Monitoring discharge from deep-sea mining ships via optical satellite observations

Deep-sea mining may disturb the water column environment,including the surface water and deep-sea,and these disturbances should be carefully treated.Remote sensing provides high-resolution and accurate long-term observations in the area around deep-sea mining.Discharge from mining ships can be identified within few days from satellite observations based on changes in reflectance.A pioneer twomonth experimental deep-sea mining cruise was conducted by The Metal Company in the eastern Pacific Ocean from September 15 to November 17,2022.A report from Greenpeace indicated incidents of surface discharge and leakage during this mining experiment.In this study,satellite observations captured a clear signal over the surface water from September 24 to October 28,indicating the location with discharged water from the mothership.The number of pixels where the potential discharged water was identified in the satellite imagery ranged from 4 to 13.The discharged water was transported by the combined effects of wind and currents,locating continuously to the downwind side of the mothership's mooring location.Remote sensing provides a timely and accurate monitoring system for tracking water discharge during deep-sea mining.

A new thermomechanical coupled FDEM model for geomaterials considering continuum-discontinuum transitions

A new thermomechanical(TM)coupled finite-discrete element method(FDEM)model,incorporating heat conduction,thermal cracking,and contact heat transfer,has been proposed for both continuous and discontinuous geomaterials.This model incorporates a heat conduction model that can accurately calculate the thermal field in continuousediscontinuous transition processes within a finite element framework.A modified contact heat transfer model is also included,which accounts for the entire contact area of discrete bodies.To align with the finite strain theory utilized in the FDEM mechanics module,the TM coupling module in the model is based on the multiplicative decomposition of the deformation gradient.The proposed model has been applied to various scenarios,including heat conduction in both continuous and discontinuous media during transient states,thermal-induced strain and stress,and thermal cracking conditions.The thermal field calculation model and the TM coupling model have been validated by comparing the numerical results with experiment findings and analytical solutions.These numerical cases demonstrate the reliability of the proposed model convincingly,making it suitable for use across a wide range of continuous and discontinuous media.

A likely paleo-autotetraploidization event shaped the high conservation of Nyssaceae genome

Scientific knowledge about the ancestral genome of core eudicot plant kingdom can potentially have profound impacts on both basic and applied research,including evolution,genetics,genomics,ecology,agriculture,forestry,and global climate.To investigate which plant conserves best the core eudicots common ancestor genome,we compared Arcto-Tertiary relict Nyssaceae and 30 other eudicot plant families.The genomes of Davidia involucrata(a known living fossil),Camptotheca acuminata and Nyssa sinensis,one per existent genus of Nyssaceae,were performed comparative genomic analysis.We found that Nyssaceae originated from a single Nyssaceae common tetraploidization event(NCT)-autotetraploidization 28-31 Mya after the core eudicot common hexaploidization(ECH).We identified Nyssaceae orthologous and paralogous genes,determined its chromosomal evolutionary trajectory,and reconstructed the Nyssaceae most recent ancestor genome.D.involucrata genome contained the entire seven paleochromosomes and 17 ECH-generated eudicot common ancestor chromosomes and was the slowest in mutation among the analyzed 42 species of 31 plant families.Combing both its high retention of paleochromosomes and its low mutation rate,D.involucrata provides the best case in conservation of the core eudicot paleogenome.

高效液相色谱法检测发酵液中四氢嘧啶及羟基四氢嘧啶

为实现发酵液样品中四氢嘧啶和羟基四氢嘧啶的分离检测,使用高效液相色谱(HPLC)技术建立一种测定中度嗜盐菌发酵液中四氢嘧啶及羟基四氢嘧啶含量的方法。使用乙醇抽提法提取样品,采用Vertex^(TM) NH_(2)(4.6×250 mm,5μm)液相色谱柱对中度嗜盐菌发酵液中四氢嘧啶及四氢嘧啶进行了分析,选用紫外(UV)检测器,对比不同检测条件。通过色谱条件优化,选定了70%乙腈作为流动相,柱温30℃,检测波长210 nm,流速0.8 mL/min。发酵液样品中四氢嘧啶和羟基四氢嘧啶在各自范围内线性关系良好,两种样品的平均回收率在99.2%~102%,精密度偏差在1%~2%范围内,检出限为1.5μg/mL,定量限为5μg/mL,分离度为1.70。该方法检测范围大,具有较好的重复性、分离度及稳定性,适用于发酵液中四氢嘧啶及羟基四氢嘧啶的分离检测。

