Microwave-Assisted Confining Growth and Liquid Exfoliation of sp^(3)-Hybrid Carbon Nitride Nano/Micro-Crystals

As one promising carbon-based material,sp^(3)-hybrid carbon nitride has been predicted with various novel physicochemical properties.However,the synthesis of sp^(3)-hybrid carbon nitride is still limited by the nanaoscale,low crystallinity,complex source,and expensive instruments.Herein,we have presented a facile approach to the sp^(3)-hybrid carbon nitride nano/micro-crystals with microwave-assisted confining growth and liquid exfoliation.Actually,the carbon nitride nano/micro-crystals can spontaneously emerge and grow in the microwave-assisted polymerization of citric acid and urea,and the liquid exfoliation can break the bulk disorder polymer to retrieve the highly crystalline carbon nitride nano/micro-crystals.The obtained carbon nitride nano/micro-crystals present superior blue light absorption strength and surprising photoluminescence quantum yields of 57.96% in ethanol and 18.05%in solid state.The experimental characterizations and density functional theory calculations reveal that the interface-trapped localized exciton may contribute to the excellent intrinsic light emission capability of carbon nitride nano/micro-crystals and the interparticle staggered stacking will prevent the aggregation-caused-quenching partially.Finally,the carbon nitride nano/micro-crystals are demonstrated to be potentially useful as the phosphor medium in light-emitting-diode for interrupting blue light-induced eye damage.This work paves new light on the synthesis strategy of sp^(3)-hybrid carbon nitride materials and thus may push forward the development of multiple carbon nitride research.

The Mars orbiter magnetometer of Tianwen-1:in-flight performance and first science results

The Mars Orbiter MAGnetometer(MOMAG)is a scientific instrument onboard the orbiter of China’s first mission for Mars—Tianwen-1.Since November 13,2021,it has been recording magnetic field data from the solar wind to the magnetic pile-up region surrounding Mars.Here we present its in-flight performance and first science results,based on its first one and one-half months’data.Comparing these early MOMAG observations to the magnetic field data in the solar wind from NASA’s Mars Atmosphere and Volatile EvolutioN(MAVEN)mission,we report that the MOMAG magnetic field data are at the same level in magnitude,and describe the same magnetic structures with similar variations in three components.We recognize 158 clear bow shock(BS)crossings in these MOMAG data;their locations match well statistically with the modeled average BS.We also identify and compare five pairs of datasets collected when Tianwen-1’s orbiter and the MAVEN probe made simultaneous BS crossings.These BS crossings confirm the global shape of modeled BS,as well as the south-north asymmetry of the Martian BS.Two cases presented in this paper suggest that the BS is probably more dynamic at flank than near the nose.So far,MOMAG performs well,and provides accurate magnetic field vectors.MOMAG is continuously scanning the magnetic field surrounding Mars.Data from MOMAG’s measurements complement data from MAVEN and will undoubt edly advance our understanding of the plasma environment of Mars.

“天问一号”火星磁强计伸杆机构

3 m多长的伸杆机构是天问一号火星磁强计的一个重要组成部分,用于将磁通门磁强计探头伸离卫星本体以减小卫星对磁场测量的影响。火星磁强计伸杆机构是一种多关节、铰链转轴驱动的一次性展开机构。在设计时充分考虑到了其功能性、可靠性和系统约束要求等因素。力学分析和地面验证试验表明火星磁强计伸杆机构足以承受最坏情况下的在轨环境。在经历了漫长的地火转移旅程后,火星磁强计伸杆机构于2021年5月25日成功展开。展开过程耗时约4.6 s,两个探头被送至远离环绕器本体位置,其中外侧探头距离环绕器3.19 m,内侧探头距离环绕器2.29 m。展开到位后,外侧探头处所测得的磁场大小由1250 nT减弱至不到6 nT。火星磁强计伸杆机构为后续探测任务中需在低温环境下长期贮存的空间展开机构的研制提供了宝贵的工程经验。

Mars Orbiter magnetometer of China’s First Mars Mission Tianwen-1

As one of the seven scientific payloads on board the Tianwen-1 orbiter,the Mars Orbiter Magnetometer(MOMAG)will measure the magnetic fields of and surrounding Mars to study its space environment and the interaction with the solar wind.The instrument consists of two identical triaxial fluxgate magnetometer sensors,mounted on a 3.19 meter-long boom with a seperation of about 90 cm.The dual-magnetometers configuration will help eliminate the magnetic field interference generated by the spacecraft platform and payloads.The sensors are controlled by an electric box mounted inside the orbiter.Each magnetometer measures the ambient vector magnetic field over a wide dynamic range(to 10,000 nT per axis)with a resolution of 1.19 pT.Both magnetometers sample the ambient magnetic field at an intrinsic frequency of 128 Hz,but will operate in a model with alternating frequency between 1 and 32 Hz to meet telemetry allocations.

