Rational design of new in situ reduction of Ni(II)catalytic system for low-cost and large-scale preparation of porous aromatic frameworks

Porous aromatic framework 1(PAF-1)is an extremely representative nanoporous organic framework owing to its high stability and exceptionally high surface area.Currently,the synthesis of PAF-1 is catalyzed by the Ni(COD)2/COD/bpy system,suffering from great instability and high cost.Herein,we developed an in situ reduction of the Ni(II)catalytic system to synthesize PAF-1 in low cost and high yield.The active Ni(0)species produced from the NiCl_(2)/bpy/NaI/Mg catalyst system can effectively catalyze homocoupling of tetrakis(4-bromophenyl)methane at the room temperature to form PAF-1 with high Brunauer-Emmett-Teller(BET)-specific surface area up to 4948 m^(2) g^(−1)(Langmuir surface area,6785 m2 g−1).The possible halogen exchange and dehalogenation coupling mechanisms for this new catalytic process in PAF's synthesis are discussed in detail.The efficiency and universality of this innovative catalyst system have also been demonstrated in other PAFs'synthesis.This work provides a cheap,facile,and efficient method for scalable synthesis of PAFs and explores their application for high-pressure storage of Xe and Kr.

Study on Strength Reduction Law and Meso-Crack Evolution of Lower Layered Cemented Tailings Backfill

The green disposal of tailings solid waste is a problem to be solved in mine production.Cemented tailings filling stoping method can realize the dual goals of solid waste resource utilization and mined-out area reduction.However,the volume of the mined-out area of the open-pit method is larger than the filling capacity,resulting in the complex stratification of the underground backfill,and the strength of the backfill cannot meet the requirements.In this paper,according to the delamination situation,the specimens of horizontal and inclination angle layered cemented tailings backfill(LCTB)is made for a uniaxial compression test,and the failure process of delamination backfill is reduced by PFC.The results show that the corresponding reduction factorφof horizontal LCTB is 0.560–0.932,and the correspondingφvalue of inclination angle LCTB is 0.338–0.772.The failure mode of backfill in different layers is mainly manifested as a tensile failure.The PFC numerical simulation results are consistent with laboratory test results,which verifies the correctness of backfill failure.The research results provide a reliable theoretical basis for the strength design of backfill in goaf,which is of great significance for solid waste utilization and environmental protection.

铂纳米粒子与氧化铁载体协同作用促进芳香硝基化合物温和条件下选择加氢（英文）

负载型Pt基催化剂是一类重要的工业催化剂,在很多还原和氧化反应中都表现出很高的催化活性,但高昂的价格一直制约着Pt基催化剂的大规模应用.另外, Pt活性位点对有机化合物不同基团的区分性差,通常造成目的产物的选择性较低.以人们熟知的芳香硝基化合物加氢为例,当有其它易还原基团如C=C、C=O、–X等存在时,在硝基加氢的同时,这些基团也不同程度地被还原.在已报道的工作中,通过合理设计Pt活性中心结构、改善Pt周围环境以及在反应中添加无机盐或有机化合物等方法,芳香硝基化合物加氢的选择性获得大幅提升,但催化剂活性对Pt负载量的依赖性仍然很高,降低催化剂中的Pt活性位数量会显著降低催化剂活性.此外, Pt纳米粒子在反应过程中的聚集以及氧化物载体在强还原气氛下的性能变化等对催化剂的稳定性产生很大影响.本文工作中我们尝试发挥载体在反应中的作用,实现氢解离和反应物加氢活性中心在空间上分离,从而降低Pt的负载量.工作思路主要是基于氢溢流的基本原理,其难点在于高效氢解离活性中心的设计和载体的选择,后者需满足活泼氢物种的输运和硝基基团的有效吸附.为了实现上述目标,本文采用胶体法制备了3–4 nm的Pt粒子,该方法可以有效地控制Pt纳米粒子的尺寸以及在载体上的分散状态,从而形成大量的Pt0活性位,实现高效氢解离.在充分考虑载体的氧化还原性和表面碱性质(给电子能力)的基础上,我们筛选了多种氧化物作为载体.反应结果显示, Pt/α-Fe_2O_3在Pt负载量仅为0.2 wt%时即表现出很高的芳香硝基化合物加氢催化活性和选择性,并且该反应可在相当温和的条件(30°C, 5 barH_2)下进行.在经过多次循环反应后, Pt纳米粒子的尺寸、分散状态以及α-Fe_2O_3载体的物相等均未发生变化,催化剂表现出很高的稳定性.Pt纳米粒子的高效氢解离能力是催化剂实现高活性的重要因素之一,而α-Fe_2O_3的表面性质也同样发挥了重要作用,其表面一定数量的氧空位具有较强的给电子能力,可以与具有较强吸电子能力的硝基基团作用,实现反应物的高效吸附;载体表面适当的氧化还原性有利于活泼氢的输运,在与Pt纳米粒子的协同作用下实现了温和条件下芳香硝基化合物的选择性加氢.本工作显著降低了Pt的使用量,实现了非常温和条件下的稳定、高效加氢,可为低成本Pt基催化剂的设计提供借鉴.