城市公园夜光跑道方案设计及应用研究

结合实体工程,进行了公园夜光跑道图案设计及实体工程应用研究。通过调研分析,设计了以蓝黄颜色区分的快慢跑、以自然、宇宙以及音乐等要素为主要图案的跑道,制定了夜光涂料组合方案,分析了夜光填料用量对余辉效果的影响,确定了最佳夜光粉掺量为238%。通过实体工程实施,证明其效果良好,为公园景观道路的设计提供了参考。

A likely autotetraploidization event shaped the Chinese mahogany(Toona sinensis)genome

Chinese mahogany(Toona sinensis) is of considerable medical and economic importance, and its genome has been deciphered. However, the process underlying its polyploidy is unclear, and the chromosomal evolutionary trajectory is poorly understood. Here, by reanalysing the T.sinensis genome, we found evidence of a tetraploidization event(T. sinensis special tetraploidization, TST) that occurred approximately 15-17 million years ago(MYA) after the core eudicot-common hexaploidization(ECH or gamma) event. We characterized the synonymous nucleotide substitution rates(Ks values) of collinear genes and found that T. sinensis genes affected by the TST evolve at a slower rate than Acer yangbiense genes. Furthermore, we identified homologous genes related to polyploidization and speciation and constructed multiple alignments with different reference genomes. Notably, the significant balance of gene retention and loss characterized in the two TST-derived subgenomes suggests an autopolyploid nature of the TST. Moreover, we deduced the chromosomal karyotypes of the two subgenomes and identified 7chromosomal fusions that have shaped the T. sinensis genome;more information is available on a newly constructed karyotype platform(http://www.cgrpoee.top/Toona_sinensis/index.html). The T. sinensis genome preserves the ancestral chromosome structure of dicotyledons well and could serve as a good reference for understanding genomic changes in other Meliaceae and Sapindales plants. In addition, we verified that tandem duplication and the ECH have promoted the expansion of terpene synthase(TPS) genes;conversely, the TST seems to have inhibited expansion of these genes. This present effort has clarified the polyploidy events of the T. sinensis genome, filled gaps in the history of karyotype evolution, and laid a solid foundation for further genomic studies in the Meliaceae research community and beyond.

Analysis of the Role of General Practitioners Services in Rural Areas during the COVID-19 Epidemic

Since the outbreak of the COVID-19,various regions of China have been rapidly deployed under the leadership of the Central Committee of the Party to actively prevent and control the COVID-19.The rural areas of my country have weak links to the prevention and management of public health emergencies.Problems include lack of medical and health resources and farmers’low awareness of epidemic prevention.Situations that correspond to the prevention and management of the COVID-19 are more serious.As the patient’s first contact and“gatekeeper”in the fight against the epidemic,the general practitioner is responsible for the“first visit-subsequent ongoing intervention”.This article is about the prevention and control of the COVID-19 epidemics and epidemic prevention in terms of dissemination of knowledge,informed crowd control,joint prevention and control,and standardized management of people.This is a summary of the efforts of general practitioners.Quarantine at home,interactive referrals to medical consortiums,special care for contracted families.The function during the management period aims to analyze the role played by general practitioners during the epidemic and to provide new ideas for the prevention and management of the epidemic.Provide more targeted general practitioner-style services in rural areas to promote the implementation and improvement of health and poverty alleviation.The health level of the rural population provides a theoretical standard.