A statistical study of the likelihood of a super geomagnetic storm occurring in a mild solar cycle

The activities of geomagnetic storms are generally controlled by solar activities. The current solar cycle(SC) 24 is found to be mild; compared to SCs 19–23, the storm occurrence and size derived by averaging the occurrence number and D_(st) around the solar maximum are reduced by about 50–82% and 36–61%, respectively. We estimate separately, for SC 19 to 24, the repeat intervals between geomagnetic storms of specific D_(st), based on fits of power-law and log-normal distributions to the storm data for each SC. Repeat intervals between super geomagnetic storms with D_(st)≤–250 nT are found to be 0.36–2.95 year(s) for SCs 19–23, but about 20 years based on the data for SC 24. We also estimate the repeat intervals between coronal mass ejections(CMEs) of specific speed(V_(CME)) since CMEs are known to be the main drivers of intense storms and the related statistics may provide information about the potential occurrence of super geomagnetic storms from the location of the Sun. Our analysis finds that a CME with V_(CME)≥1860 km/s may occur once per 3 and 5 months in SC 23 and 24, respectively. Based on a V_(CME)-D_(st) relationship, such a fast CME may cause a storm with D_(st)=–250 nT if arriving at the Earth. By comparing the observed geomagnetic storms to storms expected to be caused by CMEs, we derive the probability of CME caused storms, which is dependent on V_(CME). For a CME faster than 1860 km/s, the probability of a CME caused storm with D_(st)≤–250 nT is about 1/5 for SC 23 or 1/25 for SC 24. All of the above results suggest that the likelihood of the occurrence of super geomagnetic storms is significantly reduced in a mild SC.

肛管直肠黑色素瘤10例临床分析并文献复习

目的探讨肛管直肠恶性黑色素瘤(ARMM)的临床病理特征及诊治方法。方法回顾性分析苏州大学附属第一医院2011~2021年间收治的ARMM10例并结合文献复习,对其临床资料、病理特点、治疗结果和预后情况进行探讨并总结诊治经验。结果10例ARMM患者中,男性4例,女性6例;年龄50~79岁,平均发病年龄(61.4±7.6)岁。患者临床表现多样,但以便血为主,缺乏特异性,所有患者术前行CEA,CA19-9定量检测结果均正常;10例患者中,9例行免疫组化染色,其中主要指标有S-100、HBM、MelanA、Ki-67,9例患者S-100均为阳性;HBM8例阳性;MelanA除4例未查外,4例阳性,1例阴性。9例患者Ki-67均为阳性,其中5例阳性区>50%。6例接受腹会阴联合肿瘤切除术(Miles术),4例接受经肛门直肠肿物切除术;5例术后接受综合治疗,1例术后因泌尿系转移行尿道切除术,4例术后未行辅助治疗。患者总体生存期5.5个月~108个月,平均生存(30.6±29.5)个月,中位生存期28.0个月。结论ARMM是一种临床上罕见且恶性程度极高的恶性肿瘤,临床表现不典型,主要通过病理活检来确诊,对于确诊患者行腹会阴联合切除是主要的手术方式,术后可以辅助放化疗和免疫治疗。

Sensitive humidity sensor based on moisture-driven energy generation

The emergence of novel self-powered humidity sensors has attracted considerable attention in the fields of smart electronic devices and personal healthcare.Herein,self-powered humidity sensors have been fabricated using a moisture-driven energy generation(MEG)device based on asymmetric tubular graphitic carbon nitride(g-CN)films prepared on anodized aluminum(AAO)template.At a relative humidity(RH)of 96%,the MEG device can provide an open-circuit voltage of 0.47 V and a short-circuit current of 3.51μA,with a maximum output power of 0.08μW.With inherent self-powered ability and humidity response via current variation,an extraordinary response of 1.78×106%(41%-96%RH)can be gained from the MEG device.The possible power generation mechanism is that g-CN/AAO heterostructure can form ion gradient and diffusion under the action of moisture to convert chemical potential into electrical potential,evoking a connaturally sensitive response to humidity.Self-powered respiration monitoring device based on the sensor is designed to monitor human movement(sitting,warming up,and running)and sleep status(normal,snoring,and apnea),maintaining excellent stability during cumulative 12-h respiration monitoring.This self-powered humidity sensing technology has promising potential for extensive integration into smart electronic and round-the-clock health monitoring devices.

Near-infrared chemiluminescent carbon nanogels for oncology imaging and therapy

Carbon nanogels(CNGs)with dual ability of reactive oxygen species(ROS)imaging and photodynamic therapy have been designed with selfassembled chemiluminescent carbonized polymer dots(CPDs).With efficient deep-red/near-infrared chemiluminescence(CL)emission and distinctive photodynamic capacity,the H2O2-driven chemiluminescent CNGs are further designed by assembling the polymeric conjugate and CL donors,enabling an in vitro and in vivo ROS bioimaging capability in animal inflammation models and a high-performance therapy for xenograft tumors.Mechanistically,ROS generated in inflammatory sites or tumor microenvironment can trigger the chemically initiated electron exchange luminescence in the chemical reaction of peroxalate and H2O2,enabling in vivo CL imaging.Meanwhile,part of the excited-state electrons will transfer to the ambient H2O or dissolved oxygen and in turn lead to the type I and type II photochemical ROS production of hydroxyl radicals or singlet oxygen,endowing the apoptosis of tumor cells and thus enabling cancer therapy.These results open up a new avenue for the design of multifunctional nanomaterials for bioimaging and antienoplastic agents.