Photonic crystal surface emitting lasers(PCSELs)utilize the Bragg diffraction of two-dimensional photonic crystals to achieve a single-mode output with a high power and a small divergence angle,and has recently attrac...Photonic crystal surface emitting lasers(PCSELs)utilize the Bragg diffraction of two-dimensional photonic crystals to achieve a single-mode output with a high power and a small divergence angle,and has recently attracted much attention^([1−3]).In 2023,Kyoto University reported GaAs-based 945 nm PCSELs with a continuous-wave(CW)single-mode output power of exceeding 50 W,and a narrow beam divergence angle of 0.05°,demonstrating a brightness of 1 GW·cm^(−2)·sr^(−1),which rivals those of the existing bulky lasers^([4]).展开更多
In this paper, the influence of processing parameters and powder binder content was studied and analysed on the properties of high loft nonwoven fabrics mainly using statistical analysis method. The relationship betwe...In this paper, the influence of processing parameters and powder binder content was studied and analysed on the properties of high loft nonwoven fabrics mainly using statistical analysis method. The relationship between the bulkiness and the warmth retention property was also tested. The analytical results reveal that the increase of the powder content, heating temperature and pressure will affect the tensile strength of nonwovens. Moreover, there are interactions between these parameters. The compression properties only change a little for a powder binder content of 15％—20％. However, with the increase of the heating temperature and pressure, the bulkiness and compression rate will reduce significantly. For the bulk density of high loft nonwoven fabrics, there exists a heat transter mechanism of air convection, but the higher the bulkiness of nonwovens, the larger the thickness and the better the warmth retention property of nonwoven fabrics.展开更多
Different from the grain boundary diffusion process(GBDP),which is suitable for modifying thin magnet,a green-pressing agents permeation process(GAPP)that uses low melting point alloys was applied to the Nd-Fe-B green...Different from the grain boundary diffusion process(GBDP),which is suitable for modifying thin magnet,a green-pressing agents permeation process(GAPP)that uses low melting point alloys was applied to the Nd-Fe-B green compact with a thickness over 15 mm to reconstruct the boundary microstructure of a sintered Nd-Fe-B magnet.The coercivity increases from 12.3 kOe for the sample free of Pr80Al20 to16.8 kOe for the sample with 2 wt%Pr80Al20.By further increasing the Pr80Al20 content to 3 wt%,the coercivity increases slightly,but the remanence and Hk/Hcj deteriorate obviously.The optimal comprehensive properties of Hcj=16.8 kOe,Br=13.4 kG and Hk/Hcj=0.975 are obtained at 2 wt%Pr80Al20,since matrix phase grains are separated by relatively continuous thin grain boundary layers,which weaken the magnetic coupling between adjacent grains.The coercivities of the samples from the GAPP that use2 wt%Pr80Al20,Pr70Al30 and Pr60Tb20Al20 alloys,respectively,can be enhanced to a large extent.However,the coercivity of the magnet reconstructed with Pr80Al20 is lower than that of the sample with Pr60Tb20Al20 but is higher than that of the sample reconstructed with Pr70Cu30 alloy.Moreover,the coercivity of the sample from the GAPP using 2 wt%Pr80Al20 is much higher than that of the sample from the GBDP,which is due to a nearly uniform boundary microstructure from the surface to the interior of the thick magnet from the GAPP,thus providing new insights into the fabrication of thick and bulky permanent magnets with high coercivity.展开更多
Wide-bandgap(WBG)perovskite solar cells suffer from severe non-radiative recombination and exhibit relatively large opencircuit voltage(V_(OC))deficits,limiting their photovoltaic performance.Here,we address these iss...Wide-bandgap(WBG)perovskite solar cells suffer from severe non-radiative recombination and exhibit relatively large opencircuit voltage(V_(OC))deficits,limiting their photovoltaic performance.Here,we address these issues by in-situ forming a well-defined 2D perovskite(PMA)_(2)PbCl_(4)(phenmethylammonium is referred to as PMA)passivation layer on top of the WBG active layer.The 2D layer with highly pure dimensionality and halide components is realized by intentionally tailoring the side-chain substituent at the aryl ring of the post-treatment reagent.First-principle calculation and single-crystal X-ray diffraction results reveal that weak intermolecular interactions between bulky PMA cations and relatively low cation-halide hydrogen bonding strength are crucial in forming the well-defined 2D phase.The(PMA)_(2)PbCl_(4)forms improved type-I energy level alignment with the WBG perovskite,reducing the electron recombination at the perovskite/hole-transport-layer interface.Applying this strategy in fabricating semi-transparent WBG perovskite solar cells(indium tin oxide as the back electrode),the V_(OC)deficits can be reduced to 0.49 V,comparable with the reported state-of-the-art WBG perovskite solar cells using metal electrodes.Consequently,we obtain hysteresis-free 18.60%-efficient WBG perovskite solar cells with a high V_(OC)of 1.23 V.展开更多
Alpha-fetoprotein (AFP)-producing colorectal cancer is extremely rarely reported until now. All of the reported cases harboring synchronous hematogenous spread including liver and/or lung metastasis had a poor prognos...Alpha-fetoprotein (AFP)-producing colorectal cancer is extremely rarely reported until now. All of the reported cases harboring synchronous hematogenous spread including liver and/or lung metastasis had a poor prognosis and died within 12 mo. We here describe a 71-year old man with AFP-producing colon cancer who presented with an unusual bulky lymph node metastasis instead of hematogenous spread. He underwent adjuvant chemotherapy in addition to curative surgical resection, which prolonged his survival.展开更多