Bedding plane-embedded augmented virtual internal bonds for fracture propagation simulation in shale

To effectively simulate the fracture propagation in shale,the bedding plane(BP)effect is incorporated into the augmented virtual internal bond(AVIB)constitutive relation through BP tensor.Comparing the BP-embedded AVIB with the theory of transverse isotropy,it is found the approach can represent the anisotropic properties induced by parallel BPs.Through the simulation example,it is found that this method can simulate the stiffness anisotropy of shale and can represent the effect of BPs on hydraulic fracture propagation direction.Compared with the BP-embedded virtual internal bond(VIB),this method can account for the various Poisson’s ratio.It provides a feasible approach to simulate the fracture propagation in shale.

Research progress on integrated solar chimney system for freshwater production

Under dual crisis of energy and freshwater,solar chimney technology has been widely applied in freshwater production in recent years.According to different access to freshwater,the research progress of the coupling of solar chimney with other technologies such as solar desalination technology,humidification and humidification desalination technology,as well as integrated systems that obtain freshwater output from ambient air were summarized respectively.The integrated solar chimney system can realize multi-target production of electricity and freshwater,and improve the comprehensive utilization of solar energy,which provides new possibility for the site selection and small-scale construction of solar chimney power plant in the future.It has certain practical significance and is conducive to the promotion and application of solar chimney technology.

Unlocking the potential of amorphous calcium carbonate: A star ascending in the realm of biomedical application

Calcium-based biomaterials have been intensively studied in the field of drug delivery owing to their excellent biocompatibility and biodegradability.Calcium-based materials can also deliver contrast agents,which can enhance real-time imaging and exert a Ca^(2+)-interfering therapeutic effect.Based on these characteristics,amorphous calcium carbonate(ACC),as a brunch of calcium-based biomaterials,has the potential to become a widely used biomaterial.Highly functional ACC can be either discovered in natural organisms or obtained by chemical synthesis However,the standalone presence of ACC is unstable in vivo.Additives are required to be used as stabilizers or core-shell structures formed by permeable layers or lipids with modified molecules constructed to maintain the stability of ACC until the ACC carrier reaches its destination.ACC has high chemical instability and can produce biocompatible products when exposed to an acidic condition in vivo,such as Ca^(2+) with an immune-regulating ability and CO_(2) with an imaging-enhancing ability.Owing to these characteristics,ACC has been studied for selfsacrificing templates of carrier construction,targeted delivery of oncology drugs,immunomodulation,tumor imaging,tissue engineering,and calcium supplementation.Emphasis in this paper has been placed on the origin,structural features,and multiple applications of ACC.Meanwhile,ACC faces many challenges in clinical translation,and long-term basic research is required to overcome these challenges.We hope that this study will contribute to future innovative research on ACC.

Significant enhancement in local thermal conductivity of erythritol at interface with nanoparticles due to their interaction

When nano-fillers are used to enhance the thermal conductivity of organic phase change materials(PCMs),the naturally formed interface is considered to hinder thermal transport of the composite PCMs.However,the effect of the interface on the thermal properties of surrounding PCM has not been fully studied.In this paper,three composite PCMs(Ery@SiC,Ery@SiO_(2) and Ery@Si_(3)N_(4))were prepared by melt-blending method.The local thermal conductivity and reduced Young’s modulus(E^(*))of the erythritol at the interface and far away from the interface in the composite PCMs were simultaneously measured by scanning thermal microscopy(SThM).The results revealed significant enhancement in local thermal conductivity of erythritol at the interface and its obvious positive correlation with E^(*).For different composite PCMs,molecular dynamics(MD)simulations suggested that the increase in intrinsic thermal conductivity and E^(*)of erythritol is attributed to the increase in interaction energy between erythritol and nanoparticles,as more erythritol phonon vibrations transform from localized mode to delocalized mode and erythritol has a higher density at the interface.These findings will provide new ideas for the design of PCM for energy storage.