镁铝酸碱双功能氧化物催化剂上醇胺氧化耦合合成亚胺性能（英文）

亚胺是一类重要的含氮有机化合物,由于具有不饱和C=N双键,可以作为一种有效的氮源,用于一系列含氮衍生物的合成.目前合成亚胺的工艺路线主要是通过羰基化合物和一级胺在强酸条件下缩合;与该路线相比,醇和胺在空气或氧气存在条件下耦合是一条更为绿色的工艺路线,其副产物只有水产生.目前的报道表明,一些具有氧化还原性质的催化剂,如负载型贵金属催化剂和负载型过渡金属氧化物催化剂在该反应中表现出一定催化性能,但很少关注表面酸碱性质对该反应性能的影响.在本工作中,我们尝试将具有酸碱双功能性质的Mg-Al复合氧化物作为催化剂用于该反应中,考察了Mg/Al比、焙烧温度和后处理条件对催化性能的影响.结果显示,Mg/Al=3的催化剂在反应中表现出最优的催化活性;NH_3-TPD和CO_2-TPD显示,随着镁含量的增加,样品表面碱性中心的数量呈现出先增加后减少的趋势,其中Mg/Al=3的样品表面酸、碱总量最大,而且该样品表面弱碱中心数量也最多;我们通过焙烧和探针分子吸附等后处理手段进一步调控了催化剂表面的酸碱性质,初步结果表明在酸碱中心的协同作用下可以有效地催化醇和胺的氧化耦合反应;其中弱碱性位可能是活化醇的主要活性中心,而醇的氧化是该反应的速控步骤,因此可以推测表面弱碱中心的数量在一定程度上决定着催化剂在该反应中的性能.

肝脏分泌因子与代谢性疾病

代谢性疾病泛指代谢功能发生问题所引起的疾病,其主要症状包括中心性肥胖、胰岛素抵抗、血脂血糖异常、血压升高等。肝脏作为人体内一个重要的代谢器官,在调节全身葡萄糖和脂质代谢等许多生理过程中起关键作用。近年来的大量研究表明,肝脏可以合成和分泌多种生物信号分子,如FGF21、Fetuin-A以及ANGPTL8等,以自分泌/旁分泌的方式调节机体的代谢过程。干预相关肝脏分泌因子的表达可有助于预防、诊断和治疗代谢性疾病。然而,目前肝脏分泌因子与代谢稳态之间的互作机制仍不明确。本文对不同肝脏分泌因子与代谢性疾病的关系展开论述,以期为治疗代谢性疾病提供新的策略和参考。

Highly dispersed metal incorporated hexagonal mesoporous silicates for catalytic cyclohexanone oxidation to adipic acid

Adipic acid is a dicarboxylic acid of great industrial importance,mainly used in the production of nylon-6,6 and polyurethane.The use of nitric acid as an oxidant in the industrial production of adipic acid poses significant carbon footprint to the environment.Clean adipic acid synthesis methods using a heterogeneous catalyst with H2O2 as oxidant and water as solvent have potential advantages of low catalyst cost,easy synthesis and recovery,cleanness and environmental protection.In this work,hexagonal mesoporous silicate materials were synthesized by a sol–gel method and evaluated for cyclohexanol/cyclohexanone oxidation to adipic acid.The physical and chemical properties of Fe-HMS were characterized by XRD,HR-TEM,BET and UV–Vis.The experimental results showed that Fe-HMS materials show pore sizes ranging from 2–3 nm.W-and Mo-based polyoxometalates were also evaluated and compared to the Fe-based HMS catalysts.To improve the adipic acid yield,the influence of the transition metal as well as the effect of metal loading,reaction temperature and catalyst amount on the catalytic performances of Fe-HMS have been investigated in details.When Si/Fe atomic ratio=100,Fe-HMS catalyst shows the highest activity,with a cyclohexanone conversion of 92.3%and adipic acid selectivity of 29.4%.The reaction pathway of cyclohexanone oxidation was further proposed based on experimental data.