New unsymmetrical diamine monomer containing triaryl imidazole pendent group, 4-[4-（4,5-diphenyl-1H-imidazol-2-y1）phe- noxy]-1,3-benzenediamine, was synthesized via aromatic substitution reaction of 1-chloro-2,4-din...New unsymmetrical diamine monomer containing triaryl imidazole pendent group, 4-[4-（4,5-diphenyl-1H-imidazol-2-y1）phe- noxy]-1,3-benzenediamine, was synthesized via aromatic substitution reaction of 1-chloro-2,4-dinitrobenzene with 4-（4,5- diphenyl-1H-imidazol-2-y1）pbenol, followed by palladium-catalyzed hydrazine reduction. This new monomer was further confirmed by FT-IR, IH NMR and ^13C NMR. Novel polyamides having pendant triaryl imidazole group were prepared by the phosphorylation polycondensation of four commercially aromatic dicarboxylic acids with the prepared diamine. Inherent viscosities of polyamides were in the range 0.42-0.53 dL/g indicating formation of medium molecular weight polymers. Polyamides exhibited glass-transition temperature （Tg） in the range 236-265 ℃. These polymers are essentially amorphous and were soluble in polar aprotic solvents such as DMF, NMP, DMAc. The 10% weight loss temperatures in air atmosphere, measured by TGA were in the range 350-373 ℃ indicating their good thermal stabilities. ？2009 Mousa Ghaemy. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Objective To investigate the potential role of preoperative adjuvant chemotherapy on early stage cervical squamous carcinoma with bulky tumor. Methods One hundred and forty-five patients with cervical squamous cancer ...Objective To investigate the potential role of preoperative adjuvant chemotherapy on early stage cervical squamous carcinoma with bulky tumor. Methods One hundred and forty-five patients with cervical squamous cancer stagesⅠb-Ⅱa were investigated, among which17 patients with bulky tumors (≥4 cm) were managed by cisplatin-based chemotherapy for 1-2 courses followed by radical hysterectomy and pelvic lymphadenectomy (BC group). The change of tumor size, pelvic lymph nodes metastasis, cervical wall invasion, the involvement of surgical specimen margin, and the blood loss during operation were assessed after opera-tion and compared with those in 51 patients with bulky tumors (BN group) and 77 patients with small local tumors (S group) who underwent surgery directly. Results (1) The tumor size of 17 patients in BC group were decreased in various degrees after chemotherapy, with 13 pati-ents of clinical effectiveness (76.47%). And the responsiveness pertained to neither histological differentiation nor size of local tumors. (2) Post-operative histology has showed that patients in BC and BN group have higher incidence of lymph node metastasis and deep cervical infiltration (5/68 and 3/68, respectively) than in S group (1/77 and 1/77, respectively) while with no statistical significance. (3) Blood loss during operation in BC group was less than BN and S group. (4) Seventeen patients, including those underwent surgeries of vaginal prolongation and/or ovarian transposition, appeared disease-free survival within the follow-up time. Conclusions Most of patients with bulky early stage cervical squamous carcinoma are sensitive to cisplatin-based chem-otherapy, which could greatly reduce local tumor size and in turn facilitate the following operation by well controlling blood loss.展开更多
To achieve high power conversion efficiency(PCE),three porphyrin sensitizers have been synthesized and explored to simultaneously enhance the photocurrent(JSC)and photovoltage(VOC).On basis of the XW4,a benzothiadiazo...To achieve high power conversion efficiency(PCE),three porphyrin sensitizers have been synthesized and explored to simultaneously enhance the photocurrent(JSC)and photovoltage(VOC).On basis of the XW4,a benzothiadiazole(BTD)unit has been introduced to afford XW57 with the aim to extend the absorption wavelength and enhance the light harvesting ability.As a result,a JSC of 13.72 mA/cm^2 has been obtained for XW57,higher than that of XW4.On this basis,XW58 has been prepared by modifying the carbazole-based donor with two bulky dihexyloxyphenyl groups,and the superior anti-aggregation character raises the VOC from 781 mV(XW4)to 844 mV.When both the BTD unit and the bulky groups are introduced to the acceptor and donor units,respectively,the resulting sensitizer XW59 exhibits a highest PCE value of 7.34%with synergistically enhanced JSC of 13.19 mA/cm^2 and VOC of 793 mV.These results provide further insight into developing high performance dye-sensitized solar cells.展开更多
Tetrahydrobenzo[5]helicenediol（THB-[5]HDIOL） derivatives as additives for the efficient prolinecatalyzed asymmetric List-Lerner-Barbas（LLB） aldol reactions of bulky aldehyde substrates was described. It was found ...Tetrahydrobenzo[5]helicenediol（THB-[5]HDIOL） derivatives as additives for the efficient prolinecatalyzed asymmetric List-Lerner-Barbas（LLB） aldol reactions of bulky aldehyde substrates was described. It was found that with dibromo-substituted helical diols P-4 a/M-4 a as additives, the prolinecatalyzed LLB aldol reaction of 9-anthraldehyde and acetone gave the product in 83% yield and 99% ee.Transition state models revealed an edge-to-face p-p stacking between the anthracenyl group in TS（R）and the phenyl group of the additive, which might result in the high enantioselectivity.展开更多
Background: Cervical cancer is the second most common malignancy of women in Bangladesh. Surgery is the mainstay of treatment of patients with early invasive cancer confined to cervix. While the five-year survival rat...Background: Cervical cancer is the second most common malignancy of women in Bangladesh. Surgery is the mainstay of treatment of patients with early invasive cancer confined to cervix. While the five-year survival rate after surgery for stage IB1 disease exceeds 90%, it is only 60% - 70% for stage IB2 and IIA2 (tumor size > 4 cm). To improve the outcome of treatment, two to three cycles of Neoadjuvant Chemotherapy (NACT) has been evaluated as a treatment strategy in stage IB2 and IIA2 diseases. Objectives: This study aimed to evaluate the role of neoadjuvant chemotherapy (NACT) followed by Radical Surgery (RS) among the patients with early bulky cervical cancer (Stage IB2 & IIA2) to reduce the tumor size to achieve radical resectibility. Methods: This study was carried out at the Gynaecological Oncology Division of the Department of Obstetrics and Gynecology at Bangabandhu Sheikh Mujib Medical University (B中央人民政府) during the period July 2015 to December 2015. Thirty-eight patients with early bulky cervical cancer without any prior medical or surgical treatment received NACT using intravenous paclitaxel 175 mg/m2 and cisplatin 75 mg/m2 followed by radical surgery. The primary outcome measure assessed the response to NACT to reduce the size of the tumor. Secondary outcome measures assessed the resectibility of tumor and compared the preoperative clinical stage to the postoperative pathological stage. This study also assessed the relationship of intraoperative and postoperative complications including the adverse effects of postoperative radiotherapy and chemoradiotherapy. Results: Clinical response to NACT was 94.7% (84.2% complete response + 10.5% partial response). Progressive disease was found in two cases (5.3%). Duration of surgery was less than 2 hours in 81.6% cases and greater than 3 hours in 13.2% cases only. All women lived 5 to 10 hours away from Dhaka and could not return for in person follow-up. It was possible to get telephone follow-up on twenty-four women (63%). Seven (29%) had died from their cancers within one year of their surgery. Seventeen women were alive and disease free two years after completeion of their treatment. Conclusion: NACT is a feasible approach for improving the resectability of early stage bulky cervical cancer at B中央人民政府.展开更多