Simple and versatile in situ thermo-sensitive hydrogel for rectal administration of SZ-A to alleviate inflammation and repair mucosal barrier in ulcerative colitis

Ulcerative colitis(UC)is a chronic inflammatory bowel disease characterized by persistent inflammation of the colon and disrupted intestinal function.Ramulus mori(Sangzhi)alkaloids(SZ-A),derived from twigs of mulberry,were approved by the National Medical Products Administration in 2020 for treating type 2 diabetes mellitus.Accumulated evidence has confirmed that SZ-A also alleviates non-alcoholic fatty liver disease and ameliorates inflammation,indicating its potential to address inflammation in UC.However,the treatment of UC faces challenges due to low drug delivery efficiency and short retention time.To overcome these challenges,an injectable and adherent in-situ thermo-sensitive hydrogel containing SZ-A was developed for rectal drug delivery,utilizing the thermo-sensitive polymers Poloxamer 407and 188.The thermo-sensitive hydrogel system was designed with a moderate gelation temperature of 32±0.5℃,a short gelation time of 64 s,a p H range of 7-10,high moisturizing capability exceeding 90%,and moderate mechanical strength of 4-5 s.In a rat model with UC,the in situ thermo-sensitive hydrogel significantly extended the retention time at the colonic site and enabled sustained release after rectal administration.Symptoms of UC were markedly reduced following rectal administration of SZ-A thermosensitive hydrogel.Furthermore,the release of inflammatory factors,such as interleukin-1β(IL-1β),IL-6,IL-18,tumor necrosis factor-α(TNF-α),and transforming growth factor-β1(TGF-β1),significantly decreased in the SZ-A thermo-sensitive hydrogel group.The integrity of the colonic mucosal barrier was significantly enhanced following the application of SZ-A thermo-sensitive hydrogel.In conclusion,rectal administration of SZ-A in situ thermo-sensitive hydrogel effectively alleviated UC symptoms,inhibited the secretion of inflammatory factors,and promoted the repair of the colonic mucosal barrier.This approach holds promise as a potential treatment for UC.

In-situ embedded ultrafine Bi_(12)O_(17)Br_(2)nanotubes in MOF-derived hierarchical porous carbon for enhanced photocatalytic CO_(2)conversion to CO

Increasing the utilization efficiency of photogenerated electrons is highly recognized as one of the ef-ficient approaches to boost the photocatalytic CO_(2)conversion efficiency.Herein,ZIF-67-derived porous carbon(PC)material was employed for the construction of PC@ultrafine Bi_(12)O_(17)Br_(2)nanotubes(PC@BOB NTs)composites through a facile solvothermal synthesis in order to optimize the use of excited elec-trons in the BOB NTs.Photoelectrochemical characterization results revealed that the introduction of PC material achieved a faster charge separation rate in the PC@BOB composites,ensuring more photogener-ated electrons participate in the CO_(2)adsorption and activation process.Moreover,the pore structures of ZIF-67-derived PC material provided abundant confined spaces for the enrichment of CO_(2)molecules.Af-ter 5 h of Xenon lamp irradiation,PC@BOB composites exhibited obviously increased photocatalytic CO_(2)reduction activity in the pure water.When the addition amount of PC was 5 wt%,the PC@BOB-2 com-posite showed the highest CO evolution rate of 359.70μmol/g,which was 2.95 times higher than that of the pure BOB NTs.This work provides some independent insights into the applications of Metal-Organic Framework(MOF)-derived hierarchical porous structures to strengthen the CO_(2)enrichment,as well as the excited charge utilization efficiency,thus achieving a high solar-to-fuel conversion efficiency.

