检索结果-南通市图书馆

Dynamic Pricing with Stochastic Reference Price Effect

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of the Operations Research Society of China 2019年第1期7卷 107-125页

作者： Xin Chen Zhen-yu Hu yu-han zhang Department of Industrial Enterprise and Systems Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801USA NUS Business School National University of SingaporeSingapore 119245Singapore Two Sigma Investments New YorkNY 10036USA

We study a dynamic pricing problem of a firm facing stochastic reference price *** is incorporated in the formation of reference prices to capture either consumers’heterogeneity or exogenous factors that affect consumers’memory *** apply the stochastic optimal control theory to the problem and derive an explicit expression for the optimal pricing *** explicit expression allows us to obtain the distribution of the steady-state reference *** compare the expected steadystate reference price to the steady-state reference price in a model with deterministic reference price effect,and we find that the former one is always *** numerical study shows that the two steady-state reference prices can have opposite sensitivity to the problem parameters and the relative difference between the two can be very significant.

关键词： Reference price effect Dynamic pricing Stochastic optimal control

Probing dynamics of dark energy with latest observations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第6期17卷 5-10页

作者： yue-Cheng zhang han-yu zhang Dan-Dan Wang Yang-han Qi yu-Ting Wang Gong-Bo Zhao National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China University of Chinese Academy of Sciences Beijing 100049 China Department of Physics & Astronomy Swarthmore College Swarthmore PA 19081 USA Institute of Cosmology and Gravitation University of Portsmouth Portsmouth PO1 3FX UK

We examine the validity of the ACDM model and probe the dynamics of dark energy with the latest astronomical observations. Using the Ore（z） diagnosis, we find that various kinds of observational data are in tension within the ACDM framework. We then allow for dynamics of dark energy and investigate the constraint on dark energy parameters. We find that for two different kinds of parametri- sations of the equation of state parameter w, a combination of current data mildly favours an evolving w, although the significance is not sufficient for it to be supported by Bayesian evidence. A forecast of the DESI survey shows that the dynamics of dark energy could be detected at the 7σ confidence level and would be decisively supported by Bayesian evidence, if the best-fit model of w derived from current data is the true model.

关键词： cosmology - dark energy - large scale structure

Nonlocal advantage of quantum coherence in a dephasing channel with memory

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第3期30卷 68-73页

作者： Ming-Liang Hu yu-han zhang Heng Fan School of Science Xi’an University of Posts and TelecommunicationsXi’an 710121China Institute of Physics Chinese Academy of SciencesBeijing 100190China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

We investigate nonlocal advantage of quantum coherence(NAQC)in a correlated dephasing channel modeled by themultimode bosonic *** obtain analytically the dephasing and memory factors of this channel for the reservoirhaving a Lorentzian spectral density,and analyze how they affect the NAQC defined by the l1 norm and relative *** is shown that the memory effects of this channel on NAQC are state-dependent,and they suppress noticeably the rapiddecay of NAQC for the family of input Bell-like states with one *** the given transmission time of each qubit,we also obtain the regions of the dephasing and memory factors during which there is NAQC in the output states.

关键词： quantum coherence correlated quantum channel memory effects

Effect of Residual Stress on Corrosion Sensitivity of Carbon Steel Studied by SECM

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2014年第6期30卷 1022-1027页

作者： WANG yujie han Xiaoping LIU yu zhang Weiwei NIU Lin Key Laboratory of Colloid and Interface Chemistry Ministry of EducationSchool of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China

The effect of compressive residual stress on the reactivity of carbon steel in a neutral chloride solution was investigated by means of potentiodynamic polarization and local electrochemical measurement with scanning electrochemical microscope（SECM）. Meanwhile, X-ray diffraction, as a nondestructive technique, was employed to determine the levels of residual stress in near-surface layers of carbon steel specimen. The results show that the resi- dual stress existed in the specimen fell into the category of compressive residual stress which was inversely propor- tional to the corrosion sensitivity of carbon steel specimen. By using I/I3 couple as a redox mediator in the current feedback mode of SECM measurements, the Faradaic current on Pt tip, which was relevant to the rate of the I3- ion reduction, fell with the increase of compressive residual stress. The correlation between compressive residual stress and heterogeneous electron transfer rate has been proposed based on the inference of the localized electrochemical reactions occurred on the specimen surface,