Chloro(5,10,15,20-tetraphenyl-porphyrinato)-aluminum/tetraethylammonium bromide(Et4NBr)in combination with bulky Lewis acid was used for the copolymerization of CO_2 and cyclohexene oxide(CHO).Bulky Lewis acid having ...Chloro(5,10,15,20-tetraphenyl-porphyrinato)-aluminum/tetraethylammonium bromide(Et4NBr)in combination with bulky Lewis acid was used for the copolymerization of CO_2 and cyclohexene oxide(CHO).Bulky Lewis acid having substituents at the ortho positions of the phenolate ligands,like methylaluminum bis(2,6-di-tert-butyl-4-methylphenolate), significantly shortened the induction period and raised the catalytic activity,the corresponding turnover frequency reached 44.9 h^(-1)in 9 h,which was 23.8% higher than th...展开更多
Aminosilane bearing bulky substituents on nitrogen： LH2 （L = Me2Si（NDipp＇）2, Dipp = 2,6-diisopropylphenyl） was reacted with BuLi in toluene. The resulting bulky chelating dianion Me2Si（NDipp）2 was used to synt...Aminosilane bearing bulky substituents on nitrogen： LH2 （L = Me2Si（NDipp＇）2, Dipp = 2,6-diisopropylphenyl） was reacted with BuLi in toluene. The resulting bulky chelating dianion Me2Si（NDipp）2 was used to synthesize the unusual spirocyclic heterotriatomic complex [MeESi（NDipp）2]ESn （1） by its reaction with SnCl4 and the bulky heterotriatomic complex Me2Si（NDipp）2SnPh2 （2） with Ph2SnC12. 1 belongs to the monoclinic system, space group P21/n with a = 13.193（2）, b = 20.663（3）, c = 20.403（3）A, β = 99.954（2）°, V = 5478.3（15） A3, C55H85.5N4Si2Sn, Mr = 977.64, Z = 4, Dc. = 1.185 Mg/m3, μ（MoKa） = 0.547 mm-1, F（000） = 2086, S = 1.000, the final R = 0.0614 and wR = 0.1322 for 14446 observed reflections （1 〉 2σ（I）） and R = 0.0797 and wR = 0.1456 for all data. 2 belongs to the triclinic system, space group P1 with a = 10.36（15）, b = 13.204（7）, c = 14.363（7） A, a = 90.214（10）, β = 106.182（7）, y = 109.854（8）°, V = 1764.4（15） A3, C38HsoN2SiSn, M,. = 681.58, Z = 2, Dc = 1.283 Mg/m^3,μ（MoKa） = 0.785 mm-1, F（000） = 712, S = 1.002, the final R = 0.0498 and wR = 0.0955 for 7533 observed reβections （I 〉 2σ（I）） and R = 0.0676 and wR = 0.1018 for all data. In the structure of 1, the tin atom is located in the spirocyclic center of the two fused four-membered SnN2Si rings. The two complexes were characterized by ^1H NMR, elemental analysis, and single-crystal X-ray structural analysis.展开更多
BACKGROUND Para-aortic lymph nodes(PALNs)are common sites for the regional spread of cervical squamous cell carcinoma(SCC).CASE SUMMARY We report the case of a 36-year-old woman who presented with cervical SCC with mu...BACKGROUND Para-aortic lymph nodes(PALNs)are common sites for the regional spread of cervical squamous cell carcinoma(SCC).CASE SUMMARY We report the case of a 36-year-old woman who presented with cervical SCC with multiple bulky PALNs,largest measured 4.5 cm×5 cm×10 cm.The patient was treated with radical intent with definitive chemoradiation using sequential doseescalated adaptive radiotherapy,followed by maintenance chemotherapy.The patient achieved a complete response;she has been doing well since the completion of treatment with no evidence of the disease for 2 years.CONCLUSION Regardless of the size of PALN metastases of cervical carcinoma origin,it is still treatable(with radical intent)via concurrent chemoradiation.Adaptive radiotherapy allows dose escalation with minimal toxicity.展开更多
Organosilanes are not found in nature but play a crucial role in the sustainable development of modern society.Si-chiral organosilanes represent a type of novel chemical space that is highly desirable for research ori...Organosilanes are not found in nature but play a crucial role in the sustainable development of modern society.Si-chiral organosilanes represent a type of novel chemical space that is highly desirable for research oriented in terms of their properties,including synthetic chemistry,drug discovery,and materials and life sciences.While much effort has been given to the catalytic enantioselective construction of Si-chirality,the facile synthesis of multifunctional Si-chiral silanes remains undeveloped.Here,we report an unprecedented highly enantioselective copper-catalyzed desymmetric sulfonylation or acylation of prochiral 1,3-siladiols for the expedient synthesis of multifunctional Si-chiral silanes with both a hydroxymethyl group and an ester group as synthetic handles.A one-pot tandem desymmetric sulfonylation/substitution sequence,internally reusing waste chloride or bromide formed from the upstream sulfonylation step as the reagent for a substitution step,is also exploited for the atom-efficient synthesis of Si-chiral silylmethanols featuring a chloromethyl or bromomethyl group.A newly developed sterically confined pyridine-bis(oxazoline)(PYBOX)ligand with a bulky C4 amide-containing shielding group is crucial for achieving excellent reactivity and enantioselectivity.The scale-up synthesis and various diversifying elaborations of multifunctional Si-chiral silylmethanols further highlight the synthetic practicability of this protocol.展开更多
Cu(Ⅰ)photoredox catalysts have become popular alternatives to traditional Ir and Ru photosensitizers.However,the flattening distortion during the Cu(Ⅰ)to Cu(Ⅱ)3MLCT charge transfer is one of the main drawbacks prev...Cu(Ⅰ)photoredox catalysts have become popular alternatives to traditional Ir and Ru photosensitizers.However,the flattening distortion during the Cu(Ⅰ)to Cu(Ⅱ)3MLCT charge transfer is one of the main drawbacks preventing their broad-scale application.Avoiding this structural change using bulky ligands has been a strategy to increase the lifetime of the excited 3MLCT state.In this computational study,we discuss the effect of preventing the flattening distortion on the thermodynamics and kinetics of the electron transfer processes of the photoredox cycle.Theoretical square schemes were calculated to quantitatively separate the reduction processes into separate vertical electron transfer(ET)and structural relaxation(SR)steps.Computational results show that ET energies account for 89–99%of the reduction processes.Meanwhile,SR depends on the degree of structural changes during the Cu(Ⅱ)→Cu(ⅠI)transition and becomes less important as the bulkiness of the ligand increases.The calculated internal reorganization energies for the electron-self exchange show that preventing flattening distortion in Cu(Ⅰ)complexes may aid the electron transfer kinetics by reducing the reaction barriers.The calculated singlet–triplet energy gaps increase with the bulkiness of the ligand,which agrees with the increase of the excited state lifetimes observed in Cu(Ⅰ)species by preventing the flattening distortion.展开更多