Strategies and opportunities of micro/nano delivery systems for targeted therapy of ulcerative colitis:Focus on underlying mechanisms and future perspectives

Ulcerative colitis(UC)is a common progressive inflammatory disease whose incidence has increased rapidly in recent years,and can develop into colorectal cancer in severe cases.There are currently no adequate or effective treatments for UC due to the fact that some patients have found suboptimal results after repeated administration,while others have experienced adverse effects.With the rapid development of nanotechnology,developing innovative colon-targeting platforms is essential to improving efficacy,reducing side effects,and improving patient compliance.In this review,we summarize the pathophysiological characteristics of UC and the most recent status of numerous nanodrug delivery systems based on different targeting mechanisms in treating UC.Oral,intravenous,and rectal drug delivery nanoparticles targeting the colon are discussed,which can provide ideas for the design of colon-targeting nanoparticles for the treatment of colon diseases,especially for the treatment of UC.Last but not least,we provide a glimpse into the future of colon-targeted delivery systems,as well as future advancements in the field.

Large piezoelectric response in a family of metal-free perovskite ferroelectric compounds from first-principles calculations

Metal-free organic perovskite ferroelectric materials have been shown recently to have a number of attractive properties,including high spontaneous polarization and piezoelectric coefficients.In particular,slow evaporation of solutions containing organic amines,inorganic ammoniums,and dilute hydrohalogen acid has been shown to produce several attractive materials in the MDABCO-NH_(4)-I_(3) family(MDABCO is N-methyl-N’-diazabicyclo[2,2,2]octonium).In the present work,we study by first-principles calculations the origin of polarizaiton,electronic density of state,piezoelectric response,and elastic properties of MDABCO-NH_(4)-X_(3)(X=Cl,Br,I).We find that the dipole moments of the MDABCO and NH_(4) groups are negligible,and the large spontaneous polarization of MDABCONH_(4)-I_(3) mainly results from MDABCO and NH_(4) being off-center relative to I ions.Although the piezoelectric response of organic materials is usually very weak,we observe large piezoelectric strain components,d_(x4) and d_(x5);the calculated d_(x5) is 119 pC/N for MDABCO-NH_(4)-Cl_(3),248 pC/N for MDABCO-NH_(4)-Br_(3) and 178 pC/N for MDABCO-NH_(4)-I_(3).The large value of dx5 is found to be closely related with the large value of elastic compliance tensor,s44.These results show that MDABCO-NH_(4)-X_(3) metal-free organic perovskites have large piezoelectric response with soft elastic properties.

Noise canceled graphene-microcavity fiber laser sensor for ultrasensitive gas detection

Optical microcavities offer a promising platform for highly efficient light–matter interactions.Recently,the combination of microresonators and 2D materials in the nanoscale has further enriched the optoelectronics of microcavity geometries,spurring broad advances including lasers,nonlinear converters,modulators,and sensors.Here,we report the concept of compact dual-laser cogeneration in a graphene-microcavity fiber,which offers a way to cancel the optical common mode noises.Driven by a single 980 nm pump,orthogonally polarized laser lines are generated in a pair of degeneracy breaking modes.The two laser lines produce a heterodyne beat note at 118.96 MHz,with frequency noise down to 200 Hz~2∕Hz at 1 MHz offset,demonstrating a linewidth of 930 Hz in vacuum.This compact device enables on-line and label-free NH_(3) gas detection with high resolution,realizing a detection limit on a single pmol/L level,and a capability to quantitatively trace gas–graphene interactions.Such a combination of graphene optoelectronics and microcavity photonics demonstrates a novel physical paradigm for microlaser control and offers a new scheme for in situ chemical sensing.