On-line Chatter Detection Using an Improved Support Vector Machine

On-line chatter detection can avoid unstable cutting through monitoring the machining process.In order to identify chatter in a timely manner,an improved Support Vector Machine(SVM)is developed in this paper,based on extracted features.In the SVM model,the penalty factor(e)and the core parameter(g)have important influence on the classification,more than from Kernel Functions(KFs).Hence,first the classification results are conducted using different KFs.Then two methods are presented for exploring the best parameters.The chatter identification results show that the Genetic Algorithm(GA)approach is more suitable for deciding the parameters than the Grid Explore(GE)approach.

Evidence for pore-filling gas hydrates in the sediments through morphology observation

To provide an evidence of natural gas hydrate occurrence state,a series of experiments on multiple growth and dissociation of 90.0%methane/10.0%propane hydrates at 1.3 MPa and 270.15 K were carried out in two sediments for morphology observation via a visible jacketed-reactor.The gas hydrate crystals were observed to form and grow on the surface of sediments at the initial growth.During the thermal decomposition,gas and liquid products had an unceasingly impact on the sediments,then gas/liquid–solid migration occurred,and a large number of cavitation appeared.In the later growth and dissociation experiments,the gas hydrate particles were in suspension or supporting states in the interstitial pore space between the sediment particles,indicating that the gas hydrate displayed a pore-filling characteristics.Through analyzing the distribution of gas hydrates and bubbles,it was found that the amount of gas hydrates distributed in the sediments was improved with multiple growth-dissociation cycle proceedings.Gas migration enhanced the sediment movement,which led to the appearance of the increasing quantity of gas bubbles in the sediments during cycles.Salts affected the growth of the gas hydrates and the migration of sediment grains,which also restricted the accumulation of gas bubbles in the sediments.According to the Raman analysis,the results showed that sII hydrates were formed for CH4 and C3H8 gas mixtures in different sediments and solutions with hydration number of 5.84–6.53.The Salt restricted the access of gas into the hydrate cages.

Characterization and manipulation of the photosystem Ⅱ-semiconductor interfacial molecular interactions in solar-to-chemical energy conversion

Semi-artificial photosynthesis interfacing catalytic protein machinery with synthetic photocatalysts exhibits great potential in solar-to-chemical energy conversion. However, characterizing and manipulating the molecular integration structure at the biotic-abiotic interface remain a challenging task. Herein,the biointerface molecular integration details of photosystem II(PSII)-semiconductor hybrids, including the PSII orientation, interfacial microdomains, and overall structure modulation, are systematically interrogated by lysine reactivity profiling mass spectrometry. We demonstrate the semiconductor surface biocompatibility is essential to the PSII self-assembly with uniform orientation and electroactive structure.Highly directional localization of PSII onto more hydrophilic Ru/Sr Ti O_(3):Rh surface exhibits less disturbance on PSII structure and electron transfer chain, beneficial to the high water splitting activity.Further, rational modification of hydrophobic Ru_(2)S_(3)/Cd S surface with biocompatible protamine can improve the hybrid O_(2)-evolving activity 83.3%. Our results provide the mechanistic understanding to the structure–activity relationship of PSII-semiconductor hybrids and contribute to their rational design in the future.

Periodic Solution for Neutral Type Neural Networks

The principle aim of this paper is to explore the existence of periodic solution of neural networks model with neutral delay. Sufficient and realistic conditions are obtained by means of an abstract continuous theorem of k-set contractive operator and some analysis technique.

Impulsive Control for Synchronization of Lorenz Chaotic System

Chaotic synchronization is the key technology of secure communication. In this paper, ?an impulsive control method for chaotic synchronization of two coupled Lorenz chaotic system was proposed. The global asymptotic synchronization of two Lorenz systems was realized by using the linear error feedback of the state variables of the drive system and the response system as impulsive control signal. Based on stability theory of impulsive differential equation, conditions were obtained to guarantee the global asymptotic synchronization of two Lorenz systems. The theory analysis and computer simulation results validated its effectiveness.

风暴在长江三角洲侵蚀和沉积物向南输运中的控制作用

Densely populated coasts are vulnerable to storm damage. Episodic storm-induced redistribution of coastal sediment is known to have major geological and ecological implications [1,2], but little is known about storm-driven delta erosion and longshore sediment transport. The Yangtze (Changjiang) Delta and Zhejiang–Fujian coasts (Fig. S1 online) are among the world’s largest coastal depositional systems, and play an important role in supporting China’s socioeconomic development [3,4].