ZEO-1,the first stable aluminosilicate zeolite with extra-large pores,marks a great breakthrough in the zeolite community after decades of exploration and endeavors,opening possibilities for processing bulky substrate...ZEO-1,the first stable aluminosilicate zeolite with extra-large pores,marks a great breakthrough in the zeolite community after decades of exploration and endeavors,opening possibilities for processing bulky substrates.However,the long synthesis cycle and relatively low reproducibility hinder the wide application of this intriguing material.This work developed a‘deficient fluoride approach’for ZEO-1 zeolite synthesis by adding a small amount of fluoride to induce a charge imbalance between the OSDA and fluoride.This approach significantly accelerates crystallization(15 times faster than the reported method)and achieves higher reproducibility than the originally reported protocol.Crystallization kinetics studies demonstrate the accelerating effect of stoichiometrically deficient fluoride anions on the nucleation and crystallization process.The ZEO-1 zeolites synthesized via the‘deficient fluoride approach’show catalytic activity for phenol alkylation with tert-butyl alcohol comparable to that of ZEO-1LCS,but the products are evenly distributed,suggesting that more Brønsted acid sites might have been successfully introduced in the 16 MR channels.This work provides an incentive for feasible academic study and application of ZEO-1.展开更多
Extra-large pore zeolites clear the way for the synthesis of fine chemicals and bulky compounds unable to enter the channels of medium-and large-pore zeolites.However,such extra-large pore zeolites rarely contain cata...Extra-large pore zeolites clear the way for the synthesis of fine chemicals and bulky compounds unable to enter the channels of medium-and large-pore zeolites.However,such extra-large pore zeolites rarely contain catalytically active elements and often show limited stability.In this study,we modified the Reverse assembly–disassembly–organisation–reassembly(ADOR)process to prepare extra-large pore zeolite UTL from layered IPC-1P while simultaneously incorporating a high amount of aluminium(reaching Si/Al=15)into the framework.Using this modified Reverse ADOR approach,we significantly reduced the synthesis time of alumino-germanosilicate UTL from the 28 days needed for direct synthesis to only 24 hours for reconstruction and 14 days in total.Furthermore,in the tetrahydropyranylation of 1-decanol over the reconstructed UTL zeolite,directly synthesised UTL and commercial Beta zeolite,used as a reference,reconstructed UTL provided conversion up to 61.4%,outperforming directly synthesised UTL and Beta with 14.8 and 0%conversion,respectively.The modified Reverse ADOR procedure enables us to introduce mesoporosity into zeolites,which further improves their catalytic performance by facilitating active site accessibility.展开更多
C-Amino-1,2,4-triazoles are challenging polynitrogen substrates for metal-catalyzed arylation due to their multidentate character,enhanced coordinating ability and decreased nucleophilicity of the amino group.In the p...C-Amino-1,2,4-triazoles are challenging polynitrogen substrates for metal-catalyzed arylation due to their multidentate character,enhanced coordinating ability and decreased nucleophilicity of the amino group.In the present study,the Buchwald-Hartwig cross-coupling of diverse 3(5)-amino-1,2,4-triazoles with aryl chlorides and bromides delivering(hetero)arylamino-1,2,4-triazoles in good-to-excellent yields under Pd/NHC catalysis was developed.The use of Pd complexes with bulky NHC ligands such as IPr^(*OMe) and TPEDO(1,1,2,2-tetraphenylethane-1,2-diol)as an in situ Pd(Ⅱ)to Pd(0)reductant enabled the selective arylation of the NH_(2) group even in acidic NH unprotected substrates and deactivated 1-substituted 5-amino-and 4-substituted 3-amino-1,2,4-triazoles.The reaction mechanism and structure-activity relationships were studied with DFT calculations.A significant effect of the position of the N-substituent in the 1,2,4-triazole ring on the favorable reaction pathways was revealed.展开更多
Polypyridines functionalized withπ-donating groups constitute a class of electron-rich ligands with significant relevance in coordination chemistry and catalysis.The incorporation of strongly basic guanidinyl substit...Polypyridines functionalized withπ-donating groups constitute a class of electron-rich ligands with significant relevance in coordination chemistry and catalysis.The incorporation of strongly basic guanidinyl substituents,however,often introduces multiple binding sites,with coordination typically favoring the guanidyl nitrogen atoms.Herein,we report the synthesis and characterization of a new electron-rich 1,10-phenanthroline ligand featuring bulky NHI groups that define a well-structured coordination cavity.Protonation studies and the preparation of a zinc(II)complex reveal that Lewis acids preferentially coordinate at the phenanthroline nitrogen atoms rather than the NHI moiety.The electronic and photophysical properties of the new ligand and its complexes are explored through a combination of computational and experimental methods,demonstrating that its emission and absorption characteristics are highly sensitive to protonation,concentration,and metal coordination.展开更多
We reported herein a novel gold(I)bifluoride complex,LAuHF_(2),supported by a sterically bulky ligand(L,^(t)BuXantphos),that displays exceptional reactivity toward hydrodefluorination(HDF)and hydrosilylation of CO_(2)...We reported herein a novel gold(I)bifluoride complex,LAuHF_(2),supported by a sterically bulky ligand(L,^(t)BuXantphos),that displays exceptional reactivity toward hydrodefluorination(HDF)and hydrosilylation of CO_(2)in the presence of hydrosilanes.Compared to the LAuCl counterpart,the LAuHF_(2)complex exhibited an over 27-fold increase in turnover frequency in HDF and a 16-times higher turnover number in the hydrosilylation of CO_(2).展开更多
基金funded by National Key R&D Program of China(Grant Nos.2024YFB3612200,2023YFB3609601,2022YFB3604300,2022YFB2802801,2022YFB3604802)Natural Science Foundation of China(Grant Nos.U24A20300,62174174,62274177,62275263,62325406,62374172,62304242,62304240,62404241)+4 种基金Youth Innovation Promotion Association of CAS(Grant Nos.2022323 and 2022324)Key R&D Program of Jiangsu Province(Grant No.BE2023018-2)Basic Research Program of Jiangsu(Grant No.BK20240126)Suzhou Science and Technology Program(Grant Nos.SYC2022089,ZXL2024379,and ZXL2024376)Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2022A1515110482 and 2022A1515110004).