全球城市热辐射方向性制图揭示了城市气候遥感的潜在偏差

城市热辐射方向性限制了遥感地表温度反演精度,阻碍了对全球城市气候(如城市地表能量通量估算和城市热环境评估)的准确理解.然而,全球不同气候背景城市热辐射方向性时空特征及其造成的城市地表能量通量和热岛强度遥感估算偏差仍不清楚,在全球尺度是否存在与城市热辐射方向性密切相关且易获取的地表和气候参量尚不明晰.本研究结合多角度卫星观测地表温度和遥感云平台,分析了全球5500多个城市的热辐射方向性特征,量化了其造成的全球城市地表能量通量和热岛强度遥感估算偏差,厘清了全球尺度城市热辐射方向性与关键地表和气候参量的关系.研究发现全球城市平均热辐射方向性强度在夏季白天下午高达5.4 K.在极端情况下,当地表温度观测天顶角位于±60°时,热辐射方向性使得全球城市地表显热通量和热岛强度分别低估45.4%和43.0%.研究进一步发现全球城市热辐射方向性与地表不透水面百分比和空气温度具有良好的统计关系,这为卫星遥感城市地表温度角度纠正提供了新思路.

Generalized assembly of sandwich-like 0D/2D/0D heterostructures with highly exposed surfaces toward superior electrochemical performances

Heterostructures composed of two-dimensional(2D)nanosheets and zero-dimensional(0D)nanoparticles(NPs)have attracted increasing attention because of the synergy arising from the coupling interactions between the two mixed-dimensional components.Despite recent advances,it remains a challenge to fabricate 2D/0D heterostructures with clean and accessible surfaces,which is highly desirable for the diversity of catalytic,sensing,and energy storage applications.Herein,we report a generalized methodology that enables the facile assembly of sandwich-like 0D/2D/0D heterostructures with facilitated mass-transport channels and exposed surface active sites.A ligand-exchange strategy with HBF4 is employed to strip off the surface-coating ligands of colloidal NPs,rendering them positively charged and dispersible in polar solvents.This allows subsequent electrostatic assembly of NPs with oppositely charged 2D nanosheets to afford sandwich-like 0D/2D/0D heterostructures.The barely covered surfaces and the advantageous architectures of such sandwich-like 0D/2D/0D heterostructures induce the desired synergistic effect,making them particularly suitable for electrochemical energy storage and conversion.We demonstrate this by employing MXene/NiFe_(2)O_(4) and MXene/Fe3O4 heterostructures for high-performance electrocatalytic oxygen evolution and supercapacitors,respectively.

Highly hydrophobic oil−water separation membrane: reutilization of waste reverse osmosis membrane

The increasing applications of seawater desalination technology have led to the wide usage of polyamide reverse osmosis membranes,resulting in a large number of wasted reverse osmosis membranes.In this work,the base nonwoven layer of the wasted reverse osmosis membrane was successfully modified into the hydrophobic membrane via surface deposition strategy including TiO_(2) and 1H,1H,2H,2H-perfluorooctyltrichlorosilane(PFOTS),respectively.Various techniques were applied to characterize the obtained membranes,which were then used to separate the oil–water system.The optimally modified membrane displayed good hydrophobicity with a contact angle of 135.2°±0.3°,and its oil–water separation performance was as high as 97.8%.After 20 recycle tests,the oil–water separation performance remained more than 96%,which was attributed to the film adhesion of the anchored TiO_(2) and PFOTS layer on the surface.This work might provide a new avenue for recycling the wasted reverse osmosis membrane used in oily wastewater purification.

3D reconstruction of human head based on consumer RGB-D sensors

Three-dimensional(3D)reconstruction of a human head with high precision has promising applications in scientific research,product design and other fields.However,it still faces resistance from two factors.One is inaccurate registration caused by symmetrical distribution of head feature points,and the other is economic burden due to highaccuracy sensors.Research on 3D reconstruction with portable consumer RGB-D sensors such as the Microsoft Kinect has been highlighted in recent years.Based on our multi-Kinect system,a precise and low-cost three-dimensional modeling method and its system implementation are introduced in this paper.A registration method for multisource point clouds is provided,which can reduce the fusion differences and reconstruct the head model accurately.In addition,a template-based texture generation algorithm is presented to generate a fine texture.The comparison and analysis of our experiments show that our method can reconstruct a head model in an acceptable time with less memory and better effect.