关键词： rCarbon steel Corrosion sensitivity Residual stress Scanning electrochemical microscope(SECM)

Familial left cervical neurofibromatosis 1 with scoliosis:A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第29期9卷 8839-8845页

作者： Xia Mu han-yu zhang yue-Hong Shen Hong-yu Yang School of Stomatology Zunyi Medical UniversityZunyi 563000Guizhou ProvinceChina Department of Stomatology Peking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina Department of Oral and Maxillofacial Surgery Peking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina

BACKGROUND Neurofibromatosis type 1(NF1)is an inherited autosomal dominant disorder affecting many parts of the body with caféau lait spots,skeletal deformity,and scoliosis.A familial case of NF1 with scoliosis and a painless mass had not yet been *** SUMMARY We describe the case of a 15-year-old male patient with a painless lump on the left side of his neck for 10 years and *** right shoulder was about 5 cm lower than the left,the left side of his face was deformed,and the left submandibular skin was *** folding and drooping were obvious and movement was *** tomography revealed the involvement of the neck,upper chest wall,and surrounding left shoulder,accompanied by bone changes and *** evaluation showed subepidermal pale blue mucoid degeneration,fibrous fusiform cells in the dermis in a fascicular,woven *** mother had the same medical *** diagnosis was neurofibromatosis of the left *** parts of the tumor tissue were serially resected during several *** months after surgery,there was a slight tendency to *** This case of slow-progressing NF1 highlights the importance of early diagnosis and treatment to reduce its impact on the patient’s growth and development.

关键词： Neurofibromatosis type 1 Scoliosis Neck mass Arteriography Embolization Case report

Resolution and Crystal Structure of 9α-(3-Azabicyclo[3,3,1]nonanyl)- 2′-cyclopentyl-2′-hydroxyl-2′-thienylacetate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2006年第5期25卷 547-551页

作者： LIU He han Xiang-yu zhang Yan-Ping ZHONG Bo-Hua LIU Ke-Liang Beijing Institute of Pharmacology and Toxicology 27 Taiping Road Beijing 100850 China

The crystal structure of 9α-（3-azabicyclo[3,3,1]nonanyl）-2′-cyclopentyl-2′-hydro- xyl-2′-thienylacetate （C16H27NO3S, Mr = 349.48） has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic, space group P212121 with a = 14.937（3）, b = 8.1673（16）, c = 15.423（3） ,A, V = 1881.5（6） ,A^3, Z = 4, Dc =1.234 g/cm^3, μ = 0.188 mm^-1, F（000） = 752, the final R = 0.0468 and wR = 0.1251. The bicyclo[3,3,1]nonane ring system adopts the most favored twin-chair conformation. The crystal structure shows the existence of intramolecular O-H…O hydrogen bonds by which a one-dimensional chain structure is formed.

关键词： optical resolution crystal structure muscarinic receptor antagonist

Reconstructing the temporal evolution of the speed of light in a flat FRW Universe

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2019年第10期19卷 138-144页

作者： Dan-Dan Wang han-yu zhang Jing-Lan Zheng yu-Ting Wang Gong-Bo Zhao National Astronomical Observatories Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China Department of Physics Kansas State University116 Cardwell HallManhattanKS 66506USA School of Astronomy and Space Science University of Chinese Academy of Sciences Beijing 100049 China Institute of Cosmology and Gravitation University of Portsmouth Portsmouth POl 3FX UK

We present a novel method to reconstruct the temporal evolution of the speed of light c(z) in a flat Friedmann-Robertson-Walker(FRW) Universe using astronomical observations. After validating our pipeline with mock datasets, we apply our method to the latest baryon acoustic oscillations(BAO) and supernovae observations, and reconstruct c(z) in the redshift range of z ∈[0, 1.5]. We find no evidence of a varying speed of light, although we see some interesting features of △c(z), the fractional difference between c(z) and c0(the speed of light in the International System of Units), e.g.,△c(z) 0 at 0.2≤z≤0.5 and 0.8≤z≤1.3, respectively, although the significance of these features is currently far below statistical importance.