文摘Photonic crystal surface emitting lasers(PCSELs)utilize the Bragg diffraction of two-dimensional photonic crystals to achieve a single-mode output with a high power and a small divergence angle,and has recently attracted much attention^([1−3]).In 2023,Kyoto University reported GaAs-based 945 nm PCSELs with a continuous-wave(CW)single-mode output power of exceeding 50 W,and a narrow beam divergence angle of 0.05°,demonstrating a brightness of 1 GW·cm^(−2)·sr^(−1),which rivals those of the existing bulky lasers^([4]).
文摘In this paper, the influence of processing parameters and powder binder content was studied and analysed on the properties of high loft nonwoven fabrics mainly using statistical analysis method. The relationship between the bulkiness and the warmth retention property was also tested. The analytical results reveal that the increase of the powder content, heating temperature and pressure will affect the tensile strength of nonwovens. Moreover, there are interactions between these parameters. The compression properties only change a little for a powder binder content of 15％—20％. However, with the increase of the heating temperature and pressure, the bulkiness and compression rate will reduce significantly. For the bulk density of high loft nonwoven fabrics, there exists a heat transter mechanism of air convection, but the higher the bulkiness of nonwovens, the larger the thickness and the better the warmth retention property of nonwoven fabrics.
基金Project supported by the National Natural Science Foundation of China(51401021)the State Key Laboratory Advanced Metals and Materials(20162-14).
文摘Different from the grain boundary diffusion process(GBDP),which is suitable for modifying thin magnet,a green-pressing agents permeation process(GAPP)that uses low melting point alloys was applied to the Nd-Fe-B green compact with a thickness over 15 mm to reconstruct the boundary microstructure of a sintered Nd-Fe-B magnet.The coercivity increases from 12.3 kOe for the sample free of Pr80Al20 to16.8 kOe for the sample with 2 wt%Pr80Al20.By further increasing the Pr80Al20 content to 3 wt%,the coercivity increases slightly,but the remanence and Hk/Hcj deteriorate obviously.The optimal comprehensive properties of Hcj=16.8 kOe,Br=13.4 kG and Hk/Hcj=0.975 are obtained at 2 wt%Pr80Al20,since matrix phase grains are separated by relatively continuous thin grain boundary layers,which weaken the magnetic coupling between adjacent grains.The coercivities of the samples from the GAPP that use2 wt%Pr80Al20,Pr70Al30 and Pr60Tb20Al20 alloys,respectively,can be enhanced to a large extent.However,the coercivity of the magnet reconstructed with Pr80Al20 is lower than that of the sample with Pr60Tb20Al20 but is higher than that of the sample reconstructed with Pr70Cu30 alloy.Moreover,the coercivity of the sample from the GAPP using 2 wt%Pr80Al20 is much higher than that of the sample from the GBDP,which is due to a nearly uniform boundary microstructure from the surface to the interior of the thick magnet from the GAPP,thus providing new insights into the fabrication of thick and bulky permanent magnets with high coercivity.
基金supported by the National Natural Science Foundation of China(22179042,U21A2078,and 51902110)the Natural Science Foundation of Fujian Province(2020J06021 and 2020J01064).
文摘Wide-bandgap(WBG)perovskite solar cells suffer from severe non-radiative recombination and exhibit relatively large opencircuit voltage(V_(OC))deficits,limiting their photovoltaic performance.Here,we address these issues by in-situ forming a well-defined 2D perovskite(PMA)_(2)PbCl_(4)(phenmethylammonium is referred to as PMA)passivation layer on top of the WBG active layer.The 2D layer with highly pure dimensionality and halide components is realized by intentionally tailoring the side-chain substituent at the aryl ring of the post-treatment reagent.First-principle calculation and single-crystal X-ray diffraction results reveal that weak intermolecular interactions between bulky PMA cations and relatively low cation-halide hydrogen bonding strength are crucial in forming the well-defined 2D phase.The(PMA)_(2)PbCl_(4)forms improved type-I energy level alignment with the WBG perovskite,reducing the electron recombination at the perovskite/hole-transport-layer interface.Applying this strategy in fabricating semi-transparent WBG perovskite solar cells(indium tin oxide as the back electrode),the V_(OC)deficits can be reduced to 0.49 V,comparable with the reported state-of-the-art WBG perovskite solar cells using metal electrodes.Consequently,we obtain hysteresis-free 18.60%-efficient WBG perovskite solar cells with a high V_(OC)of 1.23 V.
文摘Alpha-fetoprotein (AFP)-producing colorectal cancer is extremely rarely reported until now. All of the reported cases harboring synchronous hematogenous spread including liver and/or lung metastasis had a poor prognosis and died within 12 mo. We here describe a 71-year old man with AFP-producing colon cancer who presented with an unusual bulky lymph node metastasis instead of hematogenous spread. He underwent adjuvant chemotherapy in addition to curative surgical resection, which prolonged his survival.