Digital identity,privacy security,and their legal safeguards in the Metaverse

The Metaverse is the digitization of the real world,supported by big data,AI,5G,cloud computing,blockchain,encryption algorithm,perception technology,digital twin,virtual engine,and other technologies that interact with human behavior and thoughts in avatars through digital identity.Cracking the trust problem brought by the avatar depends on the privacy security and authentication technology for individuals using digital identities to enter the Metaverse.To accomplish personal domination of the avatar,metaverse users need privacy data feeding and emotion projection.They must be equipped with proprietary algorithms to process and analyze the complex data generated in adaptive interactions,which challenges the privacy security of user data in the Metaverse.Distinguishing the significance of different identifiers in personal identity generation while imposing different behavioral regulatory requirements on data processing levels may better balance the relationship between personal privacy security and digital identity protection and data utilization in the Metaverse.In response to digital identity issues,there is an objective need to establish a unified digital identity authentication system to gain the general trust of society.Further,the remedies for a right to personality can be applied to the scenario of unlawful infringement of digital identity and privacy security.

Comparative analysis of temporal-spatial and time-frequency features for pattern recognition of φ-OTDR

The phase-sensitive time-domain reflectometer [φ-OTDR] has been popularly used for events detection over a long period of time.In this study,the events classification methods based on convolutional neural networks [CNNs] with different features,i.e.,the temporal-spatial features and time-frequency features,are compared and analyzed comprehensively inφ-OTDR.The developed CNNs aim at distinguishing three typical events:wind blowing,knocking,and background noise.The classification accuracy based on temporal-spatial images is higher than that based on time-frequency images[99.49% versus 98.23%).The work here sets a meaningful reference for feature extraction and application in the pattern recognition of φ-OTDR.

High-sensitivity and fast-response fiber optic temperature sensor using an anti-resonant reflecting optical waveguide mechanism

Temperature sensing is essential for human health monitoring.High-sensitivity(>1 nm∕℃)fiber sensors always require long interference paths and temperature-sensitive materials,leading to a long sensor and thus slow response(6–14 s).To date,it is still challenging for a fiber optic temperature sensor to have an ultrafast(~ms)response simultaneously with high sensitivity.Here,a side-polished single-mode/hollow/single-mode fiber(SPSHSF)structure is proposed to meet the challenge by using the length-independent sensitivity of an anti-resonant reflecting optical waveguide mechanism.With a polydimethylsiloxane filled sub-nanoliter volume cavity in the SP-SHSF,the SP-SHSF exhibits a high temperature sensitivity of 4.223 nm/℃ with a compact length of 1.6 mm,allowing an ultrafast response(16 ms)and fast recovery time(176 ms).The figure of merit(FOM),defined as the absolute ratio of sensitivity to response time,is proposed to assess the comprehensive performance of the sensor.The FOM of the proposed sensor reaches up to 263.94(nm/℃)∕s,which is more than two to three orders of magnitude higher than those of other temperature fiber optic sensors reported previously.Additionally,a threemonth cycle test shows that the sensor is highly robust,with excellent reversibility and accuracy,allowing it to be incorporated with a wearable face mask for detecting temperature changes during human breathing.The high FOM and high stability of the proposed sensing fiber structure provide an excellent opportunity to develop both ultrafast and highly sensitive fiber optic sensors for wearable respiratory monitoring and contactless in vitro detection.

基于多数据融合的circRNA–疾病关联关系预测

环状RNA(circluar RNA,circRNA)在基因表达、剪切和转录的过程中扮演着重要角色.越来越多的证据表明,circRNA与疾病的产生与发展存在着重要的联系.本文提出了一种基于多数据融合的非负矩阵分解算法(EDNMF)预测circRNA–疾病关联关系.该方法首先对circRNA–疾病关联关系进行预处理,解决了circRNA–疾病关联关系过少对算法产生的负面影响的问题.然后,EDNMF算法将circRNA表达谱和癌症相似性数据转化为约束条件,基于预处理后的circRNA–疾病关联关系采用改进的非负矩阵分解算法得到最终的打分值,从而预测circRNA–疾病关联关系.五折和十折交叉验证结果表明,EDNMF算法相比其他算法能更有效地预测circRNA–疾病关联关系.此外,采用EDNMF算法预测新的circRNA–结肠直肠癌关联关系打分排名前10的结果中,大部分结果已经得到了佐证,表明了该算法可以有效地预测未知的circRNA–疾病关联关系.

