver chip based on a silicon nanowire-arrayed waveguide grating

A high-performance monolithic integrated wavelength division multiplexing silicon(Si) photonics receiver chip is fabricated on a silicon-on-insulator platform. The receiver chip has a 25-channel Si nanowire-arrayed waveguide grating, and each channel is integrated with a high-speed waveguide Ge-on-Si photodetector. The central wavelength, optical insertion loss, and cross talk of the array waveguide grating are 1550.6 nm, 5–8 dB, and-12 –-15 dB, respectively. The photodetectors show low dark current density of 16.9 mA∕cm^2 at-1 V and a high responsivity of 0.82 A/W at 1550 nm. High bandwidths of 23 and 29 GHz are achieved at 0 and-1 V, respectively. Each channel can operate at 50 Gbps with low input optical power even under zero bias,which realizes an aggregate data rate of 1.25 Tbps.

Interference at the single-photon level based on silica photonics robust against channel disturbance

Quantum key distribution(QKD) provides a solution for communication of unconditional security. However,the quantum channel disturbance in the field severely increases the quantum bit-error rate, degrading the performance of a QKD system. Here we present a setup comprising silica planar light wave circuits(PLCs), which is robust against the channel polarization disturbance. Our PLCs are based on the asymmetric Mach–Zehnder interferometer(AMZI), integrated with a tunable power splitter and thermo-optic phase modulators. The polarization characteristics of the AMZI PLC are investigated by a novel pulse self-interfering method to determine the operation temperature of implementing polarization insensitivity. Over a 20 km fiber channel with 30 Hz polarization scrambling, our time-bin phase-encoding QKD setup is characterized with an interference fringe visibility of 98.72%. The extinction ratio for the phase states is kept between 18 and 21 d B for 6 h without active phase correction.

Multiframe weak target track-before-detect based on pseudo-spectrum in mixed coordinates

Traditional multiframe Track-Before-Detect(TBD)may incur adverse integration loss resulting from model mismatch in sensor coordinates.Its suboptimal integration strategy may cause target envelope degradation.To address these issues,a pseudo-spectrum-based multiframe TBD in mixed coordinates is proposed firstly.The data search for energy integration is conducted based on an accurate model in the x-y plane while target energy is integrated based on pseudo-spectrum in sensor coordinates.The algorithm performance is improved since the model mismatch is eliminated,and the pseudo-spectrum based integration facilitates well maintained target envelope.The detailed multiframe integration procedure and theoretical target integrated envelope are derived.Secondly,to cope with the unknown target velocity,a velocity filter bank based on pseudo-spectrum in mixed coordinates is proposed.The effect of velocity mismatch on algorithm performance is analyzed and an efficient method for filter bank design is presented.Thirdly,a parameter estimation method using characteristics of integrated envelope is presented for improved target polar position and Cartesian velocity estimation.Finally,numerical results are provided to demonstrate the effectiveness of the proposed method.

An iterative weighting method to apply ISR correction to e+e−hadronic cross-section measurements

Initial State Radiation(ISR)plays an important role in e+e−collision experiments such as the BESIII.To correct the ISR effects in measurements of hadronic cross-sections of e+e−annihilation,an iterative method that weights simulated ISR events is proposed here to assess the efficiency of event selection and the ISR correction factor for the observed cross-section.The simulated ISR events were generated only once,and the obtained cross-sectional line shape was used iteratively to weigh the same simulated ISR events to evaluate the efficiency and corrections until the results converge.Compared with the method of generating ISR events iteratively,the proposed weighting method provides consistent results,and reduces the computational time and disk space required by a factor of five or more,thus speeding-up e+e−hadronic cross-section measurements.

Application of acid protease in the industrial production of corn ethanol

Bioethanol is a renewable,clean energy and a very important basic chemical raw material,improving production efciency and reducing production cost are the goals pursued by ethanol enterprises.Adding acid protease in the process of producing ethanol from grain will have many efects on fermentation,one of the most concerned efects is to increase liquor yield.Acid protease can hydrolyze the protein in cereals to produce free amino acids that can be used directly by yeast,thus reducing the amount of sugar consumed for amino acid metabolism,and allowing more sugar to be converted to ethanol.The application method and efect of acid protease in the industrial production of ethanol from corn were studied in this study,the results showed that the addition of acid protease at the dosage of 10 U/g(raw material)during yeast seeding could replace urea,promote yeast proliferation,reduce the infection rate,shorten the fermentation period by 7.5 h and increase the alcohol yield of raw materials by 0.33 percentage point.When acid protease was used in ethanol production line with an annual output of 180,000 tons,the net proft increased by at least US$4900/day compared with the control process.It is hoped that this study can lay a foundation for the application of acid protease in ethanol industry.

Industrialization progress of lignocellulosic ethanol

Lignocellulose is an abundant and renewable biomass that is mainly composed of cellulose,hemicellulose and lignin.The development and utilization of lignocellulosic ethanol is an efective way to solve the energy problem/crises,In addition,lignocellulosic ethanol industry can play a signifcant role in controlling environmental pollution and extending agricultural industrial chain;however,it has not been able to realize large-scale industrialization due to the limitation of both biotechnology and economy.This review frst introduces industrialization status of lignocellulosic ethanol,and then focuses on the progress of practical technology and analyzing the economic feasibility of the second-generation bioethanol plant;fnally,the future development trend of the industry was prospected.To summarize,continuous technological innovation is needed in vital steps such as pretreatment,enzymatic hydrolysis,and fermentation.Meanwhile,for making the cellulosic ethanol industry truly economically competitive,we also need to achieve interdisciplinary,cross-domain integration innovation,such as the construction of raw material collection and storage system,in situ producing special enzyme system,high-value utilization of raw material components,developing a closely integration of biomass refnery with mature equipment and overall industrialization programs,etc.It is hoped that this review can provide a useful reference for the industrialization of second-generation bioethanol.