文摘New unsymmetrical diamine monomer containing triaryl imidazole pendent group, 4-[4-（4,5-diphenyl-1H-imidazol-2-y1）phe- noxy]-1,3-benzenediamine, was synthesized via aromatic substitution reaction of 1-chloro-2,4-dinitrobenzene with 4-（4,5- diphenyl-1H-imidazol-2-y1）pbenol, followed by palladium-catalyzed hydrazine reduction. This new monomer was further confirmed by FT-IR, IH NMR and ^13C NMR. Novel polyamides having pendant triaryl imidazole group were prepared by the phosphorylation polycondensation of four commercially aromatic dicarboxylic acids with the prepared diamine. Inherent viscosities of polyamides were in the range 0.42-0.53 dL/g indicating formation of medium molecular weight polymers. Polyamides exhibited glass-transition temperature （Tg） in the range 236-265 ℃. These polymers are essentially amorphous and were soluble in polar aprotic solvents such as DMF, NMP, DMAc. The 10% weight loss temperatures in air atmosphere, measured by TGA were in the range 350-373 ℃ indicating their good thermal stabilities. ？2009 Mousa Ghaemy. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘Objective To investigate the potential role of preoperative adjuvant chemotherapy on early stage cervical squamous carcinoma with bulky tumor. Methods One hundred and forty-five patients with cervical squamous cancer stagesⅠb-Ⅱa were investigated, among which17 patients with bulky tumors (≥4 cm) were managed by cisplatin-based chemotherapy for 1-2 courses followed by radical hysterectomy and pelvic lymphadenectomy (BC group). The change of tumor size, pelvic lymph nodes metastasis, cervical wall invasion, the involvement of surgical specimen margin, and the blood loss during operation were assessed after opera-tion and compared with those in 51 patients with bulky tumors (BN group) and 77 patients with small local tumors (S group) who underwent surgery directly. Results (1) The tumor size of 17 patients in BC group were decreased in various degrees after chemotherapy, with 13 pati-ents of clinical effectiveness (76.47%). And the responsiveness pertained to neither histological differentiation nor size of local tumors. (2) Post-operative histology has showed that patients in BC and BN group have higher incidence of lymph node metastasis and deep cervical infiltration (5/68 and 3/68, respectively) than in S group (1/77 and 1/77, respectively) while with no statistical significance. (3) Blood loss during operation in BC group was less than BN and S group. (4) Seventeen patients, including those underwent surgeries of vaginal prolongation and/or ovarian transposition, appeared disease-free survival within the follow-up time. Conclusions Most of patients with bulky early stage cervical squamous carcinoma are sensitive to cisplatin-based chem-otherapy, which could greatly reduce local tumor size and in turn facilitate the following operation by well controlling blood loss.
基金Central Public-interest Scientific Institution Basal Research Fund,ECSFR,CAFS(No.2018T02)the National Natural Science Foundation of China(Nos.21772041,21811530005,21971063,U1707602)the Fundamental Research Funds for the Central Universities(Nos.WK1616004,222201717003)。
文摘To achieve high power conversion efficiency(PCE),three porphyrin sensitizers have been synthesized and explored to simultaneously enhance the photocurrent(JSC)and photovoltage(VOC).On basis of the XW4,a benzothiadiazole(BTD)unit has been introduced to afford XW57 with the aim to extend the absorption wavelength and enhance the light harvesting ability.As a result,a JSC of 13.72 mA/cm^2 has been obtained for XW57,higher than that of XW4.On this basis,XW58 has been prepared by modifying the carbazole-based donor with two bulky dihexyloxyphenyl groups,and the superior anti-aggregation character raises the VOC from 781 mV(XW4)to 844 mV.When both the BTD unit and the bulky groups are introduced to the acceptor and donor units,respectively,the resulting sensitizer XW59 exhibits a highest PCE value of 7.34%with synergistically enhanced JSC of 13.19 mA/cm^2 and VOC of 793 mV.These results provide further insight into developing high performance dye-sensitized solar cells.
基金the National Natural Science Foundation of China (No. 21572233)the Strategic Priority Research Program of Chinese Academy of Sciences(No. XDB12010400) for financial supports
文摘Tetrahydrobenzo[5]helicenediol（THB-[5]HDIOL） derivatives as additives for the efficient prolinecatalyzed asymmetric List-Lerner-Barbas（LLB） aldol reactions of bulky aldehyde substrates was described. It was found that with dibromo-substituted helical diols P-4 a/M-4 a as additives, the prolinecatalyzed LLB aldol reaction of 9-anthraldehyde and acetone gave the product in 83% yield and 99% ee.Transition state models revealed an edge-to-face p-p stacking between the anthracenyl group in TS（R）and the phenyl group of the additive, which might result in the high enantioselectivity.
文摘Background: Cervical cancer is the second most common malignancy of women in Bangladesh. Surgery is the mainstay of treatment of patients with early invasive cancer confined to cervix. While the five-year survival rate after surgery for stage IB1 disease exceeds 90%, it is only 60% - 70% for stage IB2 and IIA2 (tumor size > 4 cm). To improve the outcome of treatment, two to three cycles of Neoadjuvant Chemotherapy (NACT) has been evaluated as a treatment strategy in stage IB2 and IIA2 diseases. Objectives: This study aimed to evaluate the role of neoadjuvant chemotherapy (NACT) followed by Radical Surgery (RS) among the patients with early bulky cervical cancer (Stage IB2 & IIA2) to reduce the tumor size to achieve radical resectibility. Methods: This study was carried out at the Gynaecological Oncology Division of the Department of Obstetrics and Gynecology at Bangabandhu Sheikh Mujib Medical University (B中央人民政府) during the period July 2015 to December 2015. Thirty-eight patients with early bulky cervical cancer without any prior medical or surgical treatment received NACT using intravenous paclitaxel 175 mg/m2 and cisplatin 75 mg/m2 followed by radical surgery. The primary outcome measure assessed the response to NACT to reduce the size of the tumor. Secondary outcome measures assessed the resectibility of tumor and compared the preoperative clinical stage to the postoperative pathological stage. This study also assessed the relationship of intraoperative and postoperative complications including the adverse effects of postoperative radiotherapy and chemoradiotherapy. Results: Clinical response to NACT was 94.7% (84.2% complete response + 10.5% partial response). Progressive disease was found in two cases (5.3%). Duration of surgery was less than 2 hours in 81.6% cases and greater than 3 hours in 13.2% cases only. All women lived 5 to 10 hours away from Dhaka and could not return for in person follow-up. It was possible to get telephone follow-up on twenty-four women (63%). Seven (29%) had died from their cancers within one year of their surgery. Seventeen women were alive and disease free two years after completeion of their treatment. Conclusion: NACT is a feasible approach for improving the resectability of early stage bulky cervical cancer at B中央人民政府.