SWI/SNF染色质重塑复合物亚基Baf60a调控能量代谢稳态的研究进展

代谢综合征是一种全球性的慢性流行病,其发病机理由遗传与环境等因素共同决定。表观遗传修饰是在基因的核苷酸序列不发生改变的情况下,通过可遗传的变化调控基因表达。近年来研究发现,表观遗传修饰能够应答于环境因素、调控基因表达和信号转导进程。其中,染色质重塑复合物SWI/SNF(SWItch/Sucrose non fermentable,SWI/SNF)关键亚基Baf60a,在维持机体能量代谢稳态过程中发挥着重要作用。文中重点阐述了生理和病理状态下,Baf60a维持机体脂质代谢、胆固醇代谢、尿素循环及代谢节律性稳态的分子机制。深入探讨以Baf60a为基点的能量代谢调控网络,有望为代谢综合征的改善和治疗提供潜在药物治疗靶点和扎实的研究依据。

Molecular Cloning and Function Analysis of Two SQUAMOSA-Like MADS-Box Genes From Gossypium hirsutum L.

The MADS-box genes encode a large family of transcription factors having diverse roles in plant development. The SQUAMOSA （SQUA）/APETALA1 （AP1）/FRUITFULL （FUL） subfamily genes are essential regulators of floral transition and floral organ identity. Here we cloned two MADS-box genes, GhMADS22 and GhMADS23, belonging to the SQUA/AP1/FUL subgroup from Gossypium hirsutum L. Phylogenetic analysis and sequence alignment showed that GhMAD$22 and GhMADS23 belonged to the euFUL and euAP1 subclades, respectively. The two genes both had eight exons and seven introns from the start codon to the stop codon according to the alignment between the obtained cDNA sequence and the Gossypium raimondii L. genome sequence. Expression profile analysis showed that GhMADS22 and GhMADS23 were highly expressed in developing shoot apices, bracts, and sepals. Gibberellic acid promoted GhMADS22 and GhMADS23 expression in the shoot apex. Transgenic Arabidopsis lines overexpressing 35S：：GhMADS22 had abnormal flowers and bolted earlier than wild type under long-day conditions （16 h light/8 h dark）. Moreover, GhMADS22 over- expression delayed floral organ senescence and abscission and it could also respond to abscisic acid. In summary, GhMADS22 may have functions in promoting flowering, improving resistance and delaying senescence for cotton and thus it may be a candidate target for promoting early-maturation in cotton breeding.

LHCGR and ALMS1 defects likely cooperate in the development of polycystic ovary syndrome indicated by double-mutant mice

Polycystic ovary syndrome(PCOS)is a heterogeneous disorder with evidence of polygenetic components,and obesity may be a risk factor for hyperandrogen ism.Previous studies have shown that LHCGR is en riched in the ovary and LHCGR deficiency causes infertility without typical PCOS phenotypes.ALMS1 is implicated in obesity and hyperandrogenism,the common phenotypes among PCOS patients.Through whole-exome sequencing of 22 PCOS families and targeted candidate gene sequencing of additional 65 sporadic PCOS patients,we identified potential causative mutations in LHCGR and ALMS1 in a sibling-pair PCOS family and three sporadic PCOS patients.The expression of LHCGRL638 P in granulosa-like tumor cell line(KGN)cells promoted cyclic adenosine monophosphate production and granulosa cell proliferation,indicating that LHCGRL638 P is an activating mutation.Lhcgr~(L642 P/L642 P)mice showed an irregular estrous cycle,reduced follicles with dynamic folliculogenesis,and increased testosterone(T),estradiol(E2),and dehydroepiandrosterone.Lhcgr~(+/L642 P)AIms1~(+/PB)mice displayed increased T and E2 but decreased late secondary and preovulatory follicles.We showed that activating mutation of LHCGR likely plays important roles in the pathophysiology of PCOS involving abnormal reproductive physiology,whereas ALMS1 deficiency may promote anovulatory infertility via elevated androgens,suggesting that the disturbed LHCGR and ALMS1 cooperatively induce PCOS phenotypes,characterized as anovulation and hyperandrogenemia frequently observed in PCOS patients with obesity.

Selection and Characterization of a Novel Photoperiod-Sensitive Male Sterile Line in Upland Cotton

Upland cotton （Gossypium hirsutum L.） shows strong heterosis. However, heterosis is not widely utilized owing to the high cost of hybrid seed production. Creation of a photoperiod-sensitive genetic male sterile line could substantially reduce the cost of hybrid seed production in upland cotton. Such a mutant with virescent marker was found by space mutation in near-earth orbit and its traits had been stable after 4 years of selection in Anyang and Sanya, China. This mutant was fertile with an 11-12.5 h photoperiod when the temperature was higher than 21.5 ℃ and was sterile with a 13-14.5 h photoperiod. Genetic analysis indicated that both traits were controlled by a single recessive gene or two closely linked genes. Also, the cytological observations and transcriptome profiling analysis showed that the degradation of pollen grain cytoplasm should be the primary reason why the mutant line were male sterile under long-day conditions.