关键词： cosmology-dark energy-large scale structure

Egg laying behavior of common cuckoos(Cuculus canorus): Data based on field video-recordings

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2020年第4期41卷 458-464页

作者： Long-Wu Wang Guo Zhong Gang-Bin He yu-han zhang Wei Liang State Forestry Administration of China Key Laboratory for Biodiversity Conservation in Mountainous Areas of Southwest Karst School of Life SciencesGuizhou Normal UniversityGuiyangGuizhou 550001China Ministry of Education Key Laboratory for Ecology of Tropical Islands College of Life SciencesHainan Normal UniversityHaikouHainan 571158China

DEAR EDITOR,The egg laying behavior of brood parasites is at the heart of studies on host ***,research on egg laying behavior can improve our understanding of brood parasitism and associated *** a seven year study period,we monitored 455 oriental reed warbler(Acrocephalus orientalis)nests during the egg laying period,250 of which were parasitized by common cuckoos(Cuculus canorus).We collected 53 clear videos of common cuckoo parasitism,analyzed all recorded parasitic behavior in detail.

关键词： evolution. behavior recording

Effect of Blumgart anastomosis in reducing the incidence rate of pancreatic fistula after pancreatoduodenectomy

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2019年第20期25卷 2514-2523页

作者： Ya-Tong Li han-yu zhang Cheng Xing Cheng Ding Wen-Ming Wu Quan Liao Tai-Ping zhang yu-Pei Zhao Meng-Hua Dai Department of General Surgery Peking Union Medical College Hospital

BACKGROUND Pancreatic fistula is one of the most serious complications after pancreatoduodenectomy for treating any lesions at the pancreatic head. For years, surgeons have tried various methods to reduce its incidence. AIM To investigate and emphasize the clinical outcomes of Blumgart anastomosis compared with traditional anastomosis in reducing postoperative pancreatic fistula. METHODS In this observational study, a retrospective analysis of 291 patients who underwent pancreatoduodenectomy, including Blumgart anastomosis (201 patients) and traditional embedded pancreaticojejunostomy (90 patients), was performed in our hospital. The preoperative and perioperative courses and longterm follow-up status were analyzed to compare the advantages and disadvantages of the two methods. Moreover, 291 patients were then separated by the severity of postoperative pancreatic fistula, and two methods of pancreaticojejunostomy were compared to detect the features of different anastomosis. Six experienced surgeons were involved and all of them were proficient in both surgical *** The characteristics of the patients in the two groups showed no significant differences, nor the preoperative information and pathological diagnoses. The operative time was significantly shorter in the Blumgart group (343.5 ± 23.0 vs 450.0 ± 40.1 min, P = 0.028), as well as the duration of pancreaticojejunostomy drainage tube placement and postoperative hospital stay (12.7 ± 0.9 d vs 17.4 ± 1.8 d, P = 0.031;and 21.9 ± 1.3 d vs 28.9 ± 1.3 d, P = 0.020, respectively). The overall complications after surgery were much less in the Blumgart group than in the embedded group (11.9% vs 26.7%, P = 0.002). Patients who underwent Blumgart anastomosis would suffer less from severe pancreatic fistula (71.9% vs 50.0%, P = 0.006), and this pancreaticojejunostomy procedure did not have worse influences on long-term complications and life quality. Thus, Blumgart anastomosis is a feasible pancreaticojejunost

关键词： Blumgart anastomosis Pancreaticojejunostomy Postoperative pancreatic fistula Pancreatoduodenectomy Incidence