基金The work was financially supported by the National Natural Science Foundation of China(No.20634040).
文摘Chloro(5,10,15,20-tetraphenyl-porphyrinato)-aluminum/tetraethylammonium bromide(Et4NBr)in combination with bulky Lewis acid was used for the copolymerization of CO_2 and cyclohexene oxide(CHO).Bulky Lewis acid having substituents at the ortho positions of the phenolate ligands,like methylaluminum bis(2,6-di-tert-butyl-4-methylphenolate), significantly shortened the induction period and raised the catalytic activity,the corresponding turnover frequency reached 44.9 h^(-1)in 9 h,which was 23.8% higher than th...
基金supported by the National Natural Science Foundation of China (No.21001016 and 20901009)
文摘Aminosilane bearing bulky substituents on nitrogen： LH2 （L = Me2Si（NDipp＇）2, Dipp = 2,6-diisopropylphenyl） was reacted with BuLi in toluene. The resulting bulky chelating dianion Me2Si（NDipp）2 was used to synthesize the unusual spirocyclic heterotriatomic complex [MeESi（NDipp）2]ESn （1） by its reaction with SnCl4 and the bulky heterotriatomic complex Me2Si（NDipp）2SnPh2 （2） with Ph2SnC12. 1 belongs to the monoclinic system, space group P21/n with a = 13.193（2）, b = 20.663（3）, c = 20.403（3）A, β = 99.954（2）°, V = 5478.3（15） A3, C55H85.5N4Si2Sn, Mr = 977.64, Z = 4, Dc. = 1.185 Mg/m3, μ（MoKa） = 0.547 mm-1, F（000） = 2086, S = 1.000, the final R = 0.0614 and wR = 0.1322 for 14446 observed reflections （1 〉 2σ（I）） and R = 0.0797 and wR = 0.1456 for all data. 2 belongs to the triclinic system, space group P1 with a = 10.36（15）, b = 13.204（7）, c = 14.363（7） A, a = 90.214（10）, β = 106.182（7）, y = 109.854（8）°, V = 1764.4（15） A3, C38HsoN2SiSn, M,. = 681.58, Z = 2, Dc = 1.283 Mg/m^3,μ（MoKa） = 0.785 mm-1, F（000） = 712, S = 1.002, the final R = 0.0498 and wR = 0.0955 for 7533 observed reβections （I 〉 2σ（I）） and R = 0.0676 and wR = 0.1018 for all data. In the structure of 1, the tin atom is located in the spirocyclic center of the two fused four-membered SnN2Si rings. The two complexes were characterized by ^1H NMR, elemental analysis, and single-crystal X-ray structural analysis.
文摘BACKGROUND Para-aortic lymph nodes(PALNs)are common sites for the regional spread of cervical squamous cell carcinoma(SCC).CASE SUMMARY We report the case of a 36-year-old woman who presented with cervical SCC with multiple bulky PALNs,largest measured 4.5 cm×5 cm×10 cm.The patient was treated with radical intent with definitive chemoradiation using sequential doseescalated adaptive radiotherapy,followed by maintenance chemotherapy.The patient achieved a complete response;she has been doing well since the completion of treatment with no evidence of the disease for 2 years.CONCLUSION Regardless of the size of PALN metastases of cervical carcinoma origin,it is still treatable(with radical intent)via concurrent chemoradiation.Adaptive radiotherapy allows dose escalation with minimal toxicity.
基金supported by the National Natural Science Foundation of China(22471073,22171087)the Technology Innovation Project of Shanghai Municipal Agricultural Committee(HNK(T2023302))+2 种基金the Innovation Program of Shanghai Municipal Education Commission(2023ZKZD37)the Ministry of Education(PCSIRT)the Fundamental Research Funds for the Central Universities。
文摘Organosilanes are not found in nature but play a crucial role in the sustainable development of modern society.Si-chiral organosilanes represent a type of novel chemical space that is highly desirable for research oriented in terms of their properties,including synthetic chemistry,drug discovery,and materials and life sciences.While much effort has been given to the catalytic enantioselective construction of Si-chirality,the facile synthesis of multifunctional Si-chiral silanes remains undeveloped.Here,we report an unprecedented highly enantioselective copper-catalyzed desymmetric sulfonylation or acylation of prochiral 1,3-siladiols for the expedient synthesis of multifunctional Si-chiral silanes with both a hydroxymethyl group and an ester group as synthetic handles.A one-pot tandem desymmetric sulfonylation/substitution sequence,internally reusing waste chloride or bromide formed from the upstream sulfonylation step as the reagent for a substitution step,is also exploited for the atom-efficient synthesis of Si-chiral silylmethanols featuring a chloromethyl or bromomethyl group.A newly developed sterically confined pyridine-bis(oxazoline)(PYBOX)ligand with a bulky C4 amide-containing shielding group is crucial for achieving excellent reactivity and enantioselectivity.The scale-up synthesis and various diversifying elaborations of multifunctional Si-chiral silylmethanols further highlight the synthetic practicability of this protocol.
基金supported by UTEP Rising STARs(Grant No.E210291776)the Welch Foundation under Award Number AH-2083-20210327.
文摘Cu(Ⅰ)photoredox catalysts have become popular alternatives to traditional Ir and Ru photosensitizers.However,the flattening distortion during the Cu(Ⅰ)to Cu(Ⅱ)3MLCT charge transfer is one of the main drawbacks preventing their broad-scale application.Avoiding this structural change using bulky ligands has been a strategy to increase the lifetime of the excited 3MLCT state.In this computational study,we discuss the effect of preventing the flattening distortion on the thermodynamics and kinetics of the electron transfer processes of the photoredox cycle.Theoretical square schemes were calculated to quantitatively separate the reduction processes into separate vertical electron transfer(ET)and structural relaxation(SR)steps.Computational results show that ET energies account for 89–99%of the reduction processes.Meanwhile,SR depends on the degree of structural changes during the Cu(Ⅱ)→Cu(ⅠI)transition and becomes less important as the bulkiness of the ligand increases.The calculated internal reorganization energies for the electron-self exchange show that preventing flattening distortion in Cu(Ⅰ)complexes may aid the electron transfer kinetics by reducing the reaction barriers.The calculated singlet–triplet energy gaps increase with the bulkiness of the ligand,which agrees with the increase of the excited state lifetimes observed in Cu(Ⅰ)species by preventing the flattening distortion.
基金The ZeoMat Group acknowledges the starting grant provided by the Qingdao Institute of Bioenergy and Bioprocess Technology and the support from the Shandong Energy Institute(SEI S202107)P.L.acknowledges the support from the Qingdao New Energy Shandong Laboratory of International Cooperation Project(QNESL ICP 202305)V.V.and P.L.acknowledge the collaboration within the Sino-French International Research Network‘Zeolites’framework.The authors are indebted to Yida Zhou and Shutao Xu from Dalian Institute of Chemical Physics for collecting the 19F NMR data.
文摘ZEO-1,the first stable aluminosilicate zeolite with extra-large pores,marks a great breakthrough in the zeolite community after decades of exploration and endeavors,opening possibilities for processing bulky substrates.However,the long synthesis cycle and relatively low reproducibility hinder the wide application of this intriguing material.This work developed a‘deficient fluoride approach’for ZEO-1 zeolite synthesis by adding a small amount of fluoride to induce a charge imbalance between the OSDA and fluoride.This approach significantly accelerates crystallization(15 times faster than the reported method)and achieves higher reproducibility than the originally reported protocol.Crystallization kinetics studies demonstrate the accelerating effect of stoichiometrically deficient fluoride anions on the nucleation and crystallization process.The ZEO-1 zeolites synthesized via the‘deficient fluoride approach’show catalytic activity for phenol alkylation with tert-butyl alcohol comparable to that of ZEO-1LCS,but the products are evenly distributed,suggesting that more Brønsted acid sites might have been successfully introduced in the 16 MR channels.This work provides an incentive for feasible academic study and application of ZEO-1.
基金the Czech Science Foundation for funding this research through project EXPRO(19-27551X)OP VVV“Excellent Research Teams”,project no.CZ.02.1.01/0.0/0.0/15_003/0000417-CUCAM.OV acknowledges the support from the project“Grant Schemes at CU”(reg.no.CZ.02.2.69/0.0/0.0/19_073/0016935)the Czech Science Foundation for the project 19-21534S.
文摘Extra-large pore zeolites clear the way for the synthesis of fine chemicals and bulky compounds unable to enter the channels of medium-and large-pore zeolites.However,such extra-large pore zeolites rarely contain catalytically active elements and often show limited stability.In this study,we modified the Reverse assembly–disassembly–organisation–reassembly(ADOR)process to prepare extra-large pore zeolite UTL from layered IPC-1P while simultaneously incorporating a high amount of aluminium(reaching Si/Al=15)into the framework.Using this modified Reverse ADOR approach,we significantly reduced the synthesis time of alumino-germanosilicate UTL from the 28 days needed for direct synthesis to only 24 hours for reconstruction and 14 days in total.Furthermore,in the tetrahydropyranylation of 1-decanol over the reconstructed UTL zeolite,directly synthesised UTL and commercial Beta zeolite,used as a reference,reconstructed UTL provided conversion up to 61.4%,outperforming directly synthesised UTL and Beta with 14.8 and 0%conversion,respectively.The modified Reverse ADOR procedure enables us to introduce mesoporosity into zeolites,which further improves their catalytic performance by facilitating active site accessibility.
基金supported by the Russian Science Foundation(RSF grant 22-23-00380).
文摘C-Amino-1,2,4-triazoles are challenging polynitrogen substrates for metal-catalyzed arylation due to their multidentate character,enhanced coordinating ability and decreased nucleophilicity of the amino group.In the present study,the Buchwald-Hartwig cross-coupling of diverse 3(5)-amino-1,2,4-triazoles with aryl chlorides and bromides delivering(hetero)arylamino-1,2,4-triazoles in good-to-excellent yields under Pd/NHC catalysis was developed.The use of Pd complexes with bulky NHC ligands such as IPr^(*OMe) and TPEDO(1,1,2,2-tetraphenylethane-1,2-diol)as an in situ Pd(Ⅱ)to Pd(0)reductant enabled the selective arylation of the NH_(2) group even in acidic NH unprotected substrates and deactivated 1-substituted 5-amino-and 4-substituted 3-amino-1,2,4-triazoles.The reaction mechanism and structure-activity relationships were studied with DFT calculations.A significant effect of the position of the N-substituent in the 1,2,4-triazole ring on the favorable reaction pathways was revealed.
基金the Tiroler Wissenschaftsförderung(TWF,F.45075)for funding to realize this projectthe German Academic Scholarship Foundation for a PhD fellowship(L.F.B.W.).
文摘Polypyridines functionalized withπ-donating groups constitute a class of electron-rich ligands with significant relevance in coordination chemistry and catalysis.The incorporation of strongly basic guanidinyl substituents,however,often introduces multiple binding sites,with coordination typically favoring the guanidyl nitrogen atoms.Herein,we report the synthesis and characterization of a new electron-rich 1,10-phenanthroline ligand featuring bulky NHI groups that define a well-structured coordination cavity.Protonation studies and the preparation of a zinc(II)complex reveal that Lewis acids preferentially coordinate at the phenanthroline nitrogen atoms rather than the NHI moiety.The electronic and photophysical properties of the new ligand and its complexes are explored through a combination of computational and experimental methods,demonstrating that its emission and absorption characteristics are highly sensitive to protonation,concentration,and metal coordination.
基金the National Natural Science Foundation of China(NSFC)(21571007,21621061,21778002,and 21861162008)the Chemistry and Chemical Engineering Guangdong Laboratory(1932002)for financial supportsupported by the High-performance Computing Platform of Peking University。
文摘We reported herein a novel gold(I)bifluoride complex,LAuHF_(2),supported by a sterically bulky ligand(L,^(t)BuXantphos),that displays exceptional reactivity toward hydrodefluorination(HDF)and hydrosilylation of CO_(2)in the presence of hydrosilanes.Compared to the LAuCl counterpart,the LAuHF_(2)complex exhibited an over 27-fold increase in turnover frequency in HDF and a 16-times higher turnover number in the hydrosilylation of CO_